CN108239552B - A kind of method for the treatment of of waste plastics and cellulose - Google Patents

Abstract

The invention discloses a method for processing waste plastics and cellulose. The method comprises: catalytic cracking of waste plastics under the catalysis of a modified HY molecular sieve catalyst, the obtained products are separated to obtain liquid product I, gas I and insoluble matter I, and liquid product I is extracted by tetrahydrofuran and cyclohexane respectively to obtain liquid Product II, liquid product III and the remaining liquid product IV, liquid product II and cellulose are catalyzed to react to obtain liquid product i, gas i and insoluble matter i after separation, and liquid product i is extracted by tetrahydrofuran and cyclohexane to obtain liquid Product ii and liquid product iii and the remaining liquid product iv, the liquid product IV, liquid product iv and insoluble matter I and insoluble matter i are subjected to deep catalytic cracking reaction, the obtained product is separated from gas-liquid-solid, and the separated liquid product V is separated by Tetrahydrofuran and cyclohexane were extracted and separated to obtain liquid product VI and liquid product VII. This method not only improves the overall conversion rate, but also promotes the target reaction to increase the liquid yield.

Description

A method for processing waste plastics and cellulose

technical field

The invention belongs to the technical field of solid waste treatment, in particular to a method for treating waste plastics and cellulose.

Background technique

The garbage generated by the use of a large number of plastic products not only seriously pollutes the environment, but also causes a waste of resources. At present, the consumption of plastic products is huge, and a large amount of waste plastics are produced every year. However, the recycling and sorting efficiency of waste plastics is generally low, and it is difficult to continuously supply various types of waste plastics. Therefore, it is difficult to form waste plastics separately. Large-scale continuous production. Although the output of cellulose is large, most of it is directly incinerated at present, causing a lot of air pollution and waste of resources. At present, there have been some studies on the liquefaction technology of plastics and the optimal utilization of cellulose. If waste plastics are added to cellulose for co-pyrolysis treatment, the advantages of both pyrolysis can be used to make the output of valuable products of the two higher. . However, studies on the direct liquefaction of plastics and cellulose have found that there is a large gap between the reaction conditions and catalysts required by the two. Directly liquefying waste plastics and cellulose together has a great impact on the types of reactants, reaction conditions, and catalysts. etc. have high requirements, which poses certain challenges to the co-processing of waste plastics and cellulose.

Contents of the invention

Aiming at the deficiencies in the prior art, the invention provides a method for processing waste plastics and cellulose. Compared with the existing waste plastic and cellulose treatment process, the method not only improves the overall conversion rate, but also promotes the target reaction, improves the liquid yield, and improves the economic and environmental benefits of the whole process.

A method for processing waste plastics and cellulose provided by the invention comprises the following steps:

(1) Add waste plastics to catalytic reactor A, and carry out catalytic cracking reaction under the action of catalyst 1, and the cracked product obtained is separated to obtain liquid product I, gas I and insoluble matter I;

(2) The liquid product I obtained in step (1) is passed through tetrahydrofuran and cyclohexane solvent successively after cooling to extract, respectively obtain a tetrahydrofuran solution containing liquid product II, a cyclohexane solution containing liquid product III and the remaining liquid Product IV;

(3) The tetrahydrofuran solution containing the liquid product II obtained in step (2) and the cyclohexane solution containing the liquid product III are subjected to distillation treatment respectively to remove the solvent to obtain the liquid product II and the liquid product III respectively;

(4) adding the cellulose and the liquid product II obtained in step (3) to the catalytic reactor B, carrying out a catalytic reaction under the action of the catalyst 2, and obtaining the liquid product i, the gas i and the insoluble matter i through separation;

(5) The liquid product i obtained in step (4) is passed through tetrahydrofuran and cyclohexane solvent successively after cooling to extract, respectively obtain a tetrahydrofuran solution containing liquid product ii, a cyclohexane solution containing liquid product iii and the remaining liquid product iv, treated by distillation to remove solvent to obtain liquid product ii and liquid product iii;

(6) step (2) and step (5) obtain respectively remaining liquid product IV, remaining liquid product iv and step (1) and step (4) respectively obtain insoluble matter I and insoluble matter i and add to catalytic In the reactor C, a deep catalytic cracking reaction is carried out under the action of the catalyst 3, and the resulting cracked product is separated to obtain a liquid product V, a gas V and an insoluble V;

(7) After cooling, the liquid product V obtained in step (6) is sequentially introduced into tetrahydrofuran and cyclohexane solvent for extraction to obtain respectively a tetrahydrofuran solution containing liquid product VI, a cyclohexane solution containing liquid product VII and the remaining liquid product VIII, treated by distillation to remove the solvent to give liquid product VI and liquid product VII;

Wherein, the catalyst 1 described in the step (1) is a Sn and P modified HY molecular sieve catalyst.

