WO2014041373A2

WO2014041373A2 - Apparatus and method for processing municipal waste into bio-ethanol

Info

Publication number: WO2014041373A2
Application number: PCT/GB2013/052417
Authority: WO
Inventors: Philip Lawrence Timothy Richard HALL
Original assignee: Hall Philip Lawrence Timothy Richard
Priority date: 2012-09-16
Filing date: 2013-09-16
Publication date: 2014-03-20
Also published as: GB2507949A; GB201216517D0; GB2507949B; WO2014041373A3; IN2015DN03197A; US20150210927A1

Abstract

A process and apparatus for recycling municipal domestic waste comprises subjecting the waste to steam at 150°C – 200°. After steam treatment, the resultant material is separated into constituent parts and biomass and/or plastics subjected to further treatment. The further treatment preferably produces bioethanol from the biomass and diesel from the plastics. As an alternative, some or all of the biomass may be gasified in order to produce hydrogen which may, in turn be fed to a fuel cell to produce an electrical output. The bio diesel or bioalcohol can also be used to produce electricity.

Description

Apparatus and Method for Processing Municipal Waste into Bio-ethanol

The present invention relates to the recycling of waste material and more particularly to the recycling of municipal domestic waste.

There are a number of ways of dealing with municipal domestic waste, otherwise known as municipal solid waste, but the two most common methods are either by landfill or by incineration. Both these methods have inherent problems associated with them. When utilising landfill, the waste is buried without sorting. It takes up valuable space and renders land unusable for many years. In addition, toxic effluent can leak into the land. Further, suitable locations for landfill sites are becoming increasingly difficult to find.

As far as incineration is concerned, this usually requires the waste to be sorted into combustible and non-combustible waste with the non-combustible waste being sent to a landfill site and the combustible waste burnt. However, the burning of waste usually creates sulphur emissions and requires high unsightly chimneys. Additionally, incinerators are not efficient because they require high energy inputs.

More recently, there have been proposals to dispose of municipal waste by utilising an autoclave charged with the waste material to be treated and supplied with steam from a steam accumulator. An example of this is disclosed in US-A-5, 190,226 where solid waste material is processed at pressure of 4 bar. While these proposals are a more environmentally friendly solution than the two previous common methods described above, they are inefficient as they are batch processes. A continuous process has been developed in e.g. US-A-6,752,337 but special equipment has been proposed in order to maintain a highly pressurized steam processing unit which is both expensive and hazardous.

WO-A-2008015424 discloses apparatus and methods for recycling waste materials, but the design was energetically inefficient. WO-A-2009095693 improved the initial design by injecting the steam only into the waste material.

The present invention seeks to provide further solutions to recycling municipal domestic waste which is both energy efficient and environmentally friendly. The process plant is modular in design and will take unsorted waste and thermally treat it using a continuous steam process. Preferably the system also addresses the problem of odour generated from the plant.

According to the present invention there is provided an apparatus for treating solid waste material as defined in claims land 6. Preferably, the apparatus com prises: a first cylinder with an inlet for waste to be introduced at one end and an outlet at the other end, wherein the first cylinder is rotatable about an axis along the first cylinder and the first cylinder including steam inlets for introduction of steam into the interior of the first cylinder; a heating jacket surrounding the first cylinder; a second cylinder extending along said axis and rotatable thereabout, wherein the second cylinder has an inlet at one end for receiving material from the outlet of the first cylinder and a second cylinder outlet at the other end. The new design is more energy efficient than previously known designs. The second cylinder which encases the first cylinder has heat from the heating jacket radiating thereinto rather than being lost to the atmosphere. This is also the case with other heat generated in the first, inner, cylinder. The partially treated waste that is travelling through the second cylinder thus more fully converts into biomass and/or dries whilst in the second cylinder.

