阅读说明：本技术 由c5-c6烷烃原料生产高辛烷值汽油组分的方法 (Method for producing high-octane gasoline components from C5-C6 alkane raw materials ) 是由 张秋平 王京红 马爱增 王杰广 于 2020-05-27 设计创作，主要内容包括：一种由C-(5)/C-(6)烷烃原料生产高辛烷值汽油调合组分的方法,包括将C-(5)/C-(6)烷烃原料送入精馏塔(2)进行精馏分离,塔顶得到沸点不大于异戊烷的富含异戊烷的塔顶组分,塔侧线得到富含正戊烷和正己烷的侧线组分,塔底得到沸点不小于甲基环戊烷的塔底组分,将侧线组分在100～300℃、3～6MPa、氢/烃摩尔比为0.1～6的条件下与C-(5)/C-(6)烷烃异构化催化剂接触进行C-(5)/C-(6)正构烷烃异构化反应,将塔底组分在230～300℃、1.6～3.0MPa、氢/烃摩尔比为1～6的条件下与加氢异构化催化剂接触进行加氢异构化反应。该法可有效提高烷烃原料的辛烷值,得到不含苯的高辛烷值清洁汽油调和组分。(From C 5 /C 6 A process for producing a high octane gasoline blending component from a paraffinic feedstock comprising blending C 5 /C 6 Sending alkane raw materials into a rectifying tower (2) for rectification separation, obtaining an isopentane-rich tower top component with a boiling point not more than that of isopentane at the tower top, obtaining a side line component rich in n-pentane and n-hexane at the tower side line, obtaining a tower bottom component with a boiling point not less than that of methylcyclopentane at the tower bottom, and reacting the side line component with C under the conditions of 100-300 ℃, 3-6 MPa and a hydrogen/hydrocarbon molar ratio of 0.1-6 5 /C 6 Alkane isomerization catalyst contact 5 /C 6 And (3) carrying out normal paraffin isomerization reaction, namely contacting the tower bottom component with a hydroisomerization catalyst at 230-300 ℃ and 1.6-3.0 MPa in a hydrogen/hydrocarbon molar ratio of 1-6 to carry out hydroisomerization reaction. The method can effectively improve the octane number of the alkane raw material and obtain the benzene-free high-octane-number clean gasoline blending component.)

1. From C₅/C₆A process for producing a high octane gasoline blending component from a paraffinic feedstock comprising blending C₅/C₆Sending alkane raw materials into a rectifying tower (2) for rectification separation, obtaining an isopentane-rich tower top component with a boiling point not more than that of isopentane at the tower top, obtaining a side line component rich in n-pentane and n-hexane at the tower side line, obtaining a tower bottom component with a boiling point not less than that of methylcyclopentane at the tower bottom, and reacting the side line component with C under the conditions of 100-300 ℃, 3-6 MPa and a hydrogen/hydrocarbon molar ratio of 0.1-6₅/C₆Alkane isomerization catalyst contact₅/C₆And (3) carrying out normal paraffin isomerization reaction, namely contacting the tower bottom component with a hydroisomerization catalyst at 230-300 ℃ and 1.6-3.0 MPa in a hydrogen/hydrocarbon molar ratio of 1-6 to carry out hydroisomerization reaction.

2. The process according to claim 1, wherein the overhead component, the side stream component isomerization product and the bottom component hydroisomerization product are mixed.

3. The method of claim 1, wherein said method comprisesC is₅/C₆The content of methylcyclopentane, benzene and cyclohexane in the alkane starting material is not less than 15% by mass.

4. The method according to claim 1, wherein the pressure at the top of the rectifying column is 0.5 to 0.6MPa, the temperature at the top of the rectifying column is 35 to 45 ℃, the temperature at the side line of the rectifying column is 65 to 78 ℃, and the temperature at the bottom of the rectifying column is 95 to 120 ℃.

5. The method of claim 1, wherein C is₅/C₆The alkane isomerization catalyst comprises a composite carrier and 0.01-2.0 mass% of VIII group metal by taking the composite carrier as a reference, wherein the composite carrier comprises 10-40 mass% of mordenite, 30-80 mass% of Beta zeolite and 5-30 mass% of alumina.

