CN114456834A

CN114456834A - Method and device for producing gasoline component by olefin polymerization

Info

Publication number: CN114456834A
Application number: CN202011130879.3A
Authority: CN
Inventors: 赵杰; 伏朝林; 赵丽萍; 邢恩会; 陶志平
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2020-10-21
Filing date: 2020-10-21
Publication date: 2022-05-10
Anticipated expiration: 2040-10-21
Also published as: CN114456834B

Abstract

The invention relates to a method and a device for producing gasoline components by olefin polymerization, comprising the following steps: C2-C4 olefin is used as a reaction raw material and stored in a pressure-resistant raw material tank, then the reaction raw material passes through a pretreatment reactor to remove diolefin and sulfur-containing compounds in the reaction raw material, and then the liquid phase component of the pretreated effluent is removed by a gas-liquid separator, and the gas phase component is used as a superposed raw material; the superimposed raw material enters from the upper part of the fixed bed reactor and passes through a ZSM-22 molecular sieve bed layer, under the catalytic action of the ZSM-22 molecular sieve, a product is extracted from the lower part, the product is further subjected to gas-liquid separation through a gas-liquid separator, a gas-phase component is partially circulated to a reaction raw material pipeline, a liquid-phase component is extracted as crude gasoline, and a high-octane gasoline component can be further obtained through distillation. The method has mild reaction conditions, is easy to operate, can prepare clean gasoline fractions with high octane number at high yield, and has industrial application prospect.

Description

Method and device for producing gasoline component by olefin polymerization

Technical Field

The invention relates to a method and a device for producing gasoline components, in particular to a method and a device for producing gasoline fractions through a polymerization reaction by taking a molecular sieve as a catalyst.

Background

Fifteen committees such as national development reform committee and the like jointly issue an implementation scheme about expanding the popularization and use of the ethanol gasoline for the vehicle for producing the biofuel ethanol in 2017 in 9 months. Planning a scheme: the ethanol gasoline for vehicles is popularized and used nationwide, and the full coverage is basically realized by 2020. The ethanol gasoline proposed has important effects on the whole gasoline pool structure, wherein the most remarkable change is that no other oxygen-containing compounds, mainly methyl tert-butyl ether (MTBE), can be added into the ethanol gasoline, so that the problem of surplus MTBE capacity is brought about, and once the MTBE unit stops production, a large amount of isobutene cannot go everywhere, so that a refinery has to be confronted with the problem of modification of the MTBE unit so as to consume a large amount of isobutene.

The polymerization reaction is also called oligomerization reaction, and is a process for catalytically synthesizing a large olefin molecule from low molecular olefins. The olefin in the industrial mixed C4 raw material of MTBE can be converted into clean gasoline components with high octane number mainly by olefin polymerization reaction, and the structure of a gasoline pool can be improved remarkably. The olefin polymerization has been studied for many years at home and abroad, and the studied catalysts comprise solid phosphoric acid catalysts, acidic resin catalysts, molecular sieves, ionic liquids and the like. Wherein, the solid phosphoric acid catalyst is easy to be argillized, has short service life and is not reproducible; the acid resin catalyst is not high temperature resistant, can not be regenerated and has swelling property; the molecular sieve catalyst has high use temperature; the ionic liquid is not easy to prepare and separate and has high price. The development of suitable catalysts for the polymerization reaction is therefore still the direction of research by the person skilled in the art.

