Energy from Waste Facility - establishment and acceptance of tender

STATES OF JERSEY SOLID WASTE STRATEGY TECHNOLOGY REVIEW 2008

S0871-0010-3868MDI Technology Review 2008

Title Page

MANAGEMENT SUMMARY

This technology review has been carried out as part of the then Environment and Public Services Committee's commitment to the States of Jersey as part of the Solid Waste Strategy. An original review was carried out in 2005 to inform the decision on the companies to be selected for shortlisting for the residual waste treatment facilities to replace the Bellozanne incinerator. This review was updated in late 2007 to ensure that no new entrants to the market had been missed. Following the Juniper review carried out for the Environment Scrutiny panel, the reports have been combined into a single report for States members, and some of the comments from Juniper addressed.

Over 60 suppliers of various technologies for the treatment and disposal of residual solid waste have been considered. A description of the different types of technologies and comments on individual suppliers make up the main body of this report.

These technologies and suppliers have all been reviewed, in the context of whether they would be an appropriate solution for dealing with Jersey's residual solid waste. The prime consideration that has been agreed is that the technology chosen for Jersey must be tested and proven, to give a low risk solution, which will provide a long-term secure route for disposal of the residual solid waste. In addition, it is essential that the selected technology is demonstrably capable of the disposal of all of Jersey's residual solid waste in an environmentally safe and cost effective manner.

The following types of technology have been considered, and a generic explanation of each process is provided in Section 3:

• Energy from Waste (EfW) - Conventional Incineration
• EfW - Fluidised Bed Combustors
• EfW - Gasification and Pyrolysis
• Mechanical Heat Treatment including Steam Autoclaves
• Anaerobic Digestion (AD)
• Mechanical Biological Treatment (MBT)
• Alternative technologies such as plasma gasification, bio-ethanol production, liming or plastic extrusion.

Each technology and individual suppliers have been considered in detail and the results of this review described in this report. The overall conclusions can be summarised as follows:

1. EfW - Conventional Incineration is generally considered to meet the selection criteria, and eight suppliers were identified for further investigation prior to inclusion on the short-list of tenderers.
2. EfW - Fluidised Bed Combustors. Four potential suppliers have been identified, although it is noted that few of these are currently offering this technology to process municipal solid waste. These are not considered suitable for Jersey due to the requirement for pre-treatment to remove unsuitable material, which must be disposed of in other ways.
3. EfW - Gasification and Pyrolysis – 25 suppliers have been considered and of these, only one is considered to have adequate reference plants to satisfy the selection criteria for inclusion on the short-list.
4. Mechanical Heat Treatment, including Steam Autoclaves – This is a pre-treatment process and separates the waste stream into a number of different output streams requiring further processing, including an EfW plant. Eight plant suppliers have been considered. The additional costs and difficulties involved in a further processing stage means that this technology is not considered suitable for Jersey.

5. Anaerobic Digestion – it must be understood that AD can only process organic wastes, that is it cannot  treat  the  majority  of  residual  solid  waste.  Seven  suppliers  of  this  equipment  were reviewed and it is noted that this technology is currently expanding in its use in the UK. It is necessary to separate the waste and disposal routes will be required for the non-organic material plus any  rejects,  together  with  the  digestate  from  the  AD  plant.  The  additional  costs  and difficulties involved means that this technology is not considered suitable for Jersey.
6. Mechanical Biological Treatment – MBT is a pre-treatment process, processing the waste to produce a number of output streams such as refuse derived fuel (RDF), organic material, inerts, metals and rejects. All these streams will require further processing, probably using an EfW plant. 15 plant suppliers have been considered. The additional costs and difficulties involved means that this technology is not considered suitable for Jersey.
7. Alternative Processes such as plasma gasification (5 technology suppliers), bio-fuel production (3 technology suppliers), a liming process (one supplier) and plastic extrusion (one supplier) have been reviewed, but not considered suitable due to a lack of adequate references, lack of proven flexibility to cope with all the incoming waste or doubts about the sustainability of the proposed disposal routes for the various output streams produced.

Whilst we believe we have reviewed all the potential technologies and the majority of the suppliers of these  technologies  currently  offering  solutions  in  Europe,  the  suppliers  considered  are  not  an exhaustive  list.  Some  suppliers  may  have  been  excluded  due  to  a  lack  of  publicly  available information. However, we believe that all significant residual waste treatment processes have been considered.

A key factor in determining the suitability of facilities has been the ability of the proposed process to deal with the whole waste stream. A number of technologies listed above are considered proven and commercially available, but have been rejected because they can only process part of Jersey's waste stream. Pre-treatment processes have not been rejected without careful consideration. The cost of multiple facilities, together with limited land available and a small workforce, means that these are not considered practical or affordable solutions. This is a decision questioned by Juniper, but we believe our approach has been robust. Where processes require some limited pre-treatment of the waste prior to treatment this has been considered acceptable. However, extensive pre-treatment processes where the waste is split into several different waste streams requiring further treatment facilities, or export from the Island, are unlikely to be acceptable for Jersey due to the additional cost and lack of sustainable disposal routes.

It is the considered opinion of Babtie Fichtner, and the conclusion of this report that an EfW plant, of tried and tested and proven technology is the correct solution for dealing with Jersey's residual solid waste, in the particular circumstances and factors that apply to Jersey. This opinion was supported and endorsed by the Environment & Public Services Committee (E&PSC) and the Waste Strategy Steering Group (WSSG).

Dr. John Weatherby  Mr. Phin Eddy

TABLE OF CONTENTS

MANAGEMENT SUMMARY....................................................................................................................II TABLE OF CONTENTS ..........................................................................................................................IV

1  INTRODUCTION..........................................................................................................................1

2  OVERVIEW OF TECHNOLOGIES...........................................................................................2

3  DESCRIPTION OF DIFFERENT TECHNOLOGIES...............................................................6

1. EfW - Conventional Incineration............................................................................................6
2. EfW - Fluidised bed combustion systems ...............................................................................6

3. EfW - Pyrolysis and Gasification............................................................................................7

1. Pyrolysis......................................................................................................................................... 8
2. Gasification.................................................................................................................................... 9

4. Mechanical Heat Treatment....................................................................................................9
5. Anaerobic Digestion (AD)......................................................................................................9
6. Mechanical Biological Treatment (MBT).............................................................................10
7. Other Technologies...............................................................................................................11

4  CONVENTIONAL ENERGY FROM WASTE.........................................................................12

1. CNIM / Martin......................................................................................................................12
2. Lentjes (formerly Lurgi) .......................................................................................................14
3. Cyclerval ..............................................................................................................................15

4. Keppel-Seghers.....................................................................................................................16
5. Von Roll Inova.....................................................................................................................17
6. Babcock & Wilcox Vølund...................................................................................................19
7. Fisia Babcock Environment..................................................................................................20

8. Itochu with Takuma..............................................................................................................21

5  EFW - FLUIDISED BED COMBUSTION................................................................................23

1. Austrian Energy....................................................................................................................23
2. Foster Wheeler......................................................................................................................24
3. Kvaerner (now Metso)..........................................................................................................25
4. Lurgi (then Lentjes, now AEE).............................................................................................27

6  EFW - GASIFICATION AND PYROLYSIS.............................................................................29

1. Austrian Energy - Von Roll..................................................................................................29
2. British Gas - Lurgi................................................................................................................29
3. Bowen Worldwide Developments ........................................................................................30
4. Compact Power (now Ethos Recycling)................................................................................31

5. Enerkem / Novera.................................................................................................................32
6. Ener-G / Energos AS............................................................................................................33
7. Ferco.....................................................................................................................................35
8. Foster Wheeler......................................................................................................................36
9. GEM (Graveson Energy Management).................................................................................37
10. Gibros / Marick.....................................................................................................................38
11. IET / Entech..........................................................................................................................39
12. Lurgi (Lentjes, now AEE).....................................................................................................40
13. Mitsui-Babcock ....................................................................................................................41
14. Nathaniel Energy..................................................................................................................42
15. PKA / Toshiba......................................................................................................................42
16. Thermoselect........................................................................................................................44
17. Thide ....................................................................................................................................45
18. TPS Termika.........................................................................................................................46
19. Wastegen / Techtrade............................................................................................................47
20. Wellman Process Engineering ..............................................................................................48
21. American Combustion Tech Inc ...........................................................................................49

22. Biomass Engineering............................................................................................................50
23. First London Power..............................................................................................................51
24. ITI ........................................................................................................................................51
25. Prestige.................................................................................................................................52

7  MECHANICAL HEAT TREATMENT.....................................................................................54

1. Brightstar Environmental - SWERF process.........................................................................54
2. Estech Europe.......................................................................................................................55
3. Fernwood..............................................................................................................................56
4. Thermsave / RCR.................................................................................................................57
5. Comex..................................................................................................................................58
6. Environmental Heritage Services (EHS)...............................................................................59
7. Orchid Fairport.....................................................................................................................59
8. Sterecycle.............................................................................................................................60

8  ANAEROBIC DIGESTION........................................................................................................62

1. BTA......................................................................................................................................62
2. Greenfinch............................................................................................................................63
3. Haase....................................................................................................................................64
4. Hese-Valorga........................................................................................................................65

5. Iska.......................................................................................................................................66
6. Linde ....................................................................................................................................67
7. Oak Tech Environmental......................................................................................................68

9  MECHANICAL BIOLOGICAL TREATMENT......................................................................69

1. ADAS...................................................................................................................................69
2. Advanced Recycling Technologies (ART)............................................................................69
3. Bedminster ...........................................................................................................................70
4. Eden .....................................................................................................................................71
5. Ecodeco................................................................................................................................72
6. Global Renewables...............................................................................................................73
7. Golder Associates.................................................................................................................74
8. Haase....................................................................................................................................74
9. Hese......................................................................................................................................75
10. Horstmann............................................................................................................................76
11. IWI.......................................................................................................................................77
12. Linde ....................................................................................................................................78

13. Enpure..................................................................................................................................80
14. Premier Waste ......................................................................................................................80
15. New Earth Solutions.............................................................................................................81

10 PLASMA GASIFICATION........................................................................................................83

1. Verno / Pyrogenesis..............................................................................................................83
2. Pyromex ...............................................................................................................................84
3. Advanced Plasma Power ......................................................................................................84
4. Europlasma...........................................................................................................................85
5. Solena...................................................................................................................................86

11 BIO-BUEL PRODUCTION........................................................................................................87

1. Losonoco..............................................................................................................................87
2. Green Spirit Fuels.................................................................................................................88
3. Reclaim Resources................................................................................................................88

12 OTHER PROCESSES.................................................................................................................90

1. Oxalor...................................................................................................................................90
2. Cierra....................................................................................................................................91

13 CONCLUSIONS..........................................................................................................................92 APPENDIX A  GLOSSARY..........................................................................................................94

1  INTRODUCTION

The Solid Waste Strategy for Jersey was passed by the States' Assembly in July 2005. Prior to proceeding to the procurement of an Energy from Waste (EfW) plant to replace the existing Bellozanne  incinerator,  it  was  agreed  that  a  report  would  be  produced  summarising  the technologies and suppliers of residual waste treatment facilities that had been considered.