6. The process according to claim 5, wherein C is carried out with the catalyst₅/C₆The reaction temperature for isomerization of the alkane is 220-300 ℃.

7. The method of claim 1, wherein C is₅/C₆The alkane isomerization catalyst comprises a zirconium oxide carrier containing sulfate radicals and VIII-group metals loaded on the carrier, wherein the content of the sulfate radicals in the catalyst is 1.5-7 mass%, and the content of the VIII-group metals is 0.01-2.0 mass%.

8. The method of claim 1, wherein C is₅/C₆The alkane isomerization catalyst comprises a mixed oxide carrier containing sulfate radicals and VIII-group metals loaded on the carrier, wherein the mixed oxide carrier comprises 45-85% of zirconia and 15-55% of alumina by mass, the content of the sulfate radicals in the catalyst is 1.5-7% by mass, and the content of the VIII-group metals is 0.01-2.0% by mass.

9. A process according to claim 7 or 8, characterized in that the catalysis is carried outPreparation of C₅/C₆The reaction temperature for isomerization of the alkane is 140-200 ℃.

10. The method of claim 1, wherein C is₅/C₆The alkane isomerization catalyst comprises an alumina carrier, 0.01-2.0 mass% of VIII group metal and 4-10 mass% of chlorine based on the carrier.

11. The process according to claim 10, characterized in that C is carried out with the catalyst₅/C₆The reaction temperature for isomerization of the alkane is 100-180 ℃.

12. The process according to claim 1, wherein the hydroisomerization catalyst comprises a composite support and from 0.01 to 2.0% by mass of a group VIII metal, based on the composite support, said composite support comprising from 20 to 95% by mass of mordenite and from 5 to 80% by mass of alumina, said mordenite having a sodium oxide content of not more than 0.05% by mass.

13. The process of claim 12 wherein the group VIII metal in the hydroisomerization catalyst is platinum or palladium, the mordenite has a silica to alumina molar ratio of from 60 to 82 and a crystallite size of from 0.2 to 0.6 microns.

14. The method according to claim 1, wherein the hydroisomerization reaction of the bottom component is carried out at 230 to 280 ℃ under a pressure of 1.6 to 2.0MPa and at a feed mass space velocity of 1 to 3 hours^-1And a hydrogen/hydrocarbon molar ratio of 1 to 3.

15. The method according to claim 1, wherein the isopentane-rich overhead component contains isopentane in an amount of not less than 75 mass%, the side-stream component contains n-pentane and n-hexane in an amount of not less than 55 mass%, and the bottom component contains methylcyclopentane, benzene and cyclohexane, wherein the methylcyclopentane content is 50-60 mass%5 to 15 mass% of benzene, 28 to 40 mass% of cyclohexane, and C₇ ⁺The hydrocarbon content is 1 to 3 mass%.

16. The method according to claim 15, wherein the isopentane-rich overhead component contains 75 to 90 mass% of isopentane, 5 to 15 mass% of tetraalkyl carbon, and 3 to 10 mass% of n-pentane.

17. The method according to claim 15, wherein in the side stream component rich in n-pentane and n-hexane, the content of n-pentane is 25 to 40 mass%, the content of n-hexane is 30 to 45 mass%, the content of monomethyl pentane is 25 to 35 mass%, the content of dimethyl butane is 0.5 to 4 mass%, and the sum of the contents of methylcyclopentane and isopentane is 1 to 4 mass%.

Technical Field

The invention is a C₅/C₆A process for isomerizing the raw material of paraffine includes such steps as fractionating different components, and isomerizing to obtain high-quality C₅/C₆A process for isomerizing gasoline blending components.

Background

With the increasing strictness of the environmental protection requirements, the emission standards of the motor gasoline products are rapidly upgraded. State vi (ii) stage vehicle gasoline emission standard specifies: (1) the content of aromatic hydrocarbon is not more than 35 percent; (2) the content of olefin is not more than 15 percent; (3) the content of benzene is not more than 0.8 percent, which shows that the restriction of national VI automobile gasoline standard on the content of arene, olefin and benzene is more strict, meanwhile, the national VI gasoline standard reduces the distillation range T50 of gasoline to 110 ℃, the restriction of the content of high-octane components such as arene and olefin can lead to the reduction of the octane number of the gasoline, and the compensation measure is usually to increase the content of isoparaffin in the gasoline component, which means that the automobile gasoline can be added with more C, such as C₅/C₆High-octane number high-quality light gasoline blending components such as isomerized gasoline and alkylate.

