CN116083119B

CN116083119B - Catalytic conversion method for producing propylene and high aromatic hydrocarbon gasoline by co-refining waste plastic oil and heavy oil

Info

Publication number: CN116083119B
Application number: CN202111308757.3A
Authority: CN
Inventors: 宋宝梅; 魏晓丽; 刘宪龙; 张执刚
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2021-11-05
Filing date: 2021-11-05
Publication date: 2024-04-02
Anticipated expiration: 2041-11-05
Also published as: CN116083119A

Abstract

The present disclosure provides a catalytic conversion method for producing propylene and high aromatic hydrocarbon gasoline by co-refining waste plastic oil and heavy oil, comprising: the method comprises the steps of (1) contacting waste plastic oil with a low-temperature spent agent to obtain a reaction oil solution, contacting the reaction oil solution with a low-temperature regenerant, a hot regenerant and a dechlorination agent, and carrying out catalytic conversion reaction and dechlorination reaction to obtain first reaction oil gas and a first spent agent; separating the first reaction oil gas to obtain low-chlorine plastic oil; carrying out catalytic conversion reaction on petroleum hydrocarbon and a second catalyst to obtain second reaction oil gas and a semi-spent agent; carrying out catalytic conversion reaction on the second reaction oil gas and the semi-spent agent to obtain third reaction oil gas and the second spent agent; the low-chlorine plastic oil is sent to a second catalyst for catalytic conversion reaction to obtain fourth reaction oil gas and a third spent agent; and mixing the third reaction oil gas and the fourth reaction oil gas and then separating. The method disclosed by the invention is used for processing waste plastic oil, and has the advantages of high propylene yield, high aromatic hydrocarbon gasoline yield and low chlorine content.

Description

Catalytic conversion method for producing propylene and high aromatic hydrocarbon gasoline by co-refining waste plastic oil and heavy oil

Technical Field

The present disclosure relates to the petrochemical field, and in particular, to a catalytic conversion method for producing propylene and high aromatic hydrocarbon gasoline by co-refining waste plastic oil and heavy oil.

Background

With the improvement of environmental awareness and the continuous increase of environmental pressure, the main treatment methods of plastics at present are three modes of landfill, incineration and recycling, wherein the landfill mode is difficult to effectively realize reduction and harmlessness in a short period due to low bulk density of plastic products and difficult decomposition; the incineration can generate a large amount of greenhouse gases and release harmful gases such as dioxin, and the two modes are gradually eliminated, and the recycling mode becomes the main stream of the mode for treating waste plastics. The recycling mode mainly comprises two modes: the first is physical recovery, after the waste plastics are recovered and granulated, various appliances, articles and the like are manufactured; the second method is to recycle the waste plastics and then catalytically crack the waste plastics to prepare fuel oil products with high added value, and the method has been widely applied in research and production due to higher economic benefit.

At present, most of plastic pyrolysis technology adopts a rotary kiln reactor with an intermittent method, mainly produces oil products, and has an oil product yield of 30-50%, and the balance of coke and pyrolysis gas. In the production of fuel oil by catalytic pyrolysis of waste plastics, the waste plastics contain about 10-20% of polyvinyl chloride (PVC) and/or polyvinylidene chloride (PVDC) besides Polyethylene (PE) and polypropylene (PP) as main components, and can be converted into gas products and liquid products through pyrolysis. These liquid products may contain paraffins, isoparaffins, olefins, naphthenes and aromatic components and organic chlorides in concentrations of hundreds of ppm. In addition, the plastic oil is found to contain a certain amount of organic silicon and other impurities through analysis. Therefore, plastic oils cannot be used directly as petrochemicals and require further processing.

In addition, at present, the production of low-carbon olefins is mainly carried out by petroleum hydrocarbon, and the traditional method for preparing ethylene and propylene from petroleum hydrocarbon is steam thermal cracking, wherein the steam thermal cracking is to thermally crack the petroleum hydrocarbon at the temperature of more than 800 ℃ in the presence of steam. Therefore, there is a need in the art to pretreat the existing waste plastic oil to meet the catalytic cracking feeding requirement, and co-smelt the pretreated waste plastic oil and petroleum hydrocarbon, thereby reducing the equipment investment and simultaneously producing high-value propylene and high-aromatic hydrocarbon gasoline.

Chinese patent document CN201210469849.4 discloses a method for preparing clean diesel oil by a plastic oil hydrogenation method, which comprises the steps of mixing plastic oil and hydrogen, entering a pre-hydrogenation reactor filled with a hydrogenation protection catalyst for chemical reaction, entering an effluent of the pre-hydrogenation reactor into a main hydrogenation reactor for chemical reaction, and separating reaction products to obtain clean diesel oil fractions with sulfur content of less than 5 mug/g and cetane number of more than 50.

U.S. patent document US9428695 discloses a method for producing light olefins and aromatics from waste plastics, wherein the reaction temperature is 420-730, the catalyst is a mixture of FCC catalyst and ZSM-5, the produced liquid product is reformed to produce aromatic components and non-aromatic components, and the non-aromatic components are recycled to the reactor; or separating the direct liquid product into aromatic hydrocarbon and non-aromatic hydrocarbon components, and returning the non-aromatic hydrocarbon components to the reactor; or directly separating the liquid product into aromatic hydrocarbon and non-aromatic hydrocarbon components, and returning the non-aromatic hydrocarbon components to the reactor through hydrogenation; or directly returning the liquid product to the reactor through hydrogenation; or the thermal cracking reaction is carried out, the liquid product of the thermal cracking reaction is separated into aromatic hydrocarbon and non-aromatic hydrocarbon components, and the non-aromatic hydrocarbon components are returned to the reactor. The yield of C2-C4 olefins is 34.91%, and the aromatic hydrocarbon concentration in the fraction below the distillation range of 240 ℃ is 75.37%.

US20200017772 discloses a method for producing propylene and cumene from waste plastics, which comprises pyrolyzing waste plastics into pyrolysis gas and liquid products by a pyrolysis furnace, hydrotreating the liquid products, separating the obtained c5+ hydrocarbons to obtain benzene and c5+ hydrocarbons other than benzene, sending the latter to the pyrolysis furnace to produce propylene, and reacting the propylene with benzene to produce cumene.

