Methods for producing high value chemicals from feedstocks

Abstract

A method for producing high value chemicals from a feedstock, the feedstock being or comprising a waste material. A flow reactor system is provided comprising a pyrolysis chamber (2) and a combustion chamber (12). The feedstock is introduced into the pyrolysis chamber and a pyrolysis process is carried out at a temperature in the range of 650-850°C to obtain a product gas comprising the high value chemicals.

Description

[Technical field]

[0001] The present invention relates to an improved process for producing high value chemicals from feedstocks. In particular, the present invention relates to an improved process for producing high value chemicals from waste materials. In particular, the improved process increases the yield of olefins, monocyclic aromatics, or combinations thereof, reduces side reactions, and reduces the amount of contaminants present in the product gas. [Background technology]

[0002] WO 2003 / 018723 discloses a method and an apparatus for cleaning the synthesis gas obtained during the gasification of biomass. The synthesis gas is passed through a saturator and an absorber, both of which are fed with oil. The oil is used as a washing agent to remove tars from the synthesis gas.

[0003] WO 2018 / 208163 discloses a method and apparatus for removing monocyclic aromatic compounds from a gas. The gas is contacted with a scrubbing liquid to obtain a purified gas and a spent scrubbing liquid containing dissolved monocyclic aromatic compounds. The spent scrubbing liquid is stripped with steam and the monocyclic aromatic compounds are separated by condensation and further decantation.

[0004] US 2020 / 0362248 discloses a method and apparatus for producing olefins and aromatics by catalytic pyrolysis of polymers. An exothermic additive is used to provide sufficient heat during catalyst regeneration.

[0005] US Patent No. 10,093,860 discloses a method and apparatus for treating waste, including mixed plastic waste, which includes feeding the waste to a pyrolysis reactor to produce fuel, and using the fuel to run a generator to produce electricity.

[0006] WO 2008 / 108644 and WO 2014 / 070001 disclose an apparatus for producing product gas from biomass. The fuel (e.g., biomass) fed to a riser in a reactor typically contains 80% by weight of volatile components and 20% by weight of substantially solid carbon or char. When the biomass fed to the riser is heated to a temperature above 800° C., for example between 850 and 900° C., in a low-oxygen or oxygen-free environment, the biomass is pyrolyzed and product gas is produced. The solid carbon and char only undergo pyrolysis to a limited extent, and therefore it is necessary to combust this material in a separate combustion zone of the reactor. Summary of the Invention [Problem to be solved by the invention]

[0007] It is therefore an aim of aspects of the present invention to address one or more of the above or other problems. [Means for solving the problem]

[0008] In one aspect, the present invention relates to a method for producing high value chemicals from a feedstock, wherein the feedstock is or comprises a waste material, comprising: (a) providing a flow reactor system comprising a pyrolysis chamber and a combustion chamber; and (b) charging the feedstock into the pyrolysis chamber and carrying out a pyrolysis process at a temperature in the range of 650-850° C. to obtain a product gas comprising the high value chemicals.

[0009] Moreover, all defined features relating to the method according to the invention apply equally to the use according to the invention and vice versa.

[0010] The method according to the invention allows waste materials to be pyrolyzed at sufficiently low temperatures to obtain optimized yields of high value chemicals and reduce by-products. A further advantage of the method is that the feedstock can be a mixture of biomass and plastics and is therefore cheap, e.g. the feedstock does not need to be extensively separated before use.

[0011] The waste material may be municipal solid waste.

[0012] The waste materials are preferably biomass, biomass-rich refuse-derived fuel, plastic-rich refuse-derived fuel, and plastics, or combinations thereof. Biomass may be nearly 100% biogenic, biomass-rich refuse-derived fuel is typically 50-70% biogenic, plastic-rich refuse-derived fuel is typically 50-75% non-biogenic, and plastic is typically 75-100% non-biogenic.

[0013] The waste material preferably comprises plastic material. The waste material may comprise 30-100% plastic based on the weight of the waste material. By way of example, waste-derived fuel may comprise 50-80% plastic based on the weight of the total waste-derived fuel. As the amount of plastic in the waste material increases, this in turn increases the amount of high value chemicals such as olefins.

[0014] The anthropogenic carbon present in the waste material may represent 40-100% by weight of the waste material, preferably 60-90%.

[0015] The waste material may have a moisture content of 5-30% by weight, preferably 10-25%, based on the weight of the waste material. This moisture content facilitates feeding of the plastics into the pyrolysis chamber. If waste material is provided with a moisture content of more than 30%, the operating temperature of the combustion chamber will be reduced to an ineffective level.

[0016] Preferably, the high value chemicals in the product gas are olefins and / or monocyclic aromatic compounds. The olefins are ethylene, propylene, C 4 Olefin, C 5 Olefin, C 5+ olefins, or combinations thereof. Preferably, the olefins are ethylene, propylene, C 4 Olefin, C 5 Even more preferably, the olefin is ethylene, propylene, C 4 The monocyclic aromatic compound may be benzene, toluene, styrene, ethylbenzene, xylene, or a combination thereof. In particular, the monocyclic aromatic compound may be benzene, toluene, styrene, ethylbenzene, m-xylene, p-xylene, or a combination thereof. Preferably, the monocyclic aromatic compound is benzene, toluene, xylene, styrene, or a combination thereof.

[0017] In a preferred embodiment, the olefin is ethylene, propylene, C 4 Olefin, C 5 More preferably, the olefin is ethylene, propylene, C 4 or a combination thereof, and / or the monocyclic aromatic compound is benzene, toluene, xylene, or a combination thereof. Even more preferably, the olefin is ethylene, propylene, or a combination thereof, and / or the monocyclic aromatic compound is benzene, toluene, xylene, or a combination thereof.

[0018] The product gas may contain 30-70%, preferably 45-60%, olefins based on the weight of the product gas. The product gas may contain 5-25%, preferably 10-20%, and even more preferably 12-18%, monocyclic aromatic compounds based on the weight of the product gas.

[0019] The method may further comprise circulating the bed material from the combustion chamber to the pyrolysis chamber through a transport zone and carrying out the pyrolysis and combustion processes in the bed material, where the circulation of the bed material transfers sufficient heat from the combustion chamber to the pyrolysis chamber to carry out the pyrolysis process. This allows the heat generated in the combustion chamber to be transferred to the pyrolysis chamber through the circulation of the bed material. The bed material is preferably continuously circulated from the combustion chamber to the pyrolysis chamber through a closed system or loop. In other words, the bed material is preferably continuously circulated through a closed loop between the combustion chamber and the pyrolysis chamber.

[0020] By reducing the circulation rate of the bed material, the temperature difference between the combustion chamber and the pyrolysis chamber can be increased. This allows for a higher combustion temperature, thereby allowing a lower temperature to be maintained in the pyrolysis chamber. An additional advantage is that excessive decomposition of the polymer is prevented or minimized, thereby increasing the yield of monomer product. Increasing the circulation rate can also prevent or minimize side reactions. The circulation rate of the bed material can be 10 to 100 kg of circulating bed material per kg of feed, more preferably 20 to 60 kg per kg.

[0021] By increasing the circulation rate of the bed material, the temperature difference between the combustion chamber and the pyrolysis chamber can be reduced. This allows a higher temperature to be achieved in the pyrolysis chamber. The circulation rate of the bed material can be 10-100 kg of circulating bed material per kg of feedstock, more preferably 20-60 kg per kg.

[0022] Furthermore, by adding heat directly through the hot bed material, the feedstock is exposed to a substantially uniform temperature in the pyrolysis chamber, since all or substantially all of the heat for the pyrolysis process is obtained by the bed material. In contrast, conventional heating techniques, in which heat is added indirectly through the walls of the pyrolysis reactor vessel or through internal heat tubes, result in temperature hot spots and high surface temperatures. These temperature hot spots and high surface temperatures result in excessive cracking of the feedstock. For example, the temperature at or near the chamber walls of a conventional naphtha cracker can easily be 200° C. higher than the temperature required for cracking naphtha and naphtha gas. Thus, by adding heat through the bed material, side reactions are prevented or minimized, thus increasing the yield of high-value chemicals.

