Waste plastic and petroleum mixed feeding catalytic cracking production device

Abstract

A waste plastic and petroleum mixed feeding catalytic cracking production device is composed of a waste plastic self-hot melting dechlorination pretreatment subsystem, a waste plastic molten liquid and petroleum catalytic cracking subsystem and a pyrolysis oil gas fractionation subsystem. A recycle oil pipeline and a cracking dry gas pipeline of the cracking oil-gas fractionation subsystem are respectively connected to a high-temperature dissolved oil inlet and a feeding carrying gas inlet of the waste plastic self-heating melting dechlorination pretreatment subsystem, and a waste plastic molten liquid delivery pipeline of the waste plastic self-heating melting dechlorination pretreatment subsystem is connected to a crude oil feeding pipeline; a waste plastic and crude oil mixed feeding pipeline is connected into the waste plastic molten liquid and crude oil catalytic cracking subsystem through an atomizing nozzle, and then the cracked oil gas fractionation subsystem produces gasoline, diesel oil, high-temperature recycle oil and cracked dry gas.

Description

1. Technical Field

[0001] The invention provides a catalytic cracking production device for mixed feeding of waste plastics and petroleum, 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] Catalytic cracking is the main technology for petroleum processing and the main device for producing gasoline, diesel and propylene. It has a short process, simple operation, low cost and energy consumption, and low investment. Combining rapid pyrolysis / catalytic pyrolysis of waste plastics with catalytic cracking of petroleum is an effective means to improve the clean and efficient utilization of waste plastics as raw materials, reduce the consumption of petroleum resources, solve the problem of pyrolysis feed of waste plastics, and improve the yield of gasoline and diesel and the economic benefits of the device. It is urgent to develop catalytic cracking technology and equipment technology for mixed feed of waste plastics and petroleum. 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 catalytic cracking production device for mixed feed of waste plastic and petroleum, utilize pyrolysis dry gas and high-temperature recycled oil circulation to carry out hot melt dechlorination and sulfur removal pretreatment of waste plastic and liquid phase atomization feeding, solve the difficult problems of pyrolysis feeding and removal of chlorine and sulfur heteroatoms; adopt catalytic cracking to treat mixed raw materials of waste plastic and crude oil, the cracking characteristics complement each other, inhibit condensation coking, eliminate the amplification effect, realize controllable cracking of waste plastic, maximize the production of triolefins and triphenyls, and solve the five common problems of waste plastic feed adhesion and coking, 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 pyrolysis device, 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] The waste plastic and petroleum mixed feed catalytic cracking production device consists of a waste plastic self-thermal melting dechlorination pretreatment subsystem, a waste plastic melt and petroleum catalytic cracking subsystem, and a cracking oil and gas fractionation subsystem. The waste plastic crusher is connected to the water-cooled feed pipe through a controllable feeder. The top of the water-cooled feed pipe is provided with a cracking dry gas injection port, and the bottom is connected to a hot melt dechlorination reactor with stirring. The bottom of the hot melt dechlorination reactor is connected to a high-speed circulation pipe with heating through a delivery pump and returns to the upper part of the hot melt dechlorination reactor, and the other is connected to the petroleum feed pipe. The waste plastic melt is connected to the atomizing feed nozzle of the cracking reactor of the petroleum catalytic cracking subsystem together with the line. The gas extraction port on the top of the hot melt dechlorination reactor is connected to the desulfurization and dechlorination reactor and the refinery dry gas pipeline network, forming a waste plastic self-thermal melting dechlorination pretreatment subsystem. The temperature of the water-cooled feed pipe is 20-95°C, the oil slurry melt is 240-320°C, the temperature of the molten plastic liquid high-speed circulation pipe after heating is 20-60°C higher than that of the recycled oil melt, the flow rate of the high-speed circulation pipe is 2-30m / s, and the circulation of the molten plastic liquid is The raw material ratio is 1 to 10:1; an atomizing feed nozzle is symmetrically installed on the catalytic cracking reactor, the reactor outlet is connected to an oil-gas gas-solid separator, the gas phase outlet of the oil-gas gas-solid separator is connected to a fractionation tower, and the solid phase outlet is connected to the bottom of a regeneration reactor through a return material controller; a gas-solid separator is installed on the top of the regeneration reactor and is connected to the cracking reactor through a return material, forming a waste plastic melt and petroleum catalytic cracking subsystem, the steam consumption of the atomizing feed nozzle is 4% to 12% of the raw material amount, and the cracking reaction temperature is 500 to 550 ℃, pressure is 0-0.3MPa, reaction time is 600ms-2s, regeneration temperature is 500-750℃; one cracking dry gas pipeline at the top of the fractionating tower of the cracking oil and gas fractionation subsystem is connected to the feed carrying gas inlet of the water-cooled feed pipe at the top of the hot melt dechlorination reactor, and the other is connected to the refinery dry gas network; one pipeline returning the fractionating tower to the refining is connected to the high-temperature molten oil inlet at the top of the hot melt dechlorination reactor, and the other recovers the waste heat and is sent out as a product; other side lines of the fractionating tower are liquefied gas, gasoline 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 catalytic cracking reactor is a riser reactor or a downer reactor.