Chinese patent document CN201610425196.8 discloses a method for directionally preparing aromatic hydrocarbon by pyrolyzing biomass and plastic waste, wherein biomass and plastic waste are first pyrolyzed respectively; secondly, through selective catalysis (primary catalysis) on respective pyrolysis products, macromolecular oxygen-containing compounds and long-chain hydrocarbon substances which are relatively inert and easy to form coking in the products are selectively converted into small molecular oxygen-containing compounds and short linear olefins with higher activity; then the aromatic hydrocarbon product with higher yield and selectivity is obtained through the shape-selective catalytic reaction (secondary catalysis) of the active small molecular compound on the molecular sieve catalyst.

Chinese patent document CN201410225940.0 discloses a method for producing clean fuel oil from chlorine-containing plastic oil, wherein the method comprises the steps of reacting and rectifying chlorine-containing plastic oil in a catalytic distillation tower, and hydrodechlorinating the chlorine-containing plastic oil after catalytic conversion; the distillate oil after liquid phase hydrogenation enters a hydrofining tower again, so that gasoline and diesel oil mixed oil with no peculiar smell and high quality can be obtained, and then gasoline and diesel oil distillate oil can be obtained through distillation.

From the prior art, the processing and utilizing technology of waste plastics takes fuel oil as a main product, and the technology disclosed by the prior art for producing low-carbon olefin, especially propylene, is rarely available. When the fuel oil is used as a target product, the effect of dechlorination is achieved by adopting a hydrogenation technology as a main method, the technology of generating the high aromatic hydrocarbon gasoline is not involved, the hydrogenation technology has a complex process flow due to hydrogen consumption, the requirement on equipment materials is high, and the investment cost is greatly increased.

Disclosure of Invention

The purpose of the present disclosure is to provide a method for producing propylene and high aromatic hydrocarbon gasoline from waste plastics and petroleum hydrocarbons.

In order to achieve the above object, the present disclosure provides a catalytic conversion method for producing propylene and high aromatic gasoline by co-refining waste plastic oil and heavy oil, the method comprising:

s1, injecting waste plastic oil into a low-temperature spent catalyst pipeline of a first catalyst, contacting and reacting with the low-temperature spent catalyst to obtain a first reaction oil, feeding the first reaction oil into a fluidized bed reactor, contacting with a low-temperature regenerated catalyst, a hot regenerated catalyst and a dechlorinating agent in sequence from bottom to top, and carrying out a first catalytic conversion reaction and a dechlorination reaction to obtain first reaction oil gas and a first spent catalyst; separating the first reaction oil gas to obtain dry gas, liquefied gas and low-chlorine plastic oil;

S2, feeding preheated petroleum hydrocarbon into the lower part of the first dilute phase conveying bed reactor to contact with a second catalyst and perform a second catalytic conversion reaction to obtain second reaction oil gas and a semi-spent catalyst; sending the second reaction oil gas and the semi-spent catalyst into a dense-phase fluidized bed reactor for a third catalytic conversion reaction to obtain third reaction oil gas and the second spent catalyst;

s3, feeding the preheated low-chlorine plastic oil into the lower part of a second dilute phase conveying bed reactor to contact with a second catalyst, and carrying out a fourth catalytic conversion reaction from bottom to top to obtain fourth reaction oil gas and a third spent catalyst;

s4, mixing the third reaction oil gas and the fourth reaction oil gas, and then separating to obtain dry gas, liquefied gas, pyrolysis gasoline, pyrolysis diesel oil and pyrolysis heavy oil.

Alternatively, the waste plastic oil is used in an amount of 0 to 50 wt%, preferably 5 to 30 wt%, based on the total weight of the waste plastic oil and the petroleum hydrocarbon;

optionally, the waste plastic oil is selected from at least one of polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride and polyethylene terephthalate; preferably, the properties of the waste plastic oil meet at least one of the following criteria: the density of the waste plastic oil at 20 ℃ is 750-900kg/m ³ The carbon residue content of the waste plastic oil is 0-2 wt%, the silicon content of the waste plastic oil is 50-2000mg/kg, and the chlorine content of the waste plastic oil is 50-5000mg/kg.

Optionally, the conditions of the first catalytic conversion reaction include: the reaction temperature is 300-550 ℃, the reaction time is 0.1-5 seconds, and the weight ratio of the catalyst to the oil is (5-100): 1, the weight ratio of water to oil is (0.05-0.8): 1, a step of; the conditions of the second catalytic conversion reaction include: the reaction temperature is 510-650 ℃, the reaction time is 1-20 seconds, and the weight ratio of the catalyst to the oil is (3-50): 1, the weight ratio of water to oil is (0.05-0.8): 1, a step of; the conditions for the third catalytic conversion reaction include: the reaction temperature is 500-600 ℃, and the weight hourly space velocity is 1-20 hours ^-1 The method comprises the steps of carrying out a first treatment on the surface of the The conditions for the fourth catalytic conversion reaction include: the reaction temperature is 510-650 ℃, the reaction time is 1-20 seconds, and the weight ratio of the catalyst to the oil is (3-50): 1, the weight ratio of water to oil is (0.05-0.4): 1.

optionally, the first catalyst contains a binder and a low active substance, and the mass ratio of the binder to the low active substance is 1: (0.05-0.5); the binder is silica sol and/or alumina sol; the low-activity substance is montmorillonite and/or kaolin; the montmorillonite group comprises at least one of bentonite, saponite and montmorillonite; the kaolin family comprises kaolinite and/or halloysite; the preparation method of the first catalyst comprises the following steps: mixing the binder and the low-activity substances to obtain a mixed material, and carrying out spray drying and roasting on the mixed material; optionally, the firing temperature is 630-750 ℃.

Optionally, the first catalyst further comprises alumina; alternatively, the alumina content is from 0.05 to 50 wt%, preferably from 10 to 30 wt%, based on the total weight of the first catalyst; the binder content is 50-99.5 wt%, preferably 50-90 wt%; the low active substance content is 0.5-50 wt%, preferably 10-30 wt%.

