CN108117882B - A method of processing waste plastics and cellulose - Google Patents

Abstract

The invention discloses a method for processing waste plastics and cellulose. The method comprises: separating the product obtained by catalytic cracking of waste plastics to obtain a liquid product I, a gas I and an insoluble matter I, and passing the liquid product I through a mixed solvent of tetrahydrofuran and cyclohexane to obtain a mixed solvent containing a liquid product II, and the remaining Liquid product III, the former is catalyzed with cellulose, separated to obtain liquid product i, gas i and insoluble matter i, and liquid product i is extracted by tetrahydrofuran and cyclohexane to obtain liquid product ii, liquid product iii and the remaining liquid product iv, subject liquid product III, liquid product iv, insoluble matter I and insoluble matter i to deep catalytic cracking reaction, the obtained product is subjected to gas-liquid-solid separation, and the separated liquid product V is extracted and separated by tetrahydrofuran and cyclohexane respectively to obtain a liquid product VI and the 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 of processing waste plastics and cellulose

technical field

The invention belongs to the technical field of solid waste treatment, in particular to a method for processing 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, thereby increasing the liquid yield and improving 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 cooled and passed into a mixed solvent of tetrahydrofuran and cyclohexane for extraction, to obtain a mixed solvent of tetrahydrofuran and cyclohexane containing the liquid product II and the remaining liquid product III;

(3) Add cellulose and the tetrahydrofuran solution containing liquid product II and hexanaphthene mixed solvent obtained in step (2) to catalytic reactor B, carry out catalytic reaction, and obtain liquid product i, gas i and insoluble matter through separation i;

(4) The liquid product i obtained in step (3) 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;

(5) step (2) and step (4) obtain respectively remaining liquid product III, remaining liquid product iv and step (1) and step (3) 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 2, and the resulting cracked product is separated to obtain a liquid product V, a gas V and an insoluble V;

(6) After cooling, the liquid product V obtained in step (5) is sequentially passed through tetrahydrofuran and cyclohexane solvents 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 is processed by distillation to remove solvent to obtain liquid product VI and liquid product VII; wherein, the catalyst agent 1 described in step (1) is made up of two kinds of catalysts, one of which is kaolin and montmorillonite supported naphthenic acid The catalyst of iron and/or molybdenum naphthenate, the other is 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 mass ratio of kaolin and montmorillonite loaded iron naphthenate and/or molybdenum naphthenate catalyst to HY molecular sieve catalyst in the catalyst 1 described in step (1) is 0.14-3:1, preferably 0.2- 0.7:1.

Among the present invention, in the kaolin and montmorillonite loaded iron naphthenate and/or molybdenum naphthenate catalyst in the catalyst 1 described in step (1), by weight, the weight ratio of kaolin and montmorillonite is 2.5-1 : 1, kaolin and montmorillonite account for 37.5%-87.5%, iron naphthenate and/or molybdenum naphthenate account for 12.5%-62.5%, preferably the weight ratio of kaolin and montmorillonite is 2-1:1, Kaolin and montmorillonite account for 50%-70%, molybdenum naphthenate and/or iron naphthenate account for 30%-50%.

Among the present invention, the preparation method of kaolin and montmorillonite loaded iron naphthenate and/or molybdenum naphthenate catalyst in the catalyst 1 described in step (1) is as follows:

1) kaolin and montmorillonite are roasted at 400-550° C. for 2-10 hours, preferably at a rate of 5-10° C./min when the temperature rises to the roasting temperature;

2) Add the kaolin and montmorillonite obtained in step 1) into the reactor, then add ferric naphthenate and/or molybdenum naphthenate acid dipping solution into the reactor for impregnation, preferably while impregnating Stirring, stirring rate 100-150r/min, stirring time 0.5-2.5h;

3) drying the reacted material in step 2) at 100-150° C. for 2-6 hours to prepare a kaolin and montmorillonite-supported iron naphthenate and/or molybdenum naphthenate catalyst.

In the preparation method of the described kaolin and montmorillonite-supported iron naphthenate and/or molybdenum naphthenate catalyst, the dilute acid described in step 2) is at least one of hydrochloric acid, nitric acid and acetic acid, and the dilute acid dipping solution The mass concentration is 5%-20%. The impregnation solution can be an organic solution, preferably an ethanol solution. The impregnation adopts a conventional impregnation method, such as a saturated impregnation method or a supersaturated impregnation method.

