Process for preparing chemicals by mixed feeding, grading, gas-phase dehydrogenation and cracking of waste plastics and crude oil

Abstract

A process for preparing chemicals by waste plastic and crude oil mixed feeding graded gas-phase dehydrogenation cracking comprises a waste plastic self-heating dechlorination pretreatment process, a waste plastic molten liquid and crude oil selective vaporization dehydrogenation cracking process, a high-temperature cracked oil gas gas-phase catalytic cracking process and a cracked oil gas fractionation and refining process. Recycle oil and cracking dry gas in the cracking oil-gas fractionation and refining process are respectively recycled to the waste plastic self-hot melting dechlorination pretreatment process for high-temperature melting and liquefaction and carrying feed addition; a waste plastic molten liquid in the waste plastic self-heating melting dechlorination pretreatment process is delivered out to be mixed with crude oil to serve as a raw material for the selective vaporization dehydrogenation cracking process of the waste plastic molten liquid and the crude oil, and selective vaporization dehydrogenation cracking and gas-phase catalytic cracking are sequentially completed in a grading mode through efficient feeding of an atomizing nozzle. And then producing trienyltribenzene, high-temperature recycle oil and cracking dry gas by a cracking oil-gas fractionation and refining subsystem.

Description

1. Technical Field

[0001] The invention provides a process for preparing chemicals by graded gas phase dehydrogenation and cracking of mixed feed of waste plastics and crude oil, belonging to the field of energy chemical industry. 2. Background technology

[0002] While the widespread use of plastics has brought great convenience to people's lives, it has also brought a lot of white pollution. The use cycle of plastics is very short. A large number of plastic products, especially packaging materials, are discarded after about 6-12 months. 40% of plastics are discarded after 1-2 years. The total annual output of plastic waste in the world has reached 50 million tons. In the past few decades, waste plastics have been regarded as part of municipal solid waste (MSW). According to surveys, waste plastics account for 4%-10% (wt) or 10%-20% (v%) in MSW in industrially developed countries, mainly from packaging waste, automobile garbage and processing waste. The percentages of various types of waste plastics are: low-density polyethylene (LDPE) 27%; high-density polyethylene (HDPE) 21%; polypropylene (PP) 18%; polystyrene (PS) 16%; polyvinyl chloride (PVC) 7%. Due to the lack of efficient, clean and large-scale technology, waste plastics have become an environmental problem that needs to be solved in the world.

[0003] In the treatment of urban plastic solid waste, landfill, incineration and recycling are the three main methods. Due to different national conditions, the methods vary from country to country. The United States mainly uses landfill, while Europe and Japan mainly use incineration. At present, rapid pyrolysis / catalytic pyrolysis liquefaction or chemical production of waste plastics has become a hot topic at home and abroad, and is also the waste plastic treatment technology with the most promising industrialization prospects.

[0004] Rapid pyrolysis / catalytic pyrolysis of waste plastics is an effective recycling method that heats waste plastics at high temperatures under oxygen-free or low-oxygen conditions to decompose them and produce valuable products, such as the pyrolysis and liquefaction of waste plastics to produce gasoline, diesel, petroleum wax and other chemical raw materials. However, due to the characteristics of waste plastics such as large size and light weight, difficulty in compression, airtightness, easy expansion, easy melting and bonding, and poor thermal conductivity, it is difficult to solve the problem of continuous feeding and rapid heating. At present, most of the pyrolysis and liquefaction of waste plastics adopt reactor-type intermittent reactions and horizontal rotary kiln reactions, which have slow heating rates, serious feed adhesion and coking, low liquid product yields and added value, and difficult to improve processing capacity. It is difficult to scale up the pyrolysis device, and the subsequent processing of chlorine-containing liquid products is difficult, which restricts the efficient, clean and large-scale utilization of waste plastics. At present, there is no large-scale commercial waste plastic pyrolysis device.