Optionally, the second catalyst contains zeolite, inorganic oxide, and clay; the second catalyst comprises, on a dry basis and based on the dry weight of the second catalyst, from 1 to 50 wt% zeolite, from 5 to 99 wt% inorganic oxide, and from 0 to 70 wt% clay; the zeolite comprises medium pore zeolite and/or large pore zeolite, the medium pore zeolite is ZSM series zeolite and/or ZRP zeolite, and the large pore zeolite is at least one selected from rare earth Y, rare earth hydrogen Y, ultrastable Y and high silicon Y;

alternatively, the medium pore zeolite in the second catalyst comprises from 0 to 50 wt% of the total weight of zeolite on a dry basis; preferably, the medium pore zeolite comprises from 0 to 20 wt% of the total weight of the zeolite.

Alternatively, the temperature of the low-temperature spent catalyst is 300-550 ℃, and the total amount of the low-temperature spent catalyst accounts for 5-50 wt%, preferably 10-20 wt%, of the total catalyst circulation amount of the fluidized bed reactor; the introduction position of the low-temperature spent catalyst is located at a height of 1-20%, preferably 5-10%, from the bottom of the fluidized bed reactor; the temperature of the low-temperature regenerated catalyst is 300-450 ℃, and the total amount of the low-temperature regenerated catalyst accounts for 5-50 wt%, preferably 10-20 wt%, of the catalyst circulating total amount of the fluidized bed reactor; the introduction position of the low-temperature regenerated catalyst is positioned at the bottom of the fluidized bed reactor; the temperature of the hot regenerated catalyst is 600-680 ℃, and the total amount of the hot regenerated catalyst accounts for 50-90 wt%, preferably 60-80 wt% of the catalyst circulating total amount of the fluidized bed reactor; the introduction location of the hot regenerated catalyst is located at a height of 20-30% from the bottom of the fluidized bed reactor.

Optionally, the dechlorinating agent contains a calcium compound, an inorganic oxide, and clay; the dechlorinating agent comprises 5-80 wt% of calcium compound, 5-95 wt% of inorganic oxide and 0-50 wt% of clay on a dry basis and based on the total weight of the dechlorinating agent; the calcium compound is at least one of calcium hydroxide, calcium carbonate and calcium oxide; the inorganic oxide is silicon dioxide and/or aluminum oxide; the clay is kaolin and/or halloysite.

Optionally, the dechlorinating agent is used in an amount of 200-10000mg/kg, preferably 200-10000mg/kg, based on the total weight of the waste plastic oil feed amount; the position of introducing the dechlorinating agent into the fluidized bed reactor is located at a height of 50-90% from the bottom of the fluidized bed reactor; preferably, the location of introduction of the dechlorinating agent into the fluidised bed reactor is at a height of 60-70% from the bottom of the fluidised bed reactor.

Optionally, the method further comprises: feeding a first to-be-regenerated catalyst into a first regenerator to perform first scorch regeneration to obtain a first regenerated catalyst, and returning the first regenerated catalyst to the fluidized bed reactor; feeding a second spent catalyst into a second regenerator to perform second scorching regeneration to obtain a second regenerated catalyst, and returning the second regenerated catalyst to the first dilute phase conveying bed reactor and the second dilute phase conveying bed reactor; optionally, the conditions of the first char regeneration include: the temperature is 600-700 ℃ and the pressure is 1.0-2.5MPa; preferably, the temperature is 630-680 ℃ and the pressure is 1.0-2.0MPa; the conditions for the second char regeneration include: the temperature is 600-800 ℃ and the pressure is 1.0-2.5MPa; preferably, the temperature is 650-700 ℃ and the pressure is 1.0-1.5MPa.

Through above-mentioned technical scheme, this disclosure has following technical effect:

(1) The method adopts the methods of gradual heating, sectional gasification and reaction to process the waste plastics, and can avoid the generation of high-viscosity substances in the process of heating and melting the plastics, thereby reducing the generation of coke, improving the yield of plastic oil and simultaneously improving high-quality raw materials for producing propylene and high-aromatic gasoline.

(2) The waste catalytic cracking catalyst and the waste plastics are preferentially contacted and reacted to release hydrogen chloride, and a dechlorinating agent is introduced in the reaction process, so that the generated hydrogen chloride is subjected to a decomposition reaction, the dual technical purposes of waste plastics decomposition and fuel oil dechlorination are achieved in one reaction system, and the corrosion problem of a subsequent device can be effectively avoided.

(3) The method solves the problem of high-efficiency valued utilization of waste plastics, solves the problem of difficult subsequent processing caused by high content of generated fuel oil and chlorine, and only adds a reaction zone on the existing catalytic cracking device, thereby having low investment and bringing greater economic and social benefits for petrochemical industry.

Additional features and advantages of the present disclosure will be set forth in the detailed description which follows.

Drawings

The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification, illustrate the disclosure and together with the description serve to explain, but do not limit the disclosure. In the drawings:

FIG. 1 is a schematic flow diagram of a waste plastic oil pretreatment system of the present disclosure;

fig. 2 is a schematic flow diagram of a low chlorine plastic oil and heavy oil co-refining system of the present disclosure.

Description of the reference numerals

1 fluidized bed reactor 2 first settler 3 first regenerator

4 first steam line 5 waste Plastic oil feed line 6 first Pre-lifting gas line

7 first regenerating inclined tube 8 first cyclone separator 9 first stripping section

10 first to-be-produced agent inclined tube 11 first gas collection chamber 12 first large oil gas pipeline

13 first flue gas duct 14 dechlorinating agent line 15 stripping steam line

16 fractionation column 17 dry gas 18 liquefied gas

19 Low chlorine Plastic oil line 21 spent line 25 second steam line

26 second regenerant chute 27 Petroleum hydrocarbon line 28 third steam line

29 second riser reactor 31 first riser reactor 32 dense phase fluidized bed reactor

33 second settler 34 second regenerator 35 second stripping section

36 fourth steam line 37 second pre-lift gas line 38 third regeneration pipe chute

39 second cyclone separator 40 second plenum 41 second large oil and gas pipeline

42 third spent agent inclined tube 43 third flue gas pipeline

Detailed Description

The following describes specific embodiments of the present disclosure in detail. It should be understood that the detailed description and specific examples, while indicating and illustrating the disclosure, are not intended to limit the disclosure.