[0023] The bed material is preferably a sand, such as crystalline quartz sand. Alternatively, the bed material may be olivine or dolomite. Olivine and dolomite can exhibit catalytic activity. The high temperature bed material may also include further components. To avoid particle agglomeration, clay material may be added to the bed material. Typically, high porosity clay minerals are used, such as halloysite, kaolinite, sepiolite, or combinations thereof.

[0024] The pyrolysis process can be carried out at a temperature in the range of 700-800° C., preferably in the range of 730-770° C. Carrying out the pyrolysis process between 730-770° C. results in a high amount of olefins and a reduced amount of heavy hydrocarbon fractions, such as heavy tar fractions. The temperature of the pyrolysis process is also selected based on the type of feedstock used, i.e., the temperature at which the polymer depolymerizes.

[0025] In the combustion chamber, the combustion process is carried out at a higher temperature than the pyrolysis process. In the combustion chamber, the combustion process can be carried out at a temperature in the range of 30-130 ° C higher than the pyrolysis process, preferably at a temperature in the range of 50-110 ° C higher than the pyrolysis process. For example, the pyrolysis process is carried out at a temperature in the range of 650-800 ° C and the combustion process is carried out at a temperature in the range of 30-130 ° C higher than the pyrolysis process. As a further example, the pyrolysis process is carried out at a temperature in the range of 730-770 ° C and the combustion process is carried out at a temperature in the range of 50-110 ° C higher than the pyrolysis process.

[0026] The method may further comprise (c) transferring the product gas into a product recovery unit and isolating high value chemicals. Preferably, the method further comprises transferring the product gas from the pyrolysis chamber to a tar removal system prior to performing step (c) to remove one or more tar fractions from the product gas.

[0027] The tar removal system can include an absorption unit for removing light hydrocarbon fractions, such as light tar fractions, from the product gas. A portion of the light hydrocarbon / tar fraction can be transferred to a combustion chamber. The tar removal system can include a quench unit for removing heavy hydrocarbon / tar fractions, such as heavy tar fractions, from the product gas.

[0028] The product gas is preferably quenched by a quenching medium, typically oil, at a temperature in the range of 50-95° C., preferably 60-90° C., more preferably 60-85° C. In one embodiment, the quenching is carried out at such temperature and at a pressure in the range of 0.8-2.0 bar, preferably at a pressure in the range of 1.0-1.5 bar.

[0029] In a preferred embodiment, the product gas is quenched by a quenching medium, typically oil, at a temperature in the range of 50-95° C. (at atmospheric pressure, i.e. at 1 bar), preferably 60-90° C. (at atmospheric pressure, i.e. at 1 bar), more preferably 60-85° C. (at atmospheric pressure, i.e. at 1 bar). In another embodiment, the product gas is quenched by a quenching medium, typically oil, at a temperature in the range of 55-95° C. (at 1.3 bar), preferably 65-85° C. (at 1.3 bar).

[0030] The quench medium typically cools the product gas to a water dew point temperature which is typically in the range of 50-95°C, preferably 60-90°C, more preferably 60-85°C. As the skilled person will appreciate, the water dew point temperature may vary depending on the pressure. Preferably, the pressure in this situation is in the range of 0.8-2.0 bar, more preferably 1.0-1.5 bar. In a preferred embodiment, the quench medium is used to cool the product gas to a water dew point temperature of 50-95°C (atm), preferably 60-90°C (at atmospheric pressure, i.e. at 1 bar), more preferably 60-85°C (atmospheric pressure, i.e. at 1 bar). In another embodiment, the quench medium is used to cool the product gas to a water dew point temperature of 55-95°C (at 1.3 bar), preferably 65-85°C (at 1.3 bar).

[0031] Quenching is accomplished by contacting the product gas with a quench medium, during which compounds may be removed from the product gas and dissolved in the quench medium, which may increase the viscosity of the quench medium. The quench medium after quenching is sometimes referred to as spent quench medium.

[0032] The spent quench medium obtained after quenching can have a viscosity in the range of 40-200 cP, preferably 80-160 cP, such a viscosity is ideal for the reuse of the quench medium, since any compounds that dissolve during quenching are easily removed from the spent quench medium.

[0033] Those skilled in the art can determine the appropriate method for measuring viscosity, either online or offline. In the context of the present invention, viscosity measurements are performed offline with the sample via torque measurements on a Brookfield Ametek rheometer analytical instrument (measured in units of centipoise, cP) at a temperature range of 50-95° C. Typically, the viscosity is measured at the temperature and pressure at which the quench is performed.

[0034] A portion of the heavy hydrocarbon / tar fraction can be transferred to a combustion chamber so that the heavy hydrocarbon / tar fraction is used as the primary energy source during the pyrolysis process. This advantageously prevents or limits the need to rely on external energy sources such as natural gas. Preferably, the tar removal system includes an absorption unit and a quenching unit. The quenching unit can also be used to remove particulates. An additional advantage of carrying out the pyrolysis reaction at a temperature of 700-800°C is that a sufficient amount of heavy tar is produced to maintain a suitable oil viscosity.

[0035] Tar of classes 1 to 5 is defined by the number of aromatic rings present in the tar, with class 1 tar consisting of compounds having one aromatic ring, class 2 tar consisting of compounds having two aromatic rings, class 3 tar consisting of compounds having three aromatic rings, class 4 tar consisting of compounds having four aromatic rings, and class 5 tar consisting of compounds having five or more aromatic rings. For example, naphthalene and fluorene contain two aromatic rings (benzene rings), so both are class 2 tars.

[0036] Tas classes 1 and 2 are typically considered light tars, while tar classes 4 and 5 are considered heavy tars. Class 3 tars can be considered light or heavy tars. The light Class 3 tar fraction is the tar fraction that is non-condensable in the tar removal system, and the heavy Class 3 tar fraction is the tar fraction that is condensable in the tar removal system.

[0037] Class 1 (i.e. benzene to cresols) has a viscosity of 0-30 cP; Class 2 (i.e. naphthalene to fluorene) has a viscosity of 10-20 cP; Class 3 (i.e. phenanthrene to pyrene) has a viscosity of 30-90 cP; Class 4 (i.e. benzoanthracene to benzofluoranthene) has a viscosity of 75-285 cP; and Class 5 (i.e. benzopyrene to coronene) has a viscosity of 285-715 cP. By carrying out the pyrolysis reaction at a temperature of 700-800°C, a sufficient amount of Class 3-5 tars is collected to ensure that a suitable tar:dust is obtained. Preferably, more Class 3-4 tars are collected than Class 5 tars so that the viscosity does not become too high. The term light hydrocarbons / tars can be used to include methane and olefins, and / or tars defined in Classes 1, 2, and 3 (Class 3 light tars). The term heavy hydrocarbons / tars may be used to include tars defined in Classes 3 (Class 3 heavy tars), 4, and 5.

[0038] Heavy tars are typically tars that condense when the product gas is cooled from the temperature at which the pyrolysis process takes place to a temperature near the water dew point of the product gas. This typically occurs during the tar removal step. Light tars remain gaseous at these conditions.

[0039] Preferably, the method further comprises transferring the product gas from the pyrolysis chamber to a tar removal system to remove one or more tar fractions from the product gas, where typically heavy tars are removed from the product gas.

[0040] The product gas transferred to the tar removal system preferably contains heavy tar fractions of classes 3-5, with the content of classes 3-4 being greater than the content of class 5, based on the weight of all the heavy tar fractions of classes 3-5.

[0041] The product gas transferred to the tar removal system preferably comprises, based on the weight of all Class 3-5 heavy tar fractions: (i) 50-80% Class 3 heavy tar, (ii) 10-40% Class 4 heavy tar, and (iii) 10% or less Class 5 heavy tar. Or in other words, the product gas transferred to the tar removal system preferably comprises, based on the weight of all Class 3-5 heavy tar fractions, 50-80% Class 3 heavy tar, based on the weight of all Class 3-5 heavy tar fractions, 10-40% Class 4 heavy tar, based on the weight of all Class 3-5 heavy tar fractions, and 10% or less Class 5 heavy tar, based on the weight of all Class 3-5 heavy tar fractions.