Conventional C₅/C₆The isomerization feed is typically C-rich₅/C₆Light naphtha of alkanes containing, in addition to C₅/C₆Besides the paraffins, it also contains 15% or more of Methylcyclopentane (MCP), benzene (B), and Cyclohexane (CH). In the article of the chapter "benzene content in reformed gasoline by raw material prefractionation" (vol.41NO.5 in petroleum refining and chemical industry), Zhang Daqing et al, benzene precursor in reformed raw material is removed by prefractionation, mainly cyclohexane in raw material is discharged from the top of prefractionation tower, then heavy component at the bottom of tower is catalytically reformed, and light component discharged from the top of tower is directly fed into isomerization unit to make reaction. CN1048519C adopts 85-95 wt% eta-alumina and the rest gamma-alumina as carriers, then loads eighth group metal and halogen to prepare catalyst, and then light fraction of reformate containing benzene and C are mixed₅～C₆The fraction mixture is subjected to isomerization at a relatively low temperature, wherein the benzene is hydrosaturated in the isomerization to make the final product benzene-free, but the research octane number RON is only increased from 80 to 81.3. At C₅/C₆Under the condition of alkane isomerization reaction, about 70 percent of methyl cyclopentane is subjected to isomerization reaction to generate cyclohexane and further subjected to ring opening to generate C₆Alkanes, C₆The isomerization reaction of the alkane is carried out by about 3 percentThe component (A) is cracked, about 30 percent of cyclohexane is subjected to isomerization reaction to generate methyl cyclopentane, and 70 percent of cyclohexane is subjected to ring opening to generate C₆The alkane and the benzene are all hydrogenated to generate cyclohexane, and the cyclohexane is subjected to isomerization, ring opening, cracking and other reactions. It can be seen that in C₅/C₆Under the condition of alkane isomerization reaction, the reaction of methyl cyclopentane, cyclohexane and benzene all causes the octane number of the final product of the isomerization reaction to be reduced.

Disclosure of Invention

The invention aims at providing a novel compound consisting of C₅/C₆The method for producing the high-octane gasoline blending component from the alkane raw material can effectively improve the octane value of the alkane raw material and obtain the clean gasoline blending component with high octane value and no benzene.

The invention provides a compound represented by formula C₅/C₆A process for producing a high octane gasoline blending component from a paraffinic feedstock comprising blending C₅/C₆Sending alkane raw materials into a rectifying tower for rectifying separation, obtaining an isopentane-rich tower top component with a boiling point not more than that of isopentane at the tower top, obtaining a side line component rich in n-pentane and n-hexane at the tower side line, obtaining a tower bottom component with a boiling point not less than that of methylcyclopentane at the tower bottom, and reacting the side line component with C under the conditions of 100-300 ℃, 3-6 MPa and a hydrogen/hydrocarbon molar ratio of 0.1-6₅/C₆Isomerization catalyst contact₅/C₆And (3) performing alkane isomerization reaction, namely contacting the tower bottom component with a hydroisomerization catalyst under the conditions of 230-300 ℃, 1.6-3.0 MPa and 1-6 hydrogen/hydrocarbon molar ratio to perform hydroisomerization reaction.

The method of the invention firstly carries out C₅/C₆The alkane raw material is fractionated into a tower top component rich in isopentane, a side line component rich in n-pentane and n-hexane and a tower bottom component with the boiling point not less than that of methylcyclopentane, the side line component is subjected to n-alkane isomerization reaction, the tower bottom component is subjected to hydrogenation conversion of benzene into cyclohexane under the action of a hydrogenation isomerization catalyst, and the cyclohexane is converted into methylcyclopentane to the maximum extent. The method of the invention can effectively improve the octane number of the isomerized product and produce benzene-free products by respectively isomerizing different components in the raw materials under different conditionsThe clean high-octane isomerization blending gasoline component.