It is advantageous for the recycling process to be a continuous process that is easier to achieve when each cylinder is elongate with the inlet at one end and the outlet at the other end. The drive is arranged to rotate the first, inner cylinder and in this manner transport the material along the vessel whilst also mixing the waste material to ensure that it is fully treated. Normally, the steam inlets are provided in steam pipes in the first cylinder. The steam inlets may be fixed relative to the interior of the vessel. The steam inlets are arranged to inject steam at a temperature of 160°C to 200°C, and so provide a large amount of kinetic and heat energy directly in to the waste material.

A microwave treating station can treat the biomass either in between the first cylinder and the second cylinder or at the end of the second cylinder. The microwave treating station can be used to further enhance biomass production. Clearly, removal of metallic wastes will be important before microwave treatment and it may be that this embodiment is principally used with certain specialist waste known to contain minimal amounts of metallic material such as food waste.

The treated waste material preferably comprises a biomass containing cellulose material and containing less than 1% sulphur. The biomass is useful in a large number of ways, providing key benefits of the present system.

Normally, a sorting chamber is provided where the treated waste material is separated into plastics, ferrous metals, non-ferrous metals and biomass of cellulose material. Thereafter, the biomass is transferred to a hyperbaric engine or a fuel cell or to a conversion unit for converting the biomass into bio-diesel, an organic alcohol, such as bio-ethanol or bio-butanol, or an aviation fuel. The bio-fuel can be used to power a generator or generators to produce electrical energy or may be used to power other engines (e.g. aircraft engines) or other generators. In order that the present invention is more readily understood, embodiments thereof will now be described by way of example, with reference to the accompanying drawings in which:

Fig. 1 shows a diagrammatic representation of process plant according to the present invention;

Fig. 2 shows one end of the twin contra-rotating cylinder of the present invention; Fig. 3 shows the twin contra-rotating cylinders of the present invention; Fig. 4a shows a cross section, at one end of the twin cylinder; Fig 4b shows a cross-section at the other end of the twin cylinder apparatus of the present invention; and

Fig. 5 shows a representation of the downstream plant that processes the biomass of the present invention.

Firstly, it should be noted that many of the detailed explanations of components and use are provided in WO-A-2008015424 and WO-A-2009095693 and the c ontents of these documents are incorporated herein by reference. These documents should be consulted for ways of implementing many of the parts of the overall plant of which the apparatus of the invention forms a core part. The principle difference is the use of the two cylinder design to make the production of the biomass more efficient as more of the heat energy is used in the process to either convert the waste into biomass or to further dry the biomass. The methods of producing biomass and fuels described in WO-A-2009095693 are equally applicable to the present invention.

CONTRA ROTATING WASTE PROCESSING CHAMBERS

The waste process unit comprises two contra - rotating chambers or drums.

The inner drum (or first cylinder) 10 is located on a central drive shaft, which is hollow and is connected to a drive motor 12 and chain drive 14 . The inner chamber 10 is located and connected to the drive shaft 20 by a series of "flights" 16 forming an Archimedes Screw, this screw 16 also supports the drum. The drive shaft 20 acts as the rotational axis of the inner drum 10. The inner drum 10 is fitted with a heated jacket 18 which provides heating to the inner chamber 10 by directly heating the waste and the air surrounding it to a temperature of between 160°C and 200°C. The heating jacket 18 also heats the outer chamber 22 by radiated heat from the outer surface of the heating jacket 18.

The heating jacket 18 is served by a high temperature fluid (thermal fluid oil at a temperature of up to 250°C) which is introduced into the heating jacket 18 via a two- port rotating union connected to a system of pipe work 24 which runs down the centre of the central hollow shaft 20.

Connection from the high temperature heating medium pipes 24 and the heating jacket 18 is achieved by two pipes (flow and return) radiating from the central drive shaft 20 to the jacket connections. These pipes will be positioned along the edge of one of the flights 16 so as not to cause a restriction.

