The present invention relates to an apparatus and a method for thermally processing waste. In one example, the present invention relates to an apparatus and a method for pyrolysis of waste, such as automotive shredder residue.

Background

There is an increasing desire and need to recycle waste products. At the same time, legislation is continually pushing for cleaner and more efficient processes for recycling waste products. For example, plastics are becoming more difficult to recycle due to more stringent legislation on the removal of persistent organic pollutants, which are found within their polymer matrix as flame retardants (typically brominated and chlorinated hydrocarbons).

Products formed from a single material are typically clean, easy and efficient to recycle. However, complex products that are formed from multiple different materials pose a problem because such products must undergo a number of different separation processes to allow for recovery or reuse of their materials. As legislation becomes more strict, it is likely that automotive shredder residue will be reclassified as hazardous waste.

One example of a complex product is an automotive vehicle such as an automobile. At the end of its useful life, an automotive vehicle is shredded into smaller pieces called automotive shredder residue. This automotive shredder residue is then processed to recover and recycle its constituent materials.

Ferrous and non-ferrous metals can be easily recovered from automotive shredder residue. Other materials, such as plastics (which may contain flame retardant additives and persistent organic pollutants), fibres, glass, foam, rubber and wood etc. are more difficult to recover. Typically, some of these materials are thermally processed together using pyrolysis to create various solid, liquid and gas products.

Conventional apparatus and methods cannot guarantee removal of persistent organic pollutants and do not produce products free from inorganic contamination.

Changes in legislation regarding end of life vehicle waste, increasing disposal costs, and tighter carbon reduction targets drive the need for enhanced methods of processing automotive shredder residue. In particular, there is a need for an apparatus and a method for thermally processing waste, such as automotive shredder residue, which removes the persistent organic pollutants.

It would be desirable to improve pyrolysis of waste such as automotive shredder residue. In particular, it would be desirable to produce clean and higher quality products through pyrolysis of waste such as automotive shredder residue. There is provided an apparatus for thermally processing waste, the apparatus comprising: a primary pyrolysis chamber, the primary pyrolysis chamber comprising an outlet through which a primary chamber product stream is output; and a secondary pyrolysis chamber, the secondary pyrolysis chamber comprising an inlet through which the primary chamber product stream from the primary pyrolysis chamber is received.

There is also provided an apparatus for thermally processing waste. The apparatus may comprise a primary pyrolysis chamber. The primary pyrolysis chamber may comprise an outlet through which a primary chamber product stream is output. The apparatus may comprise a secondary pyrolysis chamber. The secondary pyrolysis chamber may comprise an inlet through which the primary chamber product stream from the primary pyrolysis chamber is received.

There is provided a method for thermally processing waste, the method comprising: pyrolysing the waste in a primary pyrolysis chamber to form a primary chamber product stream; transferring the primary chamber product stream from the primary pyrolysis chamber to a secondary pyrolysis chamber; and pyrolysing the primary chamber product stream in a secondary pyrolysis chamber to form a secondary chamber product stream.

There is also provided a method for thermally processing waste The method may comprise pyrolysing the waste in a primary pyrolysis chamber to form a primary chamber product stream. The method may comprise transferring the primary chamber product stream from the primary pyrolysis chamber to a secondary pyrolysis chamber. The method may comprise pyrolysing the primary chamber product stream in a secondary pyrolysis chamber to form a secondary chamber product stream.

Pyrolysis of the primary chamber product stream within the secondary pyrolysis chamber may break down longer chain hydrocarbons within the primary chamber product stream, such as heavy oils, waxes and tars, into shorter chain hydrocarbons, such as light oils and gases. This may increase the quantity of, for example, Ci - C4 hydrocarbon gases and C2 - Ce hydrocarbon gases. One advantage of a product stream that includes a higher proportion of shorter chain hydrocarbons is that the secondary chamber product stream has a higher calorific value. This higher calorific value may make the secondary chamber product stream more suitable for use as a fuel.

The high temperature within the secondary pyrolysis chamber, and the overall increased residence time ultimately experienced by the waste, may break down persistent organic pollutants in the primary chamber product stream into non-hazardous compounds. Acidic gases may be formed through pyrolysis of the waste in the first pyrolysis chamber. Advantageously, the second pyrolysis chamber may keep the acid gases in gaseous form. The acid gases can then be removed through, for example, filtration or quenching.

The apparatus may for be thermally processing automotive shredder residue.

The inlet of the primary pyrolysis chamber may be integral with the primary pyrolysis chamber. Alternatively, the inlet of the primary pyrolysis chamber may be a separate component to the primary pyrolysis chamber. The inlet of the primary pyrolysis chamber may be attached to the primary pyrolysis chamber. The inlet of the primary pyrolysis chamber may be an aperture.

The outlet of the primary pyrolysis chamber may be integral with the primary pyrolysis chamber. Alternatively, the outlet of the primary pyrolysis chamber may be a separate component to the primary pyrolysis chamber. The outlet of the primary pyrolysis chamber may be attached to the primary pyrolysis chamber. The outlet of the primary pyrolysis chamber may be an aperture.

The primary pyrolysis chamber may include a primary pyrolysis heater. The primary pyrolysis heater may comprise a burner. The primary pyrolysis heater may comprise a plurality of burners.

The primary pyrolysis chamber may comprise an inert gas inlet. The inert gas inlet may allow the primary pyrolysis chamber to be filled at least partially filled with an inert gas. The primary pyrolysis chamber may comprise an inert gas.

The inert gas may be nitrogen.

The secondary pyrolysis chamber may comprise an outlet through which a secondary chamber product stream is output.

The secondary pyrolysis chamber may comprise an inert gas inlet. The inert gas inlet may allow the secondary pyrolysis chamber to be filled at least partially filled with an inert gas. The secondary pyrolysis chamber may comprise an inert gas.

The inert gas may be nitrogen.