The kaolin and montmorillonite-supported iron naphthenate and/or molybdenum naphthenate catalysts of the present invention can be molded by conventional methods, such as tablet molding, and molding aids can be added as needed during the molding process. In the present invention, the material obtained after drying in step (3) can be shaped to obtain a shaped catalytic cracking catalyst. After tableting and forming, sieve as required, and the particle size is 30 mesh to 70 mesh, preferably 40 to 60 mesh.

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, 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 mass ratio of tetrahydrofuran and cyclohexane mixed solvent described in step (2) to liquid product I is 1-3:1, wherein the mass ratio of tetrahydrofuran and cyclohexane is 1-3:1, preferably 1 -2:1.

In the present invention, the cooling described in step (2), step (4) and step (6) 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 (4) and step (6) is a conventional distillation method in the art to remove tetrahydrofuran or cyclohexane solvent.

In the present invention, the cellulose described in step (3) is one or more of plant fiber materials such as straw, bark, and rice straw.

In the present invention, before the cellulose described in step (3) 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 20mm. 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 tetrahydrofuran and hexanaphthene mixed solvent containing liquid product II obtained in step (2) are added in step (3), and the mass ratio of cellulose to tetrahydrofuran solution and hexanaphthene mixed solvent containing liquid product II is 0.8- 1.2:1.

In the present invention, in step (3), a certain amount of iron naphthenate and/or molybdenum naphthenate can be added as required, so that the total mass content of iron and molybdenum in the catalytic reactor B is 800-1200ppm. Step (3) when adding cellulose, add a sulfur source with a mass content of 4000-8000ppm in terms of sulfur 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 (3) 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 (3) 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 (3) is The hydrogen partial pressure of the catalytic reaction in step (1) is at least 2 MPa higher.

In the present invention, the catalyst 2 described in step (5) 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 2 is 5%-20%, preferably 10%-15%, of the total mass of all the reaction materials added to the catalytic reactor C in step (5).

In the present invention, the preparation method of the catalyst 2 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% to 20%, and dried at 80-110°C for 1-3 hour; impregnate the composite molecular sieve again with an aqueous solution of sodium tungstate with a mass concentration of 1% to 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 2.

In the present invention, the catalyst 2 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 2. 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 (5) 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 (5) is at least 50°C higher than the reaction temperature of the catalytic reaction described in step (3), and the hydrogen partial pressure ratio of the catalytic reaction described in step (5) is The hydrogen partial pressure of the catalytic reaction described in step (3) 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. In particular, use kaolin and montmorillonite-supported iron naphthenate and/or molybdenum naphthenate and HY molecular sieve as catalysts for the catalytic cracking of waste plastics, and then heat the liquid product obtained by extracting the mixed solution of tetrahydrofuran and cyclohexane with cellulose solution, in which the use of kaolin and montmorillonite-supported iron naphthenate and/or molybdenum naphthenate catalyst not only helps to improve the cracking rate of plastics, but also promotes the dissolution and dissolution of polar products during the cellulose catalytic reaction. Catalytic conversion improves 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, tetrahydrofuran and cyclohexane mixed solvent containing liquid product II; 32, remaining liquid product III; 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 preparation method of the present invention will be further described below in conjunction with specific examples, but the scope of protection of the present invention is not therefore limited to the scope of the following examples. 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 I 21, gas I 22 and insoluble matter I twenty three;

(2) The liquid product I 21 of step (1) gained passes through after cooling and is provided with the extraction device a 3 that is solvent with tetrahydrofuran and hexanaphthene mixed solvent to extract, obtain the tetrahydrofuran and hexanaphthene containing liquid product II respectively Mixed solvent 31, remaining liquid product III 32;

(3) The cellulose is first added to the catalytic reactor B4 for dehydration treatment, then the tetrahydrofuran and cyclohexane mixed solvent 31 containing the liquid product II obtained in step (2) are added, and the sulfur source is added to carry out the catalytic reaction. The gas-liquid-solid separator b 5 separates and obtains liquid product i 51, gas i 52 and insoluble matter i 53;

(4) After cooling, the liquid product i51 obtained in step (3) is sequentially passed into the extraction device b6 equipped with tetrahydrofuran and cyclohexane as solvents for extraction, respectively to obtain 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;

(5) Remaining liquid product III 32, remaining liquid product iv63 and step (1) and step (3) respectively obtained insoluble matter I 23 and insoluble matter I 53 obtained respectively for step (2) and step (4) Put it into the catalytic reactor C7, and carry out deep catalytic cracking reaction under the action of catalyst 2, 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;