The present disclosure provides a catalytic conversion method for producing propylene and high aromatic hydrocarbon gasoline by co-refining waste plastic oil and heavy oil, the method comprising:

The method for processing waste plastics has the advantages of low investment, high propylene yield, high gasoline yield with high aromatic hydrocarbon content and low chlorine content. Specifically, the method for processing waste plastics by adopting gradual heating, sectional gasification and reaction can avoid the generation of high-viscosity substances in the process of heating and melting plastics, thereby reducing the generation of coke, improving the yield of plastic oil and simultaneously improving high-quality raw materials for producing propylene and high-aromatic gasoline. The waste catalytic cracking catalyst and the waste plastics are preferentially contacted and reacted to release hydrogen chloride, and a dechlorinating agent is introduced in the reaction process, so that the generated hydrogen chloride is subjected to a decomposition reaction, the dual technical purposes of waste plastics decomposition and fuel oil dechlorination are achieved in one reaction system, and the corrosion problem of a subsequent device can be effectively avoided.

According to the present disclosure, the waste plastic oil may be used in an amount of 0 to 50 wt%, preferably 5 to 30 wt%, based on the total weight of the waste plastic oil and the petroleum hydrocarbon;

according to the present disclosure, the waste plastic oil may be selected from at least one of polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, and polyethylene terephthalate; preferably, the property of the waste plastic oil may satisfy at least one of the following indexes: the density of the waste plastic oil at 20 ℃ is 750-900kg/m ³ The carbon residue content of the waste plastic oil is 0-2 wt%, the silicon content of the waste plastic oil is 50-2000mg/kg, and the chlorine content of the waste plastic oil is 50-5000mg/kg.

According to the present disclosure, the conditions of the first catalytic conversion reaction may include: the reaction temperature is 300-550 ℃, the reaction time is 0.1-5 seconds, and the weight ratio of the catalyst to the oil is (5-100): 1, the weight ratio of water to oil is (0.05-0.8): 1, a step of; the conditions of the second catalytic conversion reaction may include: the reaction temperature is 510-650 ℃, the reaction time is 1-20 seconds, and the weight ratio of the catalyst to the oil is (3-50): 1, the weight ratio of water to oil is (0.05-0.8): 1, a step of; the third oneThe conditions for the catalytic conversion reaction may include: the reaction temperature is 500-600 ℃, and the weight hourly space velocity is 1-20 hours ^-1 The method comprises the steps of carrying out a first treatment on the surface of the The conditions of the fourth catalytic conversion reaction may include: the reaction temperature is 510-650 ℃, the reaction time is 1-20 seconds, and the weight ratio of the catalyst to the oil is (3-50): 1, the weight ratio of water to oil is (0.05-0.4): 1.

in this disclosure, the first catalyst is a spent catalyst of a catalytic cracker known to those skilled in the art. Specifically, the waste catalyst may be a waste catalyst of a catalytic cracker, or may be one or a mixture of any proportion of waste catalysts of a catalytic cracker mainly containing a multi-product gas.

According to the present disclosure, the first catalyst may contain a binder and a low active material, and the mass ratio of the binder and the low active material may be 1: (0.05-0.5); the binder may be a silica sol and/or an alumina sol; the low active material may be a smectite group material and/or a kaolin group material; the smectite group may include at least one of bentonite, saponite and montmorillonite; the kaolin family may include kaolinite and/or halloysite; the preparation method of the first catalyst may include: mixing the binder and the low-activity substances to obtain a mixed material, and carrying out spray drying and roasting on the mixed material; alternatively, the firing temperature may be 630-750 ℃.

According to the present disclosure, the first catalyst may further contain alumina; alternatively, the alumina content may be from 0.05 to 50 wt%, preferably from 10 to 30 wt%, based on the total weight of the first catalyst; the binder may be present in an amount of 50 to 99.5 wt%, preferably 50 to 90 wt%; the content of the low active substance may be 0.05 to 50% by weight, preferably 10 to 30% by weight.

According to the present disclosure, the second catalyst may contain zeolite, inorganic oxide, and clay; the second catalyst may comprise, on a dry basis and based on the dry weight of the second catalyst, from 1 to 50 wt% zeolite, from 5 to 99 wt% inorganic oxide, and from 0 to 70 wt% clay; the zeolite may include a medium pore zeolite and/or a large pore zeolite, which are defined in the present disclosure as conventional in the art, i.e., a medium pore size of 0.5 to 0.6nm and a large pore size of 0.7 to 1.0nm. The medium pore zeolite in the present disclosure may be selected from zeolites having MFI structure, preferably ZSM-series zeolite and/or ZRP zeolite, preferably one or more selected from ZSM-5, ZSM-11, ZSM-12, ZSM-23, ZSM-35, ZSM-38, ZSM-48 and other similar structure zeolites, which may be modified with non-metallic elements such as phosphorus and/or transition metal elements such as iron, cobalt, nickel; the large pore zeolite in the present disclosure may be selected from at least one of rare earth Y, rare earth hydrogen Y, ultrastable Y, and high silicon Y; alternatively, the mesoporous zeolite in the second catalyst may comprise from 0 to 50 wt% of the total weight of zeolite on a dry basis; preferably, the mesoporous zeolite may comprise from 0 to 20 wt% of the total weight of the zeolite.