The inlet of the secondary pyrolysis chamber may be integral with the secondary pyrolysis chamber. Alternatively, the inlet of the secondary pyrolysis chamber may be a separate component to the secondary pyrolysis chamber. The inlet of the secondary pyrolysis chamber may be attached to the secondary pyrolysis chamber. The inlet of the secondary pyrolysis chamber may be an aperture.

The outlet of the secondary pyrolysis chamber may be integral with the secondary pyrolysis chamber. Alternatively, the outlet of the secondary pyrolysis chamber may be a separate component to the primary pyrolysis chamber. The outlet of the secondary pyrolysis chamber may be attached to the secondary pyrolysis chamber. The outlet of the secondary pyrolysis chamber may be an aperture.

The secondary pyrolysis chamber may include a secondary pyrolysis heater. The secondary pyrolysis heater may comprise a burner. The secondary pyrolysis heater may comprise a plurality of burners.

The secondary pyrolysis chamber may be heated using excess combustion heat from the primary pyrolysis chamber. The secondary pyrolysis chamber may be heated by a heat exchanger. The secondary pyrolysis chamber may be heated by a heat exchanger using excess combustion heat from the primary pyrolysis chamber.

The primary pyrolysis chamber and the secondary pyrolysis chamber may be operated at different temperatures. Alternatively, The primary pyrolysis chamber and the secondary pyrolysis chamber may be operated at approximately the same temperature.

The secondary pyrolysis chamber may be operated at a lower temperature than the primary pyrolysis chamber. Alternatively, the secondary pyrolysis chamber may be operated at a higher temperature than the primary pyrolysis chamber.

The primary pyrolysis chamber may be operated at a temperature of at least 850°C. The primary pyrolysis chamber may be operated at a temperature of at least 900°C. The primary pyrolysis chamber may be operated at a temperature of at least 950°C.

The primary pyrolysis chamber may be operated at a temperature of less than 1000°C. The primary pyrolysis chamber may be operated at a temperature of less than 950°C. The primary pyrolysis chamber may be operated at a temperature of less than 900°C.

The primary pyrolysis chamber may be operated at a temperature of between 850°C and 1000°C. The primary pyrolysis chamber may be operated at a temperature of between 900°C and 1000°C. The primary pyrolysis chamber may be operated at a temperature of between 900°C and 950°C. The primary pyrolysis chamber may be operated at a temperature of between 850°C and 950°C. The primary pyrolysis chamber may be operated at a temperature of between 850°C and 900°C.

For the avoidance of doubt, when used in the specification, the term “between a and b” includes values a and b.

The apparatus may comprise a catalyst delivery unit. The catalyst delivery unit may be for delivering one or more catalysts to the secondary pyrolysis chamber. The catalyst delivery unit may deliver a plurality of catalysts to the secondary pyrolysis chamber. The catalyst delivery unit may deliver the one or more catalysts directly to the secondary pyrolysis chamber.

The catalyst delivery unit may comprise a catalyst outlet through which the one or more catalysts are delivered to the secondary pyrolysis chamber. The secondary pyrolysis chamber may comprise a catalyst inlet through which the one or more catalysts received from the catalyst delivery unit.

The catalyst delivery unit may comprise a reservoir for storing the one or more catalysts.

The one or more catalysts may comprise one or more molecular sieve material. The one or more catalysts may comprise one or more mesoporous molecular sieve material.

The one or more catalysts may comprise one or more mesoporous silicates.

The one or more catalysts may comprise one or more zeolites. The one or more catalysts may comprise one or more alkaline earth metal oxides. The one or more catalysts may comprise one or more palladium containing materials or one or more rhodium containing materials, or a combination thereof.

The one or more catalysts may comprise one or more solid-base catalysts. The one or more catalysts may comprise one or more heterogeneous solid-base catalysts.

The one or more catalysts may comprise a 3A molecular sieve. The one or more catalysts may comprise a 4A molecular sieve. The one or more catalysts may comprise ALIM CM -41 .

Advantageously, the one or more catalysts, or plurality of catalysts, encounter the components within the primary chamber product stream and may assist in breaking down the components of the primary chamber product stream in to components such as light oils and gases. Further breaking down the primary chamber product stream may facilitate the removal of persistent organic pollutants and metallic organics from the primary chamber product stream.

The secondary pyrolysis chamber may be operated at a temperature of at least 450°C. A temperature of 450°C is above the reformation temperature for dioxin and furan formation. Advantageously, operating the secondary pyrolysis chamber at a temperature of at least 450°C may reduce dioxin and furan formation.

The secondary pyrolysis chamber may be operated at a temperature of at least 350°C.

The secondary pyrolysis chamber may be operated at a temperature of at least 400°C. The secondary pyrolysis chamber may be operated at a temperature of at least 500°C. The secondary pyrolysis chamber may be operated at a temperature of at least 550°C. The secondary pyrolysis chamber may be operated at a temperature of at least 600°C. The secondary pyrolysis chamber may be operated at a temperature of at least 650°C. The secondary pyrolysis chamber may be operated at a temperature of at least 700°C.

The5econddary pyrolysis chamber may be operated at a temperature of less than

750°C. The secondary pyrolysis chamber may be operated at a temperature of less than

700°C. The secondary pyrolysis chamber may be operated at a temperature of less than 650°C. The secondary pyrolysis chamber may be operated at a temperature of less than

600°C. The secondary pyrolysis chamber may be operated at a temperature of less than

550°C. The secondary pyrolysis chamber may be operated at a temperature of less than

500°C.

The secondary pyrolysis chamber may be operated at a temperature of between 350°C and 750°C. The secondary pyrolysis chamber may be operated at a temperature of between 400°C and 750°C. The secondary pyrolysis chamber may be operated at a temperature of between 450°C and 750°C. The secondary pyrolysis chamber may be operated at a temperature of between 450°C and 700°C. The secondary pyrolysis chamber may be operated at a temperature of between 500°C and 750°C. The secondary pyrolysis chamber may be operated at a temperature of between 500°C and 700°C.