Steam at a pressure of between 6 to 9 bar will be injected in the waste during its travel through the inner chamber 10. This will be achieved by injecting steam into the hollow shaft 20 and allowing it to exit through a series on small jets / perforations in the wall of the hollow shaft 20 .

The external rotating chamber 22 or drum will be completely independent of the internal chamber 10 and will be provided with an external drive 26.

This external drive will be via rotating wheels 28 external to the rotating chamber 22 which will impart rotation about the drive shaft 20 via metal tires fitted to the external surface on the external chamber 22. This external chamber 22 will also be fitted with a series of flights 30 to impart motion to the waste in the opposite direction to the first rotating chamber 10.

Untreated waste is introduced into the internal rotating chamber 10 via a hopper at one end. Waste is introduced at the rate of approximately 10 tonnes per hour which means that the chamber will remain half full during its cycle.

The waste is heated to between 160°c and 200°c and injected with steam at between 6 to 9 bar pressure.

The waste will take approximately thirty minutes to traverse the internal chamber 10, at the end it will fall into the second rotating chamber 22 which is rotating in the opposite direction than the first.

The waste will take approximately thirty minutes to reach the exit by which time it has undergone further treatment and drying to a moisture content of between 20 to 30% .

At the end of the cycle (approximately one hour) the treated waste will tumble onto a conveyor to be carried to the next stage of the process.

The drive 12 for the internal chamber 10 is achieved via an electric motor and gearbox fitted with a chain 14 and sprocket drive.

The drive for the external chamber 22 is via driven wheels 28 running on a steel tire around the perimeter of the chamber.

Drive to these wheels 28 is achieved from the same motor 12 via the gearbox and drive shaft 20.

BIOMASS CONVERSIONS

The biomass produced in the current process has a number of uses as outlined above. The biomass produced in reaction chamber C (Fig. 1) has advantageously been sanitized and reduced in volume. Importantly, the steam processing has disrupted the structure of the organic materials so that the cellulose and other constituents are opened and more readily available for downstream processing. The biomass is essentially a source of cellulose that has been treated so that the cellulose is readily available for further processing, such as to form bio-fuel, bio- alcohols or the like.

FERMENTATION OF BIOMASS TO FUEL ALCOHOL

The production of alcohols by fermentation of a biomass is one of the oldest biotechnological methods. Also the use of fermentative recovered ethanol as a source of energy has been known for a long time, but has not been commercially used due to costs being higher in comparison to the recovery of petroleum in the past. The possible use of bio-ethanol has new importance as source of energy as supplies of petroleum become more scarce and the cost increases. The development of renewable biofuels is an international priority motivated by both economic and environmental concerns, including reduction of greenhouse gas emissions, enhancement of the domestic fuel supply and maintenance of the rural economy. The use of microbes to produce biofuel materials is a particularly attractive way to produce the biofuels, particularly when the microbes do so by utilising waste products generated by other processes.

GASI FICATION OF BIOMASS

Synthesis gas ('syngas') was first developed as a major by-product of the gasification of coal and of carbonaceous materials such as agricultural crops and residues. In contrast to combustion, which produces primarily carbon dioxide and water, gasification is carried out under a high fuel to oxygen ratio and produces largely hydrogen gas (H2) and carbon monoxide (CO). Thus, syngas is composed largely of H2 and CO, together with smaller amounts of CO2 and other gases. Syngas can be directly used as a low-grade fuel or as the feed for fuel cells. Alternatively, it can be used in catalytic processes to generate a wide variety of useful chemical products, such as methane, methanol and formaldehyde. The biomass of the present invention is eminently suitable as the feed for forming syngas.

Anaerobic microorganisms such as acetogenic bacteria offer a viable route to convert syngas to useful products, in particular to liquid biofuels such as bio- ethanol and bio- diesel. Such bacteria catalyze the conversion of syngas with higher specificity, higher yields and lower energy costs than can be attained using chemical processes. Several microorganisms capable of producing biofuels from waste gases and other substrates have been identified.