[0005] Crude oil graded gas phase dehydrogenation cracking to produce chemicals directly bypasses traditional crude oil processing technology routes such as atmospheric and vacuum distillation, catalytic cracking, hydrocracking, and delayed coking, and directly catalytically dehydrogenates and cracks to produce basic chemical raw materials such as triolefins and triphenyls. It has a short process, simple operation, low cost and energy consumption, and low investment. It is the most industrially promising petroleum "oil conversion" refining technology that adapts to the energy transformation brought about by automobile electrification. Combining the rapid pyrolysis / catalytic pyrolysis of waste plastics with crude oil graded gas phase dehydrogenation cracking to produce chemicals is an effective means to improve the clean and efficient raw material utilization of waste plastics, reduce the consumption of petroleum resources, solve the problem of waste plastic pyrolysis feed, and improve the chemical yield and economic benefits of the device. It is urgent to develop waste plastics and crude oil mixed feed graded gas phase dehydrogenation cracking to produce chemicals process and equipment technology. 3. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the existing waste plastic pyrolysis liquefaction technology and provide a process for preparing chemicals by graded gas phase dehydrogenation and cracking of mixed feed of waste plastic and crude oil. Pyrolysis dry gas and high-temperature recycled oil circulation are used to carry out hot melt dechlorination and sulfur removal pretreatment of waste plastic and liquid phase atomization feeding, so as to solve the difficult problems of pyrolysis feeding and removal of chlorine and sulfur heteroatoms. A down-going bed reactor is used for graded gas phase catalytic cracking, and the cracking characteristics of the mixed raw materials of waste plastic and crude oil are complementary, the liquid phase cage wall effect is eliminated, the breakage of CC and CH bonds is regulated, the condensation coke is inhibited, the amplification effect is eliminated, the controllable cracking of waste plastic is achieved, and the triolefin triphenyl is produced to the maximum extent. The five common problems in the industry, namely, adhesion and coking of waste plastic feed, difficulty in mixing with heat carrier, low yield and added value of liquid product, difficulty in removing chlorine and sulfur heteroatoms of liquid product thus affecting subsequent processing, and difficulty in amplifying the pyrolysis device are solved, so as to realize efficient, clean and high-value large-scale utilization of waste plastic and crude oil.

[0007] The technical solution of the present invention:

[0008] Waste plastics and crude oil mixed feed graded gas phase dehydrogenation cracking process for producing chemicals. The clean PE and PP waste plastics are sorted through the waste plastic crusher and the waste plastic fragments are added to the 20-95℃ water-cooled feed pipe through a controllable feeder. Under the influence of cracking dry gas, they fall into the 240-320℃ oil slurry melt in the hot melt dechlorination reactor with stirring. The melt dechlorination and desulfurization pretreatment is carried out by stirring and mixing. The molten plastic liquid extracted from the bottom of the hot melt dechlorination reactor is conveyed by a conveying pump under pressure, and a part of it is heated to a temperature higher than the oil slurry melt through a high-speed circulation pipe with external heating. The liquid temperature is 20-60℃ higher and then returns to the upper part of the hot melt dechlorination reactor. The other part is sent to the upper part of the downward cracking reactor as raw material together with crude oil through the atomizing feed nozzle. The gas extracted from the top of the hot melt dechlorination reactor is treated by the desulfurization and dechlorination reactor and then enters the refinery gas network as fuel gas. The flow rate of the high-speed circulation pipe is 2-30m / s, the circulation ratio of the molten plastic liquid to the raw material is 1-10:1, and the steam consumption of the atomizing feed nozzle is 4%-12% of the raw material amount. The atomized particle feeding of the mixture of the molten plastic liquid and crude oil is the same as that of the downward cracking reactor. The cracking regeneration catalyst falling from the top of the reactor undergoes rapid mixing, vaporization and controllable cracking reaction. The steam dosage of the atomizing feed nozzle is 4% to 12% of the raw material amount, the cracking reaction temperature is 500 to 550°C, the pressure is 0-0.3MPa, the reaction time is 600 milliseconds to 2 seconds, and the oil-gas-solid separation is carried out at the bottom of the descending cracking reactor; the separated catalyst to be regenerated flows into the bottom of the cracking riser regenerator through the return feeder and is regenerated by air fluidization burning at 500-750°C. The bottom of the cracking riser regenerator is provided with a regeneration air inlet, and the top is provided with a regeneration air inlet in sequence. It is equipped with a gas-solid separator, a heat exchanger and a regenerated flue gas outlet. The regenerated catalyst separated by the gas-solid separator at the top of the cracking riser regenerator is circulated back to the top of the descending cracking reactor through the return controller to catalytically crack the mixture of molten plastic liquid and crude oil; the high-temperature cracking oil and gas are directly sprayed from the gas phase feed hole in the upper part of the descending cracking reactor without condensation, and the cracking regenerated catalyst falling from the top is quickly mixed and controlled cracking reaction occurs, and the oil and gas are separated at the bottom of the descending cracking reactor. The cracking reaction temperature is 570-650℃ and the pressure is 0-0.3MPa, reaction time is 200 milliseconds to 1 second; the separated cracking catalyst to be regenerated flows into the bottom of the cracking riser regenerator through the return feeder and is regenerated by air fluidization burning at 600-750℃. The bottom of the cracking riser regenerator is provided with an air inlet, and the top is provided with a gas-solid separator, a heat exchanger and a regenerated flue gas outlet in sequence. The cracking regenerated catalyst separated by the gas-solid separator at the top of the cracking riser regenerator is circulated back to the top of the descending cracking reactor through the return feeder to catalytically crack the high-temperature cracking oil and gas; the high-temperature cracking oil and gas enter the fractionation tower for separation, and the cracking dry gas at the top of the fractionation tower is circulated back to the water-cooled feed pipe at the top of the hot melt dechlorination reactor as feed carrying gas, and the other way is connected to the cracking gas refining system to produce triolefins. The fractionation tower refining oil is circulated back to the upper part of the hot melt dechlorination reactor as high-temperature molten oil, and the other way is sent out as a product after recovering the waste heat. The other side lines of the fractionation tower are crude benzene fraction and diesel fraction. .