Advantageously, operating the secondary pyrolysis chamber at a temperature of between 500°C and 700°C may reduce the amount of persistent organic pollutants that are formed within the secondary pyrolysis chamber. This is because these temperatures are above the reformation temperature for persistent organic pollutants such as furans and dioxins.

Advantageously, operating the secondary pyrolysis chamber at a temperature of between 500°C and 700°C may keep all gases in the vapour phase, which reduces condensation.

The secondary pyrolysis chamber may be operated at a temperature that is dependent on the species of the one or more catalysts delivered to the secondary pyrolysis chamber by the catalyst delivery unit.

The apparatus may comprise one or more filters. The apparatus may comprise a plurality of filters.

The one or more filters may be operated at a temperature of 300°C.

The secondary pyrolysis chamber may comprise an integrated solids collection device for collecting solids from the secondary pyrolysis chamber. The solids may contain a mixture of char material and the one or more catalysts.

The apparatus may comprise a cyclone separator. The apparatus may comprise a plurality of cyclone separators. The cyclone separator may receive the primary chamber product stream and output a cyclone separator stream to the inlet of the secondary pyrolysis chamber. The cyclone separator may be configured to receive the primary chamber product stream and output a cyclone separator stream to the inlet of the secondary pyrolysis chamber. The cyclone separator may filter the primary chamber product stream so as to remove particulates from the primary chamber product stream before the primary chamber product stream enters the secondary pyrolysis chamber . The cyclone separator may be configured to filter the primary chamber product stream so as to remove particulates from the primary chamber product stream. The cyclone separator may remove char from the primary chamber product stream. The cyclone separator may remove substantially all of the char from the primary chamber product stream.

Particulate matter such as char, or a metal, within a pyrolysis chamber may act as a catalyst point for the formation of persistent organic pollutants. Advantageously, extracting particulate matter such as char from the primary chamber product stream before it is fed into the secondary pyrolysis chamber may reduce the formation of persistent organic pollutants inside the secondary pyrolysis chamber.

Advantageously, extracting solid residues from the primary chamber product stream before it is fed into the secondary pyrolysis chamber may help to keep the secondary pyrolysis chamber residue free, which may help to improve the efficiency of the secondary pyrolysis chamber.

The apparatus may comprise a ceramic filter. The ceramic filter may receive the secondary chamber product stream and output a filtered stream. The ceramic filter may be configured to receive the secondary chamber product stream and output a filtered stream. The ceramic filter may be an activated ceramic filter.

Advantageously, the ceramic filter may remove entrained fine particulate matter from the secondary chamber product stream. Removal of fine particulate matter from the secondary chamber product stream may provide a higher quality product stream. Removal of fine particulate matter from the secondary chamber product stream may increase the overall efficiency of the apparatus.

Advantageously, the ceramic filter may remove acid gases from the secondary chamber product stream.

The apparatus may comprise a quench vessel. The quench vessel may receive the secondary chamber product stream and output a quenched stream. The quench vessel may be configured to receive the secondary chamber product stream and output a quenched stream. The quench vessel may comprise sodium bicarbonate. The quench vessel may use sodium bicarbonate to remove acid gases present in the secondary chamber product stream.

Advantageously, the quench vessel may remove persistent organic pollutants such as furans and dioxins from the secondary chamber product stream. Advantageously, the quench vessel may remove acid gases, such as hydrogen chloride and hydrogen sulphide.

Advantageously, the quench vessel may remove acid gases from the secondary chamber product stream.

The apparatus may comprise a ceramic filter and a quench vessel. The secondary chamber product stream may be received in the ceramic filter before it is received in the quench vessel. The secondary chamber product stream may be received in the quench vessel before it is received in the ceramic filter.

The secondary pyrolysis chamber may comprise a heat exchanger. The secondary pyrolysis chamber may comprise an integrated heat exchanger.

The heat exchanger within the secondary pyrolysis chamber may be used to heat the primary chamber product stream with heat absorbed from the primary pyrolysis chamber.

The heat exchanger may be a static heat exchanger. The heat exchanger may be a plate heat exchanger. The heat exchanger may comprise heat exchange media.

The heat exchanger may be arranged to provide heat to the secondary pyrolysis chamber. The heat exchanger may provide heat to the secondary pyrolysis chamber The heat exchanger may be arranged to absorb heat from the primary pyrolysis chamber. The heat exchanger may be arranged to absorb heat from the primary pyrolysis chamber and transfer the heat to the secondary pyrolysis chamber. The heat exchanger may absorb heat from the primary pyrolysis chamber. The heat exchanger may absorb heat from the primary pyrolysis chamber and transfer the heat to the secondary pyrolysis chamber. The heat exchanger may be configured to exchange heat between the primary pyrolysis chamber and the secondary pyrolysis chamber. The heat exchanger may exchange heat between the primary pyrolysis chamber and the secondary pyrolysis chamber.

Advantageously, recovering heat from the primary pyrolysis chamber and using the recovered heat to heat the secondary pyrolysis chamber improves the overall thermal efficiency of the apparatus.

The apparatus may be arranged to operate as a continuous process.

The method of thermally processing waste may include any feature described above with respect to the apparatus.

The method may comprise heating the primary pyrolysis chamber to a first temperature. The method may comprise heating the secondary pyrolysis chamber to a second chamber. The method may comprise heating the primary pyrolysis chamber to a first temperature; and heating the secondary pyrolysis chamber to a second chamber. The second temperature may be lower than the first temperature.

The first temperature may be between 850°C and 1000°C. The first temperature may be between 900°C and 950°C.

The second temperature may be between 400°C and 750°C. The second temperature may be between 500°C and 700°C.

The method may comprise filtering the primary chamber product stream and/or the secondary chamber product stream. The method may comprise filtering the primary chamber product stream with a cyclone separator.

The method may comprise filtering the secondary chamber product stream with a ceramic filter.