CN 102633587 a discloses a composite catalyst: consists of 30-80 percent of HZSM-5 and 20-70 percent of binder, is used for preparing high-carbon olefin by C4 olefin conversion, has the conversion rate of C4 olefin of 84.9 percent and C of 20-70 percent₉₊The selectivity was 81.7%. CN 109097105A discloses a catalyst for superposition, which is composed of 85-94% of composite carrier and 0.2-14% of metal active component, wherein the composite carrier comprises 1-35% of H-type mesoporous Zn-ZSM-5 molecular sieve or modified mesoporous Zn-ZSM-5 molecular sieve, and alumina carrier containing tungsten doped lanthanum ferrite55-85% of mordenite, SAPO-11, MCM-22, Y molecular sieve or beta molecular sieve or one or more composite carriers in 0-35%, wherein the active component is one or more of V, Fe, Ni, Mo or W, the conversion rate of C4 olefin is up to 91%, the selectivity of C8 olefin is up to 90%, but the catalyst composition is complex, and the preparation process is complex. The article "Association of mass transfer in oligomerization of butene at high pressure on H-beta" (Applied catalysts A: General,505,394-401,2015) used beta molecular sieves for butene oligomerization at a conversion of 23% and found that the process of oligomer diffusion out of the crystals was a control step for the overall oligomerization process, and therefore beta molecular sieves were not suitable for the preparation of dimerization products.

Disclosure of Invention

The invention aims at the problems in the prior art and provides a method for producing a gasoline component by olefin polymerization. The method takes a ZSM-22 molecular sieve as a catalyst, produces gasoline components by olefin polymerization, and has the advantages of high conversion rate of raw materials, high selectivity of target products, good stability of the catalyst, long service life and easy regeneration and reuse.

The invention also provides a device for producing the gasoline component by olefin polymerization.

The invention provides a method for producing gasoline components by olefin polymerization, which comprises the following steps: C2-C4 olefin is led to pass through a pretreatment reactor to remove diene and sulfur-containing compounds, then the liquid phase component of the pretreated effluent is removed through a gas-liquid separator, and the gas phase component is used as a superimposed raw material; the superimposed raw material enters from the upper part of the fixed bed and passes through a molecular sieve bed layer, a product is extracted from the lower part under the catalytic action of a ZSM-22 molecular sieve, gas-liquid separation is further carried out through a gas-liquid separator, a gas-phase component is partially circulated to a reaction raw material pipeline, and a liquid-phase component is extracted as crude gasoline. Through distillation, the high octane gasoline component can be further separated.

The ZSM-22 molecular sieve is preferably subjected to modification treatment by a pore-expanding agent, so that the activity and the service life of the catalyst can be remarkably improved.

The invention provides a device for producing gasoline components by olefin polymerization, which comprises: a pressure-resistant raw material tank, a pretreatment reactor and a gas-liquid separator; a fixed bed reactor and a gas-liquid separator; a line for transferring the raw material from the pressure-resistant raw material tank to the upper part of the pretreatment reactor; a pipeline for conveying the pretreated feedstock to a gas-liquid separator; a pipeline for conveying the reaction raw material from the upper part of the gas-liquid separator to the upper part of the fixed bed reactor; a pipeline for conveying the by-product from the lower part of the gas-liquid separator; a pipeline for conveying the reacted material from the lower part of the fixed bed reactor to the gas-liquid separator; a pipeline for recycling the unreacted raw material part in the upper part of the gas-liquid separator to the raw material tank, a pipeline for withdrawing the unreacted raw material part in the upper part of the gas-liquid separator, and a pipeline for withdrawing the bottom product of the gas-liquid separator.

The invention takes ZSM-22 molecular sieve as the catalyst, produces gasoline components by olefin polymerization, has high conversion rate of raw materials, high selectivity of target products, good stability of the catalyst, long service life, easy regeneration and reuse and industrial application prospect. For molecular sieve catalysts, the pore structure, acid content, crystal size, etc. of the catalyst can all significantly affect the activity, selectivity, and lifetime of the catalyst. The inventors of the present application have discovered that one-dimensional molecular sieves, such as ZSM-22, have substantially straight-tubular channels and, due to their unique channel structure, have better shape selectivity compared to three-dimensional molecular sieves, such as ZSM-5, beta, etc., and two-dimensional molecular sieves, such as mordenite, etc.

However, ZSM-22 is a typical microporous molecular sieve, the diffusion of reactants and products is limited by the smaller aperture and the longer pore passage of the ZSM-22, so that coking and deactivation are easy to occur in the pore passage of the catalyst, and the service life of the catalyst is influenced.