This report was prepared by Babtie Fichtner for the then Jersey Public Services Department. The report concentrated on residual wastes, that is the waste left over following the various recycling and composting initiatives proposed in the Strategy. This report identified the key technologies and suppliers available to provide a replacement plant for the Bellozanne incinerator. This supported the list of available suppliers which had been identified from the open advertisement placed in the Official Journal of the European Community. This led to a shortlist of suppliers wishing to bid for the plant with an acceptable solution being drawn up.

Prior to tendering for the proposed plant at the end of 2007, a further review of technologies was carried out to ensure that no new supplier had emerged. Despite the two years which had elapsed, no new technology was identified. The tendering process was started with the approved shortlist of four suppliers. The technology report was also reviewed by Juniper Consultancy Services Ltd for the Environment Scrutiny Panel, leading to a number of critical comments.

This report merges the two Babtie Fichtner reports into a single report to assist States members. In addition, the more significant of the Juniper comments are addressed which we believe to be largely misconceptions of the Island's requirements, or due to a lack of clarity in the original reports.

This  report  summarises  the  processes  offered  by  the  various  suppliers  which  have  been investigated specifically for the Jersey project over the last few years. In addition, generally available information has been used to provide a short overview of each of the processes. The suitability, or otherwise, of each process for Jersey is noted.

It should be noted that this report only considers the applicability of the technology to Jersey. The report has not analysed the ability of each supplier to deliver its proposed solution. Indeed, most of the suppliers included in this list will not tender for a plant on Jersey. The list of suppliers considered is deliberately limited to those offering their solutions in Europe, on the basis that it would not make sense for Jersey to select a technology which is not being built or operated elsewhere on the continent. This is because we believe that if these technologies have a significant role to play in Europe, they would already feature in other larger countries where waste management is more flexible than on a small island, and that the requirement to have access to experienced operators and specialist maintenance staff in nearby countries should not be underestimated.

2  OVERVIEW OF TECHNOLOGIES

Since the 2005 report, there have been no entirely new processes which have entered the market. This is not surprising – the development time to reach commercial operation of waste facilities is long. We are also not aware of any revolutionary technology in the development phase which is likely to change this situation in the next few years.

Any new process needs to go through an initial design and testing phase on the pilot scale. If successful,  normally  a  demonstration  plant  would  then  be  built  and  operated  to  gather information to allow a full-scale plant to be constructed. This would lead to the construction of a commercial scale  plant, with construction  normally  taking  of the  order of  two  years. The commercial plant would then operate for an extended period of several years to show that the process works satisfactorily and to allow meaningful data to be established on reliability and long term operating and maintenance costs. The overall process from the conceptual design to a commercially proven design normally takes of the order of ten years.

1. This report has considered the technologies and suppliers available to dispose of Jersey's solid residual waste. The main criteria for the selection of technologies are:

• Technology  must  be  demonstrably  proven,  with  significant  reference  plants  in operation.  It  is  essential  for  a  small  island  such  as  Jersey,  that  no  significant technology risks are introduced. As a selection criterion, any technology must be able to provide references for a plant which has been operating for several years and processing similar wastes.
• It  is  preferred  that  reference  plants  exist  in  Europe,  although  reference  plants elsewhere have been considered if no European references exist. This is because reference  plants  in  Europe  are  more  likely  to  process  similar  waste,  and  also demonstrate the capability of the supplier to offer solutions for Jersey, rather than sub-contracting to companies with either limited knowledge of the technology or of European contracting. Where non-European references only do exist, it is considered a pre-requisite that suppliers are actively bidding their technology in Europe, on the basis that if they are not, it would not be advisable to procure a plant of which they would be the sole European example.
• Environmental performance – the technology must be clean, capable of achieving the best European standards.
• Complexity – the process must be easy to operate without excessive staff numbers, and with clearly understood operating and maintenance costs.
• The process should deal with all Jersey's solid residual waste, and where output streams are  produced, sustainable  outlets  must exist for  these.  Multiple  facility solutions were considered. Facilities which pre-treat the waste were also considered, but  in  this  case  the  complete  disposal  route  was  also  taken  into  account  in determining the viability of the solution.
• The process shall recover value as efficiently as reasonably possible from Jersey's residual  waste,  in  line with  the  Solid  Waste  Strategy  and  the European  Waste Hierarchy.

Capability of the supplier and their financial strength are also key factors in selection, but this report has not considered these. The intention was to determine which technology is best suited for Jersey, and then consider which of the various suppliers were able to deliver the solution, prior to drawing up the final short list of tenderers.

The following types of technology have been considered:

2. EfW - Conventional Incineration

1. Conventional energy from waste, i.e. incineration, using either a grate or a kiln, will dispose of all Jersey's residual waste, producing electricity and heat if required. Some material will remain, most of which is inert and suitable for reuse as secondary aggregate, with residues amounting to about 5% of the input material requiring secure landfill as hazardous waste.
2. The net electrical conversion efficiency of the plant will be about 23%, that is 23% of the input energy in the waste will be exported from the plant as electricity. It is also easy to export heat to consumers, as a Combined Heat and Power plant, or to a district heating system, if this is required.
3. 8 suppliers have been considered, all of which have significant reference plants and the capability to deliver the project for Jersey.
4. Of these eight, six expressed a strong interest in the project.

4. EfW - Fluidised Bed Combustors
   1. There  are  examples  of  large  scale  fluidised  bed  combustors  processing  treated residual waste in Europe.
   2. There are at least four suppliers capable of supplying such plants, although it is noted that not all of these are actively offering such solutions to the European market.
   3. Fluidised beds are very sensitive to over-sized material, metal and stones. To operate successfully, some pre-treatment is required, with rejection of significant amounts of unsuitable material. Fluidised bed combustors are normally used to process a refuse derived fuel from which 20-50% of the incoming material has been removed. This makes  the  overall  plant  costs  more  expensive  and  also  leaves  a  waste  stream requiring further treatment or landfill. This technology is therefore not considered as being the correct choice for an island with no landfill, such as Jersey.

4. EfW - Gasification and Pyrolysis

• There are few reference plants for successfully operating gasification or pyrolysis plants in Europe. Many of these are very small scale, only treating parts of the waste stream. This would mean that alternative disposal routes would be required for much of the rejected waste, and these do not exist on the Island.
• The environmental performance of most gasifiers is similar to conventional energy from waste plants, but the energy recovery efficiency is generally lower.
• Juniper have suggested that Jersey should consider installing a "slagging" gasifier of which  there are several  operating examples in Japan,  but  none  in Europe. We strongly disagree with this view, as we can see no advantages for the Island of this technology which has yet to be deployed successfully in Europe despite several attempts. As Juniper note it would be more expensive, and we do not believe that the claimed environmental advantages of an improved ash quality would be significant for the Island.
• 25  gasifier  or  pyrolyser  suppliers  have  been  reviewed.  Of  these,  only  one  is considered to have adequate references for the type of plant proposed for Jersey. This supplier, Ener-G, was approved and placed on the short-list of tenderers but withdrew during the tendering process.

5. Mechanical Heat Treatment

• This technology uses heat to pre-treat and break down the waste. This is often in the form of steam, using a "steam autoclave", although it can also utilise a heated rotating drum.

• This is a pre-treatment process, whereby the residual waste stream is split into a number of separate output streams. Each of these streams requires further treatment. The biggest stream is the fine organic stream, which is about 60% of the incoming waste. Whilst further treatment, such as combustion of this "fuel" or composting for use as landfill restoration material, are proposed, none of these is suitable for Jersey, as this method of combustion of the fuel would be less efficient than a conventional energy from waste plant, and there is no landfill requiring the application of the restoration material. It would therefore make more economic and environmental sense for Jersey to just install the energy from waste plant.
• These plants are currently just starting to operate in Europe and the process is relatively simple. Eight suppliers proposing to supply such equipment in the UK have been reviewed.
• However, due to the requirement for additional facilities to treat the outputs, this technology is not considered suitable for Jersey's residual waste.

6. Anaerobic Digestion

• There are a number of anaerobic digestion plants operating throughout Europe, treating either separately collected kitchen waste, or mechanically separated mixed organic waste.
• Seven reputable European suppliers have been considered.
• Separate anaerobic digestion of kitchen waste has been considered independently of this report, although it is considered that a cheaper solution for the Island than anaerobic digestion would be via in-vessel composting of this material. Even this option has shown to be more expensive than a single energy from waste plant.
• Where  mixed  waste  organic  material  is  anaerobically  digested,  the  digestate produced contains most of the contaminants present in the original material. The digestate therefore has very limited land use, usually restricted to the treatment of contaminated  land  or  as  restoration  material  for  landfills,  neither  of  which  are applicable to Jersey.
• Anaerobic digestion can only treat organic waste, and significant amounts of residual waste material such as plastics and wood are not processed. As separation facilities, together with additional facilities to treat the rejects, would be required to treat the complete residual waste stream, this solution is not seen as the most suitable option for Jersey.

7. Mechanical Biological Treatment (MBT)

• There are a number of MBT plants operating in Europe. These all pre-treat the waste by separating it into a number of different streams – recyclables such as aggregates and  metals,  refuse  derived  fuel  (RDF),  organic  material  which  can  be  further composted, and rejects.
• 15 suppliers of such systems have been considered. Several of these are considered sufficiently capable and experienced to supply an MBT plant to Jersey.

• This is a pre-treatment process, whereby the residual waste stream is split into a number of separate output streams. Each of these streams requires further treatment. The biggest stream is normally the refuse derived fuel stream, which is about 25- 50% of the incoming waste. This material would require an on-Island energy from waste plant in any case, or expensive export to other facilities off the Island. In addition, large quantities of rejects and fine organic material are produced. Whilst further treatment, such as composting for use as landfill restoration material, are proposed in Europe, this is not suitable for Jersey, as there is no landfill requiring the application of the restoration material. It would therefore make more economic and environmental sense for Jersey to just install the energy from waste plant.
• As this process is an intermediary one, and additional disposal facilities (including an  energy  from  waste  plant)  would  be  needed,  it  is  not  considered  that  this technology is the most suitable or cost effective option for the Island.