For example, three strains of acetogens have been described for use in the production of liquid fuels from syngas: Butyribacterium methylotrophicum (Grethlein et al., 1990; Jain et al., 1994b); Clostridium autoethanogenum (Abrini et al., 1994); Clostridium ljungdahlii (Arora et al, 1995; Barik et al., 1988; Barik et al. 1990; and Tanner et al., 1993). Clostridium ljungdahlii and Clostridium autoethanogenum are known to convert carbon monoxide to ethanol. US patent application No. 2007/275447 describes Clostridium carboxidivorans, ATCC BAA-624, "P7" capable of synthesizing, from waste gases, products which are useful as biofuel, in particular, P7 can convert carbon monoxide to ethanol.

ACID HYDROLYSIS OF BIOMASS FOR ALCOHOL PRODUCTION

This can be as described in WO-A-2009095693 but it is preferred if the following technique is used.

The initial steam and heat process produces a large quantity of biomass which is predominately cellulosic. With a calorific value of between 15 to 16 Mj/kg at the 15% moisture content when leaving the steam process rising to 17 to 18 Mj/kg when further dried. This biomass contains virtually no sulphur and thus provides a much cleaner fuel than fossil fuels.

This basic cellulistic fibre can be treated in many ways, namely gassified to produce a "Syngas", anaerobically digested to produce methane or used as a feed stock to produce bio-ethanol.

In all the above cases the fuels could be further processed to produce an input gas (Hydrogen and/or ethanol) suitable for use in a fuel cell. This would produce a direct current electrical output for sale to the local electricity supplier.

However our preferred route is to process the biomass fibre into bio ethanol, bio butanol, biodiesel and aviation fuel.

The biomass has been first heat treated to sanitise the material by halting undesirable anaerobic processes and to render it amenable to hydrolysis. Which is the first stage of the bio-ethanol production. The preferred hydrolysis method is acid hydrolysis, which can utilise any suitable acid but in this case will usually be sulphuric acid.

The biomass is fed into the acid treatment vessel and sulphuric acid at a concentration of 70% is added. A quantity of water is added to the treatment tank at a temperature of 90°C until the acid concentration has been reduced to 12%. During this process the temperature remains at 90°C. The hydrolysis process takes approximately 5 hours in total.

Acid hydrolysis is a chemical process in which acid is used to convert cellulose and hemicelluloses into sugar and lignin. The hydrolysing acid degrades the chemical bonds of the cellulose to produce hexose and pentose sugars to a high concentration solution necessary for commercial fermentation. The insoluble lignin within the biomass remains solid.

The acid - sugar solution is separated into its acid and sugar components by means of ion exchange technology which separates the components without diluting the sugars.

The acid component of the solution is recycled and concentrated to 70%, any acid that is left in the sugar solution is neutralised by the addition of lime which makes hydrolysed gypsum. This gypsum can be sold as a byproduct to the building industry for the manufacture of building materials or to agriculture as a soil improver. For example: the material can be used to produce plaster board.

The gypsum component (CaS04) is readily separated from the sugar solution by filtration.

At this point the system has produced a clean stream of C6 and C5 sugars suitable for fermentation The sugar solution is fed into the fermentation vessels and yeast added, normally this will be saccharomyces cervisiae (brewers yeast) which will produce a first stage ethanol of around 12% ethanol by volume. This will take around 36 hours. Further treatment of the low grade ethanol with distillation will concentrate the ethanol to approximately 85% with the final 'polishing' via molecular sieve to the final 98.9%.

Any residue of water and unfermented sugars from the distillation process are returned to the beginning of the process to recycle the water and further conversion of the sugars to bio ethanol.

Self sustainable energy usage can be achieved by the use of the lignin to fire the process steam boilers.