Drawings

FIG. 1 is a schematic view of an embodiment of a reaction apparatus according to the present invention. Which comprises the following steps: a pressure-resistant raw material tank 1, a pretreatment reactor 2, a gas-liquid separator 3, a fixed bed reactor 4, a gas-liquid separator 5, a distillation column 14, a pipeline 6 for feeding a reaction raw material to an upper portion of the pretreatment reactor 2, a pipeline 7 for feeding a pretreated raw material to the gas-liquid separator 3, a pipeline 8 for feeding a gas-phase raw material discharged from an upper portion of the gas-liquid separator 3 to an upper portion of the fixed bed reactor 4, a pipeline 9 for outputting a by-product discharged from a lower portion of the gas-liquid separator 3, a pipeline 10 for feeding a reacted material from a lower portion of the fixed bed reactor 4 to the gas-liquid separator 5, a pipeline 11 for circulating an unreacted raw material portion from an upper portion of the gas-liquid separator 5 to the raw material tank 1, a pipeline 12 for withdrawing a bottom product from the gas-liquid separator 5, and a pipeline 13 for withdrawing an unreacted raw material portion from an upper portion of the gas-liquid separator 5, a line 15 for feeding the material withdrawn from the bottom product of the gas-liquid separator 5 to the distillation column 14, and a line 16 for withdrawing a high octane gasoline component from the top of the distillation column and a line 17 for withdrawing a by-product from the bottom of the distillation column.

Detailed Description

In a first aspect, the present invention provides a process for the production of a gasoline component by olefin polymerization, comprising: C2-C4 olefin is led to pass through a pretreatment reactor to remove dialkene and sulfur-containing compounds in the olefin, and then the liquid phase component of the pretreated effluent is removed by a gas-liquid separator, and the gas phase component is used as a superposed raw material; the polymerization raw material enters from the upper part of the fixed bed reactor and passes through a molecular sieve bed layer, olefin polymerization reaction is carried out under the catalytic action of a ZSM-22 molecular sieve, a product is extracted from the lower part and then is subjected to gas-liquid separation through a gas-liquid separator, a gas-phase component is partially circulated to a reaction raw material tank, and a liquid phase is extracted as a crude gasoline component.

According to the method, after the liquid phase component is extracted, the high-octane gasoline component can be further obtained by distillation.

The reaction raw material containing C2-C4 olefin is sourced from but not limited to mixed C4 fraction and Fischer-Tropsch synthesis olefin. Mainly comprises one or a mixture of more of ethylene, propylene, butylene and isobutene. The olefin was stored in a nitrogen blanketed feed tank under pressure.

The pretreatment reactor is a fixed bed, and activated clay is filled in the fixed bed. The pretreatment conditions include: the temperature is 50-110 ℃, and preferably 60-80 ℃; the pressure is 1.0-7.0 MPa, preferably 3.0-5.0 MPa; quality of foodThe volume airspeed is 0.5-5.0 h^-1Preferably 1.0 to 3.0 hours^-1。

The pretreated olefin raw material is conveyed to the upper part of the fixed bed, and the reacted material flows out from the lower part of the fixed bed. The temperature of the superposition reaction is 140-220 ℃, and preferably 160-200 ℃; the reaction pressure is 1.0 to 7.0MPa, preferably 3.0 to 5.0 MPa. The mass airspeed is 0.5-5.0 h^-1Preferably 1.0 to 3.0 hours^-1。

The catalyst is a ZSM-22 molecular sieve, and the Si/Al ratio of the catalyst is 20-100, preferably 25-70; na (Na)₂The O content is less than 0.5 wt.%, preferably less than 0.1 wt.%; the acid center number of the ZSM-22 is 0.1 to 1.5mmol/g, preferably 0.2 to 1 mmol/g.

The ZSM-22 molecular sieve is preferably a molecular sieve subjected to pore expansion modification, and the modification method comprises the following steps: mixing the ZSM-22 molecular sieve with a pore-expanding agent aqueous solution in a reactor, dynamically treating for 4-20 hours at 130-210 ℃, washing, filtering, drying and calcining to obtain the modified ZSM-22 molecular sieve.