Drawings

FIG. 1 is a schematic flow chart of the method of the present invention.

FIG. 2 is a Scanning Electron Microscope (SEM) image of a small grain mordenite prepared by the direct synthesis method of example 4 of the present invention.

FIG. 3 is an X-ray diffraction (XRD) pattern of a small crystal mordenite prepared by the direct synthesis method of example 4 of the present invention.

FIG. 4 is a Scanning Electron Microscope (SEM) image of a conventional mordenite zeolite used in example 6 of the present invention.

Detailed Description

The method of the invention is as follows₅/C₆Fractionating alkane raw materials to obtain a tower top component rich in isopentane, a side line component rich in n-pentane and n-hexane and a tower bottom component with the boiling point not less than that of methylcyclopentane, wherein the components can be obtained at C₅/C₆In the kinetics of the isomerization reaction, C is influenced₅/C₆Isomerization catalyst Performance Methylcyclopentane (MCP), benzene (B), Cyclohexane (CH) and C₇ ⁺The hydrocarbon component is separated from the raw material and then subjected to a separate hydroisomerization reaction, so that benzene in the benzene is hydrogenated to generate cyclohexane, and the cyclohexane is converted into methylcyclopentane to the maximum extent, so as to make up the octane number loss caused by the cyclohexane generated by the benzene hydrogenation. The method of the invention can reduce C₅/C₆Adverse factors of the isomerization process improve the isomerization rate, while maintaining the octane number of the bottoms component substantially the same as that of the unhydrogenated bottoms component by hydroisomerization of the bottoms component, thereby improving the octane number of the final isomerized product.

C according to the process of the invention₅/C₆The alkane raw material mainly contains C₅、C₆The alkane includes, in addition, methylcyclopentane, benzene and cyclohexane, wherein the content of methylcyclopentane, benzene and cyclohexane is not less than 15% by mass, and the higher the content, the more suitable the process of the present invention is. Preferably, C₅/C₆The content of methylcyclopentane, benzene and cyclohexane in the alkane raw material is 15 to 45 mass%, more preferably 15 to 35 mass%.

Said C is₅/C₆The paraffinic feedstock may be light naphtha, which may be light naphtha overhead from a distillation column or a reforming prefractionator, or an aromatic raffinate.

In the method, the rectifying tower can be a conventional plate tower, a clapboard tower or a packed tower. Preferably, C is isolated₅/C₆When the alkane is used as a raw material, the top temperature of the rectifying tower is 35-45 ℃, the top pressure is 0.5-0.6 MPa, the side line distillation temperature of the rectifying tower is 65-78 ℃, and the bottom temperature of the rectifying tower is 95-120 ℃.

When the rectifying tower is used for rectifying and separating tower top components, side line components and tower bottom components, the tower top reflux ratio is preferably 8-14, more preferably 9-13, and the reflux ratio is the mass ratio of material flow returned to the top of the rectifying tower to material flow discharged from the top of the rectifying tower.

Said C is₅/C₆The alkane raw material is rectified and separated, and the tower top component discharged from the rectifying tower is rich in isopentane and also contains a small amount of C₄Alkanes and n-pentane, which have a relatively high octane number, can be used as high octane components without treatment. The content of isopentane in the tower top component rich in isopentane is not less than 75 mass%, preferably, the content of isopentane in the tower top component rich in isopentane is 75-90 mass%, the content of tetraalkyl hydrocarbon is 5-15 mass%, and the content of n-pentane is 3-10 mass%.

The side stream component discharged from the side stream of the rectifying tower is rich in n-pentane and n-hexane and also contains a proper amount of monomethyl pentane. The content of the n-pentane and the n-hexane in the side line component rich in the n-pentane and the n-hexane is not less than 55 mass%, preferably, the content of the n-pentane is 25-40 mass%, the content of the n-hexane is 30-45 mass%, the content of the monomethyl pentane is 25-35 mass%, the content of the dimethyl butane is 0.5-4 mass%, and the sum of the contents of the methyl cyclopentane and the isopentane is 1-4 mass%. The side stream component can be used for normal alkane isomerization reaction by using a conventional catalyst, normal alkane is converted into isoparaffin, the isoparaffin and normal alkane in the normal alkane and isoparaffin are separated by using a normal and isoparaffin separation technology, and the separated normal alkane is converted into isoparaffin again. The molecular sieve used for adsorbing and separating the normal paraffin and the isoparaffin is preferably a 5A molecular sieve.

