GB2498631A

GB2498631A - Thermal processing system

Info

Publication number: GB2498631A
Application number: GB1222465.5A
Authority: GB
Inventors: Philip Michael Beech; Stephen Richard Churchill; David Gardiner Downie; Andrew William Stapleton; Sean Istvan Wallace
Original assignee: Qinetiq Ltd
Current assignee: Qinetiq Ltd
Priority date: 2011-12-14
Filing date: 2012-12-13
Publication date: 2013-07-24
Also published as: WO2013088105A1; GB201222465D0; GB201121429D0

Abstract

A thermal processing system 100 for processing matter comprises a vessel 102 defining a chamber 104 and having an inlet 106 to receive the matter to be processed in the chamber and an outlet 108 for the matter that has been processed. The chamber is arranged in that there is a net flow of the matter from the inlet towards the outlet. An auger arrangement 112 is at least partially located within the chamber and has a first part 116 propelling the matter from the inlet into the chamber and a second part 118 arranged to act against the flow of the matter from the inlet towards the outlet. The first and second parts may have different handedness or rotated in different directions to one another, and each part comprises a flight arrangement. The auger may comprise a shaft 114. The shaft may have a flight-less portion 122, may comprise of a first and second shaft separate to one another or connected by gearing. The separate shafts may rotate in the same direction with the flight arrangement having different handedness. The chamber may be heated. The system may be a pyrolysis or gasification system. A scraper mechanism may be present.

Description

THERMAL PROCESSING SYSTEM

Field of the Invention

The present invention relates to a thermal processing system. In particular, the present invention relates to a thermal processing system, such as a pyrolysis or gasification system, comprising an auger arrangement for processing (waste) matter to produce synthesis gas (syngas).

Background to the Invention

Pyrolysis is a thermochemical decomposition reaction of organic material (biomass) at elevated temperatures in the absence of oxygen, a thermal processing method. Pyrolysis may occur under a range of pressures and at operating temperatures between 400°C to 750°C. Pyrolysis may occur at pressures that are a few mbar (e.g. 5-lUmbar) below atmospheric pressure.

In general, pyrolysis of organic substances produces gas and liquid products and leaves a solid residue richer in carbon content (char). The process may be used in the chemical industry to produce charcoal, activated carbon, methanol, and other chemicals from wood, to convert biomass into syngas and biochar, to turn waste into safely disposable substances, and for transforming medium-weight hydrocarbons from oil into lighter ones like gasoline.

Typically in biomass waste to energy systems, waste material containing biomass is pyrolysed in a pyrolyser (pyrolysis system) to produce syngas which can then either be combusted (e.g. in a gas turbine engine) to produce energy or which can be further processed to produce synthetic natural gas.

Figure 1 shows a known pyrolysis system 1 comprising an upright vessel 5 having a chamber 10 and a generally conical lower section 15. The vessel 5 is provided with an inlet 20 into the top of the chamber 10 and an outlet 25 at the base of the chamber 10. A gas outlet 30 is additionally provided at the top of the vessel 5. A heater 35 is provided around a lower portion of the vessel. It is noted that the heater may be an indirect heater as shown in Figure 1 or a direct heater in which host gases from the heater pass through the biomass and mix with the syngas.

In use biomass 40 is introduced into the chamber 10 through the inlet 20. The biomass pyrolyses around the boundary layer with the heater and fully pyrolysed biomass (or char) 45 is removed via the outlet 25 at the base of the vessel 5/chamber 10. Synthetic gas (syngas) produced by the pyrolysis reaction may be removed via the gas outlet 30.

The heater may conveniently comprise a conduit 50 for hot exhaust gas 55.

The pyrolyser vessel shown in Figure 1 is vertical but the system may be inclined at an angle. In certain embodiments the vessel may be rotated in order to allow the biomass to mix within the chamber in order to increase the exposure of biomass to the heated portion of the vessel.

