Method for producing naphtha by blending waste plastic with hydrocracking

Abstract

The application discloses a method for producing naphtha by hydrocracking of waste plastics, which comprises the following steps: adding waste plastics into a batch reactor with stirring function, adding a composite solvent and a potassium-based catalyst, and performing liquefaction treatment on the waste plastics; separating a liquid-solid mixture generated in the liquefaction to obtain liquefied waste plastics; mixing the liquefied waste plastics as a material stream I and a waxy oil raw material with a dry point > 500 DEG C as a material stream II, and passing the mixture through a fixed bed reactor filled with a hydrocracking catalyst to perform a hydrocracking reaction, so as to obtain base oil products; wherein the composite solvent is obtained by mixing solvent I, solvent II and solvent III according to a mass ratio of (2.5-6):(0.5-2):1. The method can produce naphtha by hydrocracking of liquefied waste plastics, realizes recycling of the waste plastics to a certain extent, reduces landfill amount, reduces influences of waste plastic garbage on air, soil, aquatic organisms and marine organisms, and reduces environmental pollution problems.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of hydrocracking, and relates to a method for producing more naphtha by blending waste plastics, mainly relates to a method for producing more naphtha by blending waste plastics and wax oil hydrocracking. BACKGROUND

[0002] The production of plastic materials such as polyethylene (PE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET) and polyvinyl chloride (PVC) is increasing every year. These plastics are widely used in packaging, construction, agriculture, electrical and electronic appliances and healthcare applications. Plastics have some unique characteristics, such as outstanding versatility, light weight, strength, water resistance, low cost, etc., which make them indispensable to modern civilization. However, most plastic articles have a very short service life, and plastic waste occupies the land for a longer period of time due to poor biodegradability, and only 1-3wt% of the hydrocarbon content in plastics is degraded within 100 years. Therefore, reducing the overall landfill volume of plastic waste has become a huge environmental problem. Today, landfills are being reduced, and the cost of landfill is skyrocketing. Some countries are enacting new legislation to reduce the amount of waste plastics sent to landfills. At the landfill, plastic materials are a burden to the environment, a waste of resources, a source of pollutants, and a source of greenhouse gases such as methane. Burning this plastic waste to generate energy will result in the emission of particulate matter and harmful gases, including unburned hydrocarbons, nitrogen oxides and sulfur oxides, which are highly unacceptable from an environmental point of view. Therefore, incineration and landfill are not the preferred way of plastic waste management, and plastic waste needs to be treated in a more sustainable and environmentally friendly way. Recycling is an alternative to landfill or incineration treatment. It not only protects the environment, but also helps to convert potential resources into useful products. Among various recycling methods, tertiary recycling, which converts waste plastic materials into petrochemical products and fuels, is attracting increasing attention worldwide. Tertiary recycling is an economical and environmentally friendly way of plastic recycling, and is recognized as the most promising method among various waste plastic management methods. Tertiary recycling can be carried out by chemical or thermal recycling technology. Solvent degradation, glycolysis, methanolysis and hydrolysis can be carried out for condensation polymers, while thermal recycling technology such as gasification, thermal cracking or pyrolysis, catalytic cracking and hydrocracking can be carried out for addition polymers (PE, PP, PS and PVC).

[0003] CN202111595049.2 discloses a preparation method of base oil, comprising the following steps: (1) the waste plastic is subjected to catalytic cracking treatment by a fixed bed reactor A filled with a catalytic cracking catalyst to obtain a material stream I; (2) the material stream I is mixed with hydrogen and then subjected to cracking by a fixed bed hydrogenation reactor B filled with a hydrocracking catalyst to obtain a material stream II; (3) the material stream II is subjected to isomerization by a fixed bed reactor C filled with an isomerization dewaxing catalyst, and a base oil product is obtained after separation. However, the method has high energy consumption, and the waste plastic needs to be subjected to catalytic cracking-hydrocracking-hydroisomerization processes to be converted into a base oil product, and the catalytic cracking reaction temperature is 380-650℃.

[0004] CN202111276209.7 discloses a method and system for pyrolysis of waste plastics, which comprises the following steps: the waste plastics containing chlorine are subjected to hot melting and dechlorination treatment in a waste plastic preliminary melting and liquefaction dechlorination unit to obtain a gas phase material containing hydrogen chloride and a dechlorinated waste plastic liquid phase material; the dechlorinated waste plastic liquid phase material and high-temperature pyrolysis raw materials are mixed in a material mixing unit to obtain mixed pyrolysis raw materials; the mixed pyrolysis raw materials are subjected to pyrolysis in a pyrolysis reaction unit to obtain pyrolysis gaseous products and coke; and the pyrolysis gaseous products are subjected to separation in a separation unit to obtain dry gas and liquefied gas, gasoline fraction, diesel fraction and wax oil fraction. The method realizes the resource utilization of waste plastics and can avoid the coking phenomenon of furnace tubes in the heating process of liquefied waste plastic oil. However, the method uses a high-temperature hot melting method of 400-500℃ to liquefy the waste plastics, and the high-temperature hot melting method can form a high-viscosity polymer melt in the melting process of the waste plastics, which can cause device blockage and coking problems. In addition, the method needs a high reaction temperature of 480-650℃ in the pyrolysis reaction unit, and the reaction conditions are difficult to control.