According to the present disclosure, the temperature of the low temperature spent catalyst may be 300 to 550 ℃, and the total amount of the low temperature spent catalyst may be 5 to 50 wt%, preferably 10 to 20 wt%, of the total catalyst circulation amount of the fluidized bed reactor; the introduction location of the low temperature spent catalyst may be located at a height of 1-20%, preferably 5-10%, from the bottom of the fluidized bed reactor; the temperature of the low temperature regenerated catalyst may be 300 to 450 ℃, and the total amount of the low temperature regenerated catalyst may be 5 to 50 wt%, preferably 10 to 20 wt%, of the total catalyst circulation amount of the fluidized bed reactor; the introduction location of the low temperature regenerated catalyst may be located at the bottom of the fluidized bed reactor; the temperature of the hot regenerated catalyst is 600 to 680 ℃, and the total amount of the hot regenerated catalyst may be 50 to 90 wt%, preferably 60 to 80 wt%, of the total catalyst circulation amount of the fluidized bed reactor; the introduction location of the hot regenerated catalyst may be located at a height of 20-30% from the bottom of the fluidized bed reactor.

According to the present disclosure, the dechlorinating agent may contain a calcium compound, an inorganic oxide, and clay; the dechlorinating agent may comprise 5-80 wt% calcium compound, 5-95 wt% inorganic oxide and 0-50 wt% clay on a dry basis and based on the total weight of the dechlorinating agent; the calcium compound may be at least one of calcium hydroxide, calcium carbonate, and calcium oxide; the inorganic oxide may be silica and/or alumina; the clay may be kaolin and/or halloysite.

According to the present disclosure, the dechlorinating agent may be used in an amount of 200-10000mg/kg, preferably 200-10000mg/kg, based on the total weight of the waste plastic oil feed amount; the location of introduction of the dechlorinating agent into the fluidized bed reactor may be located at a height of 50-90% from the bottom of the fluidized bed reactor; preferably, the location of introduction of the dechlorinating agent into the fluidised bed reactor is at a height of 60-70% from the bottom of the fluidised bed reactor.

In the present disclosure, the separation of the first reaction oil gas and the second reaction oil gas from the catalyst to be regenerated is well known to those skilled in the art, for example, a cyclone separator may be used in a settler, and a method for further separating the first reaction oil gas and the second reaction oil gas to obtain dry gas, liquefied gas and low chlorine plastic oil is also well known to those skilled in the art, and the dry gas and the liquefied gas may be further separated by a separation means conventional in the art to obtain a target product including propylene, etc. The first reaction oil gas and the second reaction oil gas may be separated in the same separation apparatus, or may be separated in different separation apparatuses, and the present disclosure is not particularly limited.

According to the present disclosure, the method may further include: feeding a first to-be-regenerated catalyst into a first regenerator to perform first scorch regeneration to obtain a first regenerated catalyst, and returning the first regenerated catalyst to the fluidized bed reactor; and sending the second spent catalyst into a second regenerator to perform second burning regeneration to obtain a second regenerated catalyst, and returning the second regenerated catalyst to the first dilute phase conveying bed reactor and the second dilute phase conveying bed reactor. The means for regenerating the first spent catalyst and the second spent catalyst by burning are well known to those skilled in the art, and may be performed in a regenerator, an oxygen-containing gas such as air may be introduced into the regenerator to contact the first spent catalyst and the second spent catalyst, and flue gas obtained by burning and regenerating may be sent to a subsequent energy recovery system after being separated from the catalyst in the regenerator. The burnt regeneration of the first spent catalyst and the second spent catalyst is each independently performed in a different regenerator. Optionally, the conditions of the first char regeneration may include: the temperature is 600-700 ℃ and the pressure is 1.0-2.5MPa; preferably, the temperature is 630-680 ℃ and the pressure is 1.0-2.0MPa; the conditions for the second char regeneration may include: the temperature is 600-800 ℃ and the pressure is 1.0-2.5MPa; preferably, the temperature is 650-700 ℃ and the pressure is 1.0-1.5MPa.

In the present disclosure, the petroleum hydrocarbon fluidized bed reactor is selected from one of a fixed fluidized bed, a bulk fluidized bed, a bubbling bed, a turbulent bed, a fast bed, a dilute phase transport bed, and a dense phase fluidized bed. The riser is selected from one of an equal diameter riser, an equal linear velocity riser and various variable diameter risers, preferably an equal diameter riser. In the present disclosure, the fluidized bed reactor for waste plastic oil is one selected from a fixed fluidized bed, a bulk fluidized bed, a bubbling bed, a turbulent bed, a fast bed, a dilute phase transport bed, and a dense phase fluidized bed. The riser is selected from one of an equal diameter riser, an equal linear velocity riser and various variable diameter risers, preferably an equal diameter riser.

In this disclosure, the oil separation apparatus and the reaction product separation apparatus are well known to those skilled in the art, and for example, the oil separation apparatus may include a cyclone, a settler, a stripper, and the like, and the reaction oil-gas separation apparatus may be a fractionation column, and the like.

In one embodiment of the present disclosure, as shown in fig. 1 and 2, a pre-lifting medium enters from the bottom of the fluidized bed reactor 1 through a first pre-lifting gas pipeline 6, a regenerated catalyst from a first regeneration inclined pipe 7 enters the fluidized bed reactor 1, and moves upward along the fluidized bed reactor under the lifting action of the pre-lifting medium, chlorine-containing waste plastic oil is mixed with steam from a first steam pipeline 4 through a waste plastic oil feeding pipeline 5 and then injected into a low-temperature spent agent pipeline from a first settler 2, and reacts to obtain a first reaction oil, and then enters the lower half of the fluidized bed reactor 1 to be mixed with an existing stream of the fluidized bed reactor, and a catalytic cracking reaction occurs on the hot catalyst and moves upward. Dechlorination agent is injected into the fluidized bed reactor 1 through a dechlorination agent line 14, is mixed and reacted with a stream from the fluidized bed reactor, and is moved upward with acceleration. The generated reaction product and the deactivated spent catalyst enter a first cyclone separator 8 in the settler 2 to separate the spent catalyst from the reaction product, the reaction product enters a first gas collection chamber 11, and the catalyst fine powder returns to the settler. The spent catalyst in the settler flows to the first stripping section 9 where it is stripped by contact with steam from stripping steam line 15. The reaction product stripped from the spent catalyst enters a first gas collection chamber 11 after passing through a cyclone separator, then enters a fractionating tower 16 through a first large oil gas pipeline 12 to be separated into dry gas 17, liquefied gas 18 and low-chlorine plastic oil 19, part of the stripped spent catalyst enters a first regenerator 3 through a first spent agent inclined tube 10, coke on the spent catalyst is burned off, the deactivated spent catalyst is regenerated, the flue gas enters a subsequent energy recovery system through a first flue gas pipeline 13, and the other part of the flue gas enters a fluidized bed reactor 1 through a spent agent pipeline 21. The dry gas is used as part or all of the pre-lifting medium for the catalytic conversion reaction. The regenerated catalyst after regeneration is circulated to the bottom of the fluidized bed reactor 1 through the first regeneration chute 7.