The method may comprise filtering the secondary chamber product stream with a quench vessel.

The method may comprise using a heat exchanger to heat the secondary pyrolysis chamber with heat absorbed from the primary pyrolysis chamber.

Brief Description of Drawings

Figure 1 illustrates schematically an example of apparatus for thermally processing waste according to the prior art;

Figure 2 illustrates schematically a first example of apparatus for thermally processing waste according to the invention;

Figure 3 illustrates schematically a second example of apparatus for thermally processing waste according to the invention;

Figure 4 is a first Fourier Transform Infrared Spectroscopy graph;

Figure 5 is a second Fourier Transform Infrared Spectroscopy graph;

Figure 6 is a third Fourier Transform Infrared Spectroscopy graph; and

Figure 7 is a fourth Fourier Transform Infrared Spectroscopy graph.

Detailed Description

There is an increasing desire and need to recycle waste products. At the same time, legislation is continually pushing for cleaner and more efficient processes for recycling waste products. For example, plastics are becoming more difficult to recycle due to more stringent legislation on the removal of persistent organic pollutants, which are found within their polymer matrix as flame retardants (typically brominated and chlorinated hydrocarbons).

Products formed from a single material are typically clean, easy and efficient to recycle. However, complex products that are formed from multiple different materials pose a problem because such products must undergo a number of different separation processes to allow for recovery or reuse of their materials.

One example of a complex product is an automotive vehicle such as an automobile. At the end of its useful life, an automotive vehicle is shredded into smaller pieces called automotive shredder residue. This automotive shredder residue is then processed to recover and recycle its constituent materials. As legislation becomes more strict, it is likely that automotive shredder residue will be reclassified as hazardous waste. Ferrous and non-ferrous metals can be easily recovered from automotive shredder residue. Other materials, such as plastics (which may contain flame retardant additives and persistent organic pollutants), fibres, glass, foam, rubber and wood etc. are more difficult to recover. Typically, some of these materials are thermally processed together using pyrolysis to create various solid, liquid and gas products.

Conventional apparatus and methods cannot guarantee removal of persistent organic pollutants and do not produce products free from inorganic contamination.

Changes in legislation regarding end of life vehicle waste, increasing disposal costs, and tighter carbon reduction targets drive the need for enhanced methods of processing automotive shredder residue. In particular, there is a need for an apparatus and a method for thermally processing waste, such as automotive shredder residue, which removes the persistent organic pollutants.

Figure 1 shows an example of conventional apparatus for thermally processing waste, such as automotive shredder residue. The apparatus 100 includes a pyrolysis chamber 101. The pyrolysis chamber 101 has an inlet 102 and an outlet 103. A feedstock stream 104 enters the pyrolysis chamber 101 through the inlet 102. In this example, the feedstock stream 104 is automotive shredder residue. In another example, the feedstock stream 104 may be a different type of waste.

The pyrolysis chamber 101 is heated to between 900°C and 950°C. At such temperatures, the automotive shredder residue within the pyrolysis chamber 101 is broken down into products such as heavy oils, waxes, light oils, and gases. These products are removed from the pyrolysis chamber 101 through the outlet 103 as a pyrolysis chamber product stream 105. The pyrolysis chamber product stream 105 may then be further processed to separate its components.

Heavy oils and waxes are not particularly valuable or useful. One problem with the apparatus shown in Figure 1 and described above is that the proportion of heavy oils and waxes is too high.

Plastics may contain additives that are deemed to be persistent organic pollutants. Persistent organic pollutants, such as furans and dioxins, are organic compounds that are resistant to environmental degradation, and as therefore subject to strict regulations. One problem with the apparatus and method shown in Figure 1 and described above is that they may not break down all of the persistent organic pollutants in the waste. The persistent organic pollutants may be retained within the oil.

It would be desirable to improve pyrolysis of waste such as automotive shredder residue. In particular, it would be desirable to produce cleaner and higher quality products through pyrolysis of waste such as automotive shredder residue. Figure 2 shows a first example of apparatus for thermally processing waste according to the invention.

The apparatus 200 includes a primary pyrolysis chamber 201. In this example, the primary pyrolysis chamber 201 is a pyrolysis reactor. The primary pyrolysis chamber 201 has a primary chamber inlet 202 and a primary chamber outlet 203. A feedstock stream 204 enters the primary pyrolysis chamber 201 through the primary chamber inlet 202. In this example, the feedstock 204 is automotive shredder residue. In another example, the feedstock stream 204 may be a different type of waste. In this example, the primary chamber inlet 202 and the primary chamber outlet 203 are integral with the structure of the primary pyrolysis chamber 201 . The feedstock stream 204 is transported to the primary chamber inlet 202 through a pipe. In this example, the primary pyrolysis chamber 201 includes a heater.

A primary chamber product stream 205 is output from the primary pyrolysis chamber 201 through the primary chamber outlet 203. The primary chamber product stream 205 is the product of pyrolysis of the feedstock stream 204 in the primary pyrolysis chamber 201. The primary chamber product stream 205 may comprise one or more of solids, liquid and gases.

The apparatus 200 includes a secondary pyrolysis chamber 210. In this example, the secondary pyrolysis chamber 210 is a pyrolysis reactor. The secondary pyrolysis chamber 210 has a secondary chamber inlet 212 and a secondary chamber outlet 213. In this example, the secondary chamber inlet 212 and the secondary chamber outlet 213 are integral with the structure of the secondary pyrolysis chamber 210. In this example, the secondary pyrolysis chamber 210 includes a heater.

In the example of Figure 2, the apparatus 200 includes a catalyst delivery unit 215. The catalyst delivery unit 215 has a catalyst outlet 217 for outputting one or more catalysts from the catalyst delivery unit 215. The secondary pyrolysis chamber 210 has a catalyst inlet 216 for receiving one or more catalysts from the catalyst delivery unit 215.