[0005] CN116064071A discloses a method for treating waste plastics containing chlorine using a delayed coking device, comprising the following steps: S1, heating and mixing the waste plastics containing chlorine to be treated in a raw material mixing and melting device (2) to obtain a waste plastic mixture; and mixing the waste plastic mixture with a high-temperature solvent and then feeding it into a liquefied dechlorination reactor (3) to perform dechlorination treatment under stripping conditions to obtain a gas phase material containing hydrogen chloride and a dechlorinated waste plastic liquid phase material. However, the dechlorinated waste plastic phase material needs to be heated in a high-temperature liquefaction unit, and the high-temperature liquefaction unit comprises a screw pump, which can cause uneven heating and coking and fouling during the plastic liquefaction process. SUMMARY

[0006] The technical problem to be solved by the present application is to efficiently convert and utilize waste plastics, and realize the recycling of waste plastics. The method of the present application realizes the goal of producing more naphtha by optimizing the anti-poisoning ability of the hydrocracking catalyst, and avoids the pollution problem caused by waste plastics.

[0007] To solve the above problems, the present application provides a method for producing more naphtha by blending waste plastics with hydrocracking, which comprises the following steps:

[0008] (1) adding waste plastics into a batch reactor with stirring function, adding a composite solvent and a potassium-based catalyst, and performing liquefaction treatment on the waste plastics, separating the liquid-solid mixture produced by liquefaction to obtain liquefied waste plastics;

[0009] (2) the liquefied waste plastics as material stream I, and the dry point > 500℃ wax oil raw material as material stream II, are mixed and passed through a fixed bed reactor filled with a hydrocracking catalyst to perform a hydrocracking reaction, and a base oil product is obtained;

[0010] In step (1), the composite solvent is obtained by mixing solvent I, solvent II and solvent III in a mass ratio of (2.5-6):(0.5-2):1.

[0011] In the method for producing more naphtha by blending waste plastics with hydrocracking of the present application, the solvent I is at least one of ethylene glycol, n-propanol, isobutyl alcohol, isoamyl alcohol and 2-phenylethanol; the solvent II is at least one of flavonoids, lignan and acetone; and the solvent III is at least one of cyclohexane and petroleum ether.

[0012] In the method for producing more naphtha by blending waste plastics with hydrocracking of the present application, in step (1), the composite solvent is obtained by mixing solvent I, solvent II and solvent III in a mass ratio of (4-6):(1.5-2).

[0013] In the method for producing more naphtha by blending waste plastics with hydrocracking of the present application, in step (1), the mass ratio of the composite solvent to waste plastics is (3-8):1, preferably 3-5:1.

[0014] In the method for producing more naphtha by blending waste plastics with hydrocracking of the present application, in step (1), the mass ratio of the potassium-based catalyst to waste plastics is 0.3-0.5:1; it should be noted that the present application does not particularly limit the type and preparation method of the potassium-based catalyst, which can be a commercially available potassium-based catalyst or prepared by a conventional method.

[0015] The method for producing naphtha by waste plastic blending and hydrocracking of the application, in step (1), the components of the waste plastic include at least one of polyethylene (PE), polypropylene (PP) and polystyrene (PS).

[0016] The method for producing naphtha by waste plastic blending and hydrocracking of the application, in step (2), the mixing ratio of the material stream I and the material stream II is (15wt%-35wt%):(85wt%-65wt%), preferably 15-20wt%:70-80wt%.

[0017] The method for producing naphtha by waste plastic blending and hydrocracking of the application, in step (2), the hydrocracking catalyst includes the following components: (a) at least one of zirconium oxide, titanium oxide, iron oxide and potassium oxide; (b) at least one of USY molecular sieve, ZSM-5 molecular sieve and SBA-16 molecular sieve; (c) amorphous silicon aluminum; (d) at least one of nickel oxide, tungsten oxide and phosphoric acid; it should be noted that the source of the hydrocracking catalyst is not particularly limited in the application, and a commercially available hydrocracking catalyst can be used, or a conventional method can be used to prepare it.

[0018] The method for producing naphtha by waste plastic blending and hydrocracking of the application, in step (1), the pressure of the reactor is 4-10Mpa, the temperature is 250-500℃, and the residence time of the waste plastic in the reactor is 0.5-6h; preferably, the pressure of the reactor is 6-8Mpa, the temperature is 280-400℃, and the residence time of the waste plastic in the reactor is 0.5-3h.

[0019] The method for producing naphtha by waste plastic blending and hydrocracking of the application, in step (2), the temperature of the hydrocracking reaction is 365-380℃, the reaction pressure is 14-17Mpa, the space velocity is 0.5-1.2h -1 , the hydrogen oil ratio is 700-1500:1; preferably, the space velocity is 0.8-1.0h -1 , the hydrogen oil ratio is 1000-1500:1.