The pre-lift medium from the second pre-lift gas line 37 enters from the bottom of the first riser reactor 31, and in the regenerated catalyst catalytic conversion reactor from the third regeneration inclined tube 38, the pre-lift medium is lifted up along the reactor, the petroleum hydrocarbon is injected into the first riser reactor 31 of the catalytic conversion reactor together with the steam from the third steam line 28 through the petroleum hydrocarbon line 27, the petroleum hydrocarbon is subjected to catalytic cracking reaction on the hot catalyst, and the petroleum hydrocarbon is accelerated up, and the petroleum hydrocarbon is injected into the dense-phase fluidized bed reactor 32 to continue to react. The low-chlorine plastic oil from the low-chlorine plastic oil line 19 enters the second riser reactor 29 together with the steam from the second steam line 25, undergoes a catalytic cracking reaction on the hot catalyst from the second regenerant chute 26, and moves upward; the generated reaction product and the deactivated spent catalyst enter a second cyclone 39 in a second settler 33 to separate the spent catalyst from the reaction product, the reaction product enters a second plenum 40, and the catalyst fines are returned to the settler. The spent catalyst in the settler flows to the second stripping section 35 where it is stripped in contact with steam from the fourth steam line 36. The reaction product stripped from the spent catalyst enters a second gas collection chamber 40 after passing through a cyclone separator, then enters a subsequent separation system through a second large oil gas pipeline 41, and the separated reaction oil gas is led out of a device and is further separated to obtain products such as propylene, high aromatic hydrocarbon gasoline and the like; the stripped spent catalyst is passed through a third spent catalyst chute 42 and into the second regenerator 34 to burn off coke on the spent catalyst to regenerate the deactivated spent catalyst, and the flue gas is passed through a third flue gas duct 43 into a subsequent energy recovery system where the regenerated catalyst is recycled to the bottom of the first riser reactor 31 through a third regeneration chute 38.

The present disclosure is further illustrated in detail by the following examples. The starting materials used in the examples are all available commercially.

The raw materials used in the examples and comparative examples were waste plastic oil and atmospheric residue, and the proportion of waste plastic oil to the total feed (waste plastic oil+petroleum hydrocarbon) was 10% by weight. Wherein the properties of the waste plastic oil are shown in Table 1.

The industrial catalytic cracker used for catalyst a was spent.

The catalyst B is prepared by spray drying a mixture of a binder (silica sol) and kaolin according to a weight ratio of 5:95 and then roasting at 700 ℃.

The properties of catalyst a, catalyst B and the catalytic cracking catalyst used in the comparative example are shown in table 2.

The preparation method of the dechlorinating agent used in the examples comprises the following steps: pulping the multi-water kaolin by using deionized water, adding pseudo-boehmite, regulating the PH of the multi-water kaolin to 2-4 by using hydrochloric acid, uniformly stirring, standing and aging for 1 hour at 60-70 ℃, keeping the PH to 2-4, cooling to below 60 ℃, adding aluminum sol, and stirring for 40 minutes to obtain mixed slurry. And adding the calcium compound into the obtained mixed slurry, uniformly stirring, spray-drying, forming and drying to obtain the dechlorination agent sample.

TABLE 1

	Waste plastic oil
		Density in kg/cubic meter	831.9
Sulfur content, micrograms/gram	439
		Carbon residue,% (by weight)	0.74
Nitrogen content, micrograms/gram	1400
		Metal content, micrograms/gram
Iron (Fe)	13.0
		Nickel (Ni)	<0.1
Vanadium (V)	<0.1
		Sodium salt	0.2
Calcium	<0.1
		Silicon, micrograms/gram	505
Chlorine content, micrograms/gram	1980

TABLE 2

Example 1

According to the process of fig. 1 and 2, a petroleum hydrocarbon and waste plastic oil co-refining test is carried out, fig. 1 is a waste plastic oil pretreatment system, a test is carried out on a medium-sized device of a riser reactor, raw oil is waste plastic oil, a catalyst is catalyst A, a waste plastic oil mixture is injected into a low-temperature spent catalyst pipeline to contact with the low-temperature spent catalyst, melting, gasification and decomposition reactions are carried out to obtain a first reaction oil agent, the first reaction oil agent enters the lower part of the riser reactor to contact with a low-temperature regenerated catalyst and continue the decomposition reactions, the reaction oil agent goes up along the reactor, and sequentially contacts with the regenerated catalyst and a dechlorination agent which are injected into the middle part of the reactor and the downstream of the reactor to carry out the decomposition reactions and the dechlorination reactions, so as to obtain first reaction oil gas and a first spent catalyst; the dosage of the dechlorinating agent is 2000 mg/kg, the dechlorinating agent reacts with chlorine chloride generated in the reactor, the first reaction oil gas and the first spent catalyst enter a closed cyclone separator from an outlet of the reactor, the first reaction oil gas and the first spent catalyst are rapidly separated, and the first reaction oil gas is separated in a separation system according to distillation ranges to obtain fractions such as dry gas, liquefied gas, low-chlorine plastic oil and the like.