The lignin, remaining a solid can be easily removed from the acid / sugar solution by centrifuge. With the removal of moisture and drying, moisture contents of less than 5% can easily be achieved providing a calorific value of around 16Mj/kg. This dried lignin can then be used as a solid fuel to power the plant steam boilers.

Being in a fibrous form, the lignin fuel can be fed directly into the boiler via a fluidised bed thus eliminating the need for pelletisation. Based on the throughput of biomass, sufficient lignin can be produced to meet the process heating load especially with the additional use of efficient heat recovery systems at the various heating and cooling stages.

The production of electricity can also be achieved with the use of gas turbine driven generators, using some of the ethanol, to provide the electrical requirement for the plant. This has the additional advantage that the energy in the exhaust gasses from the gas turbine can also contribute to the heating requirement of the plant. Alternative methods of electrical production can be achieved by the use of direct ethanol fuel cells, providing a three - fold contribution to the production plant of electricity, water and heat.

Advantages of the new acid hydrolysis process include:

methods of hydrolysis are available which would be employed to reduce the overall size of the system, in particular would be to combine the hydrolysis and fermentation steps is possible with the use of an intracellular enzyme

The improved hydrolysis technique would reduce the overall size of the plant by eliminating the need for the direct hydrolysis section but would necessitate the increase in size of the fermentation section. There would be no reduction in overall throughput time but would have significant reduction on energy usage for the plant.

With the full acid hydrolysis described above there is a considerable energy usage in both heating and maintaining the hydrolysis fluid at the required temperature also re concentrating the acid solution from 12% to 70%. The parameters are determined mainly due to the time restraints imposed. It is therefore viewed the reduction in acid concentration to 50% and the temperature being maintained at 60°C would reduce the overall energy requirement by approximately 60% and the acid usage by approximately 50%, although the hydrolysis would be extended from 5 to 8 hours.

This new acid hydrolysis and bio-ethanol production technique may be used with earlier apparatus and methods such as disclosed in WO-A-2008015424 and WO-A-2009095693 or in other fields where acid hydrolysis is desired and the technique is not in any way limited to the apparatus described herein. Microwave Catalytic Biomass

Chinese patent publication CN 100999676 (Anhui Univ of Tech) describes microwave catalytic biomass cracking process for preparing biological oil with rich acetone alcohol features using sodium carbonate as catalyst, silicon carbide as microwave absorbing medium, microwave source as heat source for cracking biomass, and ice water mixture for cooling volatile component to obtain biological oil with rich acetone alcohol.

By means of the unique temperature effect of microwave in a biomass particle and the unique catalyzing effect of sodium carbonate in cracking biomass, the process realizes the creation of acetone alcohol in high selectivity.

Production of butanol

The fermentative production of butanol is also well known. International patent publication WO 2008/025522 (Bayer Technology Services GmbH) relates to a method of producing bio-alcohol. In particular ethanol or butanol, from biomass, in which the biomass is comminuted, the remaining biomass is fed to a fermentation and the alcohol is obtained from the product of the fermentation, insoluble components and/or non-fermentable sugars being separated off from the biomass before the fermentation and/or yeast and bacteria are separated off after the fermentation.

The use of biomass in fuel cells The electric power industry has generally been looking toward the use of fuel cells in relatively large electrical power generating applications. Power generation by fuel cells offers the advantages of high efficiency and low environmental emissions. Thus, fuel cells may offer a more economical means of power production than other existing power producing technologies. Molten carbonate fuel cells and solid oxide fuel cells are well suited for using heated gas streams and, thus, show great promise in industrial power generation applications. Biomass gasifiers can be used as source for the feed suitable for use in these fuel cells. As described above, the gases required as fuel cell feed are readily obtainable from the gasification of the biomass of the present invention.