[0042] The product gas transferred to the tar removal system is preferably 20 to 30 g / Nm 3 It contains heavy tar of classes 3 to 5.

[0043] The product gas passing to the tar removal system preferably contains a ratio of dust to heavy class 3-5 tars of 1:99 to 10:90.

[0044] The product gas transferred to the tar removal system is preferably 0 to 2 g / Nm 3 Includes dust.

[0045] The gas may also be transferred into a particulate removal unit (such as a cyclone) prior to being transferred to the tar removal system. The tar removal system may include an absorption unit for removing light hydrocarbons / tar fractions, such as light tar fractions, from the product gas. Preferably, the tar removal system may include an absorption unit for removing light hydrocarbons / tar fractions, such as light tar fractions and dust, from the product gas.

[0046] The absorption unit preferably includes an absorber tower and a stripper tower that communicate with each other so that the washing agent flows continuously between the towers. Washing can be performed in either a cocurrent or countercurrent manner to remove impurities such as tar from the gas. The washing agent can be a mineral oil or a synthetic oil, such as a paraffinic oil or an organoaryl polysiloxane oil, preferably an organoaryl polysiloxane oil.

[0047] The stripping agent used in the stripper tower may be hot air, steam, nitrogen, carbon dioxide, boiler flue gas or mixtures thereof, preferably hot air. The flow rate of hot air into the stripper tower may be 50-200%, preferably 100-200%, of the product gas flow. These flow rates have the advantage that, when using air, the risk of operating above the maximum permissible level of tars at the explosion limit in the stripper gas is reduced. The stripping agent may be combustion air for the combustion chamber. The stripping tower and stripping agent allow the wash agent to be reused in the absorption tower.

[0048] The quench unit preferably includes a quench tower adapted to receive the product gas from the pyrolysis chamber. Optionally, the quench unit may include a wet electrostatic precipitator connected to the quench tower. The wet electrostatic precipitator is adapted to remove aerosols from the product gas.

[0049] The fluidizing gas can be moved into the transport zone to control the circulation rate of the bed material. The fluidizing gas can be moved into the transport zone in more than one region. The temperature difference between the combustion chamber and the pyrolysis chamber is increased or decreased by varying the ratio of the fluidizing gas moved into the first region of the transport zone, preferably to the second region of the transport zone. In a preferred embodiment, the transport zone includes a first region that allows the downflow of the bed material from the combustion chamber and a second region that allows the upflow of the bed material into the pyrolysis chamber. The fluidizing gas can be moved into the upstream portion of the second region and into the downstream portion of the second region. The terms upstream portion and downstream portion are used to indicate the direction of flow of the bed material through the fluidized reactor system. In other words, the bed material circulates from the first region into the upstream portion and then into the downstream portion before moving into the pyrolysis chamber. The fluidizing gas can be moved into the pyrolysis chamber to control the circulation rate of the bed material. By varying the amount of fluidization gas transferred into the transport zone and / or pyrolysis chamber, the circulation rate of the bed material may be increased or decreased. The advantages associated with increasing and decreasing the circulation rate of the bed material are as discussed above. By varying the amount of fluidization gas transferred into two or more regions of the transport zone, the circulation rate of the bed material may be increased or decreased. Thus, by varying the amount of fluidization gas as described above, the circulation rate of the bed material can be increased or decreased, thereby decreasing or decreasing the temperature difference between the combustion chamber and the pyrolysis chamber. Preferably, the flusidation gas is transferred only into the second region of the transport zone, or in other words, the flusidation gas is not transferred into the first region of the transport zone.

[0050] In a preferred embodiment, the circulation rate of bed material is decreased by adding more fluidizing gas in the downstream part of the second zone than in the upstream part of the second zone, where the ratio of fluidizing gas added in the upstream part to the downstream part is 1:1-6, typically 1:1.5-4. The circulation rate of bed material is increased by adding less fluidizing gas in the downstream part of the second zone than in the upstream part of the second zone, where the ratio of fluidizing gas added in the upstream part to the downstream part is 1-6:1, typically 1.5-4:1. By redistributing the fluidizing gas such that more fluidizing gas is provided in the upstream part than in the downstream part, then the flow rate of hot bed material is increased, which results in a decrease in the temperature difference from the combustion chamber to the pyrolysis chamber. Thus, said redistribution of the fluidizing gas increases the yield of high value chemicals and reduces or prevents by-products.

[0051] In a further preferred embodiment, the circulation rate of the bed material is decreased by adding more fluidizing gas in the downstream part of the second zone and / or in the pyrolysis chamber than in the upstream part of the second zone, where the ratio of fluidizing gas added to the upstream part and / or in the pyrolysis chamber to the downstream part is 1:1-6, typically 1:1.5-4. The circulation rate of the bed material is increased by adding less fluidizing gas in the downstream part of the second zone and / or in the pyrolysis chamber than in the upstream part of the second zone, where the ratio of fluidizing gas added to the upstream part to the downstream part 35 and / or in the pyrolysis chamber is 1-6:1, typically 1.5-4:1.

[0052] The fluidizing gas can also be moved into the first region. This promotes circulation of bed material into the pyrolysis chamber. A further advantage is that this prevents or reduces the flow of flue gas into the pyrolysis chamber. The flue gas is O 2 and NO x This is important because the water may contain contaminants such as

[0053] Thus, the fluidized reactor system can add different amounts of fluidizing gas to the transport zone and / or pyrolysis chamber, thereby controlling the transport rate during operation. A further advantage of providing two or more zones for adding fluidizing gas is in the event that one zone becomes closed or partially closed.

[0054] Thus, the fluidized reactor system can add different amounts of fluidizing gas to the transport zone and / or pyrolysis chamber, thereby controlling the transport rate during operation. A further advantage of feeding fluidizing gas to two or more zones is that if one zone becomes closed or partially closed, the resulting reduction in transport of bed material can be overcome without reactor modification or cleaning.

[0055] The fluidizing gas can be transferred from the stripper column and / or from an external source. Preferably, the fluidizing gas to the pyrolysis chamber is from an external source and the fluidizing gas to the combustion chamber is from the stripper column. Preferably, the fluidizing gas transferred into the transport chamber and / or pyrolysis chamber is steam. These flow rates have the advantage that secondary polymerization reactions of olefins are reduced and the formation of soot and / or high molecular weight hydrocarbons / tars is avoided or limited.

[0056] The velocity of the fluidizing gas in the second region of the transport zone may be 0.5-3 m / s, preferably 1-2.5 m / s, even more preferably 2 m / s. The velocity of the fluidizing gas in the upstream and / or downstream parts of the second region of the transport zone may be 0.5-3 m / s, preferably 1-2.5 m / s, even more preferably 2 m / s. This velocity range allows the bed material to move by actually fluidizing the bed material.

[0057] The velocity of the fluidizing gas in the pyrolysis chamber may be 5-8.5 m / s, preferably 5.5-7.5 m / s. These velocity ranges allow transport of bed material through the pyrolysis chamber. An additional advantage of these velocity ranges is that they allow bed material to be discharged from the pyrolysis chamber and circulated into the combustion chamber.

[0058] The velocity of the fluidizing gas is determined by the density of the fluidizing gas and the particle size of the bed material. Generally, the particle size has a greater effect on the required viscosity of the fluidizing gas.

[0059] The bed material may have a dp50 of 240-280 μm, preferably 260 μm. The average particle size is determined using laser diffraction particle size analysis, for example using a Malvern Mastersizer.

[0060] The density of the fluidizing gas in the transport zone is 0.9-1.1 kg / Nm 3 , preferably 1.0 kg / Nm 3 The density of the fluidizing gas in the upstream and / or downstream portions of the second region of the transport zone may be between 0.9 and 1.1 kg / Nm 3 , preferably 1.0 kg / Nm 3 The density of the fluidized bed material in the transport zone may be 900 to 1100 kg / m 3 , preferably 1000 kg / m 3 The density of the fluidized bed material in the upstream and / or downstream portion of the second region of the transport zone may be between 900 and 1100 kg / m 3 , preferably 1000 kg / m 3 It may be.