The catalyst delivery unit 215 delivers catalyst directly to the secondary pyrolysis chamber 210.

The primary chamber product stream 205 is transported from the primary chamber outlet 203 of the primary pyrolysis chamber 201 to the secondary chamber inlet 212 of the secondary pyrolysis chamber 210 via a pipe. The primary chamber product stream 205 enters the secondary pyrolysis chamber 210 through the secondary chamber inlet 212.

A secondary chamber product stream 214 is output from the secondary pyrolysis chamber 210 through the secondary chamber outlet 213. The secondary chamber product stream 214 is the product of pyrolysis of the primary chamber product stream 205 in the secondary pyrolysis chamber 210. The secondary chamber product stream 214 may comprise one or more of solids, liquid and gases. In this example, the secondary product stream 214 comprises gas and liquid.

In use, the primary pyrolysis chamber 201 is heated to between 900°C and 950°C. The feedstock stream 204 enters the primary pyrolysis chamber 201 through the primary chamber inlet 202. At the high temperature inside the primary pyrolysis chamber 201 , the feedstock stream 204 is broken down inside the primary pyrolysis chamber 201 into components such as oils, waxes, light oils, gases and solid material. These components form the primary chamber product stream 205. The primary chamber product stream 205 leaves the primary pyrolysis chamber 201 through the primary chamber outlet 203.

The primary chamber product stream 205 includes longer chain hydrocarbons such as oils and waxes, as well as aromatic hydrocarbons such as naphthalene. The primary chamber product stream 205 may also include small amounts of persistent organic pollutants present in both gas and solid phase..

The secondary pyrolysis chamber 210 is heated to between 500°C and 700°C. Therefore, in this example, the secondary pyrolysis chamber 210 is operated at a lower temperature than the primary pyrolysis chamber 201 . The temperature to which the secondary pyrolysis chamber 210 is heated is dependent on type or species of the one or more catalysts being delivered by the catalyst delivery unit 215, so that the temperature of the secondary pyrolysis chamber 210 is within the activation range of the one or more catalysts.

The primary chamber product stream 205 enters the secondary pyrolysis chamber 210 through the secondary chamber inlet 212. Inside the secondary pyrolysis chamber 210, the primary product stream 205 encounters the one or more catalysts. At the temperature inside the secondary pyrolysis chamber 210, and due to the activity of the one or more catalysts, the primary chamber product stream 205 is further broken down inside the secondary pyrolysis chamber210 into components such as light oils and gases. Further breaking down the primary chamber product stream 205 may facilitate the removal of persistent organic pollutants and metallic organics from the primary chamber product stream 205. The resulting components form the secondary chamber product stream 214. The secondary chamber product stream 214 leaves the secondary pyrolysis chamber 210 through the secondary chamber outlet 213.

Pyrolysis of the primary chamber product stream 205 within the secondary pyrolysis chamber 210 breaks the longer chain and cyclic hydrocarbons, such as oils, waxes and tars, into shorter chain hydrocarbons, such as light oils and gases. This may increase the quantity of, for example, Ci - C4 hydrocarbon gases and C2 - Ce hydrocarbon gases. In addition, presence of the one or more catalysts provides a higher degree of chain scission which assists in breaking down the persistent organic material within the solid and gas phases. One advantage of a product stream that includes a higher proportion of shorter chain hydrocarbons is that the product stream is deemed as higher quality because of its higher calorific values, and because it no longer contains potentially harmful products. In one example, the secondary chamber product stream 214 is processed into syngas, for use as a fuel. Solid material may be collected from secondary pyrolysis chamber 210 by using an integrated collection device. The solid material contains a mixture of cleaned char material and the one or more catalysts. The char material and the one or more catalysts can then be separated.

The higher temperature within the secondary pyrolysis chamber 210, the addition of the one or more catalysts, and the overall increased residence time ultimately experienced by the feedstock stream 204, may break down persistent organic pollutants in the primary chamber product stream 205 into non-hazardous compounds. In some examples, the amount of persistent organic pollutants in the secondary chamber product stream 214 is substantially reduced compared to the primary chamber product stream 205. In some examples, persistent organic pollutants are completely eliminated from the secondary chamber product stream 214.

Figure 3 shows a second example of apparatus for thermally processing waste according to the invention.

The apparatus 300 includes a primary pyrolysis chamber 301. In this example, the primary pyrolysis chamber 301 is a pyrolysis reactor. The primary pyrolysis chamber 301 has a primary chamber inlet 302 and a primary chamber outlet 303. A feedstock stream 304 enters the primary pyrolysis chamber 301 through the primary chamber inlet 302. In this example, the feedstock stream 304 is automotive shredder residue. In another example, the feedstock stream 304 may be a different type of waste. In this example, the primary chamber inlet 302 and the primary chamber outlet 303 are integral with the structure of the primary pyrolysis chamber 301. The feedstock stream 304 is transported to the primary chamber inlet 302 through a pipe.

A primary chamber product stream 305 is output from the primary pyrolysis chamber 301 through the primary chamber outlet 303. The primary chamber product stream 305 is the product of pyrolysis of the feedstock stream 304 in the primary pyrolysis chamber 301 . The primary chamber product stream 305 may comprise one or more of solids, liquid and gases.

The apparatus 300 includes a heater 306. In this example, the heater 306 is a plurality of burners. The heater 306 includes an exhaust gas stream 307. The exhaust gas stream 307 may be transported via a pipe.

The apparatus 300 includes a secondary pyrolysis chamber 310. In this example, the secondary pyrolysis chamber 310 is a pyrolysis reactor. The secondary pyrolysis chamber 310 has a secondary chamber inlet 312 and a secondary chamber outlet 313. In this example, the secondary chamber inlet 312 and the secondary chamber outlet 313 are integral with the structure of the secondary pyrolysis chamber 310.

In one example, the secondary pyrolysis chamber 310 may be at least partially filled with nitrogen. At least partially filling the secondary pyrolysis chamber 310 with nitrogen may ensure that the pyrolysis process uses heat without a flame.