Figure 2 shows a further known pyrolysis system 11. Like features between Figures 1 and 2 are denoted by like reference numerals. In addition to the features of the pyrolysis system 1 of Figure 1, the system 11 of Figure 2 comprises an auger arrangement 60, the auger arrangement comprising a shaft 65 upon which a flight arrangement 70 is mounted. In use, the auger arrangement 60 is rotated 75 about its axis in order to stir the biomass 40 and char 45 within the vessel 5. The auger arrangement helps to prevent "bridging" of material within the chamber 10 (bridging" is where the friction between the solid particles in the biomass is greater than the forces (e.g. gravity) acting upon it which results in the flow of matter from the inlet to the outlet stopping). It is noted however that a pyrolysis system corresponding to the system of Figure 2 may still experience bridging at both the inlet and outlet ends of the chamber 10.

A further drawback with some known pyrolysis systems is that material within the chamber compacts to such a degree that the flow of hot gases from the pyrolysis reaction is inhibited thereby reducing the efficiency of the reaction.

Gasification is a thermal process similar to pyrolysis that may be used to convert materials into carbon monoxide, hydrogen, carbon dioxide and methane. Gasification involves reacting the input matter at high temperatures, e.g. above 700°C, in the presence of controlled amounts of oxygen and water (steam). Known gasification systems experience similar issues to those described above in relation to pyrolysis systems.

It is therefore an object of the present invention to provide a thermal processing system that overcomes or substantially mitigates the problems with known systems.

Summary of the Invention

According to a first aspect of the present invention there is provided a thermal processing system for processing matter comprising: a vessel defining a chamber and having an inlet arranged to receive mailer for processing within the chamber and an outlet for mailer that has been processed within the chamber, the chamber being arranged such that there is a net flow of matter from the inlet towards the outlet; an auger arrangement at least partially located within the chamber wherein a first part of the auger arrangement is arranged to propel matter in a direction from the inlet into the chamber and a second part of the auger arrangement is arranged to act against the flow of mailer from the inlet towards the outlet.

As noted above a major challenge with thermal processing systems is ensuring that material passes through the chamber smoothly without bridging and that the material does not overly compact. The inventors have noted that although some pyrolysis/gasification systems with auger arrangements address bridging issues they can lead to compaction of the material in other parts within the pyrolysis/gasification chamber. For example, a known pyrolysis chamber with an auger arrangement running the length of the pyrolysis chamber was seen to prevent material bridging occurring at the inlet end of the chamber but led to the compaction of material at the base of the chamber.

The system according to the present invention provides an auger arrangement which acts differently upon matter passing through the chamber depending upon the position of the material within the chamber. A first part of the auger arrangement is arranged to propel matter from the inlet into the chamber. A second part of the auger arrangement is arranged to act against the flow of mailer from the inlet to the outlet (i.e. the second part of the auger arrangement tends to propel matter back towards the chamber). The second part of the auger arrangement therefore acts to "lift" the matter within the chamber (it is noted that the vessel need not be vertical. In the case of an inclined vessel or a vessel that is orientated horizontally the second part of the auger arrangement will generally act in a direction back towards the inlet).

It is noted that the second part of the auger arrangement acts to essentially "stir" a portion of the material within the chamber as it passes towards the outlet. It is noted that the net overall flow of matter within the chamber will be from the inlet to the outlet, even with the second part of the auger arrangement acting to "lift" or "stir".

Conveniently, the first part of the auger arrangement may be arranged to propel matter into the chamber in the region of the inlet (in other words at the inlet of the vessel/chamber and/or in the vicinity of the inlet of the vessel/chamber the auger arrangement is arranged to propel matter from the inlet into the chamber).

The second part of the auger arrangement may be arranged to act against the flow of mailer from the inlet to the outlet in the region of the outlet (in other words at the outlet of the vessel/chamber and/or in the vicinity of the outlet of the vessel/chamber the auger arrangement is arranged to tend to propel matter back towards the chamber). Thus, as discussed above, the second part of the auger arrangement at the outlet end of the chamber therefore acts to "lift" the matter within the chamber as it passes towards the outlet.