8. Plasma Gasification
   1. This is an advanced technology where significant amounts of energy are used to convert the material into its elements. Due to the intense heat, much of the material will form an inert, glassy material considered safe for disposal.
   2. The pollutants which have been released still require capture and cleaning, and the technology has more often been used for the treatment of hazardous material.
   3. This solution is not considered suitably proven for the treatment of Jersey's residual waste stream.
   4. This process does not have any commercially operating plants within Europe.

10. Bio-Ethanol Production
    1. This is a process under development, whereby organic material can be treated to produce ethanol, for use as a chemical feedstock or for fuel. The process only converts the organic fraction of waste.
    2. The process will not treat all of the residual waste stream. It is, therefore, not considered suitable for Jersey.

10. Liming Processes

• This  is  a  process  under  development  in  France,  where  lime  is  added  and  the lime/organic material is separated for use on land.
• Plastics and other rejected material will still require disposal, probably in an energy from waste plant.
• There is no identified use for large quantities of lime based mixed waste organic material in Jersey.
• The process is therefore not seen as the most suitable option for Jersey, as there would still be a need for an EfW plant, and there would be no security that the large quantities  of  lime-based  organic  material  could  be  disposed  of  to  land  on  a continuous basis.

11. Plastic Extrusion

• The extrusion of waste plastics into lower grade plastic products such as garden furniture is well established. However, it will only work adequately with reasonable quality waste plastics, and produce products with a limited market.
• The process will treat only a small proportion of the residual waste stream after separation. It is, therefore, not considered suitable for Jersey.

3  DESCRIPTION OF DIFFERENT TECHNOLOGIES

1. EfW - Conventional Incineration

Conventional incineration systems, also known as "mass-burn" have been used worldwide for many decades. There are several hundred such plants operating throughout Europe. These types of plants are by far the most developed. Contrary to public perception, this type of technology is not out of date – it has been developed to a mature level where technical risks are low and costs are well understood. Such plants easily achieve the low emission levels required by the Waste Incineration Directive and convert the energy left in the residual waste in an efficient manner into a useful form, normally as electricity, but also if required as heat, thereby displacing fossil fuels.

Countries with advanced waste management systems and high recycling rates, such as Germany, Holland or Sweden, continue to install new plants of this type to reduce the amount of waste going to landfill.

These plants are based upon grate or rotating kiln systems where largely untreated waste is fed and burnt under controlled conditions. Steam is then generated in a boiler and the flue gas is cleaned using a flue gas treatment plant.

Figure 1 shows typical mass flows of the solids for a conventional plant, together with the electricity generated.

Figure 1 : Conventional Energy from Waste

Steam Turbine 20 kg lime and PAC

590 kWh

2kg NH3

1 tonne Waste Residual Waste

Flue Gas

200 kg Bottom Ash 50 kg FGT Residue (aggregate) (Secure landfill)

Numbers are approximate for illustrative purposes only, and dependent on actual supplier and waste composition

2. EfW - Fluidised bed combustion systems

In a fluidised bed, fuel or waste is fed to a mass of hot material (the bed) suspended by air, normally sand, where it burns well due to the mixing of the bed. The hot flue gases are then used to generate steam and are cleaned in a similar manner to that used in a conventional system.  Fluidised beds are commonly used for the combustion of fuels such as coal, sludge or biomass. The use of fluidised beds to burn residual waste is more limited. This is because fluidised beds are sensitive to particle size and dense material such as glass and metal, which does not burn. Whilst there are examples of fluidised beds burning Refuse Derived Fuel, the requirement to pre- treat  the  residual  waste  means  that  the  application  of fluidised  beds  is  limited  to  specific applications, where a suitable pre-treated fuel is available.

Figure 2 shows the typical mass balance for a fluidised bed plant.

Figure 2 : Fluidised Bed Energy from Waste

Steam Turbine 20 kg lime and PAC

550 kWh

1 tonne  Shredding,

Sorting and Residual Waste Pre-treatment

Flue Gas

100kg Rejects 60 kg Bottom Ash 50 kg FGT Residue (to landfill?) 80 kg of Fly Ash (secure landfill)

(aggregate)

Numbers are approximate for illustrative purposes only, and dependent on actual supplier and waste composition

3. EfW - Pyrolysis and Gasification

Pyrolysis is thermal degradation of a substance in the absence of oxygen. Gasification is partial thermal degradation of a substance in the presence of oxygen but with insufficient oxygen to completely  oxidise the fuel (sub-stoichiometric).  The  main combustible components of  the resulting gaseous product ("syngas") in either case are methane, carbon monoxide and hydrogen. Gasification of coal, oil (and its refined fractions), and natural gas is widely used to produce Syngas  which  in  turn  is  used as  a chemical feedstock  or in  the  production  of  steam and electricity.

The distinction between pyrolysis and gasification is often blurred by the fact that in an industrial installation it is virtually impossible to have sealing that is good enough to completely exclude air from the process.

Producing electricity in a large-scale, natural gas-fired, combined cycle power plant utilising gas and steam turbines can be much more efficient than a conventional power plant with a steam turbine only. Because of this, there is interest in developing the gasification and pyrolysis techniques to turn solid fuels and wastes into syngas for power generation.

In the UK, the Government has tried to assist the development of these so called "Advanced Technologies" by allowing them to qualify for Renewable Obligation Certificates, whereas modern waste incinerators do not qualify as these are considered to be commercially mature. The Renewables  Obligation  Certificate  increases  the  electricity  revenue  by  up  to  £90/MWh (Megawatt Hours), so it is a considerable incentive and this has led to a number of suppliers actively entering the market. This incentive is not available for Jersey.

Contrary to much that is written, there is no clear evidence that the pyrolysis or gasification of waste  is  cleaner  than  conventional  techniques.  In  the  UK  and  Europe,  processes  using incineration, pyrolysis and gasification of waste are all regulated under the same Directive and with similar limits. The evidence from most existing gasification processes is that emissions from these plants are quite similar to emissions from modern mass burn incinerators.

There are only a limited number of such plants operating throughout the world, with few of any significant size.

Figure 3 shows a typical mass balance for a basic gasification process. It should be noted that there are a large number of variants of gasification and pyrolysis processes.

Figure 3 : Simple Gasification Process

Steam Turbine 20 kg lime and PAC

450 kWh

1 tonne  Shredding,

Sorting and Residual Waste Pre-treatment

Flue Gas

100 kg Rejects 140 kg Inert Ash 50 kg FGT Residue (to landfill and recycling) (aggregate) (secure landfill)

Numbers are approximate for illustrative purposes only, and dependent on actual supplier and waste composition

The total amount of residues generated in a pyrolysis or gasification process is largely similar to that from a conventional incineration process. The quantity of residues is largely dependent on the amount of ash present in the waste stream, and all thermal processes should be capable of reducing the incoming waste to the non-combustible ash in an efficient manner. Claims of low residue quantities are normally due to a low assumption of the ash content of the waste, or because the front-end rejects are excluded from the overall balance.

It can also be noted from the above diagram that the net efficiency of pyrolysis and gasification processes has to date been low, significantly less than from conventional combustion processes.

1. Pyrolysis

The general characteristics of pyrolysis are as follows:

• No oxygen is present (or almost no oxygen) other than any oxygen present in the fuel;
• Temperatures vary from 400°C to 800°C;
• Products are gas, liquid, and char (material which is not completely oxidised);
• Lower temperatures with longer residence times tend to result in more char;
• Higher temperatures with short residence times (<1 second) tend to result in more liquid (up to 80%);
• Typical  net  calorific  value  (NCV)  of  the  medium  energy  gas  produced  is 15 to 20 MJ/Nm3 (Megajoules per cubic metre at normal temperature and pressure). For comparison, the NCV for natural gas is about 38 MJ/Nm3.

2. Gasification

The general characteristics of gasification are as follows:

• Oxygen is present either as pure oxygen or in air;
• Temperatures tend to be above 750°C;
• NCV of the gas produced will be lower than for pyrolysis as product is partially oxidised;
• Typical NCV of the gas from gasification in the presence of oxygen is 10 to 15 MJ/Nm3;
• Typical  NCV  of  the  low  energy  gas  from  gasification  in  the  presence  of  air  is 4 to 10 MJ/Nm3.

4. Mechanical Heat Treatment

In these facilities, waste is loaded into a drum and heated by injecting steam or by separately applying heat. The tumbling action, together with the steam, breaks the organic material down into a fibre. The resulting material can then be mechanically separated into different output streams, such as metal, plastics, fibre and rejects. Several uses for the fibre have been suggested, such as refuse derived fuel, compost or landfill restoration material. The process is a pre- treatment one and it is necessary to ensure disposal routes exist for each output. Due to the addition of water to the process, the amount of waste actually increases unless the fibre is thermally dried.

There are a few examples of such plants which have operated worldwide.

Figure 4 shows a typical mass balance for a system based upon a steam autoclave. As noted, there are several solid waste outputs which will require additional facilities, but these facilities are not pictured on the figure. The process is a net consumer of energy, requiring electricity for the mechanical equipment and heat to produce the steam.

Figure 4 : Steam Autoclave

20 kg steam

50 kg metals (recycling)

1 tonne Waste 90 kg plastics (EfW or landfill)

Autoclave Mechanical Separation 680 kg fibre (EfW or landfill) Residual Waste 130 kg rejects (landfill)

70 kg Rejects (landill)

Numbers are approximate for illustrative purposes only, and dependent on actual supplier and waste composition

5. Anaerobic Digestion (AD)

Anaerobic digestion is a well established technique for the decomposition of organic slurries, such as sewage or farm slurries. Jersey PSD operates a digester at the sewage treatment plant at Bellozanne. Organic material is mixed into a slurry, and bacteria are used under anaerobic conditions, that is without the presence of oxygen, to decompose the waste and produce methane gas. The methane gas can be used to generate electricity in gas engines or to produce heat.

It  is  possible  to  separate  out  the  organic  fraction  of  municipal  waste  and  to  digest  it anaerobically. There are examples of such plants in Europe, normally operating on source separated streams such as kitchen waste. There are also a number of plants processing separated mixed municipal solid waste (MSW).

Where mixed MSW is treated, it is still necessary to dispose of the remainder of the waste, typically more than half, which cannot be processed in the digester. In addition, a digestate is produced which must also be disposed of. Whilst such plants do generate some electricity, the net efficiency is low, typically about one third of that of a conventional energy from waste plant.

Figure 5 shows a typical mass balance for an anaerobic digestion system. Some of the outputs (the RDF and the digestate) require additional treatment facilities to process all the waste, which are not shown in the diagram.