The pore-expanding agent may be selected from the group consisting of hexamethylenediamine, tetraethylammonium hydroxide, and preferably tetraethylammonium hydroxide.

The pore-expanding agent and SiO in the molecular sieve₂The molar ratio is 0.05 to 0.20, preferably 0.08 to 0.15.

The concentration of the pore-expanding agent aqueous solution is 10-45 wt%, and preferably 20-35 wt%.

The dynamic treatment is to make the slurry flow continuously or stir and turn. The dynamic treatment temperature can be 130-210 ℃, and is preferably 150-180 ℃; the reaction pressure may be 0.1 to 1MPa, preferably 0.1 to 0.5 MPa. The dynamic treatment time is 4-20 h, preferably 6-15 h.

The reactor can be a stirred tank, a high-pressure reaction kettle, preferably a high-pressure reaction kettle.

The washing, filtering and drying are conventional operations in the field.

The calcination condition is conventional operation, and the calcination can be carried out for 1-3 h at 500-600 ℃.

The modified molecular sieve has the following characteristics: the pore diameter is 2-10 nm, preferably 4-8 nm; volume of mesopores0.10～0.35cm³A concentration of 0.20 to 0.30cm³(ii)/g; the particle size is 200 to 600nm, preferably 300 to 500 nm.

The Si/Al ratio of the modified ZSM-22 molecular sieve is 20-100, preferably 25-70; na (Na)₂The O content is less than 0.5 wt.%, preferably less than 0.1 wt.%; the acid center number of the ZSM-22 is 0.1 to 1.5mmol/g, preferably 0.2 to 1.0 mmol/g.

Compared with an unmodified molecular sieve, the ZSM-22 molecular sieve modified by the method has the advantages that the pore volume is increased, the pore diameter is increased, the mesoporous volume is increased, and the crystal particle size is reduced, so that reactant and product molecules are not easy to block and stay in the pore diameter, a coking precursor or a coking substance generated by deep reaction can be avoided, and the stability of the catalyst is improved. The regeneration method of the modified molecular sieve is simple and convenient, and the regenerated molecular sieve still has high activity.

In a second aspect, the present invention provides an apparatus for producing a gasoline component by olefin polymerization, comprising: the device comprises a pressure-resistant raw material tank 1, a pretreatment reactor 2, a gas-liquid separator 3, a fixed bed reactor 4, a gas-liquid separator 5, a pipeline 6 for conveying reaction raw materials to the upper part of the pretreatment reactor 2, a pipeline 7 for conveying pretreated raw materials to the gas-liquid separator 3, a pipeline 8 for conveying gas-phase raw materials from the upper part of the gas-liquid separator 3 to the upper part of the fixed bed reactor 4, a pipeline 9 for outputting byproducts from the lower part of the gas-liquid separator 3, and a pipeline 10 for conveying the reacted materials from the lower part of the fixed bed reactor 4 to the gas-liquid separator 5; a line 11 for recycling an unreacted raw material portion in the upper part of the gas-liquid separator 5 to the raw material tank 1, a line 12 for withdrawing a bottom product of the gas-liquid separator 5, and a line 13 for withdrawing an unreacted raw material portion in the upper part of the gas-liquid separator 5. Preferably, a distillation tower 14 and a pipeline 15 for conveying materials produced from the bottom product of the gas-liquid separator 5 to the distillation tower, a pipeline 16 for producing high octane gasoline components from the top of the distillation tower and a pipeline 17 for producing byproducts from the bottom of the distillation tower are further included.

The following examples are provided to further illustrate the embodiments of the present invention.

In the examples, the pore diameter and the mesoporous volume of the catalyst were measured by a nitrogen physical adsorption and desorption (BET) method, and the grain size was measured by a Transmission Electron Microscope (TEM) method.

The ZSM-22 molecular sieve before modification is purchased from China petrochemical Changling catalyst factories.