The tower bottom components discharged from the tower bottom of the rectifying tower are rich in methylcyclopentane, benzene and cyclohexane, preferably, the content of the methylcyclopentane is 50-60 mass%, the content of the benzene is 5-15 mass%, the content of the cyclohexane is 28-40 mass%, and C is₇ ⁺The hydrocarbon content is 1 to 3 mass%. And (3) carrying out hydroisomerization on the tower bottom component, namely, under the hydroisomerization condition, hydrogenating benzene in the tower bottom component to convert the benzene into cyclohexane, and isomerizing the cyclohexane into methylcyclopentane to the maximum extent so as to make up the octane number loss caused by the cyclohexane generated by the hydrogenation of the benzene and ensure that the content of the methylcyclopentane in the finally obtained hydroisomerization reaction product reaches over 75 mass percent.

Preferably, the overhead component, the side-stream component isomerate, and the bottoms component hydroisomerate are combined to yield the high octane benzene-free clean gasoline blending component.

The side stream component may be used in the isomerization of the paraffins using different types of isomerization catalysts, such as zeolite-type catalysts, solid super acid-type catalysts, and chlorinated alumina-type catalysts, and the isomerization temperature may be different using different catalysts.

Preferably, said zeolite type C₅/C₆The isomerization catalyst comprises a composite carrier and 0.01-2.0 mass% of VIII group metal by taking the composite carrier as a reference, wherein the composite carrier comprises 10-40 mass% of mordenite, 30-80 mass% of Beta zeolite and 5-30 mass% of alumina. Carrying out C with the catalyst₅/C₆During the alkane isomerization reaction, the reaction temperature is preferably 220-300 ℃, the reaction pressure is preferably 16-3.5 MPa, and the liquid mass space velocity is preferably 0.5-5 hours^-1The hydrogen/hydrocarbon molar ratio is preferably 1 to 6. The mole ratio of silicon oxide to aluminum oxide of the mordenite is preferably 20-30.

The solid super strong acid type C₅/C₆The isomerization catalyst comprises a sulfate radical-containing zirconium oxide carrier and a group VIII metal loaded on the carrier, preferably, the catalyst comprises a sulfate radical-containing mixed oxide carrier and a group VIII metal loaded on the carrier, wherein the mixed oxide carrier comprises 45-85 mass percent of the group VIII metalZirconia and 15-55 mass% of alumina. The content of sulfate radical in the catalyst is 1.5-7% by mass, preferably 2-5% by mass, and the content of VIII group metal is 0.01-2.0% by mass.

Carrying out C with the solid super strong acid type catalyst₅/C₆During the alkane isomerization reaction, the reaction temperature is preferably 140-200 ℃, the pressure is preferably 1.6-3.5 MPa, and the liquid mass space velocity is preferably 1-5 hours^-1The hydrogen/hydrocarbon molar ratio is preferably 1 to 6.

The chloridized alumina type C₅/C₆The isomerization catalyst comprises an alumina carrier, 0.01-2.0 mass% of group VIII metal and 4-10 mass% of chlorine based on the carrier. Carrying out C with the catalyst₅/C₆During the alkane isomerization reaction, the reaction temperature is preferably 120-210 ℃, the pressure is preferably 1.6-3.5 MPa, and the liquid volume space velocity is 1-5 hours^-1The hydrogen/hydrocarbon molar ratio is preferably 0.1 to 0.8.

According to the method, the tower bottom components react under a hydroisomerization condition, the hydroisomerization catalyst comprises a composite carrier and 0.01-2.0 mass% of VIII family metal based on the composite carrier, the composite carrier comprises 20-95 mass% of mordenite and 5-80 mass% of alumina, and the sodium oxide content of the mordenite is not more than 0.05 mass%. The composite carrier preferably comprises 60-95 mass% of mordenite and 5-40 mass% of alumina.