[0009] The outer wall of the water-cooled feed pipe is provided with a water-cooling jacket, which is in the shape of a positive cone, a straight tube or an inverted cone, preferably a positive cone.

[0010] The controllable feeder is a rotary feeder, a double-shaft screw feeder or a single-shaft screw feeder.

[0011] The high-speed circulation tube is heated by electromagnetic induction heating, thermal oil heating, steam heating or resistance heating, preferably electromagnetic induction heating.

[0012] The cracking catalyst is a mixture of one or more of semi-coke microspheres, alumina microspheres, calcium aluminate porous microspheres, magnesium aluminum spinel porous microspheres, aluminum silicate porous microspheres, calcium silicate porous microspheres, magnesium silicate porous microspheres, and porous microsphere carriers loaded with alkali metals and / or alkaline earth metals.

[0013] The cracking catalyst is a mixture of one or more of an FCC molecular sieve catalyst, a ZSM-5 type selective molecular sieve catalyst, and an alkaline solid porous catalyst.

[0014] The riser regenerator is composed of a turbulent fluidized bed at the bottom and a carrying reactor at the top. The turbulent fluidized bed has a larger equivalent diameter, while the carrying reactor has a smaller equivalent diameter, with a diameter ratio of 2 to 3:1. The carrying reactor can be a straight tube reactor with a uniform equivalent diameter, or can be composed of large and small straight tubes with diameters of different multiples of the equivalent diameter connected by large and small head pipe fittings, with a diameter ratio of 1.2 to 2:1. The equivalent diameter of the fluidized bed is only 10%-50% of the equivalent diameter of the turbulent fluidized bed.

[0015] The present invention will be described in detail with reference to embodiments. 4. Description of the drawings

[0016] Attached Figure 1 The present invention is a schematic diagram of the process flow of preparing chemicals by graded gas phase dehydrogenation and cracking of mixed feed of waste plastics and crude oil.

[0017] Attached Figure 1 The drawing settings are as follows:

[0018] 1. Gas-solid separator, 2. Feed return controller, 3. Atomizing feed nozzle, 4. Downward cracking reaction tube, 5. Gas-solid quick separator, 6. Pyrolysis oil and gas outlet, 7. Feed return, 8. Downward cracking reactor, 9. Regeneration agent inlet, 10. Cracking riser regeneration reactor, 11. Heat exchanger, 12. Regeneration flue gas outlet, 13. Cracking riser regeneration reactor, 14. Air inlet, 15. Flue gas outlet, 16. Fractionation tower, 17. Crude benzene fraction, 18. Diesel fraction, 19. Refining oil pump, 20. Hot melt dechlorination reactor, 21. Waste plastic crusher, 22. Controllable feeder, 23. Water-cooled feed pipe, 24. Desulfurization and dechlorination reactor, 25. Delivery pump, 26. High-speed circulation pipe, 27. Refinery dry gas network

[0019] The process characteristics of the present invention are described in detail below in conjunction with the accompanying drawings and embodiments. 5. Specific implementation methods