Figure 5 : Anaerobic Digestion

Biogas to Gas Engine Flue Gas

210 kWh

1 tonne  Shredding, Organics

Sorting and

Effluent

Residual Waste organic

separation

300 kg RDF 100 kg Rejects 300 kg Digestate (for compost?) (to EfW plant) (to landfill)

Numbers are approximate for illustrative purposes only, and dependent on actual supplier and waste composition

6. Mechanical Biological Treatment (MBT)

Residual  waste  can  be  treated  using  a  combination  of  mechanical  sorting  and  biological treatment. Such MBT plants split the raw waste stream into a number of products, typically refuse derived fuel, organic material, glass/stones and metal. Some of the material is lost to the atmosphere, although this is mainly water with some decomposition of carbon and hydrogen. This type of plant is not a complete solution and it is necessary to ensure sustainable offtake routes exist for all the output streams.

There are many examples of this type of plant operating throughout Europe, and the technology can be considered mature.

Figure 6 shows the mass balance for a typical MBT system. As a pre-treatment process, several of the output streams need to be processed in additional treatment facilities, which are not shown in the diagram.

Figure 6 : Mechanical Biological Treatment Plant

250 kg of water and CO2 vapour

50 kg metals (recycling)

1 tonne Waste 450kg of RDF (EfW plant) Biological Treatment Mechanical Separation 160 kg organics (landfill)

Residual Waste 90 kg stone etc (aggregate

or landfill)

Numbers are approximate for illustrative purposes only, and dependent on actual supplier and waste composition

The process is a net consumer of electricity, required to power the mechanical equipment, with typically 70-100 kWh electricity /tonne of waste consumed. The process requires no external heat, as the heat in the process is provided from the waste itself.

7. Other Technologies

Various other technologies have been considered to determine whether these would be suitable for Jersey. These include:

• Plasma gasification, where waste is processed at high temperatures
• Bio-ethanol or diesel production, where organic material can be processed to make a chemical feedstock, for example for production of fuels
• Treatment of organic waste with chemicals, such as lime, to produce fertilisers.
• Plastic extrusion, where waste plastic is heated and then extruded into low grade plastic products.

4  CONVENTIONAL ENERGY FROM WASTE

1. CNIM / Martin

Current Position

CNIM  are  the  preferred  bidder  for  the  proposed  EfW  plants  to  be  built  in  Rufford  and Shropshire. A 220,000 tonnes per annum (tpa) plant in Sheffield was successfully completed on time in 2006, and since then has been operating well.

CNIM are licencees for the well proven Martin grate system, and the vast majority of their plants use this system.

CNIM were invited to tender for Jersey and submitted a proposal in February 2008.

Process Overview

1. Untreated waste is fed onto the CNIM/Martin "reverse-acting" grate where it combusts;
2. Combustion gases pass through a waste heat boiler to produce steam at high temperature and pressure;
3. The steam passes through a steam turbine to generate electricity for supplying the plant's internal load, with excess power exported to the Grid;
4. NOx  (oxides of nitrogen) is controlled by injecting ammonia solution at the top of the furnace (that is, by Selective Non-Catalytic Reduction SNCR);
5. Flue gases are cleaned using a fabric filter to remove particulates, plus injection of lime and activated carbon to remove other pollutants. Cleaned gases are exhausted to atmosphere via a stack;
6. Ferrous and non-ferrous metals are separated from furnace bottom ash. The metals are recycled and the remaining bottom ash is used as secondary aggregate or sent to non- hazardous landfill.

The majority of the CNIM plants produce electricity, with a net electrical efficiency of 22-24%. Some plants also produce heat for domestic or commercial use. Municipal waste contains 20- 25% inert material, and the majority of this material leaves the process as inert material which can be used as aggregates. About 5% of the mass of the incoming material is captured in the bag filter and is classified as hazardous waste, mainly due to the irritant nature of the lime added, requiring secure disposal.

Martin reverse acting grate (picture from Martin)

Reference Plants

CNIM, operating as Martin Engineering Systems (MES) in the UK, is the leading European supplier of conventional combustion technology for residual MSW.

The Martin grate, upon which the CNIM plants are based, is used in over 300 plants worldwide, incorporating over 600 units. Plants supplied by CNIM range from small units processing 20,000 tpa of waste, to very large plants with multiple units and capacities up to 400,000 tpa.

There are eight operational CNIM Plants in the UK: SELCHP in London (420,000 tpa), Sinergy in  Stoke-on-Trent  (200,000  tpa),  GEM  in  Dudley  (90,000 tpa),  WREN  in  Wolverhampton (105,000 tpa), Chineham (90,000 tpa), Southampton (160,000 tpa), Portsmouth (160,000 tpa) and Sheffield (220,000 tpa).

Suitability for Jersey

A possible solution for Jersey because of the following:

• Proven technology for thermal treatment of residual MSW;
• Many reference plants in the UK and Europe;
• Track record for delivering EPC (Engineering, Procurement and Construction) contracts for energy-from-waste plants.

2. Lentjes (formerly Lurgi)

Current Position

Lurgi is now trading under the name Lentjes UK Limited. Lentjes were sold by their parent company to Austrian Energy and Environment (AEE) in late 2007. The sale was approved by the European monopolies commission in early 2008. AEE are considered to be an acceptable parent company, with a wealth of experience in waste treatment – AEE also own Von Roll (see 4.5).

Lentjes were asked to submit a proposal to Jersey in November 2007. Due to the simultaneous acquisition,  AEE  submitted  a  proposal  utilising  both  Lentjes  and  Von  Roll  experience  in February 2008.

Process Overview

1. The untreated waste is combusted on either a reciprocating or roller-type grate;
2. High pressure/temperature steam is raised in a waste heat boiler;
3. The steam is used to generate electricity in a steam turbine generator;
4. Flue gas treatment is provided using lime and activated carbon, plus a fabric filter. SNCR is used for NOx control;
5. Metals are separated from the furnace bottom ash, with inert materials used in construction aggregates, and any residual material sent to landfill.

Most Lurgi plants produce electricity, with a net electrical efficiency of 22-24%. Some plants also produce heat for domestic or commercial use. Municipal waste contains 20-25% inert material, and the majority of this material leaves the process as inert material which can be used as aggregates. About 5% of the mass of the incoming material is captured in the bag filter and is classified as hazardous waste, requiring secure disposal.

Plant Portrait (from Website), Kirklees, Huddersfield

1 Reciprocating grate  5 Stack

2 Boiler   6 Steam turbine 3 Spray absorber  7 Air condenser 4 Fabric filter

Reference Plants

Lurgi has supplied this type of plant for many years, using both roller grates; where the grate consists of several rotating drums which allow the waste to tumble down the outside of each roller, and reciprocating grates; where grate bars oscillate backwards and forwards to push and mix the waste lying on the grate.

Lurgi have about 30 references for both their roller and reciprocating grate designs, and for complete design and build projects burning residual MSW. Plant sizes vary from small units of around 20,000 tpa of waste up to large multiple unit plants of 400,000 tpa. European examples include Huddersfield (136,000 tpa); Madeira, Portugal (128,000 tpa); Ludwigshafen (180,000 tpa), Offenbach (240,000 tpa) and Wuppertal (375,000 tpa) in Germany; Budapest (340,000 tpa).

Lurgi were the preferred bidder for the Guernsey project before the decision was taken to review the project.

Suitability for Jersey

A possible solution for Jersey because of the following:

• Proven technology for thermal treatment of residual MSW;
• Reference plants in the UK and Europe;
• Track record for delivering EPC contracts for energy-from-waste plants.

3. Cyclerval

Current Position

Cyclerval are currently involved in the development of a 60,000 tpa MSW facility in Exeter and another facility in Telford.

Cyclerval were initially named as Earth Tech's preferred equipment supplier to bid for the Jersey project. Prior to issue of tenders, Cyclerval indicated that they were unwilling to tender for the Jersey plant as they have insufficient resources and wished to pursue their other projects.

Process Overview

1. Untreated waste is combusted using Cyclerval's oscillating kiln technology;
2. The combustion gases are used to raise steam in a waste heat boiler;
3. The steam is passed to a steam turbine for the production of electricity;
4. SNCR is used for NOx reduction;
5. Flue gases are cleaned using injected lime and activated carbon, plus a fabric filter;
6. Ferrous and non-ferrous metals are removed from the bottom ash, with the remainder typically used in construction aggregates or sent to landfill. Boiler ash and flue gas residues (fly ash) are sent to hazardous landfill.

The Cyclerval plants produce electricity, with a net electrical efficiency of 22-24%. Municipal waste contains 20-25% inert material, and the majority of this material leaves the process as inert material which can be used as aggregates. About 5% of the mass of the incoming material is captured in the bag filter and is classified as hazardous waste, requiring secure disposal.

Cyclerval reciprocating kiln (picture from Cyclerval)

Reference Plants

Cyclerval's kilns are limited in size due to their large diameter. The processing range of these kilns can vary from 4-10 t/h of waste.

Earth Tech, using the Cyclerval's oscillating kiln, was the EPC contractor for the Newlincs energy from waste facility at Grimsby. The plant incinerates around 56,000 tonnes of municipal waste per year, and was commissioned in 2004.

Cyclerval has over ten similar reference plants in France and Belgium, with sizes ranging up to 160,000 tpa.

Suitability for Jersey

Possible solution for Jersey because of the following:

• Proven technology for municipal waste incineration;
• European reference plants, including one in the UK;
• Experience of delivering EPC contracts for energy-from-waste plants.

4. Keppel-Seghers

Current Position

Keppel Seghers are currently the preferred bidder for a proposed EfW facility to be built for Ineos Chlor in Runcorn.

Keppel Seghers were initially included on the potential bid list but indicated that they had insufficient resources and would be unable to bid.

Process Overview

1. Untreated waste is burnt on the Seghers air-cooled grate.
2. High pressure/temperature steam is raised in a waste heat boiler;
3. The steam is used to produce electricity in a steam turbine generator;

4. Flue gas treatment is provided using lime and activated carbon, plus fabric filter. SNCR is used for NOx control;
5. Metals are separated from the furnace bottom ash, with inert materials typically used in construction aggregates, with any residual material sent to landfill.

The majority of the Seghers plants produce electricity, with a net electrical efficiency of 22-24%. Some plants also produce heat for domestic or commercial use. Municipal waste contains 20- 25% inert material, and the majority of this material leaves the process as inert material which can be used as aggregates. About 5% of the mass of the incoming material is captured in the bag filter and is classified as hazardous waste, requiring secure disposal.