The mole ratio of silicon oxide to aluminum oxide of the mordenite in the hydroisomerization catalyst is preferably 60-82, and the grain size is preferably 0.2-0.6 micron, namely, the mordenite with small grains. The small-grain mordenite can be prepared by a direct synthesis method or a dealumination method.

The small crystal grain mordenite can be prepared by preparing an aluminum source, sodium hydroxide, a template agent and water into a mixed solution, wetting the surface of silica gel by using the mixed solution to form SiO with a molar ratio₂/Al₂O₃40-65 parts of template agent/SiO₂＝0.01～0.10、Na₂O/SiO₂＝0.01～0.10、H₂O/SiO₂4.0 to 8.0. And (3) respectively carrying out two-stage crystallization on the synthesis system at the temperature of 50-130 ℃ and 135-150 ℃ for 10-25 hours and 28-35 hours, collecting solids, washing and drying. The template agent is tetraethyl ammonium hydroxide or n-butylamine, the aluminum source is hydrated alumina, sodium metaaluminate or aluminum silicate, and the drying temperature is preferably 90-120 ℃.

The hydroisomerization reaction temperature is preferably 230-280 ℃, the pressure is preferably 1.6-2.0 MPa, and the feeding mass space velocity is preferably 0.5-3 hours, more preferably 1-3 hours^-1The hydrogen/hydrocarbon molar ratio is preferably 1 to 3.

The group VIII metal in the various catalysts described in the process of the present invention is preferably platinum or palladium.

In the process of the present invention, said C₅/C₆The alkane raw material is subjected to hydrofining treatment, and water, sulfur, nitrogen, oxygen, arsenic, lead, copper and other heavy metals in the raw material are removed. After hydrofining treatment, the water content of the raw material is less than 0.1ppm, the sulfur, nitrogen and oxygen content is less than 0.1ppm, and the arsenic, lead and copper content is less than 2ng/g, 20ng/g and 20ng/g respectively.

The invention is further illustrated by the following figures.

In FIG. 1, C₅/C₆The alkane raw material is sent to the middle part of a rectifying tower 2 through a pipeline 1, after rectification, the tower top component which is rich in isopentane and has the boiling point not more than that of the isopentane is discharged from the top of the rectifying tower and enters a pipeline 3, the side line component which is rich in n-pentane and n-hexane is discharged from a side line 4 of the rectifying tower and enters a pipeline C₅/C₆Alkane isomerization reaction unit 6, with C₅/C₆The alkane isomerization catalyst contacts in an isomerization reactor (not shown in the figure) to carry out normal alkane isomerization reaction, an isomerization product is discharged from the isomerization reactor and enters a normal alkane adsorption separation device and an isoparaffin adsorption separation device, and normal alkane obtained by adsorption separation returns to the isomerization reactor to carry out re-reaction until all normal alkane is converted into isoparaffin and is discharged from a pipeline 8; the tower bottom component with the boiling point not less than that of the methylcyclopentane is discharged from the bottom of the rectifying tower, enters a hydroisomerization reactor 7 through a pipeline 5, and is in contact reaction with a hydroisomerization catalyst, and the tower bottom component mainly containsMethylcyclopentane (MCP), benzene and cyclohexane, wherein the benzene is hydrogenated to cyclohexane, and the contained cyclohexane is then isomerized to methylcyclopentane to the maximum extent, thereby compensating for octane number loss caused by the hydrogenation of benzene to cyclohexane, and the hydroisomerized product is discharged via line 9. The materials in the pipeline 3, the pipeline 8 and the pipeline 9 are combined and then discharged from the pipeline 10 to be the high-octane gasoline blending component.

The invention is further illustrated below by way of examples, without being limited thereto.

Example 1

This example prepared chlorided alumina form C₅/C₆A paraffin isomerization catalyst.

Taking 90 grams of specific surface area as 420m²(g) total pore volume of 0.4cm³Eta-alumina powder of 10 g specific surface area 188m²(g) total pore volume of 0.53cm³The alumina carrier is prepared by uniformly mixing the gamma-alumina powder per gram, adding 10 grams of nitric acid with the concentration of 34 mass percent, kneading, extruding and molding.