In this example, the secondary pyrolysis chamber 310 includes a heat exchanger 316. The heat exchanger 316 is arranged to provide heat to the secondary pyrolysis chamber 310. The heat exchanger 316 receives the exhaust gas stream 307 from the heater 306. The heat exchanger 316 is configured to transfer heat between the exhaust gas stream 307 and the secondary pyrolysis chamber 310. In this way, heat from the exhaust gas stream 307 may be used to supply heat to the secondary pyrolysis chamber 310. The heat exchanger 316 outputs a return gas stream 317. In this example, the heater 306 receives the return gas stream 317.

The apparatus may include a first filter. In this example, the apparatus 300 includes a cyclone separator 320. A cyclone separator such as the cyclone separator 320 uses the method of cyclonic separation to remove particulates from a gas or liquid stream. In this example, the cyclone separator 320 is arranged to remove particulates from the primary chamber product stream 305. The cyclone separator 320 may remove substantially all of the particulates from the primary chamber product stream 305.

The cyclone separator 320 ©ncludes a cyclone inlet 322, a cyclone outlet 323, and a cyclone waste outlet 324. In this example, the cyclone inlet 322, the cyclone outlet 323, and the cyclone waste outlet 324 are integral with the structure of the cyclone separator 320.

The primary chamber product stream 305 enters the cyclone separator through the cyclone inlet 322. The primary chamber product stream 305 is transported from the primary chamber outlet 303 of the primary pyrolysis chamber 301 to the cyclone inlet 322 of the cyclone separator 320 via a pipe.

The primary chamber product stream 305 undergoes cyclonic separation inside the cyclone separator 320. A waste stream 325 of solids removed from the primary chamber product stream 305 is output from the cyclone separator 320 through the cyclone waste outlet 324. The waste stream 325 contains mostly solids and may be further processed. A separated primary chamber product stream 326 is output from the cyclone separator 320 through the cyclone outlet 323. The separated primary chamber product stream 326 is substantially free of particulate matter.

The separated primary chamber product stream 326 is transported from the cyclone outlet 323 of the cyclone separator 320 to the secondary chamber inlet 312 of the secondary pyrolysis chamber 310 via a pipe. The separated primary chamber product stream 326 enters the secondary pyrolysis chamber 310 through the secondary chamber inlet 312. A secondary chamber product stream 314 is output from the secondary pyrolysis chamber 310 through the secondary chamber outlet 313. The secondary chamber product stream 314 is the product of pyrolysis of the primary chamber product stream 305 in the secondary pyrolysis chamber 310. The secondary chamber product stream 314 may comprise one or more of solids, liquid and gases. In this example, the secondary product stream 314 comprises gas and liquid.

The apparatus may include a second filter. In this example, the apparatus 300 includes a ceramic filter 330. A ceramic filter such as the ceramic filter 330 uses the method of filtration to remove fine particulates from a gas or liquid stream. In this example, the ceramic filter 330 is arranged to remove fine particulates from the secondary chamber product stream 314. The ceramic filter 330 may remove substantially all of the fine particulates from the secondary chamber product stream 314. The ceramic filter 330 may operate at around 300°C.

The ceramic filter 33015econd15des a filter inlet 332, a filter outlet 333, and a filter waste outlet 334. In this example, the filter inlet 332, the filter outlet 333, and the filter waste outlet 334 are integral with the structure of the ceramic filter 330.

The secondary chamber product stream 314 enters the ceramic filter 330 through the filter inlet 332. The secondary chamber product stream 314 is transported from the secondary chamber outlet 313 of the secondary pyrolysis chamber 310 to the filter inlet 332 of the ceramic filter 330 via a pipe.

The secondary chamber product stream 314 undergoes filtration as it passes through the ceramic filter 330. A waste stream 335 removed from the secondary chamber product stream 314 is output from the ceramic filter 330 through the ceramic filter 330. The waste stream 335 may contain mostly solids and may be further processed. In one example, the waste stream 335 may include one or more of hydrogen fluoride, hydrogen chloride, and hydrogen bromide. A filtered secondary chamber product stream 336 is output from the ceramic filter 330 through the filter outlet 333. The filtered secondary chamber product stream 336 is substantially free of fine particulate matter.

The filtered secondary chamber product stream 336 is transported from the outlet 333 of the ceramic filter 330 via a pipe.

In the example of Figure 3, the apparatus 300 includes a catalyst delivery unit 338. The catalyst delivery unit 338 has a catalyst outlet 340 for outputting one or more catalysts from the catalyst delivery unit 338. The secondary pyrolysis chamber 310 has a catalyst inlet 339 for receiving one or more catalysts from the catalyst delivery unit 338.

The catalyst delivery unit 338 delivers catalyst directly to the secondary pyrolysis chamber 310. In use, the heater 306 heats the primary pyrolysis chamber 301 to a temperature of between 900°C and 950°C. The feedstock stream 304 enters the primary pyrolysis chamber 301 through the primary chamber inlet 302. At the high temperature inside the primary pyrolysis chamber 301 , the feedstock stream 304 is broken down inside the primary pyrolysis chamber 301 into components such as oils, waxes, light oils, gases and solid material. These components form the primary chamber product stream 305. The primary chamber product stream 305 leaves the primary pyrolysis chamber 301 through the primary chamber outlet 303.

The exhaust gas stream 307 absorbs waste heat from the heater 306 And flows to the heat exchanger 316.

The primary chamber product stream 305 includes longer chain hydrocarbons such as oils and waxes, as well as aromatic hydrocarbons such as naphthalene. The primary chamber product stream 305 may also include small amounts of persistent organic pollutants present in both the gas and solid phase.