Picture from Website

Reference Plants

Seghers technology has been used in about 20 plants worldwide burning MSW, including the Isvag and Indaver plants in Belgium, (2 x 80,000 tpa and 190,000 tpa respectively) and various plants in Asia and the Far East. Seghers plants vary in capacity from 15,000 to 200,000 tpa.

Suitability for Jersey

Possible solution for Jersey because of the following:

• Proven technology for thermal treatment of residual MSW;
• Reference plants in Europe;
• Experience of delivering EPC contracts for energy-from-waste plants.

5. Von Roll Inova

Current Position

Von Roll are currently the preferred EPC contractor for Riverside EfW facility, a 670,000 tpa facility targeted to be operational in 2010. They are also involved with the construction of a 130,000 tpa turnkey EfW facility near Vienna, the development of a third line at the Teesside energy from waste facility (135,000 tpa) and the development of the Newhaven EfW facility (225,000 tpa). Von Roll are owned by AEE (see 4.2 above).

When Lentjes were taken over by AEE, some of von Roll's technology was used in submitting the Lentjes/AEE proposal to Jersey.

Process Overview

1. Untreated waste is burnt on the Von Roll reciprocating grate.
2. High pressure/temperature steam is raised in a waste heat boiler;
3. Steam is used to produce electricity in a steam turbine generator;
4. SNCR is used for NOx reduction;
5. Flue gas treatment is provided using lime and activated carbon, plus a fabric filter;
6. Metals are separated from the furnace bottom ash, with inert materials typically used in construction aggregates, and any residual material sent to landfill. Boiler ash and flue gas residues are sent to secure landfill.

The majority of von Roll plants produce electricity, with a net electrical efficiency of 22-24%. Some plants also produce heat for domestic or commercial use. Municipal waste contains 20- 25% inert material, and the majority of this material leaves the process as inert material which can be used as aggregates. About 5% of the mass of the incoming material is captured in the bag filter and is classified as hazardous waste mainly due to the irritant nature of the lime added, requiring secure disposal.

Picture of Nuremburg waste incineration plant (from Von Roll Inova Website)

Reference Plants

Von Roll has supplied over 300 plants worldwide since 1954, mostly burning MSW - none in the UK although Stream 3 at Bellozanne was delivered by Von Roll. Examples of recent European plants include Thun, Switzerland (150,000 tpa); Alkmaar, Netherlands (3 x 150,000 tpa plus 1 x 225,000  tpa);  Perpignan,  France  (2  x  85,000  tpa);  Nuremberg  (3  x  85,000 tpa);  MHKW Pirmasens, Germany (2 x 100,000 tpa).

Suitability for Jersey

Possible solution for Jersey because of the following:

• Proven technology for thermal treatment of residual MSW;
• Reference plants in the UK and Europe;
• Experience of delivering EPC contracts for energy-from-waste plants.

6. Babcock & Wilcox Vølund

Current Position

Since supplying the boiler and grate to Slough Heat and Power as a sub-contractor to Agra Birwelco in 2003, Babcock & Wilcox Vølund have not supplied any other plants in the UK.

Babcock & Wilcox Vølund were unwilling to submit a proposal for the Jersey contract.

Process Overview

1. Untreated waste is burnt on a Vølund air-cooled, reciprocating grate.
2. High pressure/temperature steam is raised in a waste heat boiler;
3. Steam is used to produce electricity in a steam turbine generator;
4. Flue gas treatment is provided using lime and activated carbon, plus a fabric filter. SNCR is used for NOx reduction.
5. Metals are separated from the furnace bottom ash, with inert materials typically used in construction aggregates, and any residual material sent to landfill.

The majority of the Vølund plants produce electricity, with a net electrical efficiency of 22-24%. Some plants also produce heat for domestic or commercial use. Municipal waste contains 20- 25% inert material, and the majority of this material leaves the process as inert material which can be used as aggregates. About 5% of the mass of the incoming material is captured in the bag filter and is classified as hazardous waste mainly due to the irritant nature of the lime added, requiring secure disposal.

Picture of Cleveland plant, UK (from Website)

Reference Plants

Vølund is a Danish based company, with over 300 waste-to-energy plants supplied worldwide over a period of 70 years. Babcock Wilcox of the US took the company over in recent times. Recent European projects utilising an air-cooled grate include Charleroi, Belgium (65,000 tpa); Esbjerg, Denmark (190,000 tpa), and Nevers, France (1 x 50,000 tpa). There are two operating UK plants at Cleveland (2 x 110,000 tpa) and Slough Heat & Power (100,000 tpa). Cleveland was built by Sir Robert MacAlpine, and Slough Heat and Power by Agra Birwelco (AMEC) with Vølund as the boiler and grate supplier.

Suitability for Jersey

Possible solution for Jersey because of the following:

• Proven technology for incineration of residual MSW;
• Reference plants in the UK and Europe.

However, Babcock Wilcox Vølund is currently not bidding for full turnkey projects, and even appears to be reluctant to offer its grate and boiler together with a main contractor.

7. Fisia Babcock Environment

Current Position

After a period when Fisia Babcock were unable to bid for projects in the UK, they are now active again. They have made an agreement with Earth Tech which enables Earth Tech to bid for turnkey EPC Contracts using their technology. Fisia Babcock bid together with Earth Tech for the Jersey contract, submitting a proposal in February 2008.

Process Overview

1. Untreated waste is burnt on an air- or water-cooled grate
2. High pressure/temperature steam is raised in a waste heat boiler;
3. Steam is used to produce electricity in a steam turbine generator;
4. Flue gas treatment is provided using lime and activated carbon, plus fabric filter. SNCR is used for NOx reduction;
5. Metals are separated from the furnace bottom ash, with inert materials typically used in construction aggregates, and any residual material sent to landfill.

The majority of the Fisia Babcock plants produce electricity, with a net electrical efficiency of 22-24%. Some plants also produce  heat for domestic or commercial use. Municipal waste

contains 20-25% inert material, and the majority of this material leaves the process as inert material which can be used as aggregates. About 5% of the incoming material is captured in the bag filter and is classified as hazardous waste, requiring secure disposal.

Tyseley Energy from Waste Plant, Birmingham, England. (source Onyx)

Reference Plants

Fisia Babcock has numerous worldwide and European references. The company has supplied plants ranging from 30,000 tpa of waste up to 400,000 tpa. The company owns the Babcock, Steinmuller and Noell technologies and can offer either roller or reciprocating grates. Recent European new plant references include Århus, Denmark (water-cooled grate, 140,000 tpa); Isle of Man (Noell water-cooled grate, 65,000 tpa, plant built by Kvaerner); and Rambervillers, France (air-cooled grate, 50,000 tpa). The most recent UK reference plant is at Tyseley, Birmingham which has a capacity of 2 x 180,000 tpa.

Suitability for Jersey

Possible solution for Jersey because of the following:

• Proven technology for recovering energy from residual MSW;
• Reference plants in the UK and Europe.

Babcock Borsig Power went into receivership in 2001 and was subsequently bought by Fisia of Italy to create Fisia Babcock Environment. Due to this, the company was not active for some time, but this has now changed.

8. Itochu with Takuma

Current Position

Takuma are currently constructing the 430,000 tpa EfW plant at Lakeside near Heathrow airport. They are also preferred bidder for the Cornwall PFI contract. Takuma did not indicate any interest in pre-qualifying for the Jersey contract.

Process Overview

1. Untreated waste is fed onto the Takuma sliding grate, with individual speed control on each section;

2. NOx is controlled through the injection of ammonia solution at the top of the furnace (SNCR);
3. Combustion gases are used to raise high pressure steam in a waste heat boiler;
4. A steam turbine generator produces electricity from the steam;
5. Waste flue gases are cleaned with the injection of lime and activated carbon, plus a fabric filter to remove particulates.
6. Metals are separated from the furnace bottom ash, with inert materials typically used in construction aggregates, and any residual material sent to landfill.

Most Itochu/Takuma plants produce electricity, with a net electrical efficiency of 22-24%. Some plants also produce heat for domestic or commercial use. Municipal waste contains 20-25% inert material, and the majority of this material leaves the process as inert material which can be used as aggregates. About 5% of the mass of the incoming material is captured in the bag filter and is classified as hazardous waste, requiring secure disposal.

Illustration from Takuma

Waste Charging Hopper

Furnace Water Tube Panel Feeder

Ignition Burner

Drying Grate

Burning Grate

Chute

Burn-out Grate

Main Ash Chute

Reference Plants

There are many reference plants in Japan and the Far East ranging in size from 30,000 tpa of waste to over 400,000 tpa. Itochu / Takuma are currently constructing the 430,000 tpa Lakeside Energy-from-Waste  project  at  Colnbrook,  near  Slough,  which  will  be  the  first  European reference plant.

Suitability for Jersey

Possible solution for Jersey because of the following:

• Proven technology for incineration of residual MSW;
• Many reference plants worldwide;

However, Lakeside is the first plant built by the consortium in Europe.

5  EFW - FLUIDISED BED COMBUSTION

1. Austrian Energy

Austrian Energy & Environment (AEE) are part of the same group as Von Roll and acquired Lentjes this year.

Process Overview

1. Mechanical pre-treatment of raw waste is used to produce refuse derived fuel (RDF) suitable for combustion in a fluidised bed boiler;
2. The treated waste is combusted in a bubbling or circulating-type fluidised bed of sand, through which combustion air is blown.
3. Steam at high pressure and temperature is generated in a waste heat boiler;
4. Production of electricity from the steam using a steam turbine;
5. Flue gas cleaning is provided using lime and activated carbon, plus a fabric filter to remove particulates.

The AEE plants produce electricity, with a net electrical efficiency of 20-25%. Some plants also produce heat for domestic or commercial use. RDF contains 12-20% ash, and the majority of this material leaves the process as inert material, some of which can be used as aggregates. About 5% of the incoming material is captured in the bag filter and is classified as hazardous waste mainly due to the irritant nature of the lime added, requiring secure disposal.

Picture of Niklasdorf RDF-Plant, Austria (from Website)

Reference Plants

The main reference plant for bubbling bed (Ecofluid) plants burning Refuse Derived Fuel (RDF) is the Niklasdorf plant in Austria, including waste handling and treatment facilities. This has an electrical output of 7.5 MW and also supplies steam to a paper mill.

Suitability for Jersey

AEE fluidised beds are not considered suitable for Jersey because significant pre-treatment of raw waste is required prior to combustion. Fluidised beds are very sensitive to over-sized material, glass, metals or stones and these must be separated prior to combustion. Such a solution would therefore require a preparation facility which would create a reject stream requiring disposal, plus additional staff and operating costs, for no identified benefits.