In the present invention, the catalytic reactors A, B and C are all slurry bed catalytic cracking reactors.

In the present invention, the waste plastics described in step (1) mainly include one or more mixtures of polyethylene plastics (PE), polypropylene plastics (PP), polystyrene (PS), and its total content Not less than 80% of the total mass of waste plastics added. In the present invention, the usage amount of the catalyst 1 in step (1) is 5%-20% of the total mass of the added waste plastics, preferably 10%-15%.

In the present invention, in the catalyst 1 described in step (1), the mass content of modifiers Sn and P is 1%-12%, preferably 3%-10%. Wherein the molar ratio of Sn and P is 2-6:1, preferably 2-4:1.

In the present invention, the Sn and P modified HY molecular sieve catalysts can be modified by conventional modification methods in the field, such as ion exchange method, impregnation method and the like.

In the present invention, the reaction conditions of the catalytic cracking reaction described in step (1) are as follows: the reaction temperature is 350-550°C, preferably 400-480°C; the reaction time is 30-150 minutes, preferably 45-120 minutes; Under stirring, the stirring rate is 350-600 rpm, preferably 400-500 rpm; hydrogen gas needs to be introduced during the reaction, and the hydrogen partial pressure is 2-4MPa, preferably 2.5-3.5MPa. In the present invention, the cooling described in step (2), step (5) and step (7) preferably cools liquid product I, liquid product cold i and liquid product V to room temperature.

In the present invention, the distillation treatment described in step (3), step (5) and step (7) is a conventional distillation method in the art to remove tetrahydrofuran or cyclohexane solvent.

In the present invention, the cellulose described in step (4) is one or more of plant fiber materials such as straw, bark, and straw.

In the present invention, before the cellulose described in step (4) is added to the catalytic reactor B, it is preferably pretreated, such as at least one of pulverization and dehydration treatment. The pulverization mentioned therein means that the length of the powder obtained after pulverization is preferably no more than 20 mm. The dehydration treatment is carried out under anaerobic conditions, the treatment temperature is 100-200° C., and the treatment time is 60-120 minutes.

In the present invention, the liquid product II obtained in step (3) is added in step (4), and the mass ratio of cellulose to liquid product II is 0.8-1.2:1.

In the present invention, the catalyst 2 described in step (4) is a mixture of one or two of iron naphthenate and molybdenum naphthenate, preferably a mixture of both. The usage amount of the catalyst 2 is 800-1200ppm based on the total mass content of iron and molybdenum. Step (4) adds the sulfur source that the mass content is 4000-8000ppm in terms of sulfur while adding the catalyst 2 as a vulcanizing agent, so that the mass ratio of the sulfur content to the total content of iron and molybdenum in the catalytic reactor B is 5-7:1, Wherein the selected sulfur source is one or more of sulfur, hydrogen sulfide, carbon disulfide and the like.

In the present invention, the reaction conditions of the catalytic reaction described in step (4) are as follows: the reaction temperature is 400-600° C., preferably 450-550° C.; the reaction time is 30-100 minutes, preferably 60-100 minutes; It is carried out under stirring, and the stirring rate is 350-600 rpm, preferably 400-500 rpm; hydrogen gas needs to be introduced during the reaction, and the hydrogen partial pressure is 4-8MPa, preferably 5-6.5MPa. Further, the preferred reaction conditions are as follows: the reaction temperature of the catalytic reaction described in step (4) is at least 50°C higher than the reaction temperature of the catalytic reaction described in step (1), and the hydrogen partial pressure ratio of the catalytic reaction described in step (4) is The hydrogen partial pressure of the catalytic reaction in step (1) is at least 2 MPa higher.

In the present invention, the catalyst 3 described in step (6) is a composite molecular sieve catalyst of HZSM-5 and HY, the mass ratio of HZSM-5 and HY is 0.5-2:1, preferably HZSM-5 and HZSM-5 modified by phosphorus and tungsten HY composite molecular sieve catalyst, wherein the mass content of phosphorus is 1.5%-7.0%, and the mass content of tungsten is 0.3%-2.0%. The usage amount of the catalyst 3 is 5%-15%, preferably 6%-11%, of the total mass of all the added reaction materials added to the catalytic reactor C in step (6).