[0020] Compared with the high-temperature thermal melting treatment method of the prior art, the liquefaction treatment method of the present application is more environmentally friendly, simple to operate, and reduces production costs. In the waste plastic liquefaction process, the composite solvent is used in cooperation with the potassium-based catalyst to liquefy the waste plastic at a certain temperature and pressure, providing a basis for subsequent reactions. Among them, the potassium-based catalyst can promote the decomposition reaction of waste plastic to tilt towards non-wax oil products, through molecular fragmentation and recombination, and the similar compatibility principle of the composite solvent, so as to obtain more other valuable liquid products. The present application liquefies the waste plastic and blends it into a hydrocracking device to produce more naphtha, to a certain extent, to realize the recycling of waste plastic, reduce the landfill amount, reduce the influence of waste plastic garbage on air, soil, and aquatic and marine organisms, and reduce environmental pollution problems. At the same time, the waste plastic blending and hydrocracking can be used in the existing device, without the need to build or modify the device, saving costs. The method of the present application improves the yield of naphtha. DETAILED DESCRIPTION

[0021] The specific embodiments of the present application are further described below to make the technical scheme of the present application easier to understand and master, but the present application is not limited thereto. In the following examples, the experimental methods are conventional methods unless otherwise specified; the reagents and materials are commercially available unless otherwise specified.

[0022] The raw materials are ethylene glycol, n-propanol, isobutanol, isoamyl alcohol, 2-phenylethanol, cyclohexane, acetone, etc. from the brand Innochem, which are commercially available reagents; flavonoids are from the brand Aladdin, which are commercially available reagents; lignans are purchased from Hengyuan Bio, which are commercially available reagents; potassium carbonate, etc. are commercially available reagents, industrial grade.

[0023] Preparation of potassium-based catalyst 1:

[0024] The catalyst 50g of alumina carrier was dispersed in water, 8g of potassium carbonate was added under vigorous stirring, and stirred at room temperature for 24h. After the suspension was evaporated, it was calcined at 550℃ for 4h to obtain potassium-based catalyst A1.

[0025] Preparation of potassium-based catalyst 2:

[0026] The catalyst 50g of magnesium oxide carrier was dispersed in water, 8g of potassium carbonate was added under vigorous stirring, and stirred at room temperature for 24h. After the suspension was evaporated, it was calcined at 550℃ for 4h to obtain potassium-based catalyst A2.

[0027] Preparation of potassium-based catalyst 3:

[0028] The catalyst 50 g of zirconia support was dispersed in water, 8 g of potassium carbonate was added under vigorous stirring, and stirred at room temperature for 24 h. After the suspension was evaporated to dryness, it was calcined at 550°C for 4 h to obtain the potassium-based catalyst A3.

[0029] Preparation of hydrocracking catalyst 1:

[0030] (1) 36.7 g of titanium oxide (dry basis 68 wt% mass), 62.8 g of amorphous silica-alumina (dry basis 71.6 wt% mass), and 32.6 g of USY molecular sieve (dry basis 92 wt% mass) were weighed and mixed well, then a previously prepared dilute nitric acid solution was added, kneaded for 15 minutes, and then extruded through a 2.6 mm screen plate, dried at 120°C for 2 h, and then calcined at 540°C in air for 4 h to obtain the catalyst support.

[0031] (2) 100 g of the catalyst support was first impregnated with 80 mL of a 20 wt% potassium carbonate aqueous solution for 3 h, then vacuum dried at 100°C for 12 h, then impregnated with an equal volume of an impregnation solution of 51.6 g of nickel nitrate and 70.01 g of ammonium metatungstate in 100 mL of water for 2 h, dried at 120°C for 4 h, and calcined at 500°C in air for 4 h to obtain the hydrocracking catalyst B1.

[0032] Preparation of hydrocracking catalyst 2:

[0033] (1) 25.5 g of zirconia (dry basis 98 wt% mass), 62.8 g of amorphous silica-alumina (dry basis 71.6 wt% mass), and 32.6 g of USY molecular sieve (dry basis 92 wt% mass) were weighed and mixed well, then a previously prepared dilute nitric acid solution was added, kneaded for 15 minutes, and then extruded through a 2.6 mm screen plate, dried at 120°C for 2 h, and then calcined at 540°C in air for 4 h to obtain the catalyst support.

[0034] (2) 100 g of the catalyst support was first impregnated with 80 mL of a 20 wt% potassium carbonate aqueous solution for 3 h, then vacuum dried at 100°C for 12 h, then impregnated with an equal volume of an impregnation solution of 51.6 g of nickel nitrate and 70.01 g of ammonium metatungstate in 100 mL of water for 2 h, dried at 120°C for 4 h, and calcined at 500°C in air for 4 h to obtain the hydrocracking catalyst B2.

[0035] Preparation of hydrocracking catalyst 3:

[0036] (1) Take 25 g of iron oxide, 62.8 g of amorphous silicon aluminum (dry basis 71.6 wt% mass), 32.6 g of USY molecular sieve (dry basis 92 wt% mass), mix the three solid powders thoroughly, then add a previously prepared dilute nitric acid solution, knead for 15 minutes, then extrude through a 2.6 mm hole plate, dry at 120°C for 2h, then calcine in air atmosphere at 540°C for 4h to obtain the catalyst carrier.