[0020] The present invention provides a process for preparing chemicals by gas phase dehydrogenation and cracking of waste plastics and crude oil mixed feed. The clean PE and PP waste plastics separated are fed into a 20-95°C water-cooled feed pipe (23) through a waste plastic crusher (21). The waste plastic fragments are fed into a 20-95°C water-cooled feed pipe (23) through a controllable feeder (22). The waste plastic fragments are carried by cracked dry gas and fall into a 240-320°C oil slurry melt in a hot melt dechlorination reactor (20) with stirring. The melt dechlorination and desulfurization pretreatment is carried out by stirring and mixing. The molten plastic liquid extracted from the bottom of the hot melt dechlorination reactor (20) is fed into a delivery pump (25). The gas is conveyed under pressure, a part of it is heated to a temperature 20-60°C higher than the temperature of the slurry melt through a high-speed circulation pipe (26) with external heating, and then returned to the upper part of the hot melt dechlorination reactor (20), and the other part is sent to the upper part of the downward cracking reactor (4) together with the crude oil as a raw material through an atomizing feed nozzle (3). The gas extracted from the top of the hot melt dechlorination reactor (20) is treated by a desulfurization and dechlorination reactor (24) and then enters the refinery gas network as fuel gas. The flow rate of the high-speed circulation pipe (25) is 2-30 m / s, and the circulation ratio of the molten plastic liquid to the raw material is 1 ~10:1, the amount of steam used in the atomizing feed nozzle (3) is 4% to 12% of the amount of the raw material; the atomized particle feed of the mixture of the molten plastic liquid and the crude oil is rapidly mixed, vaporized and controllably cracked with the cracking regeneration catalyst falling from the top of the descending cracking reactor (4), the amount of steam used in the atomizing feed nozzle (3) is 4% to 12% of the amount of the raw material, the cracking reaction temperature is 500 to 550° C., the pressure is 0-0.3 MPa, the reaction time is 600 milliseconds to 2 seconds, and oil-gas-solid separation (5) is performed at the bottom of the descending cracking reactor (4) The separated catalyst to be regenerated flows into the bottom of the cracking riser regenerator (10) through a return device (7) and is regenerated by air fluidization burning at 500-750°C. The bottom of the cracking riser regenerator (10) is provided with a regeneration air inlet (9), and the top is provided with a gas-solid separator (1), a heat exchanger (11) and a regeneration flue gas outlet (12) in sequence. The regenerated catalyst separated by the gas-solid separator (1) at the top of the cracking riser regenerator (10) is circulated back to the top of the descending cracking reactor (4) through a return controller (2) to catalytically crack the mixture of molten plastic liquid and crude oil.The high-temperature cracking oil and gas are directly sprayed from the gas phase feed hole in the upper part of the descending cracking reactor (8) without condensation, and are rapidly mixed with the cracking regeneration catalyst falling from the top and undergo a controllable cracking reaction. The oil and gas gas-solid separation (5) is performed at the bottom of the descending cracking reactor (8). The cracking reaction temperature is 570-650°C, the pressure is 0-0.3MPa, and the reaction time is 200 milliseconds to 1 second. The separated cracking catalyst to be regenerated flows into the bottom of the cracking riser regenerator (113) through a return device (7) and is regenerated by air fluidization burning at 600-750°C. The bottom of the cracking riser regenerator (10) is provided with an air inlet (14), and the top is provided with a gas-solid separator (1), a heat exchanger (11) and a regeneration flue gas outlet (15) in sequence. The cracking regeneration catalyst separated by the gas-solid separator (1) at the top of the cracking riser regenerator (13) is circulated back to the top of the descending cracking reactor (13) through the return device (7) to catalytically crack the high-temperature cracking oil and gas. The high-temperature cracking oil and gas enter the fractionation tower (3) for separation. One of the cracking dry gas pipelines at the top of the fractionation tower (3) is connected to the feed carrying gas inlet of the water-cooled feed pipe (23) at the top of the hot melt dechlorination reactor (20), and the other is connected to the cracking gas refining system to produce triolefins. One of the oil refining pipelines of the fractionation tower (16) is connected to the high-temperature molten oil inlet at the top of the hot melt dechlorination reactor (20), and the other is sent out as a product after recovering the waste heat. The other side lines of the fractionation tower (16) are crude benzene fraction and diesel fraction.