[0061] In one embodiment, the velocity of the fluidizing gas in the upstream and / or downstream portion of the second region of the transport zone may be from 0.5 to 3 m / s, preferably from 1 to 2.5 m / s, even more preferably from 2 m / s; the bed material has a dp50 of from 240 to 280 μm, preferably from 260 μm; the density of the fluidizing gas in the upstream and / or downstream portion of the second region of the transport zone may be from 0.9 to 1.1 kg / Nm 3, preferably 1.0 kg / Nm 3 It may be.

[0062] The velocity of the bed material in the first zone may be between 0.05 and 0.15 m / s, preferably 0.1 m / s. The density of the bed material is between 1440 and 1760 kg / m 3 , preferably 1600 kg / m 3 It may be.

[0063] In the upper (downstream) and / or lower (upstream) part of the pyrolysis chamber, the velocity of the fluidizing gas may be 5-8.5 m / s, preferably 5.5-7.5 m / s. The density of the fluidized bed material in the upper and / or lower part of the pyrolysis chamber is 90-110 kg / m 3 , preferably 100 kg / m 3 The density of the fluidizing gas in the upper and / or lower parts of the pyrolysis chamber may be 0.9 to 1.1 kg / Nm 3 , preferably 1.0 kg / Nm 3 It may be.

[0064] When used or transferred to a portion of a fluidized reactor system where a gas or energy source is not used as a fluidizing agent, for example when a fluidizing agent is transferred from a product recovery unit to a combustion chamber, the fluidizing gas may be appropriately referred to as a non-condensable gas, combustion air, or energy source. The energy source may be a gas, liquid, or solid. Non-condensable gases include CO, H 2 , C.H. 4 , N 2 Part of C 2 and / or C. 3The non-condensable gas may be a fuel gas. The energy source may include fossil fuels, solid biomass, waste feedstock, hydrocarbon condensate from a product recovery unit, or a combination thereof. Preferably, the fluidization gas is a gas or steam generated from the product gas of the pyrolysis process. More preferably, the fluidization gas is steam. Even more preferably, the flusidation gas for the transport zone is steam. When the fluidization gas is generated from the product gas, the following steps can be used: the product gas generated in the pyrolysis chamber can be transferred to the product recovery unit, and the separated fluidization gas can be recycled into the pyrolysis chamber and / or transferred to the transport zone. Preferably, the fluidization gas for the combustion chamber is air. The advantage of transferring the fluidization gas into the combustion chamber is that the fluidization gas can act as an energy source.

[0065] The method may further comprise isolating a tail gas or off-gas from the product gas. Preferably, the tail gas or off-gas is obtained after low temperature treatment. The method may also comprise transferring at least a portion of the tail gas or off-gas to a combustion chamber. Advantageously, the tail gas or off-gas may be used as an energy source for the combustion chamber. The tail gas or off-gas may also be used instead of the tar as an energy source for the combustion chamber, so that chemicals can be isolated from the tar or the tar can be used as a source for producing carbon black. The term tail gas or off-gas may be used to mean non-condensable gases. Tail gas or off-gas typically contains CO, H 2 , C.H. 4 , and between 10 and 20% CO 2 Includes CO, H 2 , C.H. 4 Typical amounts are shown in Table 1.

[0066] At least a portion of the tail gas or off-gas can be used to produce chemicals, preferably hydrogen, CO, and / or olefins. By way of example, hydrogen can be recovered from the tail gas or off-gas using a membrane. The tail gas or off-gas can also be catalytically converted to fuels such as synthetic natural gas or methanol, the latter being an option to further increase the yield of olefins using a methanol to olefins (MtO) synthesis process.

[0067] The advantage of moving a portion of the light tar fraction to the freeboard of the combustion chamber is that the operating temperature of the combustion chamber and the pyrolysis chamber is reduced. The non-condensable gas, combustion air, or energy source may also contain steam or moisture. The non-condensable gas, combustion air, or energy source may contain 5-10% steam or moisture based on the weight of the non-condensable gas, combustion air, or energy source. This amount of steam or moisture is required to strip the tar fraction from the cleaning agent in the stripping tower in a sufficient amount. A further advantage of moving the non-condensable gas, combustion air, or energy source containing 5-10% steam or moisture based on the weight of the non-condensable gas, combustion air, or energy source into the combustion chamber is that the operating temperature of the pyrolysis chamber is reduced.

[0068] The fluidizing gas transported into the combustion chamber for fluidization may be fuel air derived, for example, via an absorption unit, in particular from a stripper column. Alternatively or additionally, the fluidizing gas may be transferred into the combustion chamber from a product recovery unit and / or an external source.

[0069] The feedstock may contain 5-30%, preferably 5-15%, even more preferably 5-10% water, derived from waste materials and / or added separately to the feedstock. If the waste materials contain insufficient water, water can be added separately to the feedstock to reach a water amount of 5-30%.

[0070] Preferably, waste water from the product recovery unit is transferred into the combustion chamber. The amount of water used may be determined by the amount of plastic in the feedstock. An advantage associated with feeding a feedstock with the stated moisture content is that the operating temperature of the feed screw is maintained at an appropriate level to avoid decomposition of the waste material within the feed screw.

[0071] Preferably, the method further comprises transferring the fraction produced by the pyrolysis process into a combustion chamber and carrying out a combustion process in the bed material to obtain flue gas, the fraction may comprise unconverted char.

[0072] The method may further include transferring the flue gas to a heat recovery system.

[0073] The flow reactor system may further include a downcomer that allows the bed material to circulate from the pyrolysis chamber to the combustion chamber. The downcomer may be arranged coaxially around the pyrolysis chamber. In use, the bed material flows over the upper part of the pyrolysis chamber into the downcomer and then circulates into the combustion chamber. Thus, a layer of bed material always surrounds the pyrolysis chamber and acts as an insulating layer between the walls of the pyrolysis chamber and the downcomer. This reduces the radial transfer of heat from the combustion chamber to the pyrolysis chamber, thereby preventing the walls of the pyrolysis chamber from heating to high temperatures that may cause further decomposition.

[0074] Fluidizing gas can also be added into the downcomer, which helps prevent product gas from entering the combustion chamber through the bed material, thus increasing product gas yield.

[0075] The velocity of the flusidation gas and / or non-condensable gas / energy source is controlled by flow transmitters in the flow reactor system.

[0076] The combustion chamber may be disposed to surround at least a portion of the pyrolysis chamber. The pyrolysis chamber may be disposed centrally or substantially centrally within the combustion chamber.

[0077] The method can further include transferring the product gas from the pyrolysis chamber to a particulate removal unit (including, for example, a cyclone) prior to transfer to a product recovery unit or a tar removal system. Preferably, the method further includes transferring the product gas from the pyrolysis chamber to a particulate removal unit, such as a cyclone, prior to transfer to the tar removal system to remove dust from the product gas.

[0078] In one embodiment, the present invention relates to the use of a flow reactor system for depolymerizing a polymer into one or more monomers, the flow reactor system including a pyrolysis chamber, a combustion chamber, and a bed material circulating from the combustion chamber to the pyrolysis chamber via a transport zone.

[0079] The pyrolysis process can be carried out in a bed material at a temperature in the range of 400-750° C. to obtain a depolymerized polymer product gas containing the monomer.

[0080] By varying the ratio of fluidizing gas transferred into the first region of the transport zone to the second region of the transport zone, the temperature differential between the combustion chamber and the pyrolysis chamber can be adjusted.