In the present invention, the preparation method of the catalyst 3 used is preferably as follows: HZSM-5 is mixed with HY to obtain a composite molecular sieve, the composite molecular sieve is impregnated with a phosphoric acid solution with a mass concentration of 10%-20%, and dried at 80-110°C for 1-3 hour; impregnate the composite molecular sieve with an aqueous sodium tungstate solution with a mass concentration of 1%-2%, dry at 80-110°C for 5-10 hours, and finally bake at 330-380°C for 4-7 hours to obtain a catalyst after molding 3.

In the present invention, the catalyst 3 can be molded by conventional methods, such as tablet molding, etc., and molding aids can be added as needed during the molding process. After tablet molding, sieve as required, and take solid particles with a particle size of 30 mesh to 70 mesh, preferably 40 to 60 mesh, as the catalyst 3 . The possible form of phosphorus in the phosphorus and tungsten modified HZSM-5 and HY composite molecular sieve catalyst is one or more of phosphotungstic acid, phosphorus oxide, phosphotungstate, phosphoric acid, phosphate, etc., The possible form of tungsten is one or more of phosphotungstic acid, tungsten oxide, phosphotungstate, etc., and the catalyst prepared by the above method is preferred.

In the present invention, the reaction conditions of the deep catalytic cracking reaction described in step (6) are: the reaction temperature is 400-700°C, preferably 500-600°C; the reaction time is 60-150 minutes; the reaction is carried out under stirring, and the stirring rate It is 350-600 rev/min; during the reaction, hydrogen gas needs to be introduced, and the hydrogen partial pressure is 5-10MPa. Further, the preferred reaction conditions are as follows: the reaction temperature of the catalytic reaction described in step (6) is at least 50°C higher than the reaction temperature of the catalytic reaction described in step (4), and the hydrogen partial pressure ratio of the catalytic reaction described in step (6) is The hydrogen partial pressure of the catalytic reaction described in step (4) is at least 1 MPa higher.

Compared with the prior art, the present invention has the following advantages:

Cellulose and waste plastics are two kinds of solid wastes that are difficult to handle. The invention combines the treatment of cellulose with the catalytic cracking of waste plastics, and at the same time makes them turn waste into treasure. The present invention makes full use of the characteristics of the two reactions, and the reaction conditions are optimized separately. Compared with the conventional co-processing of waste plastics and cellulose, it not only improves the overall conversion rate, but also promotes the target reaction to increase the cyclohexane The yield of soluble matter and tetrahydrofuran soluble matter reduced the amount of insoluble matter. The modified HY molecular sieve of Sn and P is selected as the catalyst for the catalytic cracking of waste plastics, so that the waste plastics have higher selectivity and conversion rate, which is beneficial to improve the liquid yield of the whole process. The liquid product extracted from tetrahydrofuran after catalytic cracking of waste plastics is co-pyrolyzed with cellulose, which helps to improve the dissolution of polar products in the process of cellulose catalytic reaction and improve the conversion rate of cellulose. In addition, the present invention collects and mixes the insoluble matter after the catalytic reaction of waste plastics and cellulose, and adds the remaining liquid product that has not been extracted by tetrahydrofuran and cyclohexane after the catalytic reaction of waste plastics and cellulose. Deep catalytic cracking reaction reduces the generation of a large amount of waste residue. For waste residues that are difficult to handle, especially the phosphorus and tungsten modified HZSM-5 and HY composite molecular sieve catalyst of the present invention, the cracking temperature is mild and the cracking rate is high.

In addition, the invention has a simple process flow, mild reaction conditions, simple operation, and low cost, which solves the problems of difficult disposal and low recycling value of a large amount of waste plastics and cellulose, and not only slows down the environmental pollution caused by a large amount of waste plastics and cellulose. Pressure, and turning waste into wealth, significantly increased the added value of waste plastics and cellulose.