[0013] The cracking catalyst used in the catalytic cracking reactor 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 present invention will be described in detail with reference to embodiments. 4. Description of the drawings

[0015] Attached Figure 1 The present invention is a schematic diagram of the process flow of the catalytic cracking production device of waste plastics and petroleum mixed feed.

[0016] Attached Figure 1 The drawing settings are as follows:

[0017] 1. Gas-solid separator, 2. Feed return controller, 3. Atomizing feed nozzle, 4. Cracking reactor, 5. Oil-gas gas-solid separator, 6. Fractionation tower, 7. Feed return device, 8. Refinery pump, 9. Regeneration air inlet, 10. Regeneration reactor, 11. Heat exchanger, 12. Regeneration flue gas outlet, 13. Diesel fraction, 14. Crude benzene fraction, 15. Waste plastic crusher, 16. Controllable feeder, 17. Water-cooled feed pipe, 18. Hot melt dechlorination reactor, 19. Delivery pump, 20. Desulfurization and dechlorination reactor, 21. Refinery dry gas pipeline network, 22. High-speed circulation pipe, 23. Petroleum feed line, 24. Liquefied gas

[0018] The process characteristics of the present invention are described in detail below in conjunction with the accompanying drawings and embodiments. 5. Specific implementation methods

[0019] The waste plastic and petroleum mixed feed catalytic cracking production device provided by the present invention comprises a waste plastic self-thermal melting dechlorination pretreatment subsystem, a waste plastic melt and petroleum catalytic cracking subsystem, and a cracking oil and gas fractionation subsystem. The waste plastic crusher (15) is connected to a water-cooled feed pipe (17) through a controllable feeder (16). The top of the water-cooled feed pipe (17) is provided with a cracking dry gas injection port, and the bottom is connected to a hot melt dechlorination reactor (18) with stirring. The bottom of the hot melt dechlorination reactor (18) is connected to a high-speed circulation pipe (22) with heating through a delivery pump (19) and returns to the upper part of the hot melt dechlorination reactor (18). One path is connected with the petroleum feed line (23) to the atomizing feed nozzle (3) of the cracking reactor (4) of the petroleum catalytic cracking subsystem for the waste plastic melt and the petroleum catalytic cracking subsystem, the gas extraction outlet at the top of the hot melt dechlorination reactor (18) is connected with the desulfurization and dechlorination reactor (20) and the refinery dry gas pipeline (21), forming a waste plastic self-thermal melting dechlorination pretreatment subsystem, the temperature of the water-cooled feed pipe (17) is 20-95°C, the recycled oil melt is 240-320°C, the temperature of the molten plastic high-speed circulation pipe (22) after heating is 20-60°C higher than that of the recycled oil melt, the flow rate of the high-speed circulation pipe (22) is 2-30m / s, and the melt The circulation ratio of the plastic liquid to the raw material is 1 to 10:1; an atomizing feed nozzle (3) is symmetrically installed on the catalytic cracking reactor (4); the reactor outlet is connected to an oil-gas gas-solid separator (5); the gas phase outlet of the oil-gas gas-solid separator (5) is connected to a fractionation tower (6); the solid phase outlet is connected to the bottom of a regeneration reactor (10) through a return material controller (2); a gas-solid separator (1) is installed on the top of the regeneration reactor (10) and is connected to the cracking reactor (4) through a return material controller (7); a waste plastic melt and petroleum catalytic cracking subsystem is formed; the steam consumption of the atomizing feed nozzle (3) is 4% to 12% of the raw material amount; the cracking reactor (10) is 1% to 2% of the raw material amount; the steam consumption of the atomizing feed nozzle (3) is 4% to 12% of the raw material amount; the steam consumption of the cracking reactor (10) is 1% to 2% of the raw material amount; the steam consumption of the atomizing feed nozzle (3 ... The temperature is 500-550°C, the pressure is 0-0.3MPa, the reaction time is 600 milliseconds-2 seconds, and the regeneration temperature is 500-750°C; one of the cracking dry gas pipelines at the top of the fractionation tower (6) of the cracking oil and gas fractionation subsystem is connected to the feed carrying gas inlet of the water-cooled feed pipe (17) at the top of the hot melt dechlorination reactor (18), and the other is connected to the cracking dry gas pipeline network (21); one of the oil refining pipelines of the fractionation tower (6) is connected to the high-temperature molten oil inlet at the top of the hot melt dechlorination reactor (18), and the other is used to recover the waste heat and then send it out as a product; the other side lines of the fractionation tower (6) are liquefied gas, gasoline fraction and diesel fraction.