Example 1(ZSM-22 Na)₂Examination of O content

The mixed C4 fraction was used as a feedstock, the olefin content was 20 wt%, and the mixture was stored in a feed tank using 2MPa of N₂Sealing, pumping into a pretreatment reactor filled with activated clay at 70 deg.C under 5.0MPa and at a mass space velocity of 1.0h^-1Removing the impurities such as dialkene, sulfur-containing compounds and the like, and removing liquid phase components from the pretreated effluent through a gas-liquid separator, wherein the gas phase components are used as a superposed raw material. The superimposed raw material enters from the upper part of the fixed bed and passes through a molecular sieve bed layer, and a product is extracted from the lower part under the catalytic action of the ZSM-22 molecular sieve. And further carrying out gas-liquid separation on the product through a gas-liquid separator, circulating part of the gas-phase component to a reaction raw material pipeline, extracting a liquid-phase product, and further distilling to obtain the high-octane gasoline component. Wherein the superposition reaction temperature is 180 ℃, the reaction pressure is 5.0MPa, and the mass space velocity is 1.0h^-1(ii) a After the system is stabilized for 10h, sampling is carried out at the outlet for gas chromatographic analysis, and Na in ZSM-22 is inspected₂The effect of the O content on the conversion of the blend C4 distillate and the yield of the gasoline distillate. The results are shown in table 1 below:

TABLE 1

Example 2 (investigation of the silica/alumina ratio and the acid amount of ZSM-22)

ZSM-22 (Na) was prepared according to the test method described in example 1, with different silica to alumina ratios and different amounts of acid₂O<0.1 wt%) as catalyst, after 10h reaction, sampling at the outlet for gas chromatographic analysis, and examining the influence on the conversion rate of mixed C4 fraction and the yield of gasoline fraction. The results are shown in Table 2 below.

TABLE 2

Example 3 (Effect of pore-expanding agent modification on molecular sieves)

ZSM-22-B (Na) of Table 2₂0.08 wt% of O and 36 wt% of Si/Al) was modified with tetraethylammonium hydroxide under the following conditions: the concentration of TEAOH is 27.5 percent, and the added TEAOH and SiO in the molecular sieve₂The molar ratio of n (TEAOH)/n (SiO) is 0.1₂) 0.1; the amount of water added satisfies n (H)₂O)/n(SiO₂) 10; the materials are uniformly mixed according to the proportion, then the mixture is added into a high-pressure reaction kettle, dynamic treatment is carried out for 4-18 h at the temperature of 140-200 ℃, and then the mixture is washed, filtered and dried and calcined for 2h at the temperature of 550 ℃ to obtain the modified ZSM-22-1-ZSM-22-5 molecular sieve. The pore diameter, the mesoporous volume and the grain diameter of the modified catalyst are listed in the following table 3; according to the test method described in example 1, samples were taken after 10 hours and 100 hours of the reaction and analyzed by gas chromatography, and the results are shown in Table 3 below.

Example 4

ZSM-22-C (Na) in Table 2₂O0.03%, Si/Al 70) was modified according to the conditions in example 3, but TEAOH was adjusted to SiO in the molecular sieve₂The molar ratio was 0.15 to obtain a modified catalyst ZSM-22-6, the modified catalyst pore size, mesopore volume and grain size being listed in Table 3. According to the test method described in example 1, samples were taken for analysis after 10 hours and 100 hours of reaction, and the results are shown in Table 3 below.

Example 5 (Effect of tetraethylammonium hydroxide concentration on molecular Sieve modification)

The ZSM-22-B molecular sieve was modified under the conditions of example 1, but the TEAOH concentration was adjusted to 40.0% to obtain a modified catalyst ZSM-22-7, the pore diameter, the mesoporous volume and the grain size of which are shown in Table 3. According to the test method described in example 1, samples were taken for analysis after 10 hours and 100 hours of reaction, and the results are shown in Table 3 below.