[0037] (2) 100 g of the catalyst carrier is first immersed in 80 mL of a 20 wt% potassium carbonate aqueous solution for 3h, then vacuum dried at 100°C for 12h, then immersed in an equal volume of an impregnation solution of 51.6 g of nickel nitrate and 70.01 g of ammonium metatungstate in 100 mL of water for 2h, dried at 120°C for 4h, and calcined in air atmosphere at 500°C for 4h to obtain the hydrocracking catalyst B3.

[0038] Preparation of hydrocracking catalyst 4:

[0039] (1) Take 36.7 g of titanium oxide (dry basis 68 wt% mass), 62.8 g of amorphous silicon aluminum (dry basis 71.6 wt% mass), 32.6 g of USY molecular sieve (dry basis 92 wt% mass), mix the three solid powders thoroughly, then add a previously prepared dilute nitric acid solution, knead for 15 minutes, then extrude through a 2.6 mm hole plate, dry at 120°C for 2h, then calcine in air atmosphere at 540°C for 4h to obtain the catalyst carrier.

[0040] (2) 100 g of the catalyst carrier is first immersed in an equal volume of an impregnation solution of 51.6 g of nickel nitrate and 70.01 g of ammonium metatungstate in 100 mL of water for 2h, dried at 120°C for 4h, and calcined in air atmosphere at 500°C for 4h to obtain the hydrocracking catalyst B4.

[0041] Example 1

[0042] (1) Polyethylene (PE) block-shaped waste plastics are added to a batch reactor with stirring function, and ethylene glycol, flavonoids, and cyclohexane with a mass ratio of 6:2:1 are added as composite solvents, and the mass ratio of composite solvent to waste plastics is 8.0. The mass ratio of potassium-based catalyst A1 to waste plastics is 0.3:1. The reaction pressure is 4.0 MPa, the reaction temperature is 500°C, the reaction time is 0.5h, and the stirring speed is 2000 rpm. The obtained solid-liquid mixture is subjected to solid-liquid separation to obtain liquefied waste plastics.

[0043] (2) The liquefied waste plastics as material stream I, the dry point > 500℃ wax oil raw material as material stream II, the mixing ratio of material stream I and material stream II is 15wt%:85wt%. The mixed material stream passes through the hydrogenation cracking fixed bed reactor filled with hydrogenation cracking catalyst B1, the catalyst loading volume is 200ml, the cracking reaction temperature is 380℃, the reaction pressure is 15.5Mpa, the space velocity is 1.0h -1 , the hydrogen oil ratio is 1500:1, and the hydrogenation cracking reaction is carried out to obtain a reaction product.

[0044] The example result is that the C5+ liquid yield is 95.5wt%, the product is cut by the actual boiling point, the heavy naphtha yield is 59.3wt%, the light diesel oil yield is 16.5wt%, the heavy diesel oil yield is 12.4wt%, and the tail oil yield is 7.3wt%.

[0045] Example 2

[0046] (1) The polyethylene (PE) block waste plastics are added to a batch reactor with stirring function, and ethylene glycol, flavonoids and cyclohexane with a mass ratio of 6:2:1 are added as composite solvents, the mass ratio of composite solvent to waste plastics is 8.0. The mass ratio of potassium-based catalyst A1 to waste plastics is 0.3:1. The reaction pressure is 4.0MPa, the reaction temperature is 500℃, the reaction time is 0.5h, and the stirring speed is 2000rpm. The obtained solid-liquid mixture is subjected to solid-liquid separation to obtain liquefied waste plastics.

[0047] (2) The liquefied waste plastics as material stream I, the dry point > 500℃ wax oil raw material as material stream II, the mixing ratio of material stream I and material stream II is 15wt%:85wt%. The mixed material stream passes through the hydrogenation cracking fixed bed reactor filled with hydrogenation cracking catalyst B2, the catalyst loading volume is 200ml, the cracking reaction temperature is 380℃, the reaction pressure is 15.5Mpa, the space velocity is 1.0h -1 , the hydrogen oil ratio is 1500:1, and the hydrogenation cracking reaction is carried out to obtain a reaction product.

[0048] The example result is that the C5+ liquid yield is 94.5wt%, the product is cut by the actual boiling point, the heavy naphtha yield is 55.1wt%, the light diesel oil yield is 18.2wt%, the heavy diesel oil yield is 13.4wt%, and the tail oil yield is 7.8wt%.

[0049] Example 3

[0050] (1) Polyethylene (PE) bulk waste plastics were added to a batch reactor with stirring function, adding ethylene glycol, flavonoids, cyclohexane as composite solvent with mass ratio of 6:2:1, the mass ratio of composite solvent to waste plastics was 8.0. The mass ratio of potassium-based catalyst A1 to waste plastics was 0.3:1. The reaction pressure was 4.0 MPa, the reaction temperature was 500℃, the reaction time was 0.5 h, the stirring speed was 2000 rpm, and the obtained solid-liquid mixture was subjected to solid-liquid separation to obtain liquefied waste plastics.

[0051] (2) The liquefied waste plastics were used as material stream I, and the dry point > 500℃ wax oil raw material was used as material stream II, the mixing ratio of material stream I to material stream II was 15wt%:85wt%. The mixed material stream was passed through a hydrocracking fixed bed reactor filled with hydrocracking catalyst B3, the catalyst loading volume was 200 mL, the cracking reaction temperature was 380℃, the reaction pressure was 15.5 Mpa, the space velocity was 1.0 h -1 , the hydrogen to oil ratio was 1500:1, and the hydrocracking reaction was carried out to obtain the reaction product.