The above alumina carrier was immersed in a chloroplatinic acid solution having a platinum content of 0.24 mass% (based on the alumina carrier) at 25 ℃ for 4 hours, and the solid obtained after the immersion was dried at 120 ℃ for 4 hours and calcined in air at 540 ℃ for 3 hours.

The above calcined catalyst was reduced with hydrogen at 550 ℃ for 2 hours, and then carbon tetrachloride was introduced into the hydrogen to a concentration of 20 mass%, and the treatment was carried out for 1 hour to obtain catalyst a in which the platinum content was 0.24 mass% and the chlorine content was 7.8 mass% based on the alumina support.

Example 2

This example prepared Zeolite form C₅/C₆A paraffin isomerization catalyst.

Taking 100 g of SiO₂/Al₂O₃Sodium mordenite (manufactured by Changling catalyst of Hunan province) with a molar ratio of 11.2, to which 800mL of NH was added at a concentration of 1 mol/l₄Performing ammonium ion exchange on the Cl solution at 90-95 ℃ for 3 hours, filtering, washing the obtained solid with deionized water, drying at 120 ℃ for 3 hours, repeating the ammonium ion exchange operation twice, and concentrating the obtained molecular sieve with 800mLTreating hydrochloric acid with the concentration of 1 mol/L at 90-95 ℃ for 3 hours, filtering, washing the solid with deionized water until the filtrate is neutral, and roasting at 600 ℃ in the air for 6 hours to obtain the product with the sodium content of 0.03 mass percent and the SiO₂/Al₂O₃Hydrogen mordenite in a molar ratio of 23.4 (as determined by fluorescence spectroscopy).

Taking 100 g of SiO₂/Al₂O₃Sodium type zeolite Beta (manufactured by Changling catalyst of Hunan province) having a molar ratio of 28.6 was treated with 800mL of 1 mol/L NH₄And (2) carrying out ammonium ion exchange on the Cl solution at 90-95 ℃ for 3 hours, filtering, washing the obtained solid with deionized water, drying at 120 ℃ for 3 hours, repeating the ammonium ion exchange operation twice, filtering, washing the solid with the deionized water until the filtrate is neutral, and roasting at 600 ℃ in the air for 6 hours to obtain the hydrogen type Beta zeolite with the sodium content of 0.03 mass%.

The hydrogen-type mordenite, the hydrogen-type Beta zeolite and high-purity aluminum hydroxide (SB powder, manufactured by CONDEA company in Germany) were mixed in the following ratio of 20: 60: 20, uniformly mixing the components in a dry basis mass ratio, and adding the mixture in a volume ratio of 1: 1, kneading the nitric acid solution, wherein the volume ratio of the added nitric acid solution to the solid powder is 1: 1.6, extruding and molding, drying for 2 hours at 120 ℃, and roasting for 4 hours at 550 ℃ in air to obtain the composite zeolite carrier.

20 g of composite zeolite carrier is taken, 7.5mL of chloroplatinic acid solution with the concentration of 8.6 mol/L is used for dipping for 4 hours at the temperature of 25 ℃, the dipped solid is dried for 4 hours at the temperature of 120 ℃, and is roasted for 4 hours at the temperature of 550 ℃ in the air to prepare the zeolite type isomerization catalyst B, wherein the platinum content is 0.32 percent by mass based on the composite zeolite carrier.

Example 3

This example prepares super strong acid form C₅/C₆A paraffin isomerization catalyst.

Adding a proper amount of deionized water into 100 g of zirconium oxychloride to prepare a 25 mass percent aqueous solution, dropwise adding 25 mass percent ammonia water until the pH value of the solution is 10, transferring zirconium hydroxide gel into a high-pressure autoclave, sealing, carrying out hydrothermal treatment at 90 ℃ for 20 hours, washing the obtained precipitate with deionized water until the filtrate is neutral, and drying at 110 ℃ for 48 hours to obtain the zirconium hydroxide.