Conveniently, the auger arrangement may comprise first and second parts having different handedness or may comprise first and second parts that may be rotated in different directions to one another.

The auger arrangement may conveniently be provided by a shaft and a flight arrangement mounted on the shaft. In such an arrangement, the first part of the auger arrangement is provided by a first flight portion of the flight arrangement and the second part of the auger arrangement is provided by a second flight portion of the flight arrangement, the first flight portion being located in the region of the inlet and the second flight portion being located in the region of the outlet. Preferably, in such an arrangement the first and second flight portions have different handedness. In this manner the auger arrangement may conveniently be provided by a single shaft through the system in which the flights or threads on the auger shaft are arranged to be orientated in different directions (different handedness). Rotation of such an auger arrangement then conveniently acts to propel matter in different directions depending whether the matter is in the region of the first or second part of the auger arrangement. This type of auger arrangement has the advantage of being a simple design.

Conveniently, the shaft may comprise a flight-less portion located between the first and second flight portions. Such a flight-less portion may prevent interference between the two flight portions of the auger arrangement.

The diameter of the first flight portion may be different to the diameter of the second flight portion. Preferably, the first flight portion may have a smaller diameter than the second flight portion.

The pitch of the first flight portion may be different to the pitch of the second flight portion.

An alternative auger arrangement may comprise a first shaft having a first flight arrangement mounted thereon and a second shaft having a second flight arrangement mounted thereon, the first shaft providing the first part of the auger arrangement and the second shaft providing the second part of the auger arrangement.

The two shafts may be separate to one another such that each shaft may be driven (rotated) separately. Alternatively, the shafts may be connected via a gearing arrangement that is arranged to rotate the shafts as required.

Where the auger arrangement comprises two different shafts then the two flight arrangements may have the same handedness and the required effect on the matter passing through the vessel may be achieved by rotating the shafts in different directions.

Alternatively, the first and second shafts may be arranged to be rotated in the same direction and the first and second flight arrangements may be arranged to have different handedness.

Conveniently, the first and second flight arrangements may have different diameters and/or pitches.

Where the auger arrangement comprises two shafts then conveniently, the first and second shafts may be rotated at different rotational speeds. Furthermore, the rotational speed of each shaft may be varied.

Preferably, the thermal processing system may have a vertical orientation in which the inlet is higher than the outlet. The chamber may define a vertical axis with the inlet being mounted above the outlet on the vertical axis.

The thermal processing system may be a pyrolysis system to allow mailer to be pyrolysed. Alternatively, the thermal processing system may be a gasification system.

For a pyrolysis system, the matter to be pyrolysed may preferably comprise particles having a maximum dimension of less than 50mm and the mailer received at the inlet may have a water content of less than 30%.

Preferably, the system further comprises a gas outlet arranged to extract gas produced by the pyrolysis reaction.

Preferably, the inlet may have a diameter greater than 10mm.

Preferably, the system may further comprise a heater to heat the chamber.

A further problem that can be experienced in thermal processing systems is the build-up of material (often referred to as "clinker") on the walls of the chamber of the thermal processing vessel during operation. In a typical configuration, a thermal processing vessel may comprise a cylindrical body (with the axis of the cylinder arranged vertically) and a base cone at the lower end of the cylinder, the base cone comprising the outlet.

Clinker may build up both on the internal walls of the cylinder body and also on the internal walls of the base cone.

Clinker build up causes a reduction of hot air flow within the vessel and also acts to reduce the effective volume within the vessel which may support the thermal process.

Clinker build up may be seen in many thermal processing systems with a wide variety of waste stream materials. However, high metal/alloy containing waste streams have been seen to produce relatively higher levels of clinker.