[0052] The results of the example: the C5+ liquid yield was 94.3wt%, the product was subjected to real boiling point cutting, the heavy naphtha yield was 57.3wt%, the light diesel yield was 17.5wt%, the heavy diesel yield was 14.4wt%, and the tail oil yield was 5.1wt%.

[0053] Example 4

[0054] (1) Polyethylene (PE) bulk waste plastics were added to a batch reactor with stirring function, adding ethylene glycol, flavonoids, cyclohexane as composite solvent with mass ratio of 6:2:1, the mass ratio of composite solvent to waste plastics was 8.0. The mass ratio of potassium-based catalyst A1 to waste plastics was 0.3:1. The reaction pressure was 4.0 MPa, the reaction temperature was 500℃, the reaction time was 0.5 h, the stirring speed was 2000 rpm, and the obtained solid-liquid mixture was subjected to solid-liquid separation to obtain liquefied waste plastics.

[0055] (2) The liquefied waste plastics were used as material stream I, and the dry point > 500℃ wax oil raw material was used as material stream II, the mixing ratio of material stream I to material stream II was 15wt%:85wt%. The mixed material stream was passed through a hydrocracking fixed bed reactor filled with hydrocracking catalyst B4, the catalyst loading volume was 200 mL, the cracking reaction temperature was 380℃, the reaction pressure was 15.5 Mpa, the space velocity was 1.2 h -1 , the hydrogen to oil ratio was 1500:1, and the hydrocracking reaction was carried out to obtain the reaction product.

[0056] Example results: C5+ liquid yield was 95.1 wt%, the product was cut by real boiling point, heavy naphtha yield was 55.8 wt%, light diesel yield was 19.2 wt%, heavy diesel yield was 11.4 wt%, tail oil yield was 8.7 wt%.

[0057] Example 5

[0058] (1) Polyethylene (PE) bulk waste plastics were added to a batch reactor with stirring function, adding isopropyl alcohol, acetone, cyclohexane as composite solvent in a mass ratio of 4.5:2:1, the mass ratio of composite solvent to waste plastics was 8.0. The mass ratio of potassium-based catalyst A2 to waste plastics was 0.5:1. The reaction pressure was 6.0 MPa, the reaction temperature was 300℃, the reaction time was 2h, the stirring speed was 2000rpm, and the obtained solid-liquid mixture was subjected to solid-liquid separation to obtain liquefied waste plastics.

[0059] (2) The liquefied waste plastics were used as material stream I, and the dry point≯500℃ wax oil raw material was used as material stream II, the mixing ratio of material stream I to material stream II was 25wt%:75wt%. The mixed material stream was passed through a hydrocracking fixed bed reactor filled with hydrocracking catalyst B1, the catalyst loading volume was 200mL, the cracking reaction temperature was 380℃, the reaction pressure was 15.5Mpa, the space velocity was 0.7h -1 , the hydrogen to oil ratio was 1500:1, and the hydrocracking reaction was carried out to obtain the reaction product.

[0060] Example results: C5+ liquid yield was 95.1 wt%, the product was cut by real boiling point, heavy naphtha yield was 57.3 wt%, light diesel yield was 14.5 wt%, heavy diesel yield was 16.4 wt%, tail oil yield was 6.9 wt%.

[0061] Example 6

[0062] (1) Polyethylene (PE) bulk waste plastics were added to a batch reactor with stirring function, adding isopropyl alcohol, acetone, cyclohexane as composite solvent in a mass ratio of 4.5:2:1, the mass ratio of composite solvent to waste plastics was 8.0. The mass ratio of potassium-based catalyst A2 to waste plastics was 0.5:1. The reaction pressure was 6.0 MPa, the reaction temperature was 300℃, the reaction time was 2h, the stirring speed was 2000rpm, and the obtained solid-liquid mixture was subjected to solid-liquid separation to obtain liquefied waste plastics.

[0063] (2) The liquefied waste plastics as material stream I, the dry point > 500℃ wax oil raw material as material stream II, the mixing ratio of material stream I and material stream II is 35wt%:65wt%. The mixed material stream passes through the hydrogenation cracking fixed bed reactor filled with hydrogenation cracking catalyst B1, the catalyst loading volume is 200ml, the cracking reaction temperature is 380℃, the reaction pressure is 15.5Mpa, the space velocity is 0.5h -1 , the hydrogen oil ratio is 1500:1, and the hydrogenation cracking reaction is carried out to obtain a reaction product.

[0064] The results of the example are as follows: the C5+ liquid yield is 93.8wt%, the product is cut by the actual boiling point, the heavy naphtha yield is 58.8wt%, the light diesel oil yield is 15.5wt%, the heavy diesel oil yield is 11.4wt%, and the tail oil yield is 8.1wt%.