[0020] The outer wall of the water-cooled feed pipe (17) 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.

[0021] The controllable feeder (16) is a rotary feeder, a double-shaft screw feeder or a single-shaft screw feeder.

[0022] The high-speed circulation pipe (22) is heated by electromagnetic induction heating, heat-conducting oil heating, steam heating or resistance heating, preferably electromagnetic induction heating.

[0023] The cracking reactor (4) is a riser reactor or a downer reactor.

[0024] The catalyst used in the cracking reactor (4) 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.

[0025] In specific operation, the clean PE, PP and PS waste plastics are sorted through a waste plastic crusher (15), and the waste plastic fragments are added to a water-cooled feed pipe (17) at 20-95° C. through a controllable feeder (16), and fall into a 240-320° C. oil slurry melt in a hot melt dechlorination reactor (18) with stirring under the influence of cracking dry gas, and are melted for dechlorination and desulfurization pretreatment by stirring and mixing. The molten plastic liquid extracted from the bottom of the hot melt dechlorination reactor (18) is conveyed under pressure by a conveying pump (19), and a part of the molten plastic liquid is conveyed by an external pressure pump (19). The hot high-speed circulation pipe (22) is heated to a temperature 20-60°C higher than the temperature of the recycled oil melt and then returns to the upper part of the hot melt dechlorination reactor (18). Another part is sent to the upper middle part of the cracking reactor (4) together with the petroleum as a raw material through the atomizing feed nozzle (3). The fuel gas extracted from the top of the hot melt dechlorination reactor (18) is treated by the desulfurization and dechlorination reactor (20) and then enters the refinery dry gas network (21) as fuel gas. The flow rate of the high-speed circulation pipe (22) 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 petroleum is quickly mixed, vaporized and cracked with the cracking regeneration catalyst dropped from the top of the 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 ); the separated catalyst to be regenerated flows into the bottom of the regeneration reactor (10) through a return device (7) and is regenerated by air fluidization charring at 500-750°C. The bottom of the regeneration reactor (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 regeneration reactor (10) is circulated back to the top of the cracking reactor (4) through a return controller (2) to catalytically crack the mixture of molten plastic liquid and petroleum. The high-temperature cracked oil and gas enter the fractionation tower (6) for separation. One of the cracked dry gas pipelines at the top of the fractionation tower (6) is connected to the feed carrying gas inlet of the water-cooled feed pipe (17) at the top of the hot melt dechlorination reactor (18), and the other is connected to the refinery dry gas pipeline network (21). One of the oil return pipelines of the fractionation tower (6) is connected to the high-temperature dissolved oil inlet at the top of the hot melt dechlorination reactor (18), and the other is sent out as a product after recovering the waste heat. Other side lines of the fractionation tower (6) are liquefied gas, gasoline fraction and diesel fraction.