(6) After cooling, the liquid product V81 obtained in step (5) 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 62 and Liquid product VII 92, THF solubles were liquid product ii 61 and liquid product VI 91, residue was insoluble V 83 and remaining liquid product VIII93. 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-A used in the embodiments of the present invention: based on the weight of the catalyst, the mass ratio of kaolin and montmorillonite-supported iron naphthenate and molybdenum naphthenate catalyst to HY molecular sieve catalyst is 0.32:1, kaolin and montmorillonite In the supported iron naphthenate and molybdenum naphthenate catalyst, by weight, kaolin and montmorillonite account for 60%, the weight ratio of kaolin and montmorillonite is 2:1, iron naphthenate accounts for 20% and naphthenic acid Molybdenum accounts for 20%.

Catalyst 1-B used in the embodiments of the present invention: based on the weight of the catalyst, the mass ratio of kaolin and montmorillonite supported iron naphthenate and molybdenum naphthenate catalyst to HY molecular sieve catalyst is 0.4:1, kaolin and montmorillonite In the supported iron naphthenate and molybdenum naphthenate catalyst, by weight, kaolin and montmorillonite account for 55%, the weight ratio of kaolin and montmorillonite is 1.5:1, iron naphthenate accounts for 15% and naphthenic acid Molybdenum accounts for 20%.

Wherein the preparation method of kaolin and montmorillonite supported iron naphthenate and molybdenum naphthenate catalyst is as follows: 1) kaolin and montmorillonite were originally roasted at 480°C for 6h, wherein the rate of heating up to the roasting temperature was 7°C/min; 2) Add the kaolin and montmorillonite obtained after step 1) roasting into the reaction vessel, then add the impregnation solution of dilute hydrochloric acid of iron naphthenate and molybdenum naphthenate to the reaction vessel for supersaturated impregnation, and the amount of the impregnation solution is 1.2 times the theoretical amount of saturated adsorbed water, the impregnating solution is an ethanol solution, wherein the mass fraction of hydrochloric acid is 12%, stirring, the stirring speed is 130r/min, and the stirring time is 1.0h; Dry at ℃ for 3 hours, then form into tablets, sieve, and take solid particles with a particle size of 40 mesh to 60 mesh as the 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 a total of 2g of a mixture of 50wt% HDPE, 30wt% PET, and 20wt% PS as the raw material for the reaction of waste plastics, and add it to the slurry bed catalytic cracking reactor A, under the catalytic action of catalyst 1-A. For the catalytic cracking reaction, the amount of catalyst 1-A added is 12% of the total mass of waste plastics. The reaction conditions for the catalytic cracking reaction are as follows: the reaction temperature is 455°C, the reaction time is 60 minutes, and the stirring rate is 440 rpm. It is necessary to feed hydrogen gas into the catalytic reactor A, the hydrogen partial pressure is 2.8MPa, 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 passed into tetrahydrofuran and cyclohexane mixed solvent for extraction, the mass ratio of tetrahydrofuran and cyclohexane mixed solvent to liquid product I is 1.8:1, wherein the mass ratio of tetrahydrofuran and cyclohexane is 2:1, and the tetrahydrofuran containing liquid product II is respectively obtained Mixed solvent with cyclohexane and the remaining liquid product III; crush 3g of straw to a powder with a length of about 10mm, and then perform dehydration treatment under anaerobic conditions, the treatment temperature is 130°C, and the treatment time is 70 minutes. After pretreatment The straw is added to the slurry bed catalytic cracking reactor B, and the mixed solvent of tetrahydrofuran and cyclohexane containing the liquid product II is passed into the slurry bed catalytic cracking reactor B, and then into the slurry bed catalytic cracking reactor B Add iron naphthenate and molybdenum naphthenate, make the slurry bed catalytic cracking reactor B altogether contain the iron naphthenate and the molybdenum naphthenate catalyst of mass content 500ppm altogether, add the sulfur that mass content is 6000ppm in terms of sulfur simultaneously as Vulcanizing agent, so that the mass ratio of the sulfur content to the total content of iron and molybdenum in the slurry bed catalytic cracking catalytic reactor B is 6:1, and then react under the following reaction conditions: the reaction temperature is 515 ° C, and the reaction time is 70 minutes , the stirring rate is 430 rev/min, the needs in the reaction are passed into hydrogen in the slurry bed catalytic cracking reactor B, the hydrogen partial pressure is 5.6MPa, the product after reaction is separated, obtains liquid product i, gas i and Insoluble matter i; the resulting liquid product i is cooled to room temperature and then passed through tetrahydrofuran and cyclohexane solvents for extraction to obtain a tetrahydrofuran solution containing liquid product ii and a cyclohexane solution containing liquid product iii and the remaining liquid product iv , and the THF solution containing the liquid product ii and the cyclohexane solution containing the liquid product iii are distilled to remove the solvent to obtain the liquid product ii and the liquid product iii.

