Method and device for multi-production and utilization of high-molecular long-chain organic solid waste through step-by-step thermal conversion

Abstract

The application discloses a kind of high molecular long-chain organic solid waste step heat conversion multi-linkage production utilization method and device, the method includes compatibility conditioning, low temperature pyrolysis, two catalyst steam reforming and gas-liquid separation steps, the device includes low temperature pyrolysis device, steam reforming device and gas-liquid separation device, the low temperature pyrolysis device includes low temperature pyrolysis furnace, and inlet and flue gas exhaust are equipped on the low temperature pyrolysis furnace, the furnace body of the low temperature pyrolysis furnace is equipped with heat preservation layer, and the inside of the low temperature pyrolysis furnace is equipped with waste heat drying chamber, low temperature pyrolysis chamber and combustion chamber in turn isolated, the steam reforming device is connected with low temperature pyrolysis chamber by gas shunt valve, and the gas-liquid separation device is connected with steam reforming device, and the gas-liquid separation device includes separation tank, and the inside of the separation tank is equipped with cooling pipe.The application can improve waste treatment efficiency by synergistic treatment of high molecular solid waste, and reduces the classification treatment work of garbage.

Description

Technical Field

[0001] This invention belongs to the field of solid waste resource utilization technology, and relates to a method and device for multi-product utilization of polymer long-chain organic solid waste through cascade thermal conversion. Background Technology

[0002] With the rapid development of modern industry, solid waste is increasing at a rate of 5-8% annually. Among this, complex, long-chain organic solid waste that is difficult to degrade (mainly including plastics and rubber) easily causes serious pollution to the natural environment. Statistics show that 300 million tons of plastic waste are generated globally each year, but only about 9% are recycled. With the booming development of the automotive industry, China alone generates more than 10 million tons of waste tires annually. The large amount of plastic and rubber waste faces the dilemma of being difficult to dispose of safely and lacking resource utilization methods, leading to serious social and environmental problems.

[0003] Plastics and synthetic rubber are generally chemical products generated from petroleum products through polymerization and other reactions. Pyrolysis breaks the chemical bonds of high molecules under high temperatures, yielding compounds with lower molecular weights and producing fuels with high calorific value. The gaseous products of pyrolysis are mainly hydrocarbons, primarily H2 and CO, which can be used as clean and environmentally friendly gaseous fuels. Simultaneously, pyrolysis can yield liquid oils of varying compositions, mainly alkanes, alkenes, and aromatics, which, after processing, can meet the requirements of being an alternative fuel to petroleum. The solid product of pyrolysis is semi-coke, which can be directly burned.

[0004] Current research mainly focuses on the separate pyrolysis of plastics and rubber to produce products. Although this can recycle waste plastics and rubber to a certain extent, it increases the difficulty and workload of waste sorting and treatment. Furthermore, the separate recycling of each solid waste cannot meet the inherent requirements of integrated reuse of solid waste resources. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a method and apparatus for the multi-product utilization of polymer long-chain organic solid waste through cascade thermal conversion. By co-processing various waste polymer materials to prepare three-phase products, and employing a cascade thermal conversion method that combines pyrolysis, steam reforming, and combustion disposal, the invention promotes the high-value and efficient utilization of energy.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is a method for the cascade thermal conversion and co-production utilization of long-chain organic solid waste, comprising the following steps: Compatibility and conditioning: Mix the pulverized plastic and rubber in a certain proportion; Low-temperature pyrolysis: The mixture is dried and then thermally decomposed in a pyrolysis chamber under the protection of an inert gas. The thermal decomposition produces semi-coke and pyrolysis gas. The semi-coke enters the combustion chamber for combustion to provide heat to the pyrolysis chamber. Steam reforming: Part of the pyrolysis gas is used for combustion to provide energy, and part is mixed with steam. Under the action of a catalyst, the mixture is heated to a certain temperature to react and obtain reformed gas; and Gas-liquid separation: The reformed gas is cooled to obtain hydrogen-rich syngas and pyrolysis oil.

[0007] In one embodiment of the present invention, the temperature required for thermal decomposition is 400-550°C, and the reaction time is 1-5 hours.

[0008] In one embodiment of the present invention, the heating temperature in the steam reforming step is 700-800°C, and the reaction time is 1-2 hours.

[0009] In one embodiment of the present invention, the catalyst in the steam reforming step includes a structural catalyst and a particulate catalyst. The structural catalyst is composed of a porous support material and an attached catalytically active metal, while the particulate catalyst is composed of a catalytically active metal and a high-temperature resistant support material. The steam reforming step also yields a metal-based carbon composite material.