The first spent catalyst enters a stripping section under the action of gravity, hydrocarbon products adsorbed on the spent catalyst are stripped by steam, and the stripped spent catalyst enters a regenerator to be in contact with air for regeneration; the regenerated catalyst is returned to the riser reactor for recycling;

the method comprises the steps of carrying out a catalytic conversion reaction test on atmospheric residuum on a medium-sized device with a riser and a fluidized bed connected in series, wherein the catalyst is a catalytic cracking catalyst, the commercial brand is DMMC-2, the atmospheric residuum enters the lower part of the riser reactor to be contacted with a hot catalyst and carry out catalytic conversion reaction to obtain second reaction oil gas and a semi-spent catalyst, the second reaction oil gas and the semi-spent catalyst go upward and enter the fluidized bed reactor to carry out third catalytic conversion reaction to obtain third reaction oil gas and the second spent catalyst, the low-chlorine plastic oil after the reaction in FIG. 1 carries out catalytic conversion reaction in the second riser reactor to obtain fourth reaction oil gas and the third spent catalyst, the fourth reaction oil gas and the third spent catalyst enter a cyclone separator from an outlet of the reactor, the fourth reaction oil gas and the third spent catalyst are rapidly separated, and the fourth reaction oil gas and the third spent catalyst are separated into dry gas, liquefied gas, high aromatic gas, diesel oil and other fractions in a separation system according to distillation ranges, and products such as propylene are further separated from the dry gas and the liquefied gas.

The third spent catalyst enters a stripping section under the action of gravity, hydrocarbon products adsorbed on the spent catalyst are stripped by steam, and the stripped spent catalyst enters a regenerator to be in contact with air for regeneration; the regenerated catalyst is returned to the bottom of the riser reactor for recycling; the operating conditions and products are listed in tables 3 and 4, respectively.

Example 2

Example 2 differs from example 1 in that catalyst a is replaced by catalyst B. The operating conditions and products are listed in tables 3 and 4, respectively.

Comparative example

According to FIG. 2, the test is carried out on a medium-sized device with a riser connected in series with a fluidized bed reactor, raw oil is waste plastic oil and atmospheric residuum, the catalyst is a catalytic cracking catalyst, the commercial grade is DMMC-2, the atmospheric residuum enters the lower part of a first riser reactor to be contacted with a hot catalyst for catalytic conversion reaction, the waste plastic oil enters the lower part of a second reactor to be contacted with the hot catalyst for catalytic conversion reaction, a dechlorinating agent is injected into the downstream of the second reactor, the dechlorinating agent is 2000 mg/kg, the dechlorinating agent is mixed with the existing material flow in the reactor for continuous reaction, the reaction product and the catalyst go into the fluidized bed reactor for further reaction, the reaction product and the spent catalyst enter a closed cyclone separator from an outlet of the reactor, the reaction product and the spent catalyst are rapidly separated, the reaction product is separated into products such as dry gas, liquefied gas, gasoline, diesel oil and the like in a separation system according to distillation ranges, and the liquefied gas is further separated to obtain products such as propylene and gasoline.

The spent catalyst enters a stripping section under the action of gravity, hydrocarbon products adsorbed on the spent catalyst are stripped by steam, and the stripped spent catalyst enters a regenerator to be in contact with air for regeneration; the regenerated catalyst is returned to the riser reactor for recycling; the operating conditions and products are listed in tables 3 and 4, respectively.

As can be seen from the results in Table 4, the propylene yield was 18.26%, the gasoline yield was 27.30%, the aromatic hydrocarbon content in the gasoline was 32% by weight, and the chlorine content in the gasoline was 286 mg/kg.

TABLE 3 Table 3

TABLE 4 Table 4

As can be seen from the results in table 4, the propylene yield of example 1 was 22.12%, the gasoline yield was 32.05%, the aromatic hydrocarbon content in the gasoline was 45% by weight, and the chlorine content in the gasoline was 19 mg/kg; the propylene yield of example 2 was 22.32%, the gasoline yield was 32.66%, the aromatic hydrocarbon content in the gasoline was 46% by weight, and the chlorine content in the gasoline was 13 mg/kg. Compared with the comparative example, the method for processing waste plastic oil has high propylene yield, high aromatic hydrocarbon gasoline yield and low chlorine content.

The preferred embodiments of the present disclosure have been described in detail above, but the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solutions of the present disclosure within the scope of the technical concept of the present disclosure, and all the simple modifications belong to the protection scope of the present disclosure.

In addition, the specific features described in the above embodiments may be combined in any suitable manner without contradiction. The various possible combinations are not described further in this disclosure in order to avoid unnecessary repetition.

Moreover, any combination between the various embodiments of the present disclosure is possible as long as it does not depart from the spirit of the present disclosure, which should also be construed as the disclosure of the present disclosure.

Claims

1. A catalytic conversion method for producing propylene and high aromatic hydrocarbon gasoline by co-refining waste plastic oil and heavy oil, which is characterized by comprising the following steps:

s4, mixing the third reaction oil gas and the fourth reaction oil gas, and then separating to obtain dry gas, liquefied gas, pyrolysis gasoline, pyrolysis diesel oil and pyrolysis heavy oil;

the first catalyst comprises a binder and a low-activity substance, wherein the mass ratio of the binder to the low-activity substance is 1: (0.05 to 0.5); the binder is silica sol and/or alumina sol; the low-activity substance is montmorillonite and/or kaolin; the smectite group includes at least one of bentonite, saponite and montmorillonite; the kaolin family comprises kaolinite and/or halloysite;

The second catalyst contains zeolite, inorganic oxide and clay; the second catalyst comprises, on a dry basis and based on the dry weight of the second catalyst, from 1 to 50 wt% zeolite, from 5 to 99 wt% inorganic oxide, and from 0 to 70 wt% clay; the zeolite comprises medium pore zeolite and/or large pore zeolite, the medium pore zeolite is ZSM series zeolite and/or ZRP zeolite, and the large pore zeolite is at least one selected from rare earth Y, rare earth hydrogen Y, ultrastable Y and high silicon Y;

the temperature of the low-temperature spent catalyst is 300-550 ℃, and the total amount of the low-temperature spent catalyst accounts for 5-50 wt% of the catalyst circulating total amount of the fluidized bed reactor; the introduction position of the low-temperature spent catalyst is positioned at a height of 1-20% from the bottom of the fluidized bed reactor;

the temperature of the low-temperature regenerated catalyst is 300-450 ℃, and the total amount of the low-temperature regenerated catalyst accounts for 5-50 wt% of the catalyst circulating total amount of the fluidized bed reactor; the introduction position of the low-temperature regenerated catalyst is positioned at the bottom of the fluidized bed reactor;

the temperature of the hot regenerated catalyst is 600-680 ℃, and the total amount of the hot regenerated catalyst accounts for 50-90 wt% of the catalyst circulating total amount of the fluidized bed reactor; the introduction location of the hot regenerated catalyst is located at a height of 20-30% from the bottom of the fluidized bed reactor;

The dechlorinating agent contains a calcium compound, an inorganic oxide and clay; the dechlorinating agent comprises 5-80 wt% calcium compound, 5-95 wt% inorganic oxide and 0-50 wt% clay on a dry basis and based on the total weight of the dechlorinating agent.