Greater efficiency in conventional fuel cells may be obtained through integration with biomass gasifiers, for example, a combined gasifier and fuel cell system wherein the gas stream travels from the gasifier through an external carbon dioxide separator. US patent application No. 2002/194782 (Paisley) describes an integrated biomass gasification and fuel cell system wherein the electrochemical reaction in the fuel cell is effected by providing the reactant gases from a gasifier. Fuel gas from the gasifier is directed to the anode of the fuel cell and at least a portion of the exhaust gas from the anode is directed to a combustor. The portion of the exhaust gas from the anode is then combusted to recover residual energy to increase the overall efficiency of integrated biomass gasification and fuel cell system. Also, the oxidant gas from the combustor may be directed to the cathode of the fuel cell.

US 5736026 (Energy Res Corp) entitled "Biomass-fuel cell cogeneration apparatus and method" describes the integrated ethanol manufacturing by fermentation of biomass, with an electrical fuel cell generator of electrical and heat energy, the cogeneration including use by the fuel cell of the alcohol, and of the carbon dioxide from the fermentation, which increases the generation of energy, and use by the alcohol manufacturing of the heat and electrical energy from the fuel cell, which increases the fuel manufacture.

It is shown from the foregoing description, that the biomass produced by the present invention can be used in a wide variety of ways. Normally, a particular plant will concentrate on a particular one of these downstrea m processes, e.g. generating electricity from a fuel cell, or the production of bio-fuels and bio- alcohols. The skilled person may implement this using one of the techniques described or referenced, or other techniques known in the art or as may be developed. Summary

In this document, the term ambient pressure is used to define the pressure in the vessel 30 when the vessel is not sealed to gas flow. The pressure in the vessel will thus normally be atmospheric pressure or whatever the prevailing pressure is around the plant. The pressure within the vessel may be negliably higher than the pressure around the plant due to the steam injection even without the vessel being sealed.

The term ambient temperature is used in this document to refer to the temperature surrounding the plant which will vary due to location, season and general weather conditions. Cellulose material generally refers to cellulose and hemicellulose unless the context clearly indicates differently.

Generally, this invention relates to a process and apparatus for recycling municipal domestic waste comprises subjecting the waste to steam at 150°C - 200°C. After steam treatment, the resultant material is separated into constituent parts and biomass and/or plastics subjected to further treatment. The steam treatment advantageously sanitizes the treated material and significantly reduces the volume thereof. Importantly, the steam treatment disrupts the cellulose and other organic materials so that the fibres are open allowing the steam treated biomass to be more easily converted to bio-fuel, bio-alcohols, etc. The further treatment preferably produces bio-ethanol from the biomass and diesel from the plastics. As an alternative, some or all of the biomass may be gasified in order to produce hydrogen which may, in turn be fed to a fuel cell to produce an electrical output.

Claims

CLAIMS:

1. An apparatus for treating solid waste material, the apparatus comprising:

an inner drum with an inlet for waste to be introduced at one end and an outlet at the other end, wherein the inner drum is rotatable about its axis; and

an outer drum at least partially surrounding the inner drum and rotatable thereabout, wherein the outer drum is adapted to receive material from the outlet of the inner drum and is provided with an outlet to output treated material.

2. The apparatus of claim 1, wherein the outlet of the outer drum is located at the same end of the apparatus as the inlet of the inner drum and waste is received by the outer drum from the inner drum towards the other end.

3. The apparatus of claim 1 or 2 further comprising means for introducing steam into the interior of the inner drum.

4. The apparatus of claim 3 wherein means for introducing steam into the interior of the inner drum comprises a hollow shaft with perforations through which steam is injected into the interior of the inner drum.

5. The apparatus of any of the preceding claims further comprising heating means for heating the inner drum.

6. An apparatus for treating solid waste material comprising:

a first cylinder with an inlet for waste to be introduced at one end and an outlet at the other end, wherein the first cylinder is rotatable about an axis along the first cylinder and the first cylinder including steam inlets for introduction of steam into the interior of the first cylinder;

a heating jacket surrounding the first cylinder;

a second cylinder extending along said axis and rotatable thereabout, wherein the second cylinder has an inlet at one end for receiving material from the outlet of the first cylinder and a second cylinder outlet at the other end.