Preferably the system may further comprise a scraper mechanism for preventing and removing clinker build-up on the walls of the thermal processing vessel.

The scraper mechanism may conveniently be of complementary shape to the internal dimensions of the vessel. The scraper mechanism may be arranged to rotate within the vessel. Where the mechanism is of complementary shape to the internal dimensions of the vessel the mechanism may therefore maintain a consistent gap from the internal liner of the vessel as it rotates.

The scraper mechanism may comprise a scraper member, the scraper member being of complementary shape to the internal dimensions of the vessel and the scraper member may be attached to the auger arrangement. Where the auger arrangement comprises a shaft, the scraper member may conveniently be attached to the shaft by at least one support member.

The at least one support member may comprise a scraper flight arrangement. Depending on the handedness of the scraper flight arrangement, the flight arrangement may be arranged to either lift the matter within the chamber as it passes towards the outlet or alternatively may be arranged to propel matter within the chamber towards the outlet.

Where the scraper flight arrangement acts against the flow of matter through the vessel the scraper flight arrangement may therefore form the second part of the auger arrangement.

The scraper mechanism may be arranged to be attached to a rotating component within the vessel. The rotating component may either be the shaft of the auger arrangement, the flight arrangement attached to the shaft or a further rotating component within the vessel.

In one form the scraper mechanism may comprise a helical shaped member.

Preferably the scraper mechanism is located in the lower portion of the vessel.

According to a second aspect of the present invention there is provided a method of operating a thermal processing system, the method comprising: providing a thermal processing system according to the first aspect of the present invention; introducing mailer for processing at the inlet; rotating the auger arrangement; removing matter that has been processed from the outlet.

The second aspect of the present invention may comprise preferred features of the first aspect of the present invention.

Brief Description of the Drawings

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which like reference numerals are used for like parts, and in which: Figure 1 shows a known pyrolysis system; Figure 2 shows a further known pyrolysis system; and Figures 3 to 5 show a pyrolysis system according to an embodiment of the present invention; Figures 6 to 9 show a pyrolysis system and scraper mechanism according to further embodiments of the present invention.

Detailed Description of the Invention

Embodiments of the present invention are described below in relation to a pyrolysis system. It is however noted that the arrangements described below could be used in other thermal processing methods, e.g. in a gasification system.

Figure 3 shows a pyrolysis system 100 in accordance with an embodiment of the present invention. The system 100 comprises a vessel 102 defining a chamber 104. The vessel is provided with an inlet 106 arranged to receive matter for pyrolysis within the chamber 104 (i.e. a matter/biomass inlet 106 to allow matter/fuel/biomass to be supplied into the chamber 104).

The inlet 106 receives matter for pyrolysis within the chamber. It is noted that such mailer may also be variously referred to as "matter", biomass", iuel" and "feedstock".

The vessel 102 is also provided with an outlet 108 for matter that has been pyrolysed within the chamber 104 (i.e. a pyrolysed mailer (char) outlet 108 to allow the removal of char material from the chamber 104).

A gas outlet 110 is provided adjacent to the inlet 106 for the extraction of synthetic gas during use. A heater (not shown in Figure 3) may also be provided in order to facilitate the pyrolysis of matter within the chamber.

The pyrolysis system further comprises an auger arrangement 112. In the embodiment of Figure 3 the auger arrangement comprises a single auger shaft 114, a first flight portion 116 and a second flight portion 118. It is noted that the first flight portion 116 is of opposite handedness to the second flight portion 118.

The pyrolysis system 100 of Figure 3 is orientated vertically such that the mailer inlet 106 and gas outlet 110 are at the top of the vessel 102 and the pyrolysed matter outlet 108 is at the base of the vessel 102. The first flight portion 116 is therefore located above the second flight portion 118.