[0065] Example 7

[0066] (1) The polyethylene (PE) block waste plastics are added to a batch reactor with stirring function, and isopentanol, acetone and cyclohexane with a mass ratio of 4:2:1 are added as a composite solvent, the mass ratio of the composite solvent to the waste plastics is 3.0. The mass ratio of potassium-based catalyst A1 to the waste plastics is 0.5:1. The reaction pressure is 10.0MPa, the reaction temperature is 400℃, the reaction time is 3h, and the stirring speed is 2000rpm. The obtained solid-liquid mixture is subjected to solid-liquid separation to obtain liquefied waste plastics.

[0067] (2) The liquefied waste plastics as material stream I, the dry point > 500℃ wax oil raw material as material stream II, the mixing ratio of material stream I and material stream II is 35wt%:65wt%. The mixed material stream passes through the hydrogenation cracking fixed bed reactor filled with hydrogenation cracking catalyst B1, the catalyst loading volume is 200ml, the cracking reaction temperature is 380℃, the reaction pressure is 15.5Mpa, the space velocity is 0.5h -1 , the hydrogen oil ratio is 1500:1, and the hydrogenation cracking reaction is carried out to obtain a reaction product.

[0068] The results of the example are as follows: the C5+ liquid yield is 95.7wt%, the product is cut by the actual boiling point, the heavy naphtha yield is 53.3wt%, the light diesel oil yield is 19.3wt%, the heavy diesel oil yield is 16.1wt%, and the tail oil yield is 7.0wt%.

[0069] Example 8

[0070] (1) Polyethylene (PE) bulk waste plastics were added to a batch reactor with stirring function, and isopentanol, acetone, and cyclohexane with a mass ratio of 4:2:1 were added as a composite solvent. The mass ratio of the composite solvent to the waste plastics was 3.0. The mass ratio of the potassium-based catalyst A1 to the waste plastics was 0.3:1. The reaction pressure was 10.0 MPa, the reaction temperature was 400°C, the reaction time was 3h, and the stirring speed was 2000 rpm. The obtained solid-liquid mixture was subjected to solid-liquid separation to obtain liquefied waste plastics.

[0071] (2) The liquefied waste plastics were used as material stream I, and the dry point > 500°C wax oil raw material was used as material stream II. The mixing ratio of the material stream I to the material stream II was 35wt%:65wt%. The mixed material stream was passed through a hydrocracking fixed bed reactor filled with hydrocracking catalyst B1, the catalyst loading volume was 200 mL, the cracking reaction temperature was 380°C, the reaction pressure was 15.5 MPa, the space velocity was 0.5h -1 , the hydrogen to oil ratio was 1500:1, and the hydrocracking reaction was carried out to obtain a reaction product.

[0072] The results of the example: the C5+ liquid yield was 96.1wt%, the product was subjected to real boiling point cutting, the heavy naphtha yield was 53.4wt%, the light diesel yield was 20.1wt%, the heavy diesel yield was 14.5wt%, and the tail oil yield was 8.1wt%.

[0073] Example 9

[0074] (1) Polyethylene (PE) bulk waste plastics were added to a batch reactor with stirring function, and isopentanol, acetone, and cyclohexane with a mass ratio of 4:2:1 were added as a composite solvent. The mass ratio of the composite solvent to the waste plastics was 3.0. The mass ratio of the potassium-based catalyst A1 to the waste plastics was 0.3:1. The reaction pressure was 10.0 MPa, the reaction temperature was 400°C, the reaction time was 3h, and the stirring speed was 2000 rpm. The obtained solid-liquid mixture was subjected to solid-liquid separation to obtain liquefied waste plastics.

[0075] (2) The liquefied waste plastics were used as material stream I, and the dry point > 500°C wax oil raw material was used as material stream II. The mixing ratio of the material stream I to the material stream II was 35wt%:65wt%. The mixed material stream was passed through a hydrocracking fixed bed reactor filled with hydrocracking catalyst B1, the catalyst loading volume was 200 mL, the cracking reaction temperature was 380°C, the reaction pressure was 15.5 MPa, the space velocity was 0.5h -1 , the hydrogen to oil ratio was 1500:1, and the hydrocracking reaction was carried out to obtain a reaction product.

[0076] Example results: C5+ liquid yield was 95.5wt%, the product was cut by real boiling point, heavy naphtha yield was 59.3wt%, light diesel yield was 16.5wt%, heavy diesel yield was 12.4wt%, tail oil yield was 7.3wt%.

[0077] Example 10

[0078] (1) The polystyrene (PS) block-shaped waste plastics were added to a batch reactor with stirring function, and ethylene glycol, flavonoids, and cyclohexane with a mass ratio of 6:2:1 were added as composite solvents. The mass ratio of composite solvent to waste plastics was 8.0. The mass ratio of potassium-based catalyst A1 to waste plastics was 0.3:1. The reaction pressure was 4.0 MPa, the reaction temperature was 500℃, the reaction time was 0.5 h, and the stirring speed was 2000 rpm. The obtained solid-liquid mixture was subjected to solid-liquid separation to obtain liquefied waste plastics.