[0081] By varying the circulation rate of the bed material, the temperature differential between the combustion chamber and the pyrolysis chamber can be increased or decreased. [Brief description of the drawings]

[0082] [Figure 1] FIG. 1 shows a schematic diagram of a reactor system according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0083] In one embodiment shown in the schematic diagram of FIG. 1, a fluidized reactor system for producing high value chemicals from a feedstock is provided, the feedstock being or including waste material. The waste material is biomass, biomass-rich waste-derived fuel, plastic-rich waste-derived fuel, and plastic, or a combination thereof. The reactor system includes a pyrolysis chamber 2 including a feedstock input 4 (which may include a feedstock silo), a first fluidizing gas input 6, a second fluidizing gas input 8, and a product gas output 10. A combustion chamber 12 bounded by a wall 14 at least partially surrounds the pyrolysis chamber 2 and is connected to a flue gas output 16, a first combustion air input 20, and a second combustion air gas input 18. The combustion chamber 12 is also connected to a water input 22, which is preferably wastewater from a product recovery unit 24. The product recovery unit 24 has a tail gas output 26, as well as one or more product outputs, e.g., C 2 Exit 28, C 3 Exits 30 and C 4The pyrolysis chamber 2 includes a first region 44 that allows downflow of bed material from the combustion chamber 12 and a second region 46 that allows upflow of bed material to the pyrolysis chamber 2. The second region 46 includes a downstream portion 47 and an upstream portion 48. The first region 44 is connected to a third fluidization gas input 50 for supplying fluidization gas to the pyrolysis chamber 2 via the transport zone 42. The pyrolysis chamber 2 is connected to the first fluidization gas input 6 via the transport zone 42. Or in other words, the first fluidization gas input 6 is connected to the upstream portion 48 of the second region 46, so that the fluidization fluid can flow into the second region 46, and the fluidization liquid moves to the pyrolysis chamber 2. The pyrolysis chamber 2 can be connected to the second fluidization gas input 8 through the transport zone 42. Or in other words, the second fluidization gas input 8 is connected to the downstream portion 47 of the second region 46, so that the fluidization fluid can flow into the second region 46, and the fluidization liquid moves to the pyrolysis chamber 2. Alternatively, the second fluidization gas input 8 can be directly connected to the pyrolysis chamber 2, so that the fluidization fluid can flow directly into the pyrolysis chamber 2. The second region 46 can be part of the pyrolysis chamber 2. The transport zone 42 is for circulating the bed material between the combustion chamber 12 and the pyrolysis chamber 2. The product gas discharge 10 can be directly connected to the tar removal system 52, which can include a quench unit 54 and / or an absorption unit 56. Alternatively, the product gas outlet 10 may be connected to a particulate removal unit 58 (such as a cyclone). The particulate removal unit 58 includes a product gas outlet 60 that is connected to the tar removal system 52.The product gas outlet 10 can be connected to a cooler 62, which in turn is connected to a particulate removal unit 58. The particulate removal unit 58 further includes an ash gas outlet 64 for transferring ash to the fluidized bed zone 34 of the combustion chamber 12. Preferably, the quench unit 54 includes a quench tower 66 adapted to receive the product gas from the pyrolysis chamber 2. The quench tower 66 includes an ash and tar outlet 68 and a quenched product gas outlet 70. The product gas outlet 70 is connected to a wet electrostatic precipitator 72. The wet electrostatic precipitator 72 includes an aerosol liquid outlet 74 connected to an oil circulation loop (not shown) of the quench tower 66, which is connected to the combustion chamber 12. The wet electrostatic precipitator 72 further includes an aerosol-free product gas outlet 76 connected to the absorption unit 56. The absorption unit 56 includes an absorber tower 78 connected to the aerosol-free product gas outlet 76 and a stripper tower 80 in communication with the absorber tower 78. The absorber 78 includes a product gas outlet 82 connected to the product recovery unit 24. The stripper column 80 includes a stripping section 84 and a degassing section 86. The stripping section 84 communicates with the first combustion air input 20 to the freeboard 38 and from the combustion air input 20 to the combustion bed. The degassing section 86 includes a degassing agent input 90 for degassing the cleaning agent. Preferably, the stripping section 84 uses air and the degassing section 86 uses steam. Alternatively, the stripper column 80 may include only a stripping section that uses steam. When only a stripping section is present, combustion air is supplied to the combustion chamber via a separate source and not by the stripper column 80.

[0084] The combustion air inputs 18 and 20 are arranged to supply a further source of combustible gas, i.e. tar from the stripper tower 80, to the combustion chamber 34 to heat the bed material and freeboard 38 of the combustion chamber 12. The combustion gas moving through the combustion air input 20 also serves as a fluidizing gas for the bed material. The flue gas discharge 16 of the combustion chamber 12 can be connected to a gas cooler 92 which in turn is connected to a gas filter 94 for removing fly ash. The gas filter 94 includes a cleaned flue gas discharge 98 and a fly ash discharge 96. The first region 44 of the transport zone 42 is adapted to extract the flue gases, particularly O2, from the circulating bed material. 2 and a steam input 100 for stripping of Nox, so that the product gas is freed of these contaminants before entering the product recovery unit 24.

[0085] In use, bed material (preferably sand such as crystalline quartz sand, or olivine or dolomite) is continuously circulated between the pyrolysis chamber 2 and the combustion chamber 12 via the downcomer 40 and the transport zone 42. The feedstock is introduced into the pyrolysis chamber 2 via the feedstock inlet 4 and the pyrolysis process is carried out in the bed material at a temperature in the range of 650-850°C to obtain a product gas containing high value chemicals and side fractions. The side fractions are transferred by the bed material (via the settling chamber 102 and the downcomer 40) from the pyrolysis chamber 2 to the combustion chamber 12 and combusted in air at a temperature 30-130°C higher than the pyrolysis process in the fluidized bed zone 34 to obtain flue gas, which is used to heat the bed material in the combustion chamber 12. The flue gas then leaves the combustion chamber 12 via the freeboard 38. The flue gas is mainly composed of N 2 , CO 2 , and H 2 O. Flue gas contains one or more of the following pollutants: CO, NO x , S.O. x, and HCl. The bed material retains the heat of the combustion process, which is used in the pyrolysis process as the bed material circulates from the combustion chamber 12 to the pyrolysis chamber 2 via the transport zone 42. Using the heat from the combustion process to pyrolyze the feedstock in the pyrolysis chamber 2 creates a temperature difference between the combustion chamber 12 and the pyrolysis chamber 2. Increasing the circulation rate of the bed material reduces the temperature difference between the combustion chamber 12 and the pyrolysis chamber 2, thereby allowing a lower temperature to be achieved in the pyrolysis chamber 2. However, the higher temperature achieved is lower than that at which excessive decomposition occurs. Reducing the circulation rate of the bed material increases the temperature difference between the combustion chamber 12 and the pyrolysis chamber 2, thereby allowing a higher combustion temperature to be obtained while maintaining a lower temperature in the pyrolysis chamber 2.

[0086] The first, second and third fluidizing gas inputs 6, 8 and 50 and the combustion air inputs 18 and 20 can advantageously be used in combination with each other or separated from each other. The first, second and third fluidizing gas inputs 6, 8 and 50 and the combustion air inputs 18 and 20 are used to control the temperature in the pyrolysis chamber 2 and the combustion chamber 12. The fluidizing gas (preferably steam) from the first, second and third fluidizing gas inputs 6, 8 and 50 is used to control the flow rate of the bed material through the transport zone 42. In particular, the velocity of the fluidizing gas in the second region 46 of the transport zone 42 may be 0.5-3 m / s, preferably 0.5-2 m / s. The velocity of the fluidizing gas in the pyrolysis chamber 2 may be 5-8.5 m / s, preferably 5.5-7.5 m / s.

[0087] The first fluidization gas input 6 moves the fluidization gas into the upstream portion 48 of the second region 46 of the transport zone 42. The second fluidization gas input 8 moves the fluidization gas into the downstream portion 47 of the second region 46 of the transport zone 42. The third fluidization gas input 50 moves the fluidization gas into the first region 44 of the transport zone 42. The fluidization gas input 20 moves the fluidization gas into the air chamber 36 of the combustion chamber 12. The bed material flows from the first region 44 to the second region 46. In the first region 44, the fluidization gas flows downward from the combustion chamber 12. In the second region 46, the fluidization gas flows upward from the combustion chamber 12 into the pyrolysis chamber 2. The fluidization gas can be moved into the pyrolysis chamber 2 to control the circulation rate of the bed material. By varying the amount of fluidizing gas transferred into the transport zone 42 and / or pyrolysis chamber 2, the circulation rate of the bed material can be increased or decreased.