It is noted that the auger arrangement 112 is partially located with the vessel 102. The first flight portion 116 is at the inlet 106 end of the vessel 102. The second flight portion 118 is at the outlet 108 end of the vessel 102. As shown in Figure 3 the first flight portion 116 of the auger arrangement is generally located within the mailer inlet 106 and comprises a section 120 located outside the chamber 104.

The first flight portion 116 and second flight portion 118 are separated by a clear (i.e. flight-less) section 122 of the shaft 114.

In use, matter 124 to be pyrolysed within the chamber is introduced through the mailer inlet 106. A hopper (not shown in Figure 3) may be used to deliver matter to the auger arrangement 112 at the matter inlet 106. The system of Figure 3 may be arranged to take a wide range of feedstock matter providing the particle size of the feedstock is suitable and the calorific content is not too low. For example, the system may run on wood pellets, sewage sludge pellets, refuse derived from fuel pellets, shredded tyres, municipal solid waste etc. The feedstock should be solid mailer as opposed to liquid (although some residual liquid may be present in a substantially solid feedstock) and generally have a maximum particle size of no more than approximately 50mm and an average particle size of 10mm or higher.

The auger arrangement is rotated in use and the first flight portion 116 is arranged such that matter 124 is propelled into the chamber 104 of the vessel 102. In other words the handedness of the flight portion 116 is chosen such that during rotation of the shaft 114, mailer 124 is propelled through the inlet 106 into the chamber 104.

The second flight portion 118 is chosen to have the opposite handedness to the first flight portion 116. In use of the pyrolysis system 100, and during rotation of the shaft 114, the second flight portion 118 acts against the general flow of material from the matter inlet 106 to the char outlet 108 by stirring the char material 126 formed during the pyrolysis of the biomass matter 124.

The auger arrangement of Figure 3 therefore acts to prevent bridging in the vicinity of the mailer inlet 106 and to reduce the chances of compaction in the vicinity of the char outlet 108 by "lifting" char material 126.

Conduit 158 receives heated gas to enable the pyrolysis reaction to occur.

Figures 4 and 5 show a further view of a pyrolysis system in accordance with embodiments of the present invention. Like numerals are used to denote like features with Figure 3.

In Figure 4, feedstock for the pyrolysis system 100 is added via a screw feeder 150 which is fed by a hopper 152. A diesel burner 154 (used during system start up) and a syngas burner 156 provide hot gas through a conduit 158 into the chamber 102.

The gas outlet 110 is connected to a cyclone 160 which is arranged to remove fly ash and other solids within the syngas flow from the pyrolysis chamber 102. The filtered syngas is then sent via a recovery conduit 162 to an energy recovery system (not shown in Figure 4). A proportion of the recovered syngas is drawn through a heater supply pipe 164 by a hot gas fan 166 to supply the syngas burner 156.

The pyrolysis system 100 further includes a char removal system 168.

EXAMPLE

An example of an auger arrangement in accordance with the embodiments shown in Figures 3 and 4 is depicted in Figure 5. The pyrolysis chamber 102 has an internal diameter of approximately 1 metre. The inlet tube 106 has a diameter of approximately 600 mm and an exit 108 of approximately 500mm. The diameter of the auger shaft 114 is approximately 100mm. The diameter of the flights in the first flight portion 116 is approximately 450mm and the diameter of the flights in the second flight portion 118 is approximately 600mm. The pitch of the flights in both the first and second flight portions is approximately 325mm. Overall the auger has a length of around 3.8 metres.

The unit depicted in Figure 5 is designed to take in the region of 250kg per hour of feedstock.

It is noted that the unit depicted in Figure 5 is just one example of a pyrolysis system in accordance with embodiments of the present invention and other systems may have different vessel, chamber, shaft and flight dimensions and different feedstock size and throughput flow rates depending on the particular environment that they are to be used in.

Figures 6 to 9 show pyrolysis systems and scraper mechanisms according to further embodiments of the present invention.