Description of drawings

Fig. 1 is the technological process schematic diagram of the present invention;

Reference signs are explained as follows: 1. Catalytic reactor A; 2. Gas-liquid-solid separator a; 3. Extraction device a using tetrahydrofuran and cyclohexane as solvents; 4. Catalytic reactor B; 5. Gas-liquid-solid separator a; Liquid-solid separation device b; 6, sequentially equipped with extraction device b using tetrahydrofuran and cyclohexane as solvent; 7, catalytic reactor C; 8, gas-solid separation device c; 9, sequentially equipped with tetrahydrofuran and cyclohexane 21, liquid product I; 22, gas I; 23 insoluble matter I; 31, liquid product II, 32, liquid product III; 33, remaining liquid product IV; 51, liquid product i; 52 , gas i; 53, insoluble matter i; 61, liquid product ii; 62, liquid product iii; 63, remaining liquid product iv; 81, liquid product V; 82, gas V; 83, insoluble matter V; 91, liquid Product VI; 92, liquid product VII; 93, remaining liquid product VIII.

Detailed ways

The processing method of the present invention will be further described below in conjunction with specific examples, but the protection scope of the present invention is not limited to the scope of the following examples. Wherein in the present invention, wt% represents mass fraction.

As shown in Figure 1, the method for processing waste plastics and cellulose provided by the invention comprises the following steps:

(1) Add waste plastics to catalytic reactor A1, and carry out catalytic cracking reaction under the action of catalyst 1, and the resulting cracked product passes through gas-liquid-solid separator a2 to obtain liquid product I21, gas I22 and insoluble matter I 23;

(2) The liquid product I 21 of step (1) gained is passed through successively after cooling and is provided with the extraction device a 3 with tetrahydrofuran and hexanaphthene as solvent and carries out extraction, obtains respectively the tetrahydrofuran solution containing liquid product II, the liquid product containing Cyclohexane solution of III and remaining liquid product IV 33;

(3) The tetrahydrofuran solution containing the liquid product II obtained in step (2) and the cyclohexane solution containing the liquid product III are subjected to distillation treatment respectively to remove the solvent, and the liquid product II 31 and the liquid product III 32 obtained respectively;

(4) The cellulose is first added to the catalytic reactor B 4 for dehydration treatment, and then the liquid product II 31 obtained in step (3) is added, and the catalytic reaction is carried out under the action of the catalyst 2, and the gas-liquid-solid separator b 5 separated to obtain liquid product i 51, gas i 52 and insoluble matter i 53;

(5) After cooling, the liquid product i51 obtained in step (4) is sequentially passed into the extraction device b6 equipped with tetrahydrofuran and cyclohexane as solvents for extraction, to obtain respectively a tetrahydrofuran solution containing liquid product ii, a liquid containing A solution of product iii in cyclohexane and the remaining liquid product iv 63, treated by distillation to remove the solvent to give liquid product ii 61 and liquid product iii 62;

(6) The remaining liquid product IV 33 obtained in step (2) and step (5), the remaining liquid product iv63 and the insoluble matter I 23 and insoluble matter I 53 obtained in step (1) and step (4) respectively Put it into the catalytic reactor C7, and carry out deep catalytic cracking reaction under the action of the catalyst 3, and the cracked product obtained is separated by the gas-liquid-solid separation device C8 to obtain liquid product V81, gas V82 and insoluble matter V83;

(7) After cooling, the liquid product V81 obtained in step (6) is passed through an extraction device c9 that uses tetrahydrofuran and cyclohexane as solvents for extraction, respectively, to obtain a tetrahydrofuran solution containing liquid product VI and a liquid product containing VI. A solution of VII in cyclohexane and the remaining liquid product VIII 93 were worked up by distillation to remove the solvent to give liquid product VI 91 and liquid product VII 92 .

Among them, the insoluble matter V 83 is waste residue that no longer participates in the reaction, and the remaining liquid product VIII 93 can be recycled to the catalytic reactor C 7 for further catalytic cracking reaction.

Wherein, the product in table 1 is gas, cyclohexane soluble matter, tetrahydrofuran soluble matter, waste residue, wherein, gas is gas I 22, gas i 52 and gas V82, and cyclohexane soluble matter is liquid product III 32, Liquid product iii 62 and liquid product VII 92, THF solubles as liquid product ii 61 and liquid product VI 91, residue as insoluble V 83 and remaining liquid product VIII 93. The conversion rate refers to the percentage of the total mass of gas, cyclohexane solubles and tetrahydrofuran solubles in the product to the mass of the four products. In the present invention, the gas is mainly low-carbon olefins with carbon four or less such as ethylene and propylene.

Catalyst 1 in the embodiment of the present invention uses the impregnation method to modify the HY molecular sieve to obtain the Sn and P modified HY molecular sieve catalyst.