[0010] In one embodiment of the present invention, the volume of the particulate catalyst is 1.3 to 2 times that of the structural catalyst.

[0011] In one embodiment of the present invention, the mass ratio of the plastic to the rubber is 9:1 to 5:5.

[0012] In one embodiment of the present invention, both the plastic and the rubber are waste materials, and the drying temperature of the mixture is 100-200°C.

[0013] In one embodiment of the present invention, either the plastic or the rubber can be replaced by biomass.

[0014] A device for the cascade thermal conversion and co-production utilization of long-chain organic solid waste includes a low-temperature pyrolysis device, a steam reforming device, and a gas-liquid separation device. The low-temperature pyrolysis device includes a low-temperature pyrolysis furnace, which is provided with a feed inlet and a flue gas exhaust outlet. The furnace body of the low-temperature pyrolysis furnace is provided with a heat insulation layer. Inside the low-temperature pyrolysis furnace, there are a waste heat drying chamber, a low-temperature pyrolysis chamber, and a combustion chamber that are sequentially separated. The combustion chamber is used to supply heat to the heat insulation layer, the waste heat drying chamber, and the low-temperature pyrolysis chamber. The waste heat drying chamber is used to hold the solid waste to be treated. There is an isolation component between the low-temperature pyrolysis chamber and the waste heat drying chamber to control the connection between the two. The steam reforming unit is connected to the low-temperature pyrolysis chamber via a gas diversion valve. The steam reforming unit includes a heat exchange chamber and a secondary combustion chamber. The diversion valve supplies gas to the heat exchange chamber and the secondary combustion chamber respectively. The secondary combustion chamber is isolated from the heat exchange chamber. The heat exchange chamber is covered with an insulating shell. The secondary combustion chamber is used to heat the insulating shell. The heat exchange chamber is provided with a steam inlet for inputting steam. The heat exchange chamber consists of several heat exchange tubes, an upper cover, and a lower cover. The heat exchange tubes are located between the upper cover and the lower cover. A sealed space is formed between the upper cover, the heat exchange tubes, and the lower cover. A catalyst support device extends into the heat exchange tubes for placing the catalyst. The gas-liquid separation device is connected to the steam reforming device. The gas-liquid separation device includes a separation box. The separation box is equipped with a cooling pipe for cooling the gas in the separation box. The separation box is provided with a synthesis gas outlet and a liquid drain outlet. The synthesis gas outlet is used to discharge the gas, and the liquid drain outlet is used to discharge the cooled liquid oil.

[0015] In one embodiment of the present invention, the catalyst support device is fixedly connected to the upper cover. The catalyst support device includes a support rod and a catalyst placement plate fixedly connected to the support rod. The catalyst placement plate includes a structural catalyst placement plate and a particulate catalyst placement plate. The structural catalyst placement plate is located above the particulate catalyst placement plate.

[0016] In one embodiment of the present invention, a compatibility conditioning device is further included for crushing and mixing plastics and rubber, the compatibility conditioning device being disposed at the feed inlet. The feed inlet is used to transport solid waste to the waste heat drying chamber.

[0017] In one embodiment of the present invention, the catalyst placement plate has holes.

[0018] In one embodiment of the present invention, the heat exchange chamber is further provided with a protective net for covering the catalyst support device, and the protective net is fixedly connected to the upper cover.

[0019] In one embodiment of the present invention, the heat exchange chamber is further provided with a flue gas purification device, which is installed on the heat insulation shell.

[0020] In one embodiment of the present invention, the diversion valve has two gas supply pipes, namely a first gas supply pipe and a second gas supply pipe. The first gas supply pipe is connected to the heat exchange chamber, and the second gas supply pipe is connected to the secondary combustion chamber.

[0021] In one embodiment of the present invention, a partition is provided between the low-temperature pyrolysis chamber and the combustion chamber, and the partition is rotatable relative to the low-temperature pyrolysis furnace. The low-temperature pyrolysis chamber and the waste heat drying chamber are connected by an openable baffle.