Figure 6 shows an embodiment of the present invention comprising a pyrolysis system and scraper mechanism. Figure 6 shows the base end of the vessel 102. Part of the auger arrangement 112 is visible along with the second flight portion 118. It is noted that the base of the vessel is formed into a generally conical section 200 that incorporates the outlet 108.

A scraper mechanism 202 is provided comprising a scraper member 204 and a number of support members 206. It can be seen that the scraper member 204 extends from the chamber 104 into the conical section 200 and is shaped to be of complementary shape to the internal walls of the chamber 104 and conical section 200.

As the auger arrangement 112 rotates the scraper mechanism 202 rotates with the auger arrangement 112 such that the scraper member remains at a set distance from the chamber and conical section internal walls. As the scraper mechanism rotates it (or part of it, e.g., the scraper member) connects with any clinker that has built up in this area thus breaking it away from the walls of the vessel 102. Loosened clinker falls into the char material 126 (as shown in Figure 3) and is removed through the outlet 108 into the char system 168 (as shown in Figure 4).

In the example shown in Figure 6 the scraper mechanism comprises square section steel bars, 40mm square. There are three support members 206 which are welded to three individual flights of the flight portion 118 and a single scraper member 204.

Figure 7 shows a further embodiment of the present invention comprising a pyrolysis system and scraper mechanism. The embodiment of Figure 7 comprises two scraper members 204 that are both similar to the scraper member shown in Figure 6. In Figure 7 however the support member that attaches scraper members 204 to the shaft 114 of the auger arrangement 116 takes the form of a number of flight members 208 rather than via the "bar shaped" support member 206 (as per the embodiment of Figure 6).

The flight members 208 may be substantially flat and may further be angled relative to the horizontal by a suitable "angle of attack" (e.g. between 0 to 25 degrees). Depending on the handedness of the flight members 208, the flight members 208 may be arranged to either lift the waste matter 124 within the thermal processing vessel 102 or propel it towards the base section 204 and the outlet 108.

Figure 6 shows a single scraper member 204 and Figure 7 shows two scraper members 204. It is to be appreciated however the number of scraper members 204 may be varied depending on the particular environment that they are to be used in. It is also noted that the number of support members 206 or flight members 208 may also be varied.

Figures 8 and 9 show a yet further embodiment of the present invention comprising a pyrolysis system and scraper mechanism. In Figures 8 (side view) and 9 (top view) a scraper mechanism 202 is provided in which the scraper member 210 takes a helical form, the axis of the helix being coincident with the axis of the auger shaft 114. The scraper member 210 is arranged to maintain a constant distance/gap from the refractory lining 212 in a similar manner to the arrangements of Figures 6 and 7. The support members shown in Figures 8 and 9 are flight members 208 similar to those shown in Figure 7.

It is noted that although the support members shown in each of Figures 6 to 9 comprise either one type of support member or another (e.g. bar-shaped member or flight member) it is to be noted that any combination of support member types may be used.

Furthermore, the auger shaft 114 may, in Figures 7 to 9, additionally comprise a separate flight arrangement such as the flight portion 118 shown in Figure 6.

Further arrangements of the scraper mechanism may be envisaged by the skilled person such as a mechanism that is mounted on a separate rotating component within the vessel other than the auger shaft 114. It is also noted that the flight arrangement may be mounted via such an arrangement rather than on the shaft as described above. Further combinations of such arrangements may also be made.

Within a pyrolysis chamber (or other thermal processing system) waste matter introduced into the chamber of the thermal processing vessel may build up on the internal walls of the chamber. In the case of a pyrolysis system waste, during pyrolysis, a clinker ot pyrolysed waste and partially melted alloys may form and bond to the internal walls (Refractory lining) of the chamber of the vessel. Such a build-up of material reduces the hot air flow through the pyrolysis chamber and the waste mailer being processed, as well as reducing the volumetric area with in the chamber.

The constant build-up of the clinker if left will eventually bridge the outlet from the vessel and cause a break down scenario where the plant will have to be cooled before repair.