[0088] The circulation rate of the bed material is decreased by adding more fluidizing gas in the downstream portion 47 of the second zone 46 than in the upstream portion 48 of the second zone 46. Here, the ratio of fluidizing gas added to the upstream portion 48 to the downstream portion 47 is 1:1-6, typically 1:1.5-4. The circulation rate of the bed material is increased by adding less fluidizing gas in the downstream portion 47 of the second zone 46 than in the upstream portion 48 of the second zone 46. Here, the ratio of fluidizing gas added to the upstream portion 48 to the downstream portion 47 is 1-6:1, typically 1.5-4:1. Alternatively, the circulation rate of the bed material is decreased by adding more fluidizing gas in the downstream portion 47 of the second zone 46 and / or the pyrolysis chamber 2 than in the upstream portion 48 of the second zone 46. Here, the ratio of fluidizing gas added to the upstream portion 48 to the downstream portion 47 and / or the pyrolysis chamber 2 is 1:1-6, typically 1:1.5-4. By adding less fluidizing gas in the downstream portion 47 of the second zone 46 and / or the pyrolysis chamber 2 than in the upstream portion 48 of the second zone 46, the circulation rate of the bed material is increased. Here, the ratio of fluidizing gas added to the upstream portion 48 to the downstream portion 47 and / or the pyrolysis chamber is 1-6:1, typically 1.5-4:1. The fluidizing gas can also be transferred into the first zone 44. Thus, the fluidized reactor system can add different amounts of fluidizing gas to the transport zone 42 and / or the pyrolysis chamber 2, thereby controlling the transfer rate during operation. Using a fluidizing gas to increase the flow rate of the hot bed material has the advantage of reducing the temperature difference between the combustion chamber 12 and the pyrolysis chamber 2. This reduction in temperature difference prevents or minimizes side reactions, thereby increasing the yield of high value chemicals.

[0089] The flow rate of the fluidizing gas may be the same for each of the first, second, and third fluidizing gas inputs 6, 8, and 50. Alternatively, the flow rate of the fluidizing gas may be different for one or more of the first, second, and third fluidizing gas inputs 6, 8, and 50. Preferably, the fluidizing gas from the first, second, and third fluidizing gas inputs 6, 8, and 50 is obtained from an external source.

[0090] The product gas (for example at a temperature of 750° C.) preferably travels from the pyrolysis chamber 2 to a gas cooler 62 via the product gas outlet 10. The product gas is then cooled (for example to a temperature of 500° C.) and then travels to a fine particle removal unit 58 to remove solid fine particles (bed material and carbon-containing ash) and subsequently to a quench tower 66. The removed solid fine particles (such as ash) in the fine particle removal unit 58 are sent to the combustion chamber 12 via an ash gas outlet 64. This is done mainly to combust the char content of the ash, resulting in a carbon-free ash, which travels from the combustion chamber 12 via the flue gas outlet 16. This reduces or eliminates the need for processing carbon-containing ash, which has high processing costs. Furthermore, this reduces the need for handling pyrophoric carbon-containing ash. The product gas is quenched in quench tower 66 using circulating oil at a temperature of 50-90°C, typically 60-90°C, and even more typically 60-80°C at atmospheric pressure, or higher if higher pressures are used. This is commonly known as "hot oil" quenching. The oil is used to cool the gas to a temperature just above the water dew point. Temperatures below 50°C are not used because the oil becomes viscous and therefore difficult to pump. The amount of oil used in quench tower 66 is adjusted so that the temperature of the oil does not exceed 200°C. The separated ash and tar from quench tower 66 is passed to combustion chamber 12 via ash and tar discharge 68. The separated ash and tar provide the energy source in combustion chamber 12, and the circulation of bed material from combustion chamber 12 into pyrolysis chamber 2 provides heat for the pyrolysis process. This reduces or eliminates the need for external support fuel for the pyrolysis process. The quenched product gas is then sent via the quenched product gas outlet 70 of the quench tower 66 to a wet electrostatic precipitator 72. The wet electrostatic precipitator 72 removes oil-coated ash particles in the product gas. This is achieved by spreading the gas into a uniform flow profile using a gas distribution system, then applying a high voltage (40+ kV) between spray electrodes to charge the particles, and subsequently collecting the charged particles at a collection electrode, where they are agglomerated and washed away.The aerosol liquid containing the separated tar fraction travels to the combustion chamber 12 via the aerosol liquid outlet 74. The separated tar becomes an energy source in the combustion chamber 12, which provides heat for the pyrolysis process by circulating bed material from the combustion chamber 12 into the pyrolysis chamber 2. This reduces or eliminates the need for external support fuel for the pyrolysis process. The aerosol-free product gas then travels to the absorption tower 78 via the aerosol-free product gas outlet 76. Preferably, the aerosol-free product gas is introduced at one end (i.e., the bottom) of the tower and the washing agent (e.g., oil) is introduced at the opposite end (i.e., the top) of the tower. The contact between the upwardly flowing gas and the downwardly flowing washing agent can be improved over conventional means such as spraying using packed or plate towers. To remove impurities such as tar from the gas, washing can be carried out either in a cocurrent or countercurrent manner. Absorber 78 can be operated at atmospheric or slightly above atmospheric pressure, for example at a temperature between 80-90° C., preferably 80° C., or at a higher temperature if a higher pressure is used. If a higher pressure is used, absorber 32 should be operated at a temperature of 220° C. or less, preferably 200° C. or less.

[0091] The purified product gas then travels from the absorber 78 to the product recovery unit 24 via product gas outlet 82. The spent scrubbing agent is then recycled to the stripper tower 80 where the impurities / tars are desorbed from the scrubbing agent by the stripping agent in stripping section 84. The stripping agent (e.g., hot air, steam, nitrogen, carbon dioxide, flue gas, or mixtures thereof, preferably hot air) is introduced via inlet 88. Combustion air that travels into the combustion chamber 12 and is used as a fluidizing gas may travel into the stripper unit 80 and then back into the combustion chamber 12.

[0092] The spent scrubbing agent is then circulated to the degassing section 86, where it is degassed by the degassing agent and then circulated out of the stripper column 80 into the absorber column 78 for further scrubbing. Degassing of the scrubbing agent prevents the inclusion of air in the stripping agent and then in the product gas via the absorber column. The degassing agent may be, for example, steam, which is introduced into the degassing section 86 via an inlet 90. If the same pressure is used, the stripper column 80 is operated at a temperature about 100° C. higher than that of the absorber column 78, more typically between 70 and 120° C. higher than that of the absorber column 78. At atmospheric pressure, this temperature may be between 150 and 220° C. Instead of using a higher temperature, the stripper column 80 can be operated at a lower pressure than the absorber column 78. Air from the stripper column 80 can be circulated into the combustion chamber 12 and used in the combustion process. The absorption / desorption process can be carried out by a temperature swing process or a pressure swing process. The temperature swing process can be used to strip the light tars absorbed in the oil at lower pressures (0.3 barg to 0.4 barg). The pressure swing process can be used to strip the light tars absorbed in the oil at higher pressures.

[0093] Gas ash removed by particulate removal unit 58 may be transferred into the combustion chamber 12. The product gas in product recovery unit 24 is then classified and isolated into one or more product streams and transferred from product recovery unit 24 using one or more outlets 28, 30, and 32. Hot flue gas (e.g., at a temperature of 850° C.) from the combustion chamber 12 is transferred to a gas cooler 92 where the flue gas is cooled (e.g., to a temperature of 180° C.) and then transferred to a gas filter 94 where ash is removed from the flue gas.