7. The apparatus according to any of the preceding claims, wherein the second cylinder or outer drum rotates in the opposite direction to the first cylinder, or inner drum.

8. The apparatus according to any of the preceding claims, wherein drive means is arranged to rotate the drums or cylinders.

9. The apparatus according to any one of claims 6 to 8, wherein the steam inlets are provided in steam pipes in the first cylinder.

10. The apparatus according to any one of claims 6 to 9 wherein the steam inlets are fixed relative to the interior of the first cylinder.

11. The apparatus according to any one of the preceding claims, wherein steam is injected into the apparatus at a temperature of 150°C to 200°C.

12. The apparatus according to any one of claims 5 to 11, wherein heating means heat and/or maintain the interior of the first cylinder or inner drum at a temperature of 160°C to

13. The apparatus according to any of claims 5 to 12, wherein the heating means is selected from the group consisting of heated air, an exterior steam jacket and a heating element.

14. The apparatus according to any of claims 5 to 13 wherein the heating means comprises only a heating jacket heated by steam.

15. The apparatus according to any one of the preceding claims, wherein the interior of the cylinders or drums is at a pressure under 2 bar.

16. The apparatus according to any one of the preceding claims, wherein the interior of the cylinders or drums is substantially at ambient pressure.

17. The apparatus according to any one of the preceding claims, wherein the apparatus is arranged to treat waste material continuously.

18. The apparatus according to any one of the preceding claims, further including means for transferring waste material from the inlet of the inner drum or first cylinder to the outlet of the outer drum or second cylinder.

19. The apparatus of any of claim 18 wherein the means for transferring material comprises an Archimedes screw provided on the inner surface of one or both of the drums or cylinders.

20. The apparatus according to any one of the preceding claims, wherein the treated waste material comprises a biomass of cellulose material containing less than 1% sulphur.

21. The apparatus according to any one of the preceding claims, wherein the second/outer outlet is connected to a sorting chamber where the treated waste material is separated into plastics, ferrous metals, non-ferrous metals and biomass of cellulose material.

22. The apparatus according to claim 21, wherein the biomass is transferred to a hyperbaric engine or a fuel cell or to a conversion unit for converting the biomass into biodiesel or an organic alcohol, such as bio-ethanol or bio-butanol, or an aviation fuel.

23. The apparatus of claim 22, wherein the apparatus further includes electrical generators powered by the biodiesel or organic alcohol.

24. The apparatus of any of the preceding claims wherein the outer drum, or second cylinder surrounds the inner drum or first cylinder such so as to provide a overlap over at least half of the length of the inner drum or first cylinder.

25. The apparatus of claim 24 wherein the overlap extends over at least 75% of the length of the inner drum or first cylinder.

26. The apparatus of claim 24 or 25 wherein the overlap extends over the substantially all of the length of the inner drum or first cylinder.

27. A method for treating waste material comprising the steps of:

a) inputting waste material into an apparatus according to any one of the preceding claims, and

b) treating the waste material with steam at a temperature of 150°C to 200°C in the first cylinder or inner drum.

28. The method of claim 27 wherein the first cylinder or inner drum is at ambient pressure and/or the steam is injected only in to the waste material

29. The method of claim 27 or claim 28 wherein the waste material is particulate waste material.

30. The method of any of claims 27 to 29 wherein the waste material is biomass.

31. The method according to claim 30, wherein the biomass is further treated to form a fuel selected from: biodiesel, fuel for a fuel cell, bio-alcohol, aviation fuel or a substitute fossil fuel.

32. An apparatus as hereinbefore described with reference to and/or as

illustrated by the accompanying drawings.

33. A method as hereinbefore described with reference to and/or as illustrated by the accompanying drawings.

34. A method of acid hydrolysis with combined hydrolysis and fermentation steps as herein before described.