The primary chamber product stream 305 enters the cyclone separator 320 through the cyclone inlet 322. Inside the cyclone separator 320, particulates such as char are removed from the primary chamber product stream 305. The particulates leave the cyclone separator 320 through the cyclone outlet 324 as a waste stream 325. The separated primary chamber product stream 326 leaves the cyclone separator 320 through the cyclone outlet 323. At this stage, the separated primary chamber product stream 320 is substantially free from particulates.

The heat exchanger 316 is heated by the exhaust gas stream 307. In this way, the heat exchanger 316 is indirectly heated by the heater 306. In this example, the heat exchanger 316 provides sufficient heat to increase the temperature of the secondary pyrolysis chamber 310 to between 500°C and 700°C. In another example, the secondary pyrolysis chamber 310 includes a supplementary heater. The temperature to which the secondary pyrolysis chamber 310 is heated is dependent on type or species of the one or more catalysts being delivered by the catalyst delivery unit 338 so that the temperature of the secondary pyrolysis chamber 310 is within the activation range of the one or more catalysts.

In this example, the secondary pyrolysis chamber 310 is operated at a lower temperature than the primary pyrolysis chamber 301 .

The separated primary chamber product stream 326 enters the secondary pyrolysis chamber 310 through the secondary chamber inlet 312. Inside the secondary pyrolysis chamber 310, the primary product stream 305 encounters the one or more catalysts At the temperature inside the secondary pyrolysis chamber 310, and due to the activity of the one or more catalysts, the separated primary chamber product stream 326 is further broken down inside the secondary pyrolysis chamber 310 into components such as light oils and gases. Further breaking down the primary chamber product stream 305 may facilitate the removal of persistent organic pollutants and metallic organics from the primary chamber product stream 305. The resulting components form the secondary chamber product stream 314. The secondary chamber product stream 314 leaves the secondary pyrolysis chamber 310 through the secondary chamber outlet 313.

Pyrolysis of the separated primary chamber product stream 326 within the secondary pyrolysis chamber 310 breaks the longer chain and cyclic hydrocarbons, such as heavy oils, waxes and tars, into shorter chain hydrocarbons, such as light oils and gases. This may increase the quantity of, for example, C1 - C4 hydrocarbon gases and C2 - C6 hydrocarbon gases. In addition, presence of the one or more catalysts provides a higher degree of chain scission which assists in breaking down the persistent organic material within the solid and gas phases. One advantage of a product stream that includes a higher proportion of shorter chain hydrocarbons is that the product stream is deemed as higher quality because of its higher calorific values. In one example, the secondary chamber product stream 314 is processed into syngas, for use as a fuel.

The higher temperature within the secondary pyrolysis chamber 310, the addition of the one or more catalysts, and the overall increased residence time ultimately experienced by the feedstock stream 304, may break down persistent organic pollutants in the separated primary chamber product stream 326 into non-hazardous compounds. In some examples, the amount of persistent organic pollutants in the secondary chamber product stream 314 is substantially reduced compared to the primary chamber product stream 305. In some examples, persistent organic pollutants are completely eliminated from the secondary chamber product stream 314.

The secondary chamber product stream 314 enters the ceramic filter 330 through the filter inlet 332. Inside the ceramic filter 330, fine particulates such as entrained carbonaceous material are removed from the secondary chamber product stream 314. The fine particulates leave the ceramic filter 330 through the filter outlet 333 as a waste stream 335. The filtered secondary chamber product stream 336 leaves the ceramic filter 330 through the filter outlet 333. At this stage, filtered secondary chamber product stream 336 is substantially free from fine particulates.

If particulate matter such as char is present within a pyrolysis chamber then it may act as a catalyst point for the formation of persistent organic pollutants. Removal of particulate matter such as char from the primary chamber product stream 305 before it is fed into the secondary pyrolysis chamber 310 may therefore reduce the formation of persistent organic pollutants inside the secondary pyrolysis chamber 310. As such, the provision of a cyclone separator may advantageously reduce the amount of persistent organic pollutants formed within the secondary pyrolysis chamber 310.

Advantageously, extracting solid residues from the primary chamber product stream 305 before it is fed into the secondary pyrolysis chamber 310 may help to keep the secondary pyrolysis chamber 310 residue free, which may help to improve the efficiency of the secondary pyrolysis chamber 310.

Pyrolysis of the separated primary chamber product stream 326 within the secondary pyrolysis chamber 310 breaks the longer chain hydrocarbons and cyclic hydrocarbons, such as heavy oils, waxes and tars, into shorter chain hydrocarbons, such as light oils and gases. This may increase the quantity of, for example, Ci - C4 hydrocarbon gases and C2 - Ce hydrocarbon gases. One advantage of a product stream that includes a higher proportion of shorter chain hydrocarbons is that the product stream is deemed as higher quality because of its higher calorific values. In one example, the secondary chamber product stream 314 is processed into syngas, for use as a fuel. This may reduce the amount of persistent organic pollutants present in the gas.

The high temperature within the secondary pyrolysis chamber 310, and the overall increased residence time ultimately experienced by the feedstock stream 304, may break down persistent organic pollutants in the separated primary chamber product stream 326 into non-hazardous compounds. In some examples, the amount of persistent organic pollutants in the secondary chamber product stream 314 is substantially reduced compared to the separated primary chamber product stream 326. In some examples, persistent organic pollutants are completely eliminated from the secondary chamber product stream 314.

Advantageously, any organic material attached to lighter solids in the separated primary product stream 326 may be volatilised inside the secondary pyrolysis chamber 310. The organic material may be broken down after interacting with the one or more catalysts.

The ceramic filter 330 removes entrained fine particulate matter that may remain in the secondary chamber product stream 314 after pyrolysis, such as volatilised organic material. Advantageously, removal of fine particulate matter from the secondary chamber product stream 314 may provide a higher quality product stream. Advantageously, removal of fine particulate matter from the secondary chamber product stream 314 may increase the overall efficiency of the apparatus 300.