Catalyst 1-A in the embodiment of the present invention is a Sn and P modified HY molecular sieve catalyst, the mass content of Sn and P in the catalyst is 5%, and the molar ratio of Sn and P is 3:1.

Catalyst 1-B in the embodiment of the present invention is a Sn and P modified HY molecular sieve catalyst, the mass content of Sn and P in the catalyst is 8%, and the molar ratio of Sn and P is 2.5:1.

The catalyst used in the comparative example of the present invention is an unmodified HY molecular sieve catalyst.

The phosphorus and tungsten modified HZSM-5 and HY composite molecular sieve catalyst CAT-A used in the examples of the present invention are as follows: the mass ratio of HZSM-5 and HY composite molecular sieve is 1:1, the mass content of phosphorus is 3%, and the tungsten The mass content is 1.2%, and its preparation method is as follows: HZSM-5 is mixed with HY molecular sieve, impregnated with a phosphoric acid solution with a mass concentration of 15% to impregnate the composite molecular sieve, and dried at 100°C for 2 hours; Sodium acid aqueous solution impregnated with composite molecular sieves, dried at 100°C for 8 hours, and finally roasted at 350°C for 6 hours, pressed into tablets, sieved, and solid particles with a particle size of 40 mesh to 60 mesh were used as phosphorus and tungsten modified HZSM-5 and HY composite molecular sieve catalyst CAT-A.

The HZSM-5 and HY composite molecular sieve catalyst CAT-B used in the examples of the present invention are as follows: the mass ratio of HZSM-5 and HY composite molecular sieve is 1:1, and the preparation method is as follows: HZSM-5 and HY composite molecular sieve are mixed, Dry at 100°C for 8 hours, and finally bake at 350°C for 6 hours, press into tablets, sieve, and take solid particles with a particle size of 40 mesh to 60 mesh as the composite molecular sieve catalyst CAT-B of HZSM-5 and HY.

Example 1

Select 50wt% HDPE, 30wt% PET, 20wt% PS, a mixture of three kinds of plastics, 2g in total, as raw material for waste plastics reaction, add it to slurry bed catalytic cracking reactor A, under the catalytic action of catalyst 1-A Carry out the catalytic cracking reaction, the amount of catalyst 1-A added is 12% of the total mass of waste plastics, the reaction conditions of the catalytic cracking reaction are as follows: the reaction temperature is 460 ° C, the reaction time is 60 minutes, the stirring speed is 430 rpm, the reaction It is necessary to feed hydrogen into the catalytic reactor A, the hydrogen partial pressure is 2.9MPa, and the product after the reaction is separated to obtain liquid product I, gas I and insoluble matter I; the liquid product I is cooled to room temperature and then fed into Tetrahydrofuran and cyclohexane solvent are extracted to obtain respectively a tetrahydrofuran solution containing liquid product II, a cyclohexane solution containing liquid product III and remaining liquid product IV; for the obtained tetrahydrofuran solution containing liquid product II and liquid product III The cyclohexane solution is distilled to remove the solvent, and the obtained liquid product II and liquid product III are obtained; 2 g of straw is crushed to a powder with a length of about 10 mm, and then dehydration is carried out under anaerobic conditions, and the treatment temperature is 130 ° C. The treatment time is 70 minutes, and the stalk after the pretreatment is added in the slurry bed catalytic cracking reactor B, and then in the slurry bed catalytic cracking reactor B, iron naphthenate and molybdenum naphthenate with a mass content of 500ppm are added as Catalyst, while adding sulfur with a mass content of 6000ppm as a vulcanizing agent, so that the mass ratio of sulfur content to the total content of iron and molybdenum in the catalytic cracking catalyst B is 6:1, and the liquid product II is passed into the slurry bed catalytic cracking reaction Reactor B is then reacted under the following reaction conditions: the reaction temperature is 515 ° C, the reaction time is 80 minutes, and the stirring speed is 450 revs/min, and the needs in the reaction are passed into hydrogen in the slurry bed catalytic cracking reactor B, The partial pressure of hydrogen is 5.6MPa, and the product after the reaction is separated to obtain liquid product i, gas i and insoluble matter i; the obtained liquid product i is cooled to room temperature and then sequentially introduced into tetrahydrofuran and cyclohexane solvents for extraction, to obtain a tetrahydrofuran solution containing the liquid product ii and a cyclohexane solution containing the liquid product iii and the remaining liquid product iv, and distilling the tetrahydrofuran solution containing the liquid product ii and the cyclohexane solution containing the liquid product iii to remove the solvent, Liquid product ii and liquid product iii are obtained.