The remaining liquid product III, the remaining liquid product iv and the insoluble matter I and insoluble matter i are added to the slurry bed catalytic cracking reactor C to carry out the 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 12% 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 570°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 7.0MPa. 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 condition of the catalytic cracking reaction that carries out in the slurry bed catalytic cracking reactor A among the embodiment 1: temperature of reaction is 460 ℃, and the reaction times is 110 minutes, and stirring rate is 480 rev/mins, needs in the reaction to Pass into hydrogen in the slurry bed catalytic cracking reactor A, hydrogen partial pressure is 3.6MPa, the condition of slurry bed catalytic cracking reactor C carrying out deep catalytic cracking reaction is changed: reaction temperature is 575 ℃, and reaction time is 120 minutes, The stirring rate is 500 rpm, and the reaction needs to feed hydrogen into the slurry bed catalytic cracking reactor C, and the hydrogen partial pressure is 7.4MPa.

Example 3

Just change the catalyst 1-A in the embodiment 1 into the catalyst 1-B, and the others are the same as the embodiment 1.

Example 4

The catalyst CAT-A among the embodiment 1 is changed into CAT-B, and others are the same as embodiment 1.

Comparative example 1

Take 2g of the mixture of three kinds of plastics of 50wt% HDPE, 30wt% PET, and 20wt% PS, and grind 3g of straw to a powder with a length of about 10mm, and add it to the slurry bed catalytic cracking reactor together. The catalytic cracking reaction is carried out under the catalysis of HY molecular sieve. The addition amount of HY molecular sieve 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, the reaction time is 70 minutes, and the stirring rate is 430 rev/min, during the reaction, it is necessary to feed hydrogen into the slurry bed catalytic cracking reactor, the hydrogen partial pressure is 5.6MPa, and the product after the reaction is separated to obtain the liquid product 1, gas and waste residue; the liquid product 1 is cooled After reaching room temperature, tetrahydrofuran and cyclohexane solvents are introduced successively 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 to the tetrahydrofuran solution containing liquid product 2 , The cyclohexane solution containing the liquid product 3 is distilled to remove the solvent to obtain the liquid product 2 and the liquid product 3.

Table 1 embodiment 1-4 and comparative example 1 the distribution and conversion rate comparison of the product obtained

Numbering Example 1 Example 2 Example 3 Example 4 Comparative example 1 Product distribution, wt% gas 4.1 7.1 5.8 9.4 13.3 Cyclohexane solubles 34.2 36.0 34.7 27.9 19.6 THF soluble matter 50.3 47.6 46.5 37.8 23.4 The residue 11.4 9.3 13.0 24.9 43.7 Conversion rate, wt% 88.6 90.7 87.0 75.1 56.3

Claims (18)

1. a kind of method for processing waste plastics and cellulose, 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 passed through tetrahydrofuran after cooling and hexamethylene mixed solvent is extracted, point The tetrahydrofuran and hexamethylene mixed solvent, remaining product liquid III of the II containing product liquid are not obtained；

(3) tetrahydrofuran and hexamethylene mixed solvent of cellulose and step (2) resulting II containing product liquid are added to catalysis In reactor B, catalysis reaction is carried out, is isolated to product liquid i, gas i and insoluble matter i；

(4) by the resulting product liquid i of step (3) 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；

(5) remaining product liquid III, remaining product liquid iv and the step that step (2) and step (4) are respectively obtained (1) be added in catalytic reactor C with step (3) the insoluble matter I that respectively obtains and insoluble matter i, under the action of catalyst 2 into Row Deep catalytic cracking reaction, resulting pyrolysis product are isolated to product liquid V, gas V and insoluble matter V；

(6) by the resulting product liquid V of step (5) 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 made of two kinds of catalyst, and one is kaolin and montmorillonite load aphthenic acids The catalyst of iron and/or molybdenum naphthenate, secondly being HY molecular sieve catalyst；Catalyst 2 described in step (5) is HZSM-5 and HY Composite molecular sieve catalyst.