[0021] The outer wall of the water-cooled feed pipe (23) is provided with a water-cooled jacket, which is in the shape of a positive cone, a straight tube or an inverted cone, preferably a positive cone.

[0022] The controllable feeder (22) is a rotary feeder, a double-shaft screw feeder or a single-shaft screw feeder.

[0023] The high-speed circulation pipe (26) is heated by electromagnetic induction heating, heat-conducting oil heating, steam heating or resistance heating, preferably electromagnetic induction heating.

[0024] The cracking catalyst used in the descending cracking reaction tube (4) is a mixture of one or more of semi-coke microspheres, alumina microspheres, calcium aluminate porous microspheres, magnesium aluminum spinel porous microspheres, aluminum silicate porous microspheres, calcium silicate porous microspheres, magnesium silicate porous microspheres, and porous microsphere carriers loaded with alkali metals and / or alkaline earth metals.

[0025] The cracking catalyst used in the downstream cracking reactor (8) is a mixture of one or more of an FCC molecular sieve catalyst, a ZSM-5 type selective molecular sieve catalyst, and an alkaline solid porous catalyst.

[0026] The riser regenerator is composed of a turbulent fluidized bed at the bottom and a carrying reactor at the top. The turbulent fluidized bed has a larger equivalent diameter, while the carrying reactor has a smaller equivalent diameter, with a diameter ratio of 2 to 3:1. The carrying reactor can be a straight tube reactor with a uniform equivalent diameter, or can be composed of large and small straight tubes with diameters of different multiples of the equivalent diameter connected by large and small head pipe fittings, with a diameter ratio of 1.2 to 2:1. The equivalent diameter of the fluidized bed is only 10%-50% of the equivalent diameter of the turbulent fluidized bed.

[0027] The process of producing chemicals by graded gas-phase dehydrogenation and cracking of mixed feed of waste plastics and crude oil can continuously, on a large scale, efficiently and cleanly utilize waste plastics and crude oil to produce high value-added chemicals such as triolefins and triphenyls. It has solved the five common industry problems of waste plastic feed adhesion and coking, difficulty in mixing with high-temperature catalysts, low yield and added value of liquid products, difficulty in scaling up pyrolysis equipment, and difficulty in subsequent processing of liquid products containing chlorine. The triolefins yield is ≥50%, the triphenyls yield is ≥15%, the diesel yield is ≥20%, and the total yield of liquid products is above 93% (including liquefied gas), which is more than 25 percentage points higher than the traditional waste plastic pyrolysis technology, ensuring safe, stable, full and optimal operation of the device.