[0079] (2) The liquefied waste plastics were used as material stream I, and the dry point≯500℃ wax oil raw material was used as material stream II. The mixing ratio of material stream I to material stream II was 15wt%:85wt%. The mixed material stream was passed through a hydrocracking fixed bed reactor filled with hydrocracking catalyst B1, the catalyst loading volume was 200 mL, the cracking reaction temperature was 380℃, the reaction pressure was 15.5 Mpa, the space velocity was 1.0 h -1 , the hydrogen to oil ratio was 1500:1, and the hydrocracking reaction was carried out to obtain the reaction product.

[0080] Example results: C5+ liquid yield was 95.5wt%, the product was cut by real boiling point, heavy naphtha yield was 59.3wt%, light diesel yield was 16.5wt%, heavy diesel yield was 12.4wt%, tail oil yield was 7.3wt%.

[0081] Example 11

[0082] (1) The polystyrene (PS) block-shaped waste plastics were added to a batch reactor with stirring function, and ethylene glycol, flavonoids, and cyclohexane with a mass ratio of 6:2:1 were added as composite solvents. The mass ratio of composite solvent to waste plastics was 8.0. The mass ratio of potassium-based catalyst A1 to waste plastics was 0.3:1. The reaction pressure was 4.0 MPa, the reaction temperature was 500℃, the reaction time was 0.5 h, and the stirring speed was 2000 rpm. The obtained solid-liquid mixture was subjected to solid-liquid separation to obtain liquefied waste plastics.

[0083] (2) The liquefied waste plastics as material stream I, the dry point > 500℃ wax oil raw material as material stream II, the mixing ratio of material stream I and material stream II is 15wt%:85wt%. The mixed material stream passes through the hydrogenation cracking fixed bed reactor filled with hydrogenation cracking catalyst B2, the catalyst loading volume is 200ml, the cracking reaction temperature is 380℃, the reaction pressure is 15.5Mpa, the space velocity is 1.0h -1 , the hydrogen oil ratio is 1500:1, and the hydrogenation cracking reaction is carried out to obtain a reaction product.

[0084] The results of the example are as follows: the C5+ liquid yield is 94.5wt%, the real boiling point cutting is carried out on the product, the heavy naphtha yield is 55.1wt%, the light diesel oil yield is 18.2wt%, the heavy diesel oil yield is 13.4wt%, and the tail oil yield is 7.8wt%.

[0085] Example 12

[0086] (1) The polypropylene (PP) block waste plastics are added to a batch reactor with stirring function, isobutyl alcohol, flavonoids and cyclohexane with a mass ratio of 6:1.5:1 are added as composite solvents, the mass ratio of composite solvent to waste plastics is 8.0. The mass ratio of potassium-based catalyst A1 to waste plastics is 0.4:1. The reaction pressure is 4.0MPa, the reaction temperature is 500℃, the reaction time is 0.5h, and the stirring speed is 2000rpm. The obtained solid-liquid mixture is subjected to solid-liquid separation to obtain liquefied waste plastics.

[0087] (2) The liquefied waste plastics as material stream I, the dry point > 500℃ wax oil raw material as material stream II, the mixing ratio of material stream I and material stream II is 15wt%:85wt%. The mixed material stream passes through the hydrogenation cracking fixed bed reactor filled with hydrogenation cracking catalyst B4, the catalyst loading volume is 200ml, the cracking reaction temperature is 380℃, the reaction pressure is 15.5Mpa, the space velocity is 1.2h -1 , the hydrogen oil ratio is 1500:1, and the hydrogenation cracking reaction is carried out to obtain a reaction product.

[0088] The results of the example are as follows: the C5+ liquid yield is 95.1wt%, the real boiling point cutting is carried out on the product, the heavy naphtha yield is 55.8wt%, the light diesel oil yield is 19.2wt%, the heavy diesel oil yield is 11.4wt%, and the tail oil yield is 8.7wt%.

[0089] Example 13

[0090] (1) polypropylene (PP) bulk waste plastics were added to a batch reactor with stirring function, 2-phenylethanol, lignan and petroleum ether were added as composite solvents, the mass ratio of which was 6:0.5:1, the amount of composite solvent added was 8.0 times the mass of waste plastics. The mass ratio of potassium-based catalyst A1 to waste plastics was 0.4:1. The reaction pressure was 4.0 MPa, the reaction temperature was 500℃, the reaction time was 0.5h, and the stirring speed was 2000rpm. The obtained solid-liquid mixture was subjected to solid-liquid separation to obtain liquefied waste plastics.

[0091] (2) The liquefied waste plastics were used as material stream I, and the dry point > 500℃ wax oil raw material was used as material stream II, the mixing ratio of material stream I and material stream II was 15wt%:85wt%. The mixed material stream was passed through a hydrocracking fixed bed reactor filled with hydrocracking catalyst B4, the catalyst loading volume was 200mL, the cracking reaction temperature was 380℃, the reaction pressure was 15.5Mpa, the space velocity was 1.2h -1 , the hydrogen to oil ratio was 1500:1, and the hydrocracking reaction was carried out to obtain the reaction product.

[0092] The results of the example: the C5+ liquid yield was 95.8wt%, the product was subjected to real boiling point cutting, the heavy naphtha yield was 53.1wt%, the light diesel yield was 19.2wt%, the heavy diesel yield was 11.4wt%, and the tail oil yield was 12.1wt%.