[0022] This technical solution has the following beneficial effects: This invention prepares high-value products—hydrogen-rich syngas and pyrolysis oil—through a combination of conditioning, low-temperature pyrolysis, steam reforming, and gas-liquid separation. Simultaneously, a stepped thermal conversion method combining pyrolysis / steam reforming and combustion achieves self-sufficiency in heat supply, increasing hydrogen yield and production of metal-based carbon composite materials and pyrolysis oil while reducing the energy recycling pathway. Addressing the research gap in the co-processing of waste plastics and rubber and other polymeric solid wastes to prepare three-phase products, this invention proposes a new approach to value-added and efficiency-enhancing three-phase product preparation through co-production. By co-processing different types of polymeric solid waste, waste treatment efficiency is improved, the workload of waste sorting is reduced, and economic and environmental benefits are enhanced. Attached Figure Description

[0023] Figure 1 This is a process flow diagram of an embodiment of the present invention; Figure 2 This is a schematic diagram of the device in one embodiment of the present invention. Detailed Implementation

[0024] The following is a description of the embodiments and appendices. Figure 1 and 2 The present invention will be further described below.

[0025] A cascade thermal conversion and co-production utilization device for long-chain organic solid waste includes a compatibility conditioning device, a low-temperature pyrolysis device, a steam reforming device, and a gas-liquid separation device. The compatibility conditioning device is used to crush and mix plastics and rubber. The compatibility conditioning device is located at the feed inlet, which is used to transport the solid waste to the waste heat drying chamber.

[0026] The low-temperature pyrolysis device includes a low-temperature pyrolysis furnace, which has a feed inlet and a flue gas exhaust outlet. The furnace body is equipped with a heat insulation layer. Inside the low-temperature pyrolysis furnace, there are a waste heat drying chamber, a low-temperature pyrolysis chamber, and a combustion chamber that are sequentially separated. The combustion chamber is used to supply heat to the heat insulation layer, the waste heat drying chamber, and the low-temperature pyrolysis chamber. The waste heat drying chamber is used to hold the solid waste to be treated. The low-temperature pyrolysis chamber and the waste heat drying chamber are connected by an openable baffle. A partition is provided between the low-temperature pyrolysis chamber and the combustion chamber. The partition can rotate relative to the low-temperature pyrolysis furnace, thereby causing the semi-coke produced by pyrolysis to fall into the combustion chamber.

[0027] The steam reforming unit is connected to the low-temperature pyrolysis chamber via a gas diversion valve. The steam reforming unit includes a heat exchange chamber and a secondary combustion chamber. The diversion valve supplies gas to both the heat exchange chamber and the secondary combustion chamber, which are isolated from the heat exchange chamber. The diversion valve has two gas supply pipes, a first gas supply pipe and a second gas supply pipe. The first gas supply pipe is connected to the heat exchange chamber, and the second gas supply pipe is connected to the secondary combustion chamber. The heat exchange chamber is covered with an insulated outer shell, and the secondary combustion chamber heats the insulated outer shell. The heat exchange chamber has a steam inlet for inputting steam. The heat exchange chamber consists of several heat exchange tubes, an upper cover, and a lower cover. The heat exchange tubes are located between the upper cover and the lower cover, forming a sealed space.

[0028] A catalyst support device extends into the heat exchange tube for placing the catalyst. The catalyst support device is fixedly connected to the upper cover and includes a support rod and a catalyst placement plate fixedly connected to the support rod. The catalyst placement plate includes a structural catalyst placement plate and a particulate catalyst placement plate, with the structural catalyst placement plate located above the particulate catalyst placement plate. The catalyst placement plate has openings. A protective net covers the outer periphery of the catalyst support device and is fixedly connected to the upper cover to prevent the catalyst from falling into the heat exchange tube during catalyst replacement. The heat exchange chamber is also equipped with a flue gas purification device, which is mounted on the insulation shell.

[0029] The gas-liquid separation device is connected to the steam reforming device. The gas-liquid separation device includes a separation box. The separation box is equipped with a cooling pipe for cooling the gas in the separation box. The separation box is provided with a synthesis gas outlet and a liquid drain outlet. The synthesis gas outlet is used to discharge the gas, and the liquid drain outlet is used to discharge the cooled liquid oil.

[0030] The following describes a method for the multi-product utilization of polymer long-chain organic solid waste through cascade thermal conversion, using the aforementioned apparatus as an example. This method includes, in sequence, the steps of compatibility conditioning, low-temperature pyrolysis, two-stage catalyst steam reforming, and gas-liquid separation.

[0031] Compatibility and conditioning: Plastic and rubber enter the hopper 12 through the feed inlet 11. The waste plastic and rubber raw materials are mixed in a ratio of 9:1 to 5:5. In this embodiment, an 8:2 ratio is selected. The mixture is crushed into 40-120 mesh particles by the crusher 14. The arc-shaped stirrer 17 installed in the feed hopper 15 is driven to rotate by the speed control motor 18 to stir the mixed sample to achieve uniform material distribution. The homogenized sample enters the low-temperature pyrolysis device through the feed inlet.