Example 6 (Effect of hexamethylenediamine on modification of the molecular sieves)

The ZSM-22-B molecular sieve was modified according to the conditions of example 1, but with hexamethylenediamine instead of tetraethylammonium hydroxide, the hexamethylenediamine concentration being 10%, the hexamethylenediamine being added with SiO in the molecular sieve₂The molar ratio is 0.05, i.e. n (hexamethylene diamine)/n (SiO)₂) The modification was carried out at 170 ℃ for 6 hours under the same conditions as those for the other modifications, 0.05, to obtain modified catalyst ZSM-22-8, and the pore diameter, mesoporous volume and crystal grain size of the modified catalyst are shown in table 3. According to the test method described in example 1, samples were taken for analysis after 10 hours and 100 hours of reaction, and the results are shown in Table 3 below.

TABLE 3

Example 7 (examination of reaction temperature)

Following the experimental procedure described in example 1, using ZSM-22-2 of example 3 as the catalyst, the mixed C4 fraction was fed at a mass space velocity of 1h^-1After 10 hours of reaction under the condition that the reaction pressure in the fixed bed is kept at 5MPa, sampling is carried out at an outlet for gas chromatographic analysis, the influence of different reaction temperatures is examined, and the results are shown in the following table 4:

TABLE 4

Example 8 (examination of reaction pressure)

Following the experimental procedure described in example 1, using ZSM-22-2 of example 3 as the catalyst, the mixed C4 fraction was fed at a mass space velocity of 1h^-1After 10 hours of reaction at the reaction temperature of 180 ℃, sampling at the outlet for gas chromatographic analysis, and examining the influence of different reaction pressures, the results are shown in the following table 5:

TABLE 5

Example 9 (investigation of Mass space velocity)

According to the test method described in example 1, ZSM-22-2 of example 3 was used as the catalyst, and gas chromatography was performed after 10 hours of reaction at 180 ℃ and 5MPa to examine the effect of different mass space velocities, as shown in Table 6 below:

TABLE 6

Example 10 (examination of raw Material pretreatment Unit)

The experimental procedure described in example 1 was followed, using ZSM-22-2 of example 3 as catalyst, with a feed mass space velocity of 1h for the mixed C4 cut^-1Respectively sampling at an outlet for gas chromatography analysis after 10h and 100h of reaction at the reaction temperature of 180 ℃ and the reaction pressure of 5 MPa;

in addition, for comparison, the experimental procedure described in example 1 was followed, but the feed was passed directly to the fixed bed of the superposition reaction without passing through a pretreatment unit, using ZSM-22-2 as catalyst in example 3, at a mixed C4 fraction feed mass space velocity of 1h^-1After 10h and 100h of reaction at the reaction temperature of 180 ℃ and the reaction pressure of 5MPa, samples were taken at the outlet respectively for gas chromatography analysis, and the effect of the raw material pretreatment unit was examined, the results of which are shown in the following Table 7:

TABLE 7

Example 11 (investigation of catalyst regeneration)

The method is further described in example 3Calcining 100h ZSM-22-B catalyst and 300h ZSM-22-2 catalyst at 450 deg.C for 5h in air atmosphere, reacting at 180 deg.C under 5.0MPa and feeding space velocity of 1h^-1The regeneration activity of the catalyst was examined according to the protocol described in example 1, the results of which are shown in table 8 below:

TABLE 8

Claims

1. A process for the production of a gasoline component by olefin polymerization comprising: C2-C4 olefin passes through a pretreatment reactor, after liquid phase components of pretreated effluents are removed by a gas-liquid separator, the gas phase components enter the fixed bed reactor from the upper part and pass through a ZSM-22 molecular sieve bed layer, olefin polymerization reaction is carried out under the catalytic action of the ZSM-22 molecular sieve, products are extracted from the lower part, gas-liquid separation is further carried out by the gas-liquid separator, part of the gas phase components are circulated to a reaction raw material pipeline, and the liquid phase components are extracted as crude gasoline.

2. The process of claim 1 wherein the high octane gasoline component is obtained by distillation after the liquid phase component is recovered.

3. The process of claim 1 wherein said C2-C4 olefins are derived from but not limited to mixed C4 cuts, Fischer-Tropsch olefins.