[0094] The feedstock input section 4 may include a feed screw. The feed screw often exhibits high operating temperatures, which may cause some of the feedstock, such as the polymer in the screw feed, to melt and subsequently cause blockage of the screw feed. The temperature of the feed screw is reduced by the introduction of the feedstock with a fuel feed at a sufficiently high velocity. Preferably, the fuel feed velocity, expressed as the velocity through the feed screw, is between 0.3 m / s and 1.0 m / s. The temperature of the feed screw may also be reduced by cooling the screw and its closed casing with air at 60-80° C. from the outside of the casing, passing the screw and its closed casing through an air chamber towards the pyrolysis zone. The temperature of the feed screw may also be reduced by adding water and / or ash to the feedstock. Alternatively, if the feedstock is derived from biomass, it may have a sufficient moisture content, so that no additional water needs to be added to the feedstock. The feedstock may preferably contain 5% to 30% water based on the weight of the feedstock, more preferably 5% to 15% water based on the weight of the feedstock, more preferably 5% to 10% water. The feed may also contain 1% to 15% ash based on the weight of the feed, and pressure control valves may be used to ensure constant operating pressures between the product recovery unit 24, the quench unit 54, and the absorption unit 56. This has the added advantage that changes in pressure differential across the cooler 62 are compensated for. EXAMPLES

[0095] Table 1 shows a set of high-value chemicals obtained by the claimed method when using wood, biogenic waste (2 / 3 of which is composed of biogenic materials) and plastic waste (2 / 3 of which is composed of plastic materials). In particular, the pyrolysis process was carried out at 750°C. Table 1 also shows, as a comparative example, high-value chemicals obtained by conventional naphtha cracking. The amounts are given on a dry and N 2 / CO 2 Reported on a free basis.

[0096] [Table 1]

[0097] Tests were carried out to determine the melting behavior of five types of pure plastics (polypropylene (PP), polyethylene (PE), polystyrene (PS), polycarbonate (PC), and polycarbonate acrylonitrile butadiene styrene (PC-ABS)) with electronic waste (e-waste). It was shown that these materials can start to melt at temperatures between 140 and 230 °C without becoming a low viscosity liquid (see Table 2). Due to this behavior, clogging of the plastics could sometimes occur inside the feed screw, which previously operated at high temperatures.

[0098] [Table 2]

[0099] In contrast to Table 2, no feeding problems were observed with biogenic waste or plastic waste. This is at least partially due to the ash and moisture content of these materials. Table 3 shows typical ash and moisture contents for wood, biogenic waste, and plastic waste. Tests have shown that adding both ash and moisture to pure plastic reduces feeding-related problems. In particular, the moisture reduces the temperature in the feedstock in the screw, and the ash forms a protective coating on sticky particles, reducing particle agglomeration in the feed screw.

[0100] [Table 3]

[0101] Tables 4 and 5 show a series of high-value chemicals that can be obtained by different methods when using waste-derived fuel. It was found that the pyrolysis process operated at 700-800°C can obtain a large amount of high-value chemicals in the product gas. The amounts are shown on a dry and N 2 / CO 2 Reported on a free basis.

[0102] [Table 4]

[0103] [Table 5]

[0104] Tests performed on a pre-prepared mixture of 26 wt.% biomass, 32 wt.% polypropylene, and 42 wt.% polyethylene by the method of the present invention showed similar results. As can be seen from Table 6, the yield of olefins is maximum at about 750° C., while benzene, toluene, and tars obtained by excessive cracking increase at higher temperatures. Carbon yields for specific components, such as flue gas, are also shown in Table 6.

[0105] [Table 6]

[0106] Surprisingly, it was found that performing the pyrolysis process between 700 and 800 °C improves the operability of the quench unit downstream of the pyrolysis chamber 1. Table 7 shows the tar distribution after the pyrolysis of biomass or waste-derived fuel at 750 or 850 °C based on class 1 (benzene to indene), class 2 (naphthalene to fluorene), class 3 (phenanthrene to fluoranthene), class 4 (pyrene to benzo(k)fluoranthene), and class 5 (benzo I pyrene to coronene) at 10 g / Nm 3The dew point designation based on tar (°C) is shown along with the average viscosity (cP) obtained per class. At lower temperatures (i.e. 750°C) more tar is formed, which has been found to be beneficial in the case of the quench unit since the tar is a lighter tar fraction (i.e. lower molecular weight) and therefore has a lower tar dew point and lower viscosity. A lower tar dew point reduces the risk of fouling between the pyrolysis chamber and the quench unit, while a lower viscosity reduces the risk of fouling inside the quench unit itself.

[0107] Operating the pyrolysis chamber 2 at a lower temperature results in a larger amount of light tar fraction, thus increasing the amount of tar in the absorption unit 56 and causing the stripper process 84 to approach the lower explosion limit when the combustion air inputs 18 and 20 are used for stripping. The tar is absorbed from the gas into a washing agent (such as oil) in the absorption tower 78. The saturated oil is then sent to the stripper tower 80 where a stripping agent is used to remove the tar. The stripping agent may be combustion air to the combustion chamber 12. The stripping agent ensures that the process is carried out below 50% of the lower explosion limit (LEL) of the tar in air. This is achieved by the use of primary and secondary air for stripping. The LEL is 37 g / Nm 3 It is desired that the combustion air be reintroduced into the combustion chamber 12, for example partially into the freeboard zone above the combustion bed 34. This reduces the temperature of the combustion bed 34 in the combustion zone 12, since some of the light tar tar is combusted above the fluidized bed zone 34 rather than within it. Alternatively, water can be injected into the fluidized bed zone 34 to reduce the temperature of the fluidized bed zone 34. This water may be waste water obtained by condensation of water in the product recovery unit 24.

[0108] [Table 7]

[0109] The increase in viscosity of the liquid in the quench system was found to be problematic. Firstly, a highly viscous tar was produced at temperatures >800°C and collected in the quench unit. Secondly, a high concentration of ash fraction remained in the treated gas in the fines removal unit 58 (i.e., cyclone). In particular, the viscosity was increased due to a large amount of fines in the product gas, caused for example by a high calcium content in the feedstock. Furthermore, ash particles were also found to accumulate in the pyrolysis chamber. Therefore, cyclones were developed to facilitate the separation of the ash particles from the depolymerized polymer product gas, in order to allow sufficient time for the ash particles to agglomerate in the cyclone. Thus, these cyclones are smaller than conventional cyclones to allow more particle-particle interaction, but are taller to allow sufficient residence time for particle agglomeration. Table 8 shows the results of the cyclones as a function of inlet particle size distribution, mg / Nm 3 1 shows the particle size distribution of ash remaining in the depolymerized polymer product gas in units of (milligrams per standard cubic meter).

[0110] [Table 8]

[0111] Table 9 shows the sand flow and sand to fuel ratio as a function of fluidizing gas velocity through the transport zone 42. The operating temperature of the pyrolysis chamber 1 can be changed by adding more fluidizing gas below the transport zone 42 and less above or in the transport zone 42. This redistribution of fluidizing gas changes the temperature differential between the pyrolysis chamber 2 and the combustor chamber 12 because the flow of fluidizing gas (i.e. sand) through the transport zone 42 can be increased without mechanically changing the size of the transport zone 42. By increasing the velocity, this can be increased significantly.

[0112] [Table 9]

[0113] The amount of contaminants in the product gas can be reduced by modifying the operating conditions of the system upstream of the product recovery unit 24. It has been found that oxygen can be entrained in the product gas either by the hot bed material (i.e. sand) being transported from the combustion chamber 12 into the pyrolysis chamber 2 or by air flowing into the wash agent (i.e. oil) and stripping it with a whist stripping agent to remove the tar fraction. As shown in Table 10, the solubility of contaminant gases in the stripped wash is low. The presence of carbon dioxide and nitrogen is not considered because these gases are already present in the product gas in significant amounts. However, the amount of oxygen should be kept low (i.e. ppb level). Prevention or reduction of oxygen entrainment in the wash oil is achieved by using the degassing section 86 of the stripper tower 80. In addition, steam can be injected into the top of the transport zone 42 to strip the circulating hot bed material (i.e. sand) from the flue gas. This not only reduces the amount of oxygen entrained in the product gas in the pyrolysis chamber 2, but also reduces the amount of NO. For example, oxygen and NO react to form solid N 2 O 3 and N 2 O 4 These solids have a tendency to accumulate and can react with ammonia to form the explosive chemical ammonium nitrate. 2 O 3 It has been shown in industry to react violently with ethylene and propylene at 25° C. Steam can also be used to dilute the product gases in the pyrolysis chamber 2.

[0114] Table 10 shows the solubility of contaminant gases collected in the stripped wash oil as a function of oil temperature.