The scraper mechanism described above facilitates the cleaning or knocking down of the build-up on the refractory lining I walls and the Pyro base cones. The addition of the scraper mechanism therefore mitigates against the build-up of material within the pyrolysis chamber and promotes a more uniform thermal processing of the material.

Further variations and modifications not explicitly described above may also be contemplated without departing from the scope of the invention as defined in the appended claims.

Claims

<claim-text>CLAIMS1. A thermal processing system for processing matter comprising a vessel defining a chamber and having an inlet arranged to receive matter for processing within the chamber and an outlet for matter that has been processed within the chamber, the chamber being arranged such that there is a net flow of matter from the inlet towards the outlet; an auger arrangement at least partially located within the chamber wherein a first part of the auger arrangement is arranged to propel matter in a direction from the inlet into the chamber and a second part of the auger arrangement is arranged to act against the flow of matter from the inlet towards the outlet.</claim-text> <claim-text>2. A system as claimed in Claim 1, wherein the first part of the auger arrangement is in the region of the inlet and the second part of the auger arrangement is in the region of the outlet.</claim-text> <claim-text>3. A system as claimed in Claim 1 or Claim 2, wherein the first and second parts of the auger arrangement either have different handedness or are rotated in different directions to one another.</claim-text> <claim-text>4. A system as claimed in any of Claims 1 to 3, wherein the auger arrangement comprises a shaft and a flight arrangement mounted on the shaft.</claim-text> <claim-text>5. A system as claimed in Claim 4, wherein the first part of the auger arrangement is provided by a first flight portion of the flight arrangement and the second part of the auger arrangement is provided by a second flight portion of the flight arrangement, the first flight portion being located in the region of the inlet and the second flight portion being located in the region of the outlet.</claim-text> <claim-text>6. A system as claimed in Claim 5, wherein the shaft comprises a flight-less portion located between the first and second flight portions.</claim-text> <claim-text>7. A system as claimed in Claim 5 or Claim 6, wherein the first and second flight portions have different handedness.</claim-text> <claim-text>8. A system as claimed in any one of Claims 5 to 7, wherein the diameter of the first flight portion is different to the diameter of the second flight portion.</claim-text> <claim-text>9. A system as claimed in as claimed in Claim 8, wherein the first flight portion has a smaller diameter than the second flight portion.</claim-text> <claim-text>10. A system as claimed in any one of Claims 5 to 9, wherein the pitch of the first flight portion is different to the pitch of the second flight portion.</claim-text> <claim-text>11. A system as claimed in any one of Claims 1 to 3, wherein the auger arrangement comprises a first shaft having a first flight arrangement mounted thereon and a second shaft having a second flight arrangement mounted thereon, the first shaft providing the first part of the auger arrangement and the second shaft providing the second part of the auger arrangement.</claim-text> <claim-text>12. A system as claimed in Claim 11, wherein the first and second flight arrangements have the same handedness and the first and second shafts are arranged to be rotated in different directions.</claim-text> <claim-text>13. A system as claimed in any either of Claims 11 or 12, wherein the first and second shafts are separate to one another.</claim-text> <claim-text>14. A system as claimed in of Claim 13, wherein the first and second shafts are connected by a gearing arrangement.</claim-text> <claim-text>15. A system as claimed in Claim 11, wherein first and second shafts are arranged to be rotated in the same direction and the first and second flight arrangements are arranged to have different handedness.</claim-text> <claim-text>16. A system as claimed in any one of Claims 11 to 15, wherein the first and second flight arrangements have different diameters and/or pitches.</claim-text> <claim-text>17. A system as claimed in any one of Claims 11 to 16, wherein the first and second shafts are rotated at different rotational speeds.