Claims

1. A process for producing chemicals by gas phase dehydrogenation and cracking of waste plastics and crude oil mixed feed, the technical characteristics of which are The clean PE and PP waste plastics are sorted through the waste plastic crusher. The waste plastic fragments are added to the 20-95℃ water-cooled feed pipe through a controllable feeder, and fall into the 240-320℃ oil slurry melt of the hot melt dechlorination reactor with stirring under the support of the cracking dry gas. The melt dechlorination and desulfurization pretreatment is carried out by stirring and mixing. The molten plastic liquid extracted from the bottom of the hot melt dechlorination reactor is pressurized and transported by a delivery pump. A part of it is heated to 20-60℃ higher than the temperature of the oil slurry melt through a high-speed circulation pipe with external heating and then returned to the upper part of the hot melt dechlorination reactor. The other part is sent to the upper part of the downward cracking reactor together with the crude oil as raw material through the atomizing feed nozzle. The gas extracted from the top of the hot melt dechlorination reactor is treated in the desulfurization and dechlorination reactor and then enters the refinery gas network as fuel gas. The flow rate of the high-speed circulation pipe is 2-30 m / s, the circulation ratio of the molten plastic liquid to the raw material is 1-10:1, and the steam dosage of the atomizing feed nozzle is 4wt%-12wt% of the raw material amount; the atomized particle feed of the mixture of the molten plastic liquid and the crude oil is quickly mixed, vaporized and controllably cracked with the cracking regeneration catalyst falling from the top of the descending cracking reactor. The steam dosage of the atomizing feed nozzle is 4wt%-12wt% of the raw material amount, the cracking reaction temperature is 500-550°C, the pressure is 0-0.3MPa, and the reaction time is 600 milliseconds to 2 seconds, and oil and gas are separated at the bottom of the descending cracking reactor; the separated catalyst to be regenerated flows into the bottom of the cracking riser regenerator through the return device and is regenerated by air fluidization at 500-750°C. The bottom of the cracking riser regenerator is provided with a regeneration air inlet, and the top is provided with a gas-solid separator, a heat exchanger and a regeneration flue gas outlet in sequence. The regenerated catalyst separated by the gas-solid separator at the top of the cracking riser regenerator is circulated back to the top of the descending cracking reactor through the return controller to catalytically crack the mixture of molten plastic liquid and crude oil; the high-temperature cracking oil and gas are directly sprayed from the gas phase feed hole in the upper part of the descending cracking reactor without condensation, and the cracking regeneration catalyst falling from the top is directly sprayed into the bottom of the cracking riser regenerator. The catalyst undergoes rapid mixing and controllable cracking reaction, and oil and gas are separated from each other at the bottom of the descending cracking reactor. The cracking reaction temperature is 570-650°C, the pressure is 0-0.3MPa, and the reaction time is 200 milliseconds to 1 second. The separated cracking catalyst flows into the bottom of the cracking riser regenerator through a return device and is regenerated by air fluidization at 600-750°C. The bottom of the cracking riser regenerator is provided with an air inlet, and the top is provided with a gas-solid separator, a heat exchanger and a regenerated flue gas outlet in sequence. The cracking regenerated catalyst separated by the gas-solid separator at the top of the cracking riser regenerator is circulated back to the top of the descending cracking reactor through a return device to catalytically crack the high-temperature cracked oil and gas. The high-temperature cracking oil and gas enter the distillation tower for separation. The cracking dry gas at the top of the distillation tower is circulated back to the water-cooled feed pipe at the top of the hot melt dechlorination reactor as feed carrying gas, and the other way is connected to the cracking gas refining system to produce trienes. The refining oil from the distillation tower is circulated back to the upper part of the hot melt dechlorination reactor as high-temperature melting oil, and the other way is sent out as a product after recovering the waste heat. The other side lines of the distillation tower are crude benzene fraction and diesel fraction.

2. The process for preparing chemicals by gas phase dehydrogenation cracking of waste plastics and crude oil mixed feed according to claim 1, characterized in that The outer wall of the water-cooled feed pipe is provided with a water-cooled jacket, which is in the shape of a positive cone, a straight tube or an inverted cone, preferably a positive cone.

3. The process for preparing chemicals by gas phase dehydrogenation cracking of waste plastics and crude oil mixed feed according to claim 1, characterized in that The controllable feeder is a rotary feeder, a double-shaft screw feeder or a single-shaft screw feeder.

4. The process for preparing chemicals by gas phase dehydrogenation cracking of waste plastics and crude oil mixed feed according to claim 1, characterized in that The high-speed circulation tube is heated by electromagnetic induction heating, thermal oil heating, steam heating or resistance heating, preferably electromagnetic induction heating.

5. The process for preparing chemicals by gas phase dehydrogenation cracking of waste plastics and crude oil mixed feed according to claim 1, characterized in that The cracking catalyst is a mixture of one or more of semi-coke microspheres, alumina microspheres, calcium aluminate porous microspheres, magnesium aluminum spinel porous microspheres, aluminum silicate porous microspheres, calcium silicate porous microspheres, magnesium silicate porous microspheres, and porous microsphere carriers loaded with alkali metals and / or alkaline earth metals.

6. The process for preparing chemicals by gas phase dehydrogenation cracking of waste plastics and crude oil mixed feed according to claim 1, characterized in that The cracking catalyst is a mixture of one or more of an FCC molecular sieve catalyst, a ZSM-5 selective molecular sieve catalyst, and an alkaline solid porous catalyst.

7. The process for preparing chemicals by gas phase dehydrogenation cracking of waste plastics and crude oil mixed feed according to claim 1, characterized in that The riser regenerator is composed of a turbulent fluidized bed at the bottom and an entrained reactor at the top, the ratio of the equivalent diameter of the turbulent fluidized bed to the equivalent diameter of the entrained reactor is 2 to 3:1; the entrained reactor is a straight tube reactor with a uniform equivalent diameter, or is composed of large and small straight tubes with diameters of different multiples of the equivalent diameter connected by large and small head pipe fittings, the diameter ratio of the large and small straight tubes is 1.2 to 2:1; the equivalent diameter of the fluidized bed is 10%-50% of the equivalent diameter of the turbulent fluidized bed.

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