[0032] Low-temperature pyrolysis: The furnace body of the low-temperature pyrolysis device is an insulated furnace body 25. The mixed sample is initially dried in the residual heat drying chamber 21 at a drying temperature of 100-200℃ for a certain period of time. Then, the baffle 22 on the grate is flipped under the drive of the motor, and the mixed sample falls into the low-temperature pyrolysis chamber 24 for thermal pyrolysis. The temperature required for thermal pyrolysis is 400-550℃, and the reaction time is 1-5h. Before the reaction begins, inert gas is introduced into the low-temperature pyrolysis chamber for protection. The generated pyrolysis gas is discharged through the pyrolysis gas exhaust port 28 and split into two streams by the high-temperature gas diversion valve 29, which enter the steam reforming device respectively. The generated pyrolysis semi-coke enters the combustion chamber 210 through the flipping baffle 27. Due to the slight negative pressure state of the combustion chamber, a small amount of pyrolysis gas will enter the combustion chamber and act as fuel. Then, the blower 212 blows in sufficient air, which is ignited by the combustor 211 and undergoes oxygen combustion. The heat is supplied to the low-temperature pyrolysis chamber through the heat-conducting baffle 27. At the same time, the generated high-temperature flue gas heats the pyrolysis chamber wall from bottom to top through the ceramic heat storage material 23, making the sample heat more uniformly heated. The residual heat continues to provide a heat source for the drying chamber 21. The flue gas is discharged through the flue gas exhaust port 214 on the furnace body, treated by the flue gas purification device 215, and assisted by the first blower 216. The combustion residue is discharged into the slag quenching chamber 213. The aforementioned two-piece flip-over baffle 22 includes a flip-over shaft 210, a mesh baffle 220, and a flip-over baffle 230. The baffle 220 is configured as a mesh structure to ensure the flow of flue gas.

[0033] Steam reforming: The pyrolysis gas is diverted via the high-temperature gas diversion valve 29: 70-75% of the pyrolysis gas enters the reforming chamber through the pyrolysis gas inlet 31, and after being fully mixed with the steam entering through the steam inlet 32, it enters the vertical heat exchange tube 38 for steam reforming reaction. The heating temperature in the steam reforming step is 700-800℃, and the reaction time is 1-2 hours. A catalyst support device is installed in the heat exchange tube, which is connected to the top cover 33. The top cover can be opened for catalyst replacement. A protective net 35 prevents the catalyst from falling into the heat exchange tube. The structural catalyst placement plate holds the structural catalyst, and the granular catalyst placement plate holds the granular catalyst. The structural catalyst placement plate 36 has large pores to hold the structural catalyst, while the granular catalyst placement plate 37 has a small pore structure to allow gas flow during the catalytic reforming process. The volume of the granular catalyst used is 1.3 to 2 times that of the structural catalyst. Since the secondary combustion chamber 312 is located at the top of the heat exchange tube, the residual heat of the pyrolysis gas and the wall temperature are relatively high. Therefore, the partial structure catalyst is set to extend the activity and service life of the catalyst. The particulate catalyst in the lower part generates carbon / catalyst nanocomposite material while playing a catalytic role. 25-30% of the pyrolysis gas enters the secondary combustion chamber and is ignited by the combustion booster 311. The burning pyrolysis gas passes from top to bottom through the ceramic heat storage material 313 to provide heat for the steam reforming reaction. At the same time, this process greatly extends the residence time of the pyrolysis gas in the secondary combustion chamber, effectively reducing the generation of toxic gases such as dioxins. The flue gas is treated by the flue gas purification device 315 and discharged with the assistance of the second fan 316.

[0034] Gas-liquid separation: The generated gas enters the gas-liquid separator through the reformer gas outlet 39. The reformer gas enters the inlet chamber 43 through the reformer gas inlet 42 and flows from bottom to top into the cooling sleeve 41 for cooling. After condensation, the liquid sinks by gravity and flows into the storage chamber 49 through the liquid outlet 48. Finally, the drain port 410 is opened to transfer the pyrolysis oil to the storage tank 411 for subsequent processing. The non-condensable gas passes through the cooling sleeve and is discharged through the synthesis gas outlet 45. During the condensation process, the refrigerant enters through the cold coal / water inlet 46 and is discharged through the refrigerant / water outlet 47.