AEE fluidised beds are in operation in Europe successfully burning refuse derived fuel (see also section 9). However, this would require the installation of a MBT plant to produce the refuse derived fuel and a significant amount of rejected material, with no clear disposal route. An energy from waste plant would therefore still be required. Even though this would be smaller in capacity, the overall cost of both facilities, and the need to find disposal routes for a significant quantity of rejected material, means that this is not considered an attractive solution.

2. Foster Wheeler

Current Position

FW supply mainly biomass fired boilers worldwide, although they do continue to market and construct refuse derived fuel fired plants. FW are currently installing a third stream at the Lomellina plant in Italy.

Process Overview

1. Mechanical pre-treatment of raw waste is used to produce refuse derived fuel (RDF) suitable for combustion in a fluidised bed boiler;
2. The treated waste is then combusted in a circulating-type fluidised bed (CFB) boiler;
3. Steam at high pressure and temperature is generated in a waste heat boiler;
4. Electricity is produced from the steam using a steam turbine;
5. Flue gas cleaning is provided using lime and activated carbon, plus a fabric filter to remove particulates. SNCR is not normally required.

FW plants normally produce electricity, with a net electrical efficiency of up to 25%, or process steam. RDF contains 12-20% ash, and the majority of this material leaves the process as inert material, some of which can be used as aggregates. About 5% of the mass of the incoming material is captured in the bag filter and is classified as hazardous waste mainly due to the irritant nature of the lime added, requiring secure disposal.

Picture of Lomellina RDF-fired plant, Italy (from FW Website)

Reference Plants

FW  supplied  the  Lomellina  waste-to-energy  plant  in  Parona,  Italy,  which  processes  about 120,000 tpa of RDF and is currently being expanded. The plant is designed to recover material and  energy  from  MSW.  About  60%  of  the  MSW  can  be  converted  into  RDF,  following separation of aluminium, ferrous materials, glass and compost from the raw waste. The fuel is then fed into the CFB boiler and burnt at temperatures between 850 and 900°C.

Suitability for Jersey

FW fluidised beds are not considered suitable for Jersey because significant pre-treatment of raw waste is required prior to combustion. Fluidised beds are very sensitive to over-sized material, glass, metals or stones and these must be separated prior to combustion. Such a solution would therefore require a preparation facility which would create a reject stream requiring disposal, plus additional staff and operating costs, for no identified benefits.

FW fluidised beds are in operation in Europe successfully burning refuse derived fuel (see also section 9). However, this would require the installation of a MBT plant to produce the refuse derived fuel and a significant amount of rejected material, with no clear disposal route. An energy from waste plant would therefore still be required. Even though this would be smaller in capacity, the overall cost of both facilities, and the need to find disposal routes for a significant quantity of rejected material, means that this is not considered an attractive solution.

3. Kvaerner (now Metso)

Current Position

The fluidised bed section of Aker Kvaerner was acquired by Metso in 2007. Metso primarily supply biomass fired fluidised bed boilers, using fuels such as wood. However, they also market refuse derived fuel boilers.

Process Overview

1. Mechanical  pre-treatment  of  raw  waste  is  used  to  produce  suitable  fuel  (RDF)  for combustion in a fluidised bed boiler;
2. The treated waste is combusted in a bubbling or circulating-type fluidised bed of sand, through which combustion air is blown;
3. Steam at high pressure and temperature is generated in a waste heat boiler;
4. Electricity is produced from the steam using a steam turbine;
5. Flue gas cleaning is provided using lime and activated carbon, plus a fabric filter to remove particulates.

Metso plants normally produce electricity, with a net electrical efficiency of about 25%. Some plants also produce heat for domestic or commercial use. RDF contains 12-20% ash, and the majority of this material leaves the process as inert material, some of which can be used as aggregates. About 5% of the mass of the incoming material is captured in the bag filter and is classified as hazardous waste, requiring secure disposal.

Kvaerner Norrköping CFB Boiler plant [from The Finnish Environment report: "Finnish Expert Report on best available techniques in energy production from solid recovered fuels"]

Reference Plants

There are some reference plants burning refuse-derived fuel (RDF) / solid recovered fuel (SRF), including:

• Norrköping, Sweden burning assorted municipal solid waste in a fuel mix with industrial waste, sewage sludge, rubber chips and demolition waste wood. 75 MWth plant capacity;
• Sogama plant in North West Spain processing 650,000 tpa of MSW to 400,000 tpa of solid recovered fuel, for firing in CFB boilers and subsequent electricity generation.
• Baldovie waste-to-energy plant, Dundee burning mainly treated municipal waste in two 17 MWth bubbling fluidised bed boilers. The steam raised is used to generate electricity in a single condensing turbine generator with up to 8.3 MW being exported to the national electricity network. The plant is designed to treat 120,000 tpa of waste.

Suitability for Jersey

Metso fluidised beds are not considered suitable for Jersey because significant pre-treatment of raw waste is required prior to combustion. Fluidised beds are very sensitive to over-sized material, glass, metals or stones and these must be separated prior to combustion. Such a solution would therefore require a preparation facility which would create a reject stream requiring disposal, plus additional staff and operating costs, for no identified benefits.

Metso fluidised beds are in operation in Europe successfully burning refuse derived fuel (see also section 9). However, this would require the installation of a MBT plant to produce the refuse derived fuel and a significant amount of rejected material, with no clear disposal route. An energy from waste plant would therefore still be required. Even though this would be smaller in capacity, the overall cost of both facilities, and the need to find disposal routes for a significant quantity of rejected material, means that this is not considered an attractive solution.

4. Lurgi (then Lentjes, now AEE)

Current Position

Lurgi UK were renamed Lentjes UK after their German division. Lentjes has subsequently been acquired by AEE. Lentjes UK are currently constructing the Allington Quarry 500,000 tpa fluidised bed plant in Kent. This project has been delayed following a series of problems. As AEE have their own in-house fluidised bed technology, it is not currently clear if AEE will continue to provide the Lentjes design of fluidised bed. During pre-tendering discussions and the

tender process, Lentjes did not indicate that their proposed technical solution for Jersey would be a fluidised bed, and offered a standard grate design instead.

Process Overview

The Lentjes fluidised bed process includes:

1. Mechanical processing of waste including at least a reduction in size to below 300mm. Due to the special, robust design of the fluidised bed, the pre-treatment of the waste is not arduous;
2. Combustion of treated waste in the Rowitec® fluidised bed;
3. Generation of steam at high pressure and temperature in a waste heat boiler;
4. Production of electricity using a steam turbine;
5. Flue  gas  cleaning  using  lime  and  activated  carbon,  plus  a  fabric  filter  to  remove particulates.

Lentjes fluidised bed plants produce electricity, with a net electrical efficiency of up to 25%, from either pre-treated municipal waste or RDF. Some plants also produce heat for domestic or commercial use. RDF contains 12-20% ash, and the majority of this material leaves the process as inert material, some of which can be used as aggregates. About 5% of the mass of the incoming material is captured in the bag filter and is classified as hazardous waste, requiring secure disposal.

Mulhouse, France (170,000 tpa) (Picture from Lurgi Lentjes Website)

Reference Plants

There are several European references for Rowitec® CFB boilers burning municipal solid waste as part of waste mixture. Plants include:

• Madrid, Spain: 400,000 tpa plant processing municipal waste.
• Gien, France: 75,000 tpa of municipal, commercial, hospital wastes, plus sludge;
• Mulhouse, France: 170,000 tpa of municipal waste and sewage sludge;
• Macomer, Italy: 45,000 tpa municipal plus hospital waste.

The Rowitec® technology has also been used to construct the 500,000 tpa Allington Quarry plant in  the  UK,  which  includes  material  recovery  facilities  for  pre-treatment  of  waste  prior  to combustion. This plant is under construction.

Suitability for Jersey

Lentjes fluidised beds are not considered suitable for Jersey because pre-treatment of raw waste is required prior to combustion. Fluidised beds are very sensitive to over-sized material, glass, metals or stones and these must be separated prior to combustion. Such a solution would therefore require a preparation facility which would create a reject stream requiring disposal, plus additional staff and operating costs, for no identified benefits.

6  EFW - GASIFICATION AND PYROLYSIS

1. Austrian Energy - Von Roll

Austrian Energy & Environment (AEE) and Von Roll are part of the same company. Process Overview

AEE has a process called RCP (Recycled Clean Products). It includes pyrolysis and controlled high-temperature melting with oxygen injection to yield an immediately usable raw material for the construction industry. Slag is vitrified in the RCP process, with extraction of heavy metals in the slag refinement step.

Reference Plants None known.

Suitability for Jersey

The technology is not considered suitable for Jersey because there are no reference plants with residual MSW.

2. British Gas - Lurgi

Process Overview

This gasification process, which uses an oxygen blown gasifier to produce a medium calorific value fuel gas, was developed to process coal. Material is fed to a fixed bed gasifier and heated with oxygen to produce a gas. The gas can be used in processes or burnt to generate steam in a boiler or gas turbine. The process also requires an air separation plant in order to provide the necessary oxygen for gasification.

Reference Plants

Schwarze Pumpe BG-Lurgi gasifier

There is an operating plant at Schwarze Pumpe, Germany, where RDF and commercial waste are gasified, together with some coal.

Suitability for Jersey

The British Gas-Lurgi gasifier is not being marketed for waste disposal in the UK.

The process is not considered suitable, as the process requires RDF, not residual waste, and additional fuel such as coal. In addition, the requirement for an air separation plant means that the process is complicated and requires additional land space.

3. Bowen Worldwide Developments

Process Overview

Bowen describes their process as follows:

• Raw waste is first separated by manual picking. The separated waste is then shredded, dried and pelletised. Material such as glass, metal and stones are rejected;
• The process pyrolyses waste using indirect heat;
• The resulting gases are then burnt in a secondary chamber;
• The hot flue gases are used to generate steam which is used to produce electricity in a steam turbine;
• The flue gases are then cleaned using a wet scrubber.

Schematic taken from Bowen Worldwide presentation to Jersey PSD

Reference Plants

None identified. We understand there is a small thermal oxidiser unit operating in America, but no details of size or waste type treated have been provided.

Suitability for Jersey

The technology is not considered suitable for Jersey because:

• No suitable reference plants have been identified.
• Staffing requirements – according to Bowen, 60 staff are required for a 50,000 tpa unit.

4. Compact Power (now Ethos Recycling)

Current Position

Compact Power have sold the Dumfries site, for which they had planning consent to build a plant, as they were unable to develop this project. Compact Power went into administration on 16th January 2008. Compact Power were subsequently taken over by Ethos Recycling, who were formed from the skip-hire firm Sweeney Environmental, and who intend to continue to market the technology. According to Ethois Recycling, work has started on the construction of a larger Avonmouth facility to process residual municipal waste.