</claim-text> <claim-text>18. A system as claimed in any preceding claim, wherein the inlet is higher than the outlet.</claim-text> <claim-text>19. A system as claimed in any preceding claim, wherein the chamber defines a vertical axis, the inlet being mounted above the outlet on the vertical axis.</claim-text> <claim-text>20. A system as claimed in any preceding claim, wherein the system is a pyrolysis system for pyrolysing the input matter.</claim-text> <claim-text>21. A system as claimed in Claim 20, wherein the matter to be pyrolysed comprises particles having a maximum dimension of less than 50mm.</claim-text> <claim-text>22. A system as claimed in Claim 20 or Claim 21, wherein the material received at the inlet has a water content of less than 30%.</claim-text> <claim-text>23. A system as claimed in any of Claims 20, 21 or 22, further comprising a gas outlet arranged to extract gas produced by the pyrolysis reaction.</claim-text> <claim-text>24. A system as claimed in any preceding claim, wherein the inlet has a diameter greater than 10mm.</claim-text> <claim-text>25. A system as claimed in any preceding claim, further comprising a heater to heat the chamber.</claim-text> <claim-text>26. A system as claimed in any preceding claim, further comprising a scraper mechanism arranged to mitigate against matter build-up on the walls of the vessel.</claim-text> <claim-text>27. A system as claimed in Claim 26, wherein the scraper mechanism is of complementary shape to the internal dimensions of the chamber.</claim-text> <claim-text>28. A system as claimed in Claim 26 or Claim 27, wherein the scraper mechanism is arranged to rotate within the chamber.</claim-text> <claim-text>29. A system as claimed in Claim 28, wherein the scraper mechanism is arranged to be attached to a rotating component within the vessel.</claim-text> <claim-text>30. A system as claimed in Claim 29, wherein the auger arrangement comprises a shaft and the scraper mechanism is arranged to be attached to the shaft.</claim-text> <claim-text>31. A system as claimed in Claim 29, wherein the auger arrangement comprises a shaft and a flight arrangement mounted on the shaft, the scraper mechanism arranged to be attached to the flight arrangement.</claim-text> <claim-text>32. A system as claimed in Claim 30 or Claim 31, wherein the scraper mechanism comprises a scraper member, the scraper member being of complementary shape to the internal dimensions of the chamber, and a support member, the scraper member being attached to the auger arrangement by the support member.</claim-text> <claim-text>33. A system as claimed in Claim 29, wherein the scraper mechanism comprises a scraper member, the scraper member being of complementary shape to the internal dimensions of the chamber, and a support member, the scraper member being attached to the rotating component by the support member.</claim-text> <claim-text>34. A system as claimed in Claim 32 or Claim 33, wherein the scraper member comprises a helical shaped member.</claim-text> <claim-text>35. A system as claimed in Claim 32 or Claim 33, wherein the scraper member comprises a bar member.</claim-text> <claim-text>36. A system as claimed in any one of claims 32 to 35, wherein the support member comprises a scraper flight arrangement.</claim-text> <claim-text>37. A system as claimed in Claim 36, wherein the scraper flight arrangement is arranged to act against the flow of matter from the inlet towards the outlet.</claim-text> <claim-text>38. A system as claimed in Claim 37, wherein the scraper flight arrangement forms the second part of the auger arrangement.</claim-text> <claim-text>39. A system as claimed in any preceding claim, wherein the scraper mechanism is located in the vicinity of the outlet of the vessel.</claim-text> <claim-text>40. A system as claimed in Claim 39, wherein the vessel comprises a generally cylindrical body and a base cone at the lower end of the cylinder, the base cone comprising the outlet.</claim-text> <claim-text>41. A system as claimed in Claim 40, wherein the scraper mechanism is located in part within the cylindrical body and in part within the base cone.</claim-text> <claim-text>42. A method of operating a thermal processing system, the method comprising: providing a thermal processing system according to any one of claims 1 to 41; introducing matter for processing at the inlet; rotating the auger arrangement; removing matter that has been processed from the outlet.</claim-text>