4. The process of claim 1 wherein said pretreatment reactor is a fixed bed containing activated clay.

5. The method of claim 1, wherein the pre-treatment conditions comprise: the temperature is kept between 50 and 110 ℃, and preferably between 60 and 80 ℃; the pressure is 1.0-7.0 MPa, preferably 3.0-5.0 MPa; the mass space velocity is 0.5-5.0 h^-1Preferably 1.0 to 3.0 hours^-1。

6. The process according to claim 1, wherein the polymerization temperature is 140 to 220 ℃, preferably 160 to 200 ℃; the reaction pressure is 1.0 to 7.0MPa, preferably 3.0 to 5.0 MPa. The mass space velocity is 0.5-5.0 h^-1Preferably 1.0 to 3.0 hours^-1。

7. The process of claim 1, wherein the catalyst is a ZSM-22 molecular sieve having a Si/Al ratio of 20 to 100, preferably 25 to 70; na (Na)₂The O content is less than 0.5 wt.%, preferably less than 0.1 wt.%; the acid center number of the ZSM-22 is 0.1 to 1.5mmol/g, preferably 0.2 to 1 mmol/g.

8. The process of claim 1 wherein the ZSM-22 molecular sieve is pore-expanded and modified, the modification process comprising: mixing the ZSM-22 molecular sieve with a pore-expanding agent aqueous solution in a reactor, dynamically treating for 4-20 hours at 130-210 ℃, washing, filtering, drying and calcining to obtain the modified ZSM-22 molecular sieve.

9. The method of claim 8 wherein the pore-expanding agent is selected from the group consisting of hexamethylenediamine and tetraethylammonium hydroxide.

10. The method of claim 8 wherein the pore-expanding agent is mixed with SiO in the molecular sieve₂The molar ratio is 0.05 to 0.20, preferably 0.08 to 0.15.

11. A method according to claim 8, wherein the aqueous pore-expanding agent solution has a concentration of 10 to 45 wt%, preferably 20 to 35 wt%.

12. The process according to claim 8, wherein the dynamic treatment temperature is 130 to 210 ℃, preferably 150 to 180 ℃; the pressure is 0.1-1 MPa, preferably 0.1-0.5 MPa; the dynamic treatment time is 4-20 h, preferably 6-15 h.

13. The process of claim 1, wherein the modified molecular sieve has the following characteristics: the pore diameter is 2-10 nm, preferably 4-8 nm; the mesoporous volume is 0.10-0.35 cm³A concentration of 0.20 to 0.30cm³(ii)/g; the particle size is 200 to 600nm, preferably 300 to 500 nm.

14. An apparatus for producing gasoline components by olefin polymerization, comprising: a pressure-resistant raw material tank 1, a pretreatment reactor 2, a gas-liquid separator 3, a fixed bed reactor 4, a gas-liquid separator 5, a pipeline 6 for conveying a reaction raw material to an upper portion of the pretreatment reactor 2, a pipeline 7 for conveying a pretreated raw material to the gas-liquid separator 3, a pipeline 8 for conveying a gas-phase raw material discharged from an upper portion of the gas-liquid separator 3 to an upper portion of the fixed bed reactor 4, a pipeline 9 for outputting a by-product discharged from a lower portion of the gas-liquid separator 3, a pipeline 10 for outputting a reacted material from a lower portion of the fixed bed reactor 4, a pipeline 11 for circulating an unreacted raw material portion of an upper portion of the gas-liquid separator 5 to the raw material tank 1, a pipeline 12 for withdrawing a bottom product of the gas-liquid separator 5, and a pipeline 13 for withdrawing an unreacted raw material portion of an upper portion of the gas-liquid separator 5.

15. The apparatus according to claim 14, further comprising a distillation column 14 and a line 15 for feeding a material produced from the bottom product of the gas-liquid separator 5 to the distillation column, and a line 16 for producing a high octane gasoline component from the distillation column and a line 17 for producing a by-product at the bottom of the distillation column.