Process Overview

1. Materials recovery facility is used for taking out bulky materials and recyclables;
2. Pyrolysis is carried out at 800°C in externally heated screw tube pyrolysers;
3. Gasification of residues follows with air and steam;
4. Thermal  oxidation  (combustion)  of  the  syngas  (from  the  pyrolysis  and  gasification processes) with air at high temperature (>1250°C for 2 seconds) converts the gas to hot flue gases.
5. Steam is then generated in a waste heat boiler;
6. Power is generated from the steam via a steam turbine;
7. Flue gas cleaning is provided by a bag filter with sodium bicarbonate  injection and selective catalytic reduction (SCR) with ammonia for NOx reduction. .

The estimated net electrical efficiency of the process is only about 14%. The process will create similar amounts of residues (or perhaps slightly more) as a conventional incineration process.

Picture from Compact Power Website

Reference Plants

Compact Power has a single reference plant operating commercially at Avonmouth, with a capacity of 6,000 tpa. The plant was tested using residual municipal solid waste (RMSW) but normally burns clinical waste.

Suitability for Jersey

Not considered suitable for Jersey because:

• There are no reference plants of sufficient capacity;
• The suitability of ash for use as secondary aggregate is unclear due to higher potential amounts of unburnt material;
• The process has a low electrical efficiency of less than 20%.

5. Enerkem / Novera

Current Position

Enerkem gasification technology is marketed under licence by Novera Energy in the UK for MSW application.

Novera are developing the ELSEF project. The ELSEF project is ongoing but will not reach financial close in the short term and therefore will not be operational for at least 2 years. The plant will take 90,000 tonnes of refuse derived fuel (RDF) from the Shanks MBT plant at Frog Island providing Ford with between 8 and 10 MW of energy.

Process Overview

The proposed process includes the following steps:

1. Feedstock reception and storage;

2. Gasification in a bubbling fluidised bed with silica alumina as the fluidising medium. The quantity of air, or optionally oxygen, fed into the fluidised bed represents about 30% of the stoichiometric amount required for complete combustion of the organics in the feedstock;
3. Removal and disposal of coarse char particles from hot syngas via cyclones;
4. Gas cleaning and cooling with gas quench tower, venturi scrubber, demister, electrostatic precipitator and dehumidification to produce a clean syngas suitable for use in gas engines or turbines;
5. Power generation using either a conventional steam cycle or a gas engine / turbine. The estimated net electrical efficiency is only 15% with a conventional steam cycle. This is estimated to rise to 22% in a gas engine, although this has yet to be tested with MSW.

Picture from Enerkem website

Reference Plants

There is a single reference plant in Castellon, Spain using gas engines for power generation. The feedstock for the reference plant was plastics with a high net calorific value in the order of 38 MJ/kg.

Suitability for Jersey

Not considered suitable for Jersey because there are no reference plants of sufficient capacity or with experience of processing MSW. The process can only process refuse derived fuel.

6. Ener-G / Energos AS

Current Position

EnerG are constructing an EfW facility on the Isle of Wight for the treatment of the Island's waste. This will be a single unit processing about 35,000 tpa of material.

EnerG were placed on the shortlist for Jersey and asked to provide a proposal. Midway through the tendering stage the company withdrew from the process as they were having difficulties fitting their process into the available footprint, and also had resource problems due to several other projects which they considered they had a better chance of winning.

Process Overview

1. Feed preparation (shredding) is required to increase surface area of waste;
2. Static grate gasifier with combustion chamber directly above grate burns the processed waste;
3. Each module can process around 35,000 tpa of raw waste. Additional capacity is achieved with multiple modules;
4. Steam generation is carried out in a boiler, and the steam used to generate electricity in a turbine;
5. Flue gas cleaning by fabric filter with lime and carbon injection.

Energos plants produce electricity, with a net electrical efficiency of about 18%. Some plants also produce heat for domestic or commercial use. Municipal waste contains 20-25% ash, and the majority of this material leaves the process as inert material, some of which can be used as aggregates. About 5% of the incoming material is captured in the bag filter and is classified as hazardous waste mainly due to the irritant nature of the lime added, requiring secure disposal.

Picture from EnerG Website

Reference Plants

Six plants are operating commercially (five in Norway, one in Germany), for between 2 and 7 years,  processing  MSW,  commercial  and  industrial  wastes.   Plant  capacities  range  from 10,000 tpa to 75,000 tpa.

Energos ceased to trade in 2002 and was taken over by EnerG, who own the Isle of Wight energy from waste plant.

Suitability for Jersey

This was considered a possible solution for Jersey because of the following:

• Proven technology for thermal treatment of residual MSW;
• Reference plants in Europe.

7. Ferco

Process Overview

The Ferco SilvaGas gasification process is specifically designed for processing biomass, and the organic fraction of MSW. The process incorporates the following:

1. Fuel drying;
2. Gasification in a circulating fluidised bed;
3. Steam gasification to produce syngas. Char combustion takes place in a second fluidised bed to provide heat to the sand carried over from the gasifier. This hot sand is recycled back into the gasifier to provide heat for the chemical reactions;
4. Syngas from demonstration plant has been used in a power station but FERCO intends to burn the gas in a gas turbine. Some testing of syngas in a very small (200kW) Solar Spartan gas turbine has been undertaken at the pilot plant.

FERCO process – illustration supplied by FERCO

Reference Plants

Single demonstration plant in Vermont (USA) processing biomass. The syngas was exported for co-firing at an existing conventional power plant. MSW has not been tested at the demonstration plant but RDF has been tested for a short period in a small pilot plant.

Suitability for Jersey

The technology is not considered suitable for Jersey because there are no commercially operating plants processing MSW. In addition, the process is not tolerant of raw MSW. MSW requires extensive preparation and drying prior to gasification. If the syngas is to be used in a gas turbine, this would require extensive testing due to the high risk of damage to the gas turbine blades with a dirty gas.

8. Foster Wheeler

Process Overview

The proposed process includes:

1. Gasification of prepared RDF in a circulating fluidised bed at atmospheric pressure using air;
2. Flue gas clean-up;
3. Use of syngas in a power station or industrial process.

Diagram from Foster Wheeler

Reference Plants

The main reference plant is a demonstration plant at Lahti, Finland processing recycled fuel containing plastics, paper, cardboard and wood. The fuel input is 60 MWth. The syngas is co- fired in a conventional power station. Foster Wheeler is targeting the gasifier for processing RDF to produce syngas for use in power stations, which would require significant pre-processing of MSW. There are also four smaller Finnish plants supplied between 1983 and 1986 to the pulp and paper industry which use bark and waste wood as the feedstock.

Suitability for Jersey

The technology is not considered suitable for Jersey because:

• The technology is more suited to gasification of biomass and RDF, not raw MSW which would need significant pre-processing in order to produce RDF;
• The main FW concept is based upon producing gas for use in a power station or similar process, and no such process exists in Jersey;
• The requirement for pre-processing of MSW would require additional staff over existing levels.

9. GEM (Graveson Energy Management)

Current Position

As part of the UK New Technologies Demonstration Programme, an EfW facility is to be built in North Yorkshire by a partnership of Yorwaste, NEL and GEM. The project is to be known as Scarborough Power and will process 18,000 tonnes per year of MSW into a prepared fuel. This fuel will then be converted into syngas using the GEM Technology. According to GEM, this plant is in construction and will be operational in 2008.

Process Overview

The proposed GEM process includes the following:

1. Three-stage  pre-treatment  comprising:  (i)  removal  of  metals,  glass  and  ceramics,  (ii) shredding into small flakes, (iii) thermal drying to around 5% moisture;
2. Continuous feed and fast pyrolysis in an externally heated stirred reactor;
3. Hot gas filtration;
4. Syngas cooling in a heat exchanger cooled with atomised mineral oil coolant;
5. Syngas compression and after cooling. The syngas is then fired in a gas engine, with an estimated net electrical efficiency of about 24%.

GEM Converter – illustration supplied by GEM

Reference Plants

GEM have operated a small test plant at Bridgend. The plant supplying the waste fuel was dismantled in 2004 and the gasifier has not operated for several years. A gas engine was tested on site for about four weeks for trials but it is not clear how many operating hours were achieved. There are no commercially operating plants.

Suitability for Jersey

The technology is not considered suitable for Jersey because:

• There are no reference plants operating commercially.
• Pre-sorting and significant pre-treatment of the waste stream is required. The gasifier cannot accept broken glass and waste must be dried to a low moisture content of only a few percent prior to gasification.

10. Gibros / Marick

Process Overview

The company is dedicated to the development and sale of commercially viable small scale gasification plant with CHP, ranging from 25 kW to 500 kW electricity.

Illustration from Marick website

Reference Plants

No significant references known.

Suitability for Jersey

Not suitable for Jersey because:

• There are no commercial plants in operation processing similar wastes;
• The process appears to be designed for biomass, rather than raw MSW;
• The proposed scale of the plants is too small to meet the required waste throughput at Jersey

11. IET / Entech

Process Overview

The Entech system is marketed by IET Energy in the UK. The process is as follows:

1. Continuous feeding of waste into stepped hearth;
2. Syngas combustion in a thermal reactor with flue gas recirculation (FGR) and SNCR for NOx reduction;
3. Power generation using boiler and steam turbine. Estimated net electrical efficiency is about 20%;
4. Flue gas cleaning system consisting of bag filter with reagent injection for control of volatile organic compounds (VOC) and packed tower for acid control. IET/Entech will offer to guarantee compliance with WID;
5. Recovery of ferrous and non-ferrous metals and glass from the gasifier residues.

Minimal or no waste pre-treatment is necessary, but pre-treatment to recover recyclables is not precluded.

IET/Entech Process - illustration supplied by IET Energy

Reference Plants

Around 145 reference plants processing a variety of waste including 11 plants processing MSW with capacities up to 130 tonnes per day (c. 40,000 tpa). There is only one plant in Europe (Poland), which has a capacity 5 tonnes of clinical waste per day and where steam is vented to atmosphere, i.e. no energy recovery.

Suitability for Jersey

There are a number of plants in the Far East. However, the plants reviewed were of a smaller scale and the proposed feeding systems would not be suitable for the much larger tonnages in Jersey. It has not been possible to establish sufficient confidence in the applicability of this solution.

12. Lurgi (Lentjes, now AEE)

Process Overview

The process is based upon:

1. Gasification in circulating fluidised bed;
2. Ash discharge, cooling, and transportation to raw mill on cement manufacturing plant;
3. Syngas fired in calciner of cement plant.