Add the remaining liquid product IV, the remaining liquid product iv, insoluble matter I and insoluble matter i into the slurry bed catalytic cracking reactor C to carry out deep catalytic cracking reaction, and the phosphorus and tungsten modified HZSM- 5 and HY composite molecular sieve are used as catalyst CAT-A, and the usage amount of this catalyst is 11% of the total mass of all reaction materials added to the slurry bed catalytic cracking reactor C, and the deep catalytic cracking reaction is carried out under the following reaction conditions: reaction temperature The temperature is 590°C, the reaction time is 100 minutes, and the stirring rate is 440 rpm. During the reaction, hydrogen gas needs to be introduced into the slurry bed catalytic cracking reactor C, and the hydrogen partial pressure is 8.0MPa. The resulting cracked product is obtained by separation Liquid product V, gas V and insoluble matter V; after cooling, the obtained liquid product V is sequentially passed through tetrahydrofuran and cyclohexane solvents for extraction to obtain a tetrahydrofuran solution containing liquid product VI and cyclohexane containing liquid product VII respectively. The solution and the remaining liquid product VIII are worked up by distillation to remove the solvent to give liquid product VI and liquid product VII.

Example 2

Just change the reaction conditions of the catalytic cracking reaction carried out in the catalytic cracking reactor A in the slurry state bed catalytic cracking reactor A among the embodiment 1: temperature of reaction is 450 ℃, and the reaction times is 100 minutes, and stirring speed is 480 rev/mins, needs in the reaction Pass hydrogen into the slurry bed catalytic cracking reactor A, the hydrogen partial pressure is 3.2MPa, the conditions for the deep catalytic cracking reaction of the slurry bed catalytic cracking reactor C are changed to: the reaction temperature is 570°C, and the reaction time is 110 minutes , the stirring rate is 500 revs/min, and the need in the reaction feeds hydrogen into the slurry bed catalytic cracking reactor C, and the hydrogen partial pressure is 6.6Pa.

Example 3

Just modify the iron naphthenate and molybdenum naphthenate with a mass content of 500 ppm in Example 1 to iron naphthenate with a mass content of 1000 ppm, and change the cellulose catalytic reaction conditions to: the reaction temperature is 535 ° C, hydrogen Pressure is 7.0MPa, other is the same as embodiment 1.

Example 4

Just modify each 500ppm iron naphthenate and molybdenum naphthenate in embodiment 1 to 1000ppm molybdenum naphthenate, and the others are the same as embodiment 1.

Example 5

The catalyst CAT-A in embodiment 4 is changed into CAT-B, and other is the same as embodiment 1.

Example 6

Just change catalyst 1-A in embodiment 1 into catalyst 1-B, other is with embodiment 1.

Comparative example 1

Get 2g of the mixture of three kinds of plastics of 50wt% HDPE, 30wt% PET, 20wt% PS, 2g of stalks are crushed to a powder with a length of about 10mm, and they are jointly added to the slurry bed catalytic cracking reactor. The catalytic cracking reaction is carried out under the catalysis of the permanent HY molecular sieve catalyst. The amount of HY molecular sieve added is 12% of the total mass of waste plastics and cellulose. The reaction conditions of the catalytic cracking reaction are as follows: the reaction temperature is 520 ° C, and the reaction time is 70 minutes. , the stirring rate is 430 rev/min, need to pass into hydrogen in the slurry bed catalytic cracking reactor in the reaction, hydrogen partial pressure is 5.6MPa, the product after reaction is separated, obtains liquid product 1, gas and waste residue; After the liquid product 1 is cooled to room temperature, it is sequentially introduced into tetrahydrofuran and cyclohexane solvents for extraction to obtain respectively a tetrahydrofuran solution containing liquid product 2, a cyclohexane solution containing liquid product 3 and the remaining liquid product IV, and the liquid product IV containing Product 2 in tetrahydrofuran, liquid product 3 in cyclohexane were distilled to remove the solvent to give liquid product 2 and liquid product 3.