[0093] Comparative example 1

[0094] The dry point > 500℃ wax oil raw material was used as material stream I, which was passed through a hydrocracking fixed bed reactor filled with hydrocracking catalyst B1, the catalyst loading volume was 200mL, the cracking reaction temperature was 380℃, the reaction pressure was 15.5Mpa, the space velocity was 1.2h -1 , the hydrogen to oil ratio was 1500:1, and the hydrocracking reaction was carried out to obtain the reaction product.

[0095] The results of the comparative example: the C5+ liquid yield was 96.5wt%, the product was subjected to real boiling point cutting, the naphtha yield was 52.4wt%, the light diesel yield was 18.2wt%, the heavy diesel yield was 7.4wt%, and the tail oil yield was 18.5wt%.

[0096] Comparative example 2

[0097] The difference from example 1 is that step (1) uses high temperature melting method to liquefy the waste plastics, specifically:

[0098] (1) polyethylene (PE) bulk waste plastics were added to a high temperature liquefaction reactor, the reaction pressure was 0.3MPa, the reaction temperature was 600℃, and the reaction time was 1h to obtain high temperature liquefied waste plastics.

[0099] (2) The high-temperature liquefied waste plastics as material stream I, and the dry point > 500℃ wax oil raw material as material stream II, the mixing ratio of material stream I and material stream II is 15wt%:85wt%. The mixed material stream passes through the hydrogenation cracking fixed bed reactor filled with hydrogenation cracking catalyst B1, the catalyst loading volume is 200mL, the cracking reaction temperature is 380℃, the reaction pressure is 15.5Mpa, the space velocity is 1.0h -1 , the hydrogen oil ratio is 1500:1, and the hydrogenation cracking reaction is carried out to obtain a reaction product.

[0100] The results of the comparative example are as follows: the C5+ liquid yield is 98.1wt%, the product is subjected to the true boiling point cutting, the naphtha yield is 50.3wt%, the light diesel oil yield is 20.1wt%, the heavy diesel oil yield is 13.5wt%, and the tail oil yield is 14.2wt%.

[0101] From the results of the examples and the comparative example, compared with the high-temperature hot melt heat treatment method, the method of the present application improves the naphtha yield by using the composite solvent and the potassium-based catalyst for the liquefaction treatment of the waste plastics.

[0102] Of course, the present application can have other various embodiments, and those skilled in the art can make various corresponding changes and modifications according to the present application without departing from the spirit and essence of the present application, but these corresponding changes and modifications should all belong to the protection scope of the claims of the present application.

Claims

1. A method for blending waste plastics with hydrocracking to produce more naphtha, characterized in that, Includes the following steps: (1) Add waste plastics to an intermittent reactor with stirring function, add composite solvent and potassium-based catalyst to liquefy waste plastics, separate the liquid-solid mixture generated by liquefaction to obtain liquefied waste plastics; (2) Liquefied waste plastics are used as material stream I, and wax oil raw material with a dry point of ≤500℃ is used as material stream II. They are mixed and passed through a fixed bed reactor filled with hydrocracking catalyst to carry out hydrocracking reaction to obtain base oil products. The composite solvent in step (1) is obtained by mixing solvent I, solvent II and solvent III in a mass ratio of (2.5~6):(0.5~2):1; Solvent I is at least one of ethylene glycol, n-propanol, isobutanol, isoamyl alcohol, and 2-phenylethanol; solvent II is at least one of flavonoids, lignans, and acetone; and solvent III is at least one of cyclohexane and petroleum ether.

2. The method according to claim 1, characterized in that, In step (1), the composite solvent is obtained by mixing solvent I, solvent II and solvent III in a mass ratio of (4-6):(1.5~2):

1.

3. The method according to claim 1, characterized in that, In step (1), the mass ratio of the composite solvent to the waste plastic is (3~8):

1.

4. The method according to claim 1, characterized in that, In step (1), the mass ratio of the potassium-based catalyst to the waste plastic is 0.3~0.5:

1.

5. The method according to claim 1, characterized in that, In step (1), the waste plastics include at least one of polyethylene (PE), polypropylene (PP), and polystyrene (PS).

6. The method according to claim 1, characterized in that, In step (2), the mixing ratio of material flow I and material flow II is (15wt%-35wt%): (85wt%-65wt%).

7. The method according to claim 1, characterized in that, In step (2), the hydrocracking catalyst comprises the following components: (a) at least one of zirconium oxide, titanium oxide, iron oxide, and potassium oxide; (b) at least one of USY molecular sieve, ZSM-5 molecular sieve, and SBA-16 molecular sieve; (c) amorphous silica-alumina; and (d) at least one of nickel oxide, tungsten oxide, and phosphoric acid.

8. The method according to claim 1, characterized in that, In step (1), the pressure of the reactor is 4-10 MPa, the temperature is 250-500℃, and the residence time of the waste plastic in the reactor is 0.5-6 h.

9. The method according to claim 1, characterized in that, In step (2), the hydrocracking reaction is carried out at a temperature of 365-380℃, a reaction pressure of 14-17 MPa, and a space velocity of 0.5-1.2 h⁻¹. -1 The hydrogen-to-oil ratio is 700-1500:1.