2. according to the method for claim 1, it is characterised in that kaolin and montmorillonite in catalyst 1 described in step (1) The mass ratio for loading iron naphthenate and/or molybdenum naphthenate catalyst and HY molecular sieve catalyst is 0.14-3:1；The catalysis The usage amount of agent 1 is the 5%-20% of added waste plastics gross mass.

3. according to the method for claim 2, it is characterised in that kaolin and montmorillonite in catalyst 1 described in step (1) The mass ratio for loading iron naphthenate and/or molybdenum naphthenate catalyst and HY molecular sieve catalyst is 0.2-0.7:1；The catalysis The usage amount of agent 1 is the 10%-15% of added waste plastics gross mass.

4. according to the method for claim 1, it is characterised in that kaolin and montmorillonite in catalyst 1 described in step (1) It loads in iron naphthenate and/or molybdenum naphthenate catalyst, by weight, the weight ratio of kaolin and montmorillonite is 2.5-1:1, high Ridge soil and montmorillonite account for 37.5%-87.5%, and iron naphthenate and/or molybdenum naphthenate account for 12.5%-62.5%.

5. according to the method for claim 4, it is characterised in that kaolin and montmorillonite in catalyst 1 described in step (1) It loads in iron naphthenate and/or molybdenum naphthenate catalyst, by weight, the weight ratio of kaolin and montmorillonite is 2-1:1, kaolinite Soil and montmorillonite account for 50%-70%, and molybdenum naphthenate and/or iron naphthenate account for 30%-50%.

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 in reaction, hydrogen partial pressure is 2.5-3.5 MPa.

8. according to the method for claim 1, it is characterised in that waste plastics described in step (1) include polyethylene, The mixture of one or more of PP type plastics, polystyrene, total content is not less than addition waste plastics gross mass 80%；Cellulose described in step (3) is one or both of stalk, bark；The cellulose is added to catalytic reactor B Before, it is first pre-processed, the pretreatment includes at least one of pulverization process, dehydration, fiber after pulverization process Of length no more than 20mm of plain material, the dehydration carry out under anaerobic, and treatment temperature is 100-200 DEG C, Handling the time is 60-120 minutes.

9. according to the method for claim 1, it is characterised in that step (3) be added cellulose while be added mass content with Sulphur is calculated as the sulphur source of 4000-8000ppm as vulcanizing agent, the mass ratio of sulfur content and iron and molybdenum total content in catalytic reactor B For 5-7:1, selected sulphur source are as follows: one of sulphur, hydrogen sulfide, carbon disulfide are a variety of.

10. according to the method for claim 1, it is characterised in that the reaction condition of catalysis reaction described in step (3) 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.

11. according to the method for claim 10, it is characterised in that the reaction condition of catalysis reaction described in step (3) 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 in reaction, hydrogen partial pressure is 5-6.5 MPa.

12. according to method described in claim 10 or 11, it is characterised in that the reaction temperature ratio of step (3) the catalysis reaction The reaction temperature of step (1) the catalysis reaction is at least 50 DEG C high, and the hydrogen partial pressure of step (3) the catalysis reaction is than step (1) At least high 2MPa of hydrogen partial pressure of the catalysis reaction.

13. according to the method for claim 1, it is characterised in that catalyst 2 described in step (5) 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%；The usage amount of catalyst 2 is reaction mass gross mass added by step (5) middle whole being added in catalytic reactor C 5%-20%.

14. according to the method for claim 13, it is characterised in that the usage amount of catalyst 2 is that catalysis is added in step (5) The 10%-15% of reaction mass gross mass added by whole in reactor C.

15. according to the method for claim 13, it is characterised in that catalyst 2 described in step (5) 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 2.

16. according to the method for claim 1, it is characterised in that the reaction item of step (5) the Deep catalytic cracking reaction Part are as follows: reaction temperature is 400-700 DEG C, and the 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.

17. according to the method for claim 16, it is characterised in that the reaction temperature of step (5) the Deep catalytic cracking reaction Degree is 500-600 DEG C.

18. according to benefit require 16 or 17 described in method, it is characterised in that step (5) it is described catalysis reaction reaction temperature than step Suddenly the reaction temperature of (3) described catalysis reaction is at least 50 DEG C high, and the hydrogen partial pressure of step (5) the catalysis reaction is than step (3) institute State at least high 1MPa of hydrogen partial pressure of catalysis reaction.