Table 1

Table 1 shows the concentration of carbon©), hydrogen (H2), nitrogen (N2), sulphur (S) and chlorine (Cl) in the solid residue removed by the cyclone separator 320 and the ceramic filter 330. The “Cyclone waste stream” in Table 1 is the waste stream 325 of the cyclone separator 320. The “Ceramic Filter waste stream” in Table 1 is the waste stream 335 of the ceramic filter 330.

As is shown in Table 1 , there is more hydrogen in the ceramic filter waste stream 330 than in the cyclone separate waste stream 320. This may mean that there is more hydrogen present in the secondary chamber product stream 314 than in the primary chamber product stream 305. The presence of an increased amount of hydrogen in the secondary chamber product chamber 314 may indicate that long chain molecules in the primary chamber product stream have undergone further decomposition into short chain molecules. The long chain molecules may have undergone further decomposition into short chain molecules due to the secondary pyrolysis as well as the presence of the one or more catalysts.

As is also shown in Table 1 , there is less sulphur (S) and chlorine (Cl) in the ceramic filter waste stream 330 than in the cyclone separate waste stream 320.

Table 2

Table 2 shows the concentration of carbon monoxide (CO), methane (CH4), ethane (C2H6), hydrogen (H2) and hydrogen sulphide (H2S) in the primary chamber product stream 305 and in the secondary chamber product stream 314. As is shown in Table 2, the concentration of carbon monoxide (CO), methane (CH4), ethane (C2H6) and hydrogen (H2) is much higher in the secondary chamber product stream 314 than in the primary chamber product stream 305. This is because pyrolysis within the secondary pyrolysis chamber 310 breaks longer chain hydrocarbons into shorter chain hydrocarbons, such as light oils and gases, which increases the quantity of shorter chain hydrocarbons. One advantage of a product stream that includes a higher proportion of shorter chain hydrocarbons is that the product stream is deemed as higher quality fuel because of its higher calorific values.

As is also shown in Table 2, the concentration of hydrogen sulphide (H2S) is much lower in the secondary chamber product stream 314 than in the primary chamber product stream 305. This is because the high temperature within the secondary pyrolysis chamber 310, and the overall increased residence time ultimately experienced by the feedstock stream 304, breaks down pollutants such as hydrogen sulphide into non-hazardous compounds.

Table 3

Table 3 shows the concentration of nitrogen (N), car© (C), hydrogen (H), oxygen (O) and sulphur (S) in char collected from the secondary pyrolysis chamber 210, when different catalysts (3A, 4A and AL-MCM-41) are delivered to the secondary pyrolysis chamber 310.

The catalyst 3A is a molecular sieve having the formula Nai2[(AIO2)i2(SiC>2)i2] ■ XH2O. The catalyst 3A has a Chemical Abstracts Service number of 308080-99-1 and was obtained from Sigma-Aldrich, Germany.

The catalyst 4A is a molecular sieve having the formula K _n Nai2-n[(AIC>2)i2(SiO2)i2] ■ XH2O. The catalyst 4A has a Chemical Abstracts Service number of 70955-01-0 and was obtained from Sigma-Aldrich, Germany.

The catalyst AL-MCM-41 has the formula (SiO2)i(Al2Os)25. The catalyst AL-MCM-41 has a Chemical Abstracts Service number of 1318-02-1 and was obtained from ACS Material, California, USA.

Advantageously, as is shown in Table 3, with the addition of a catalyst into the secondary pyrolysis chamber 310, sulphur is substantially removed from the char. The temperature inside the secondary pyrolysis chamber 310, combined with the activity of the catalyst, breaks down pollutants such as hydrogen sulphide into non-hazardous compounds. Figures 4, 5, 6 and 7 shows Fourier Transform Infrared Spectroscopy analysis of oil condensed from the secondary chamber product stream 314.

Figure 4 shows a graph of Fourier Transform Infrared Spectroscopy analysis of the secondary chamber product stream 314 when no catalyst was delivered to the secondary pyrolysis chamber 310.

Figure 5 shows a graph of Fourier Transform Infrared Spectroscopy analysis of the secondary chamber product stream 314 when a catalyst was delivered to the secondary pyrolysis chamber 310. In this example, the catalyst is a molecular sieve 3A having the formula Nai2[(AIO2)i2(SiC>2)i2] ■ XH2O. The catalyst has a Chemical Abstracts Service number of 308080-99-1 and was obtained from Sigma-Aldrich, Germany.

Figure 6 shows a graph of Fourier Transform Infrared Spectroscopy analysis of the secondary chamber product stream 314 when a catalyst was delivered to the secondary pyrolysis chamber 310. In this example, the catalyst is a molecular sieve 4A having the formula K _n Nai2-n[(AIC>2)i2(SiO2)i2] ■ XH2O. The catalyst has a Chemical Abstracts Service number of 70955-01-0 and was obtained from Sigma-Aldrich, Germany.

Figure 7 shows a graph of Fourier Transform Infrared Spectroscopy analysis of the secondary chamber product stream 314 when a third catalyst was delivered to the secondary pyrolysis chamber 310. In this example, the catalyst is AL-MCM-41 having the formula (SiO ₂ )i(AI ₂ O ₃ )25. The catalyst has a Chemical Abstracts Service number of 1318-02-1 and was obtained from ACS Material, California, USA.

Oxygen retained in the secondary chamber product stream 310 may reduce it heating value and prevent it from being used effectively as a fuel for transportation purposes and within industry. Oxygen is generally retained within hydrocarbon chains as an O-H group connected to a C bond. As is shown in Figures 5, 6 and 7 when compared to Figure 4, when the catalyst is delivered to the secondary pyrolysis chamber 310, the secondary chamber product stream 314 has a lower presence of O-H bonding, indicating that the oxygen content within the oil has been reduced. Reducing the oxygen content in the oil may increase the heating value of the oil.

The examples described above are not intended to limit the scope of the claims. Other examples consistent with the exemplary examples described above will be apparent to those skilled in the art. Features described in relation to one example may also be applicable to other examples.