[0035] The specific embodiments described above are only used to explain and illustrate the present invention, and are not intended to limit the present invention. Any changes and substitutions made to the present invention without creative effort within the scope of the inventive concept and claims shall fall within the protection scope of the present invention patent.

Claims

1. A device for the cascade thermal conversion and co-production utilization of long-chain organic solid waste, characterized in that, This includes a low-temperature pyrolysis unit, a steam reforming unit, and a gas-liquid separation unit; The low-temperature pyrolysis device includes a low-temperature pyrolysis furnace, which is provided with a feed inlet and a flue gas exhaust outlet. The furnace body of the low-temperature pyrolysis furnace is provided with a heat insulation layer. Inside the low-temperature pyrolysis furnace, there are a waste heat drying chamber, a low-temperature pyrolysis chamber, and a combustion chamber that are sequentially separated. The combustion chamber is used to supply heat to the heat insulation layer, the waste heat drying chamber, and the low-temperature pyrolysis chamber. The waste heat drying chamber is used to hold the solid waste to be treated. There is an isolation component between the low-temperature pyrolysis chamber and the waste heat drying chamber to control the connection between the two. The steam reforming unit is connected to the low-temperature pyrolysis chamber via a gas diversion valve. The steam reforming unit includes a heat exchange chamber and a secondary combustion chamber. The diversion valve supplies gas to the heat exchange chamber and the secondary combustion chamber respectively. The secondary combustion chamber is isolated from the heat exchange chamber. The heat exchange chamber is covered with an insulated outer shell, and the secondary combustion chamber heats the insulated outer shell. The heat exchange chamber has a steam inlet. The heat exchange chamber consists of several heat exchange tubes, an upper cover, and a lower cover. The heat exchange tubes are located between the upper cover and the lower cover, forming a sealed space. A catalyst support extends into the heat exchange tubes. An apparatus for placing a catalyst; the catalyst includes a structural catalyst and a particulate catalyst, the structural catalyst being composed of a porous support material and an attached catalytically active metal, and the particulate catalyst being composed of a catalytically active metal and a high-temperature resistant support material; the catalyst support device is fixedly connected to a top cover, the catalyst support device including a support rod and a catalyst placement plate fixedly connected to the support rod, the catalyst placement plate including a structural catalyst placement plate and a particulate catalyst placement plate, the structural catalyst placement plate being located above the particulate catalyst placement plate; The gas-liquid separation device is connected to the steam reforming device. The gas-liquid separation device includes a separation box. The separation box is equipped with a cooling pipe for cooling the gas in the separation box. The separation box is provided with a synthesis gas outlet and a liquid drain outlet. The synthesis gas outlet is used to discharge the gas, and the liquid drain outlet is used to discharge the cooled liquid oil.

2. The apparatus according to claim 1, characterized in that, It also includes a compatibility conditioning device for crushing and mixing plastics and rubber, the compatibility conditioning device being located at the feed inlet.

3. A method for the cascade thermal conversion and co-production utilization of long-chain organic solid waste using the apparatus described in claim 1 or 2, characterized in that, Includes the following steps: Compatibility and conditioning: Mix the pulverized plastic and rubber in a certain proportion; Low-temperature pyrolysis: The mixture is dried and then thermally decomposed in a pyrolysis chamber under the protection of an inert gas. The thermal decomposition produces semi-coke and pyrolysis gas. The semi-coke enters the combustion chamber for combustion to provide heat to the pyrolysis chamber. Steam reforming: Part of the pyrolysis gas is used for combustion to provide energy, and part is mixed with water vapor and heated to a certain temperature under the action of a catalyst to react and obtain reformed gas; wherein, the catalyst includes a structural catalyst and a particulate catalyst. The structural catalyst is composed of a porous support material and an attached catalytically active metal, and the particulate catalyst is composed of a catalytically active metal and a high-temperature resistant support material. And gas-liquid separation: the reformed gas is cooled to obtain hydrogen-rich syngas and pyrolysis oil.

4. The method according to claim 3, characterized in that, The required temperature for thermal pyrolysis is 400-550℃, and the reaction time is 1-5h.

5. The method according to claim 3, characterized in that, The heating temperature in the steam reforming step is 700-800℃, and the reaction time is 1-2 hours.

6. The method according to claim 3, characterized in that, The mass ratio of the plastic to the rubber is 9:1 to 5:

5.

7. The method according to any one of claims 3 to 6, characterized in that, Both the plastic and rubber are waste materials, and the drying temperature of the mixture is 100-200℃.

8. The method according to claim 7, characterized in that, Either the plastic or the rubber can be replaced with biomass.

Images