[0026] The catalytic cracking production unit with mixed feed of waste plastic and petroleum is capable of continuously, on a large scale, efficiently and cleanly utilizing waste plastic and crude oil for catalytic cracking to produce gasoline and diesel. It has solved five common industry problems: adhesion and coking of waste plastic feed, difficulty in mixing with high-temperature catalysts, low yield and added value of liquid products, difficulty in scaling up the pyrolysis unit, and difficulty in subsequent processing of liquid products containing chlorine. The yield of liquefied gas is ≥16%, the yield of gasoline is ≥42%, the yield of diesel is ≥36%, and the total yield of liquid products is above 94%, which is more than 24 percentage points higher than that of traditional waste plastic pyrolysis technology, realizing safe, stable, full and optimal operation of the unit.

Claims

1. A waste plastic and petroleum mixed feed catalytic cracking production device, which is technically characterized by comprising a waste plastic self-thermal melt dechlorination pretreatment subsystem, a waste plastic melt and petroleum catalytic cracking subsystem, and a cracking oil and gas fractionation subsystem. The waste plastic crusher is connected to a water-cooled feed pipe through a controllable feeder. The top of the water-cooled feed pipe is provided with a cracking dry gas injection port, and the bottom of the water-cooled feed pipe is connected to a hot melt dechlorination reactor with stirring. The bottom of the hot melt dechlorination reactor is connected to a high-speed circulation pipe with heating through a delivery pump and returns to the upper part of the hot melt dechlorination reactor, and the other way The atomizing feed nozzle of the cracking reactor of the waste plastic molten liquid and the petroleum catalytic cracking subsystem is connected together with the petroleum feed pipeline. The gas extraction outlet at the top of the hot melt dechlorination reactor is connected with the desulfurization and dechlorination reactor and the refinery dry gas pipeline network, forming a waste plastic self-thermal melting dechlorination pretreatment subsystem. The temperature of the water-cooled feed pipe is 20-95°C, the oil slurry molten liquid is 240-320°C, the temperature of the molten plastic liquid high-speed circulation pipe after heating is 20-60°C higher than the recycled oil molten liquid, the flow rate of the high-speed circulation pipe is 2-30m / s, and the molten plastic liquid The circulation to raw material ratio is 1 to 10:1; an atomizing feed nozzle is symmetrically installed on the catalytic cracking reactor, the reactor outlet is connected to an oil-gas gas-solid separator, the gas phase outlet of the oil-gas gas-solid separator is connected to a fractionation tower, and the solid phase outlet is connected to the bottom of the regeneration reactor through a return material controller, and a gas-solid separator is installed on the top of the regeneration reactor and connected to the cracking reactor through a return material, forming a waste plastic melt and petroleum catalytic cracking subsystem, the steam consumption of the atomizing feed nozzle is 4% to 12% of the raw material amount, and the cracking reaction temperature is 500 to 550 ℃, pressure is 0-0.3MPa (gauge pressure), reaction time is 600 milliseconds to 2 seconds, and regeneration temperature is 500-750℃; one cracking dry gas pipeline at the top of the fractionating tower of the cracking oil and gas fractionation subsystem is connected to the feed carrying gas inlet of the water-cooled feed pipe at the top of the hot melt dechlorination reactor, and the other is connected to the refinery dry gas network, one pipeline returning the fractionating tower to the refining is connected to the high-temperature molten oil inlet at the top of the hot melt dechlorination reactor, and the other recovers the waste heat and is sent out as a product, and other side lines of the fractionating tower are liquefied gas, gasoline fraction and diesel fraction.

2. The catalytic cracking production device of waste plastics and petroleum mixed feed according to claim 1, characterized in that 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.

3. The catalytic cracking production device of waste plastics and petroleum 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 catalytic cracking production device of waste plastics and petroleum 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 catalytic cracking production device of waste plastics and petroleum mixed feed according to claim 1, characterized in that The catalytic cracking reactor is a riser reactor or a downer reactor.

6. The catalytic cracking production device of waste plastics and petroleum mixed feed according to claim 1, characterized in that The catalyst used in the cracking reactor 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.

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