Reference Plants

One  reference  plant  at  Rüdersdorf,  Germany  which  utilises  various  types  of  RDF  for  the production of syngas and char for use in a cement kiln. This plant is based on fluidised bed technology.

Suitability for Jersey

The technology is not considered suitable for Jersey because:

• Lurgi have now withdrawn from the waste gasification market;
• MSW  would  require  pre-treatment  to  obtain  a  suitable  RDF  fuel  for  gasification,  and disposal routes for the non-gasified waste would need to be found.

13. Mitsui-Babcock

Process Overview

Mitsui-Babcock market the Mitsui Engineering and Shipbuilding Pyrolysis process which is based  on  the  R21  process  developed  by  Siemens  (who  have  since  withdrawn  from  the gasification market). The Mitsui-Babcock process is designed to process municipal household and commercial waste, and comprises:

1. sorting, possibly manual, of bulky waste for recovery of large recyclables;
2. shredding of the residual MSW before delivery to the storage pit;
3. pre-sorting of MSW, if required, to remove glass and metals;
4. low temperature pyrolysis at below 450°C in rotary kiln that is indirectly heated by hot air;
5. metals recovery from char;
6. combustion of the syngas and char from the pyrolysis process at over 1300°C in an ash- melting furnace;
7. power generation via a steam cycle
8. collection of fly ash in a bag filter for recycling to the main combustion chamber;
9. collection of lime-based flue gas treatment residues to be sent to landfill.

Image taken from Mitsui-Babcock website

Reference Plants

There are six plants in Japan operating on MSW and commercial waste with capacities between approximately 40,000 and 120,000 tonnes per year. No plants are operating outside Japan.

Suitability for Jersey

The technology is not considered suitable for Jersey because:

• There are no operating European plants;
• The process has a low electrical efficiency of around 15%.
• Pre-treatment of waste streams will be required.

14. Nathaniel Energy

Process Overview

The process includes:

1. a fuel preparation system to produce fuel pellets from processed municipal waste;
2. a gasification stage where the waste is heated and gasified using controlled air flows;
3. a secondary combustion chamber where the gases are burnt;
4. a boiler to convert the heat in the flue gas to steam;
5. a flue gas cleaning system, using a wet scrubber (or potentially dry cleaning);
6. a steam turbine to generate electricity from the steam.

The plant is therefore quite similar in make-up to a conventional incineration plant.

Reference Plants

Two small units, processing around 1.5 t/h of pellets produced from RDF, were commissioned in Cologna Veneta, Italy in early 2005.

Gasifier unit (source Nathaniel Energy web-site)

Suitability for Jersey

The technology is not considered suitable for Jersey because:

• Limited reference plant and none at the capacity required for Jersey;
• The reference plant processes RDF. As this is then converted into pellets at the site, the process would not be suitable for raw MSW.

15. PKA / Toshiba

Process Overview

The process is based upon the following steps:

1. Separation of glass and metals and preparation of the incoming waste;
2. The remaining material then goes through a size reduction process. Drying to below 15% moisture is recommended, but not mandatory

3. The prepared waste is fed to an externally-heated rotary kiln for pyrolysis / gasification at 500-600°C;
4. The product gases and vapours are transferred to a gasification chamber where they are cracked at around 1000°C into lighter components;
5. The gases are transferred to a gas cleaning system, which removes chlorides and sulphur, leaving a clean reusable gas.
6. The metal residue from the kiln can be reused. The pyrolytic char can be supplied to a secondary gasification device to produce additional syngas, which is mixed with the syngas from the pyrolysis process.

Diagram from PKA website

Reference Plants

A PKA facility in Aalen, Germany has been operating on a blend of MSW, commercial waste, and sewage sludge since 2001. The plant has a capacity of around 25,000 tonnes per year.

PKA also has a plant processing approximately 30,000 tpa at Freiberg, Germany where high aluminium content industrial waste is pyrolysed for recovery of the aluminium.

Suitability for Jersey

The technology is not considered suitable for Jersey because:

• There are limited reference plants and none at the capacity or processing the type of waste required for Jersey
• The process is a relatively complex plant with pre-treatment of waste, pyrolysis, gasification and power generation plant.

16. Thermoselect

Process Overview

The process is based upon the following:

1. Pyrolysis in externally heated tubes with waste feeding by ramming;
2. High temperature (2,000°C) gasification using oxygen as the gasification medium;
3. Melting of ash into slag at high temperatures;
4. Solidification of metals and minerals by quenching with water;
5. Magnetic separation of metals from the mixed slag;
6. Syngas held at over 1,100°C for at least 2 seconds before quenching down to 90oC;
7. Water condensed from syngas cooling is treated for re-use as cooling water;

If the syngas is used for electricity generation using a gas engine, the estimated net electrical efficiency of the plant is only about 13%.

Illustration from Thermoselect website

Reference Plants

There were three plants in commercial operation processing a range of domestic and industrial wastes:

• One plant (3 streams x 75,000 tpa) in Karlsrühe, Germany, operational since 1999;
• One plant in Chiba, Greater Tokyo, Japan (2 x 50,000 tpa) operational since 1999; and
• One plant, c. 40,000 tpa, in Mutsui, Japan.

Thermoselect tried to market this process in the UK several years ago but it is considered as extremely complicated and no projects have been established. The Karlsruhe plant has had a series of problems and it is no longer operating.

Suitability for Jersey

The technology is not considered suitable for Jersey because:

• The main European reference plant is closed having not operated successfully;
• It  is  a  very  complex  process  including  oxygen  production,  syngas  cleaning  and  water treatment, likely to require significant additional staff;
• The stated electrical conversion efficiency of less than 14% is very low.

17. Thide

Process Overview

The process consists of the following steps:

1. Fuel preparation including grinding, screening and metals removal;
2. Drying of the waste to 10-15% moisture using a rotary hot air dryer, with hot gases supplied from the gasifier;
3. Gasification of the waste in a rotary tube, heated to 450-700°C using the combusted syngas from the gasification process;
4. Energy recovery from the hot flue gases for hot water, steam or electricity production;
5. Flue gas treatment with activated carbon injection, plus a bag filter;
6. Scrubbing, sorting and processing of the carbonaceous solids from the gasifier to separate coke/coal  substitute  (Carbor®),  ferrous  and  non-ferrous  metals,  glass  and  inerts,  and

chloride salts.

Picture from Thide website

Reference Plants

There are three operating reference plants:

• One plant in France operated by Thide Environment. Capacity of 50,000 tpa, processing household and small business waste, with steam exported to a local plant.
• Two plants in Japan at Izumo and Itoigawa built under licence by Hitachi:

Izumo: Capacity 70,000 tpa of household waste. Outputs are electricity and Carbor® vitrified on site.

Itoigawa: Capacity 25,000 tpa of household waste. Hot water output, with Carbor® used for combustion in a local cement plant.

Suitability for Jersey

The technology is not considered suitable for Jersey because:

• There  are  no  clear  disposal  routes  for  all  the  by-products  from  the  post-gasification processing, including salts, Carbor®  (a coal/coke substitute), metals, glass and inerts, plus salts;
• The process is not sufficiently proven, and there is only one European reference plant;
• There is a low electrical conversion efficiency as the process does not convert all the available heat in the waste.

18. TPS Termika

Process Overview

The process includes the following stages:

1. RDF reception, storage, and feeding;
2. Gasification using a circulating fluidised bed;
3. Syngas combustion;
4. Power generation via steam cycle;
5. Flue gas treatment.

Reference Plants

One reference plant processing RDF in Italy.

The Arbre project in the UK used biomass fuel as the feedstock and intended to generate power using a combined gas and steam turbine cycle. The project failed to get past the commissioning phase due to problems with cleaning of the syngas and has been abandoned.

Plant Greve-in -Chianti, Italy

Suitability for Jersey

The technology is not considered suitable for Jersey because:

• There are no reference plants processing MSW.
• The Arbre project in the UK was unsuccessful and raises questions over the capability of the company and the technology. Some of the lessons learned from the Arbre project are also relevant to other similar processes where production of sticky tars can lead to rapid fouling of surfaces.

19. Wastegen / Techtrade

Process Overview

The process steps are as follows:

1. Pyrolysis in rotary kiln with lime addition;
2. Syngas combustion;
3. Generation of electricity via steam cycle;
4. SNCR for NOx control;
5. Flue gas cleaning by fabric filter with sodium bicarbonate and activated carbon injection. The estimated net electrical efficiency is about 20%.

Picture of pyrolysis rotary kiln

Reference Plants

The Techtrade technology is marketed in the UK by Wastegen. One reference plant in Burgau, Germany, has been in operation since 1984 based on a standalone configuration, with a capacity of 35,000 tpa using two rotary kilns, with electricity production (2.2 MWe max). The residues contain 26% carbon. A carbon recovery unit (probably based on a rotary kiln or fluidised bed technology) is being considered for future standalone configurations;

There is a more recent reference plant at Hamm-Uentrop, Germany, which is based on firing of the syngas and char produced in the pyrolyser in a conventional coal fired power station. Whilst this is an interesting concept, Jersey has no equivalent power station.

Suitability for Jersey

The technology is not considered suitable for Jersey because of the following:

• There are limited reference plants – the configuration of the Hamm plant, providing gas for a power plant, would not be suitable for Jersey, because there is no equivalent power station operating in Jersey;
• The electrical conversion efficiency is low;
• The pyrolyser residue contains large amounts of unburnt material making it unsuitable as secondary aggregate. This would require further treatment.

20. Wellman Process Engineering

Process Overview

Wellman is a supplier of low pressure, updraft, fixed bed gasifiers for coal and wood feedstocks. They have designed and built an Integrated Fast Pyrolysis Plant' to produce pyrolysed liquid from biomass feedstock.

Integrated Fast Pyrolysis Plant

Reference Plants

None for residual MSW.

Suitability for Jersey

The technology is not considered suitable for Jersey because there are no reference plants processing residual MSW.

21. American Combustion Tech Inc

Process Overview

The process involves the formation of a syngas, cleaning of the syngas and energy recovery in a gas engine. The key process steps are:

1. Indirect heating of waste material to 540oC;
2. Transformation of solid waste into a syngas;
3. Cleaning of the syngas;
4. Liquefaction of the syngas or use in a gas engine;
5. Use of the excess gas for continuation of the process.

The process has one demonstration plant in the USA, processing cow manure. This plant does not use a gas engine. The process is being marketed in the UK by Bedminster, as part of an overall municipal waste treatment facility.

Gasification process from American Combustion Tech website

Simple  System  

diagram  Flue  Vapor  

Sludge bin  Stack  condenser  

Pressurized

gas storage Vacuum

pump