Table 1 embodiment 1-6 and comparative example 1 the distribution and conversion rate comparison of the obtained product

Numbering Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative example 1 Product distribution, wt% gas 3.3 5.6 8.5 9.3 12.9 4.1 13.5 Cyclohexane solubles 32.2 35.4 34.2 34.0 28.1 37.9 19.8 THF soluble matter 58.6 51.2 44.6 43.4 36.1 51.4 24.2 The residue 5.9 7.8 12.7 13.3 22.9 6.6 42.5 Conversion rate, wt% 94.1 92.2 87.3 86.7 77.1 93.4 57.5

Claims (20)

1. a kind for the treatment of of waste plastics and cellulose method, comprising the following steps:

(1) waste plastics is added in catalytic reactor A, catalytic cracking reaction is carried out under the action of catalyst 1, it is resulting to split Solution product is isolated to product liquid I, gas I and insoluble matter I；

(2) the resulting product liquid I of step (1) is successively passed through tetrahydrofuran after cooling, cyclohexane solvent is extracted, respectively Obtain the tetrahydrofuran solution of the II containing product liquid, the cyclohexane solution of the III containing product liquid and remaining product liquid IV；

(3) cyclohexane solution of the tetrahydrofuran solution for the II containing product liquid that step (2) is obtained and the III containing product liquid point It does not carry out distillation to handle to remove solvent, the product liquid II and product liquid III that respectively obtain；

(4) cellulose and step (3) resulting product liquid II are added in catalytic reactor B, under the action of catalyst 2 into Row catalysis reaction, is isolated to product liquid i, gas i and insoluble matter i；

(5) by the resulting product liquid i of step (4) is successively passed through tetrahydrofuran after cooling, cyclohexane solvent extracts, point The tetrahydrofuran solution of the ii containing product liquid, the cyclohexane solution of the iii containing product liquid and remaining product liquid iv are not obtained, By distillation processing to remove solvent, product liquid ii and product liquid iii are obtained；

(6) remaining product liquid IV, remaining product liquid iv and the step (1) that step (2) and step (5) are respectively obtained The insoluble matter I and insoluble matter i respectively obtained with step (4) is added in catalytic reactor C, is carried out under the action of catalyst 3 Deep catalytic cracking reaction, resulting pyrolysis product are isolated to product liquid V, gas V and insoluble matter V；

(7) by the resulting product liquid V of step (6) is successively passed through tetrahydrofuran after cooling, cyclohexane solvent extracts, point The tetrahydrofuran solution of the VI containing product liquid, the cyclohexane solution of the VII containing product liquid and remaining product liquid are not obtained VIII obtains product liquid VI and product liquid VII by distillation processing to remove solvent；

Wherein, catalyst 1 described in step (1) is Sn and P modified HY zeolite catalyst；Catalyst 2 described in step (4) is One or two kinds of mixture in iron naphthenate and molybdenum naphthenate；Catalyst 3 described in step (6) is that HZSM-5 and HY is compound Molecular sieve catalyst.

2. according to the method for claim 1, it is characterised in that waste plastics described in step (1) includes vinyon, gathers The mixture of one or more of Acrylic plastic, polystyrene, 80% of total content not less than addition waste plastics gross mass.

3. according to the method for claim 1, it is characterised in that the usage amount of the catalyst 1 is the total matter of added waste plastics The 5%-20% of amount；The mass content of Sn and P is 1%-12% in Sn the and P modified HY zeolite catalyst, wherein Sn Molar ratio with P is 2-6:1.

4. according to the method for claim 3, it is characterised in that the usage amount of the catalyst 1 is the total matter of added waste plastics The 10%-15% of amount.

5. according to the method for claim 3, it is characterised in that Sn and P in Sn the and P modified HY zeolite catalyst Mass content be 3%-10%, wherein the molar ratio of Sn and P be 2-4:1.

6. according to the method for claim 1, it is characterised in that the reaction condition of catalytic cracking reaction described in step (1) is such as Under: reaction temperature is 350-550 DEG C, and the reaction time is 30-150 minutes, and reaction carries out under stiring, stirring rate 350- 600 revs/min, need to be passed through hydrogen, hydrogen partial pressure 2-4MPa in reaction.

7. according to the method for claim 6, it is characterised in that the reaction condition of catalytic cracking reaction described in step (1) is such as Under: reaction temperature is 400-480 DEG C, and the reaction time is 45-120 minutes, and reaction carries out under stiring, stirring rate 400- 500 revs/min, need to be passed through hydrogen, hydrogen partial pressure 2.5-3.5MPa in reaction.