[0115] [Table 10]

[0116] Unlike conventional naphtha cracking, which requires high steam dilution, the present invention requires only low steam dilution. Table 11 shows that the driving factor for the formation of ethylene and propylene is the temperature at which the reaction is carried out, not the steam-to-carbon ratio. With a fluidizing gas velocity in the transport zone of 0.5-3 m / s, the steam-to-carbon ratio is typically on the order of 0.05-0.10 at the low end and 0.75-1.50 at the high end.

[0117] Table 11 shows the carbon yields of different components at different decomposition temperatures and steam to carbon (StC) ratios for mixtures containing wood, polypropylene, and polyethylene.

[0118] [Table 11]

Claims

1. A method for producing a high-value chemical substance from a supply raw material, wherein the supply raw material is waste material or includes waste material: (a) To provide a fluid reactor system including a pyrolysis chamber (2) and a combustion chamber (12), (b) The supply material is introduced into the pyrolysis chamber (2), and a pyrolysis process is carried out at a temperature in the range of 650 to 850°C to obtain a product gas containing high-value chemical substances. A method that includes this.

2. The method according to claim 1, wherein the thermal decomposition process is carried out at a temperature in the range of 700 to 800°C, preferably 730 to 770°C.

3. The method according to claim 1 or 2, further comprising moving the generated gas from the pyrolysis chamber to a tar removal system to remove one or more tar fractions from the generated gas.

4. below: - The generated gas transferred to the tar removal system contains heavy tar fractions of class 3 to 5, and the content of class 3 to 4 is greater than the content of class 5, based on the total weight of all heavy tar fractions of class 3 to 5; - The generated gas to be transferred to the tar removal system contains, based on the weight of all Class 3 to 5 heavy tar fractions: (i) 50 to 80% Class 3 heavy tar, (ii) 10 to 40% Class 4 heavy tar, and (iii) 10% or less Class 5 heavy tar; - The generated gas to be transferred to the tar removal system is 20-30 g / Nm³ ３ It must contain heavy tars of class 3 to 5; - The generated gas transferred to the tar removal system contains a dust-to-class 3-5 heavy tar ratio of 1:99 to 10:90; - The generated gas to be transferred to the tar removal system is 0 to 2 g / Nm³ ３ Including dust, The method according to claim 3, wherein one or more of the following apply.

5. below: - The aforementioned waste material is municipal solid waste; - The waste material is biomass, biomass-rich solid waste fuel, plastic-rich solid waste fuel, and plastic, or a combination thereof; - The aforementioned waste material contains plastic; - The waste material contains 30 to 100%, preferably 50 to 80%, of plastic based on the weight of the waste material; - The supply material contains 5 to 30% water derived from and / or separately added to the supply material; - The anthropogenic carbon present in the waste material accounts for 40 to 100%, preferably 60 to 90%, of the total carbon in the waste material. The method according to claim 1 or 2, wherein one or more of the above apply.

6. The high-value chemical substance in the generated gas is an olefin and / or a monocyclic aromatic compound, preferably the olefin is ethylene, propylene, C ４ Olefin, C ５ The method according to claim 1 or 2, wherein the monocyclic aromatic compound is an olefin or a combination thereof, and / or benzene, toluene, xylene, styrene, or a combination thereof.

7. The method according to claim 1 or 2, further comprising (c) moving the product gas into a product recovery unit to isolate the high-value chemical, and optionally, before performing step (c), moving the product gas from the pyrolysis chamber (2) to a tar removal system (52) to remove one or more tar fractions from the product gas.

8. - The tar removal system (52) preferably includes an absorption unit (56) for removing light tar fractions such as light tar fractions and light tar fractions such as dust from the generated gas, and optionally moves a portion of the light tar fractions to the combustion chamber (12); and / or - The tar removal system (52) includes a quenching unit (54) for removing heavy tar fractions from the generated gas, and optionally the generated gas is quenched with a quenching body, typically oil, at a temperature in the range of 50 to 95°C, preferably 60 to 90°C, more preferably 60 to 85°C, preferably the used quenching body obtained after quenching has a viscosity in the range of 40 to 200 cP, preferably 80 to 160 cP, and optionally a portion of the heavy tar fraction is moved to the combustion chamber (12). The method according to claim 7.

9. The method according to claim 1 or 2, wherein in the combustion chamber, the combustion process is carried out at a temperature that is 30 to 130°C higher than that of the pyrolysis process, preferably 50 to 110°C higher.

10. The process further includes circulating the floor material from the combustion chamber (12) to the pyrolysis chamber (2) via a transport zone (42), wherein the pyrolysis process and the combustion process are carried out in the floor material, and optionally includes the following: - The circulation of the floor material ensures that sufficient heat for carrying out the pyrolysis process is transferred from the combustion chamber (12) to the pyrolysis chamber (2); - By reducing the circulation rate of the floor material, the temperature difference between the combustion chamber (12) and the pyrolysis chamber (2) increases, and by increasing the circulation rate of the floor material, the temperature difference between the combustion chamber (12) and the pyrolysis chamber (2) decreases; - The circulation rate of the flooring material is 10 to 100 kg of circulating flooring material per 1 kg of supplied raw material, more preferably 20 to 60 kg per 1 kg; - In order to control the circulation speed of the floor material, the fluidizing gas is moved into the transport zone (42) in two or more regions, preferably by changing the ratio of the fluidizing gas moved into the first region of the transport zone to the second region of the transport zone, thereby increasing or decreasing the temperature difference between the combustion chamber (12) and the pyrolysis chamber (2); - The transport zone includes a first region (44) that allows for a downflow of floor material from the combustion chamber (12) and a second region (46) that allows for an upflow of floor material to the pyrolysis chamber (2), preferably moving the fluidizing gas through the upstream portion (48) of the second region (46) and the downstream portion (47) of the second region (46); - The fluidizing gas is moved into the transport zone (42) at a speed of 0.5 to 3 m / s, preferably 1 to 2.5 m / s, and more preferably 2 m / s, and preferably the speed of the fluidizing gas in the upstream portion (48) and / or downstream portion (47) is 0.5 to 3 m / s, preferably 1 to 2.5 m / s, and more preferably 2 m / s. The method according to claim 1 or 2, wherein one or more of the above apply.

11. The method according to claim 1 or 2, wherein, in order to control the circulation rate of the floor material, the fluidizing gas is moved, typically from the product recovery unit (40) of the fluid reactor system into the pyrolysis chamber (2), and preferably the velocity of the fluidizing gas in the pyrolysis chamber (2) is 5 to 8.5 m / s, more preferably 5.5 to 7.5 m / s.

12. The method according to claim 1 or 2, further comprising isolating a tail gas or off gas from the generated gas, preferably moving at least a portion of the tail gas or off gas to the combustion chamber (12), and / or using at least a portion of the tail gas or off gas for the production of a chemical substance, preferably hydrogen, CO, and / or olefins for the production of the chemical substance.

13. The method according to claim 1 or 2, further comprising moving the generated gas from the pyrolysis chamber to a particulate removal unit such as a cyclone in order to remove dust from the generated gas before moving it to a tar removal system.

14. A method for producing a high-value chemical substance from a supply raw material, wherein the supply raw material is waste material or includes waste material: (a) To provide a fluid reactor system including a pyrolysis chamber (2) and a combustion chamber (12); (b) The supply material is introduced into the pyrolysis chamber (2), and a pyrolysis process is carried out at a temperature in the range of 650 to 850°C to obtain a product gas containing high-value chemical substances; (c) Transferring the generated gas from the pyrolysis chamber to a particulate removal unit to remove dust from the generated gas; (d) Transferring the generated gas from the particulate removal unit to a tar removal system (52) including a rapid cooling unit (54) to remove heavy tar fractions, Includes, The generated gas to be transferred to the tar removal system is 0 to 2 g / Nm³ ３ Dust and 20-30 g / Nm ３ A method comprising heavy tars of Class 3 to 5, wherein, based on the total weight of the heavy tars of Class 3 to 5, the composition includes (i) 50 to 80% of Class 3 heavy tars, (ii) 10 to 40% of Class 4 heavy tars, and (iii) 10% or less of Class 5 heavy tars.

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