2. The catalytic conversion process according to claim 1, wherein,

the amount of the waste plastic oil is 0 to 50 wt% based on the total weight of the waste plastic oil and the petroleum hydrocarbon;

the waste plastic oil is at least one selected from polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride and polyethylene terephthalate.

3. The catalytic conversion process according to claim 2, wherein,

the amount of the waste plastic oil is 5 to 30% by weight based on the total weight of the waste plastic oil and the petroleum hydrocarbon.

4. The catalytic conversion process according to claim 2, wherein,

the properties of the waste plastic oil meet at least one of the following criteria: the density of the waste plastic oil at 20 ℃ is 750-900kg/m ³ The carbon residue content of the waste plastic oil is 0-2 wt%, the silicon content of the waste plastic oil is 50-2000mg/kg, and the chlorine content of the waste plastic oil is 50-5000mg/kg.

5. The catalytic conversion process according to claim 1, wherein,

the conditions of the first catalytic conversion reaction include: the reaction temperature is 300-550 ℃, the reaction time is 0.1-5 seconds, and the weight ratio of the catalyst to the oil is (5-100): 1, the weight ratio of water to oil is (0.05-0.8): 1, a step of;

the conditions of the second catalytic conversion reaction include: the reaction temperature is 510-650 ℃, the reaction time is 1-20 seconds, and the weight ratio of the catalyst to the oil is (3-50): 1, the weight ratio of water to oil is (0.05-0.8): 1, a step of;

the conditions for the third catalytic conversion reaction include: the reaction temperature is 500-600 ℃, and the weight hourly space velocity is 1-20 hours ^-1 ；

The conditions for the fourth catalytic conversion reaction include: the reaction temperature is 510-650 ℃, the reaction time is 1-20 seconds, and the weight ratio of the catalyst to the oil is (3-50): 1, the weight ratio of water to oil is (0.05-0.4): 1.

6. the catalytic conversion process according to claim 1, wherein,

the preparation method of the first catalyst comprises the following steps: mixing the binder and the low-activity substances to obtain a mixed material, and carrying out spray drying and roasting on the mixed material;

the roasting temperature is 630-750 ℃.

7. The catalytic conversion process according to claim 1, wherein,

the first catalyst further comprises alumina;

The content of alumina is 0.05-50 wt% based on the total weight of the first catalyst; the content of the binder is 50-99.5 wt%; the content of the low active substance is 0.05-50 wt%.

8. The catalytic conversion process according to claim 7, wherein,

the content of alumina is 10-30 wt% based on the total weight of the first catalyst; the content of the binder is 50-90 wt%; the content of the low active substance is 10-30 wt%.

9. The catalytic conversion process according to claim 1, wherein,

the medium pore zeolite in the second catalyst comprises from 0 to 50 wt% of the total weight of zeolite on a dry basis.

10. The catalytic conversion process according to claim 9, wherein,

the medium pore zeolite comprises 0-20 wt% of the total weight of the zeolite.

11. The catalytic conversion process according to claim 1, wherein,

the total amount of the low-temperature spent catalyst accounts for 10-20 wt% of the total catalyst circulation amount of the fluidized bed reactor; the introduction position of the low-temperature spent catalyst is positioned at a height of 5-10% from the bottom of the fluidized bed reactor;

the total amount of the low-temperature regenerated catalyst accounts for 10-20 wt% of the total catalyst circulation amount of the fluidized bed reactor;

The total amount of the hot regenerated catalyst is 60 to 80 wt% of the total catalyst circulation amount of the fluidized bed reactor.

12. The catalytic conversion process according to claim 1, wherein the calcium compound is at least one of calcium hydroxide, calcium carbonate and calcium oxide;

the inorganic oxide is silicon dioxide and/or aluminum oxide;

the clay is kaolin and/or halloysite.

13. The catalytic conversion process according to claim 1, wherein,

the dosage of the dechlorinating agent is 200-10000mg/kg based on the total weight of the feeding amount of the waste plastic oil;

the location of introduction of the dechlorinating agent into the fluidized bed reactor is located at a height of 50-90% from the bottom of the fluidized bed reactor.

14. The catalytic conversion process according to claim 13, wherein,

the location of introduction of the dechlorinating agent into the fluidized bed reactor is located at a height of 60-70% from the bottom of the fluidized bed reactor.

15. The catalytic conversion process of claim 1, wherein the process further comprises: feeding a first to-be-regenerated catalyst into a first regenerator to perform first scorch regeneration to obtain a first regenerated catalyst, and returning the first regenerated catalyst to the fluidized bed reactor; and sending the second spent catalyst into a second regenerator to perform second burning regeneration to obtain a second regenerated catalyst, and returning the second regenerated catalyst to the first dilute phase conveying bed reactor and the second dilute phase conveying bed reactor.

16. The catalytic conversion process of claim 15, wherein the conditions of the first char regeneration comprise: the temperature is 600-700 ℃ and the pressure is 1.0-2.5MPa; the conditions for the second char regeneration include: the temperature is 600-800 ℃, and the pressure is 1.0-2.5MPa.

17. The catalytic conversion process of claim 16, wherein the conditions of the first char regeneration comprise: the temperature is 630-680 ℃, and the pressure is 1.0-2.0MPa; the conditions for the second char regeneration include: the temperature is 650-700 ℃ and the pressure is 1.0-1.5MPa.