8. according to the method for claim 1, it is characterised in that cellulose described in step (4) is stalk, one in bark Kind or two kinds；The cellulose is added to before catalytic reactor B, is first pre-processed, it is described pretreatment include pulverization process, At least one of dehydration, of length no more than 20mm of cellulose substances after pulverization process, the dehydration is in nothing It is carried out under the conditions of oxygen, treatment temperature is 100-200 DEG C, and the processing time is 60-120 minutes.

9. according to the method for claim 1, it is characterised in that catalyst 2 described in step (4) is iron naphthenate and cycloalkanes The mixture of sour molybdenum.

10. according to method described in claim 1 or 9, it is characterised in that the usage amount of catalyst 2 described in step (4) is with iron 800-1200ppm is calculated as with the gross mass content of molybdenum；Mass content is added while catalyst 2 are added in step (4) to be calculated as with sulphur The sulphur source of 4000-8000ppm is as vulcanizing agent, and the mass ratio of sulfur content and iron and molybdenum total content is 5-7 in catalytic reactor B: 1, selected sulphur source are as follows: one of sulphur, hydrogen sulfide, carbon disulfide are a variety of.

11. according to the method for claim 1, it is characterised in that the reaction condition of catalysis reaction described in step (4) is as follows: Reaction temperature is 400-600 DEG C, and the reaction time is 30-100 minutes, and reaction carries out under stiring, stirring rate 350-600 Rev/min, need to be passed through hydrogen, hydrogen partial pressure 4-8MPa in reaction.

12. according to the method for claim 11, it is characterised in that the reaction condition of catalysis reaction described in step (4) is such as Under: reaction temperature is 450-550 DEG C, and the reaction time is 60-100 minutes, and reaction carries out under stiring, stirring rate 400- 500 revs/min, need to be passed through hydrogen, hydrogen partial pressure 5-6.5MPa in reaction.

13. according to method described in claim 11 or 12, it is characterised in that the reaction temperature ratio of step (4) the catalysis reaction The reaction temperature of step (1) described catalytic cracking reaction is at least 50 DEG C high, and the hydrogen partial pressure of step (4) the catalysis reaction compares step (1) at least high 2MPa of the hydrogen partial pressure of the catalytic cracking reaction.

14. according to the method for claim 1, it is characterised in that catalyst 3 described in step (6) is that phosphorus and tungsten are modified HZSM-5 and HY composite molecular sieve catalyst, wherein the mass content of phosphorus is 1.5%-7.0%, and the mass content of tungsten is 0.3%- 2.0%.

15. according to method described in claim 1 or 14, it is characterised in that the usage amount of catalyst 3 described in step (6) is step Suddenly the 5%-15% of reaction mass gross mass added by the whole in catalytic reactor C is added in (6).

16. according to the method for claim 15, it is characterised in that it is characterized in that catalyst 3 described in step (6) makes Dosage is that reaction mass gross mass added by the middle whole being added in catalytic reactor C of step (6) is 6%-11%.

17. according to the method for claim 14, it is characterised in that catalyst 3 described in step (6) the preparation method comprises the following steps: HZSM-5 and HY carries out being mixed to get composite molecular screen with mass ratio 0.5-2:1, and the phosphoric acid for being 10%-20% with mass concentration is molten The mass ratio of liquid dipping composite molecular screen, phosphoric acid solution and composite molecular screen is 0.5-1:1, and dry 1-3 is small at 80-110 DEG C When, then the sodium tungstate solution dipping composite molecular screen for being 1%-2% with mass concentration, the matter of sodium tungstate solution and composite molecular screen Amount is 5-10 hours dry at 80-110 DEG C than being 0.5-1:1, then roasts 4-7 hours at 330-380 DEG C, after molding To catalyst 3.

18. according to the method for claim 1, it is characterised in that the reaction item of step (6) the Deep catalytic cracking reaction Part are as follows: reaction temperature is 400-700 DEG C；Reaction time is 60-150 minutes；Reaction carries out under stiring, stirring rate 350- 600 revs/min；Need to be passed through hydrogen, hydrogen partial pressure 5-10MPa in reaction.

19. according to the method for claim 18, it is characterised in that the reaction item of step (6) the Deep catalytic cracking reaction Part are as follows: reaction temperature is 500-600 DEG C.

20. according to method described in claim 18 or 19, it is characterised in that step step (6) the Deep catalytic cracking reaction The reaction temperature catalysis reaction more described than step (4) reaction temperature it is at least 50 DEG C high, step (6) Deep catalytic cracking is anti- At least high 1MPa of hydrogen partial pressure of the hydrogen partial pressure the answered catalysis reaction more described than step (4).