80g of the zirconium hydroxide and 20 g of aluminum hydroxide (SB powder, produced by CONDEA, Germany, the content of alumina is 76 mass%) are uniformly mixed, 120mL of sulfuric acid with the concentration of 4 mass% is added for dipping for 1 hour, drying is carried out at 110 ℃ for 12 hours, 3.4 g of sesbania powder, 8mL of nitric acid with the concentration of 63 mass% and 108 g of deionized water are added, strips are extruded after kneading to prepare strips with the diameter of 1.8mm, drying is carried out at 110 ℃ for 12 hours, and roasting is carried out in the air at 600 ℃ for 3 hours to obtain the mixed oxide carrier containing sulfate radicals.

10 g of mixed oxide support were loaded with 7.9mL of HPtCl having a Pt content of 3.1mg/mL₆Soaking the solution at 25 deg.C for 4 hr, drying at 120 deg.C for 12 hr, and calcining at 550 deg.C in air for 3 hr to obtain super acidic alkane isomerization catalyst C containing 0.26 wt% of platinum and SO₄ ^2-3.5 mass%, alumina 18.98 mass%, and zirconia 77.26 mass%.

Example 4

This example uses synthetically prepared small crystallite mordenite to prepare the hydroisomerization catalyst.

(1) Synthesis of small grain mordenite with high silicon-aluminium ratio

Sodium metaaluminate, sodium hydroxide, tetraethyl ammonium hydroxide (template agent) and deionized water are prepared into mixed solution, and 80g of silica gel is wetted by the mixed solution to form SiO with the mol ratio₂/Al₂O₃60, template agent/SiO₂＝0.06、Na₂O/SiO₂＝0.08、H₂O/SiO₂Synthetic system 6.6.

Subjecting the above synthesis system to first-stage hydrothermal crystallization at 120 deg.C for 20 hr, and second-stage hydrothermal crystallization at 145 deg.C for 30 hr, collecting solid, and adding 500mL of 0.5 mol/L NH₄Ammonium ion exchange of Cl solution for 3 hr, filtering, washing the obtained solid with deionized water, drying at 120 deg.C for 3 hr to obtain Na₂O0.05 mass%, SiO₂/Al₂O₃A scanning electron microscope image of the mordenite a with the mole ratio of 60 is shown in figure 2, the grain diameter of the mordenite is 0.2-0.6 microns, the pore volume and pore diameter data are shown in table 1, and an XRD image is shown in figure 3.

(2) Preparation of hydroisomerization catalysts

Taking 100 g of the small-grain mordenite prepared in the step (1) and high-purity aluminum hydroxide (SB powder) according to a weight ratio of 80: 20, uniformly mixing the components in a dry basis mass ratio, and adding the mixture in a volume ratio of 1: 1, kneading the nitric acid solution, wherein the volume ratio of the added nitric acid solution to the solid powder is 1: 1.6, extruding and molding, drying for 2 hours at 120 ℃, and roasting for 4 hours at 540 ℃ in air to obtain the composite carrier.

20 g of the composite carrier was immersed in 7.5mL of a chloroplatinic acid solution having a concentration of 8.6 mol/l at 25 ℃ for 24 hours, dried at 120 ℃ for 4 hours, and calcined in air at 550 ℃ for 4 hours to obtain a hydroisomerization catalyst D, in which the platinum content was 0.32 mass% based on the composite carrier.

Example 5

This example uses a small crystallite mordenite prepared by dealumination to prepare a hydroisomerization catalyst.

(1) Preparation of high silica-alumina ratio small crystal grain mordenite

Taking 100 g of the small-grain mordenite a prepared by the method of example 4, dealuminizing the small-grain mordenite a by using 800mL of hydrochloric acid with the concentration of 1 mol/L at the temperature of 90-95 ℃ for 3 hours, filtering, washing the small-grain mordenite a by using deionized water until the filtrate is neutral, and roasting the small-grain mordenite a at the temperature of 600 ℃ for 6 hours to obtain the mordenite a with the sodium content of 0.02 mass percent and SiO₂/Al₂O₃The pore volume and pore size data for the small crystallite mordenite b at a molar ratio of 78.8 are shown in table 1.

(2) Preparation of hydroisomerization catalysts

Taking small-grain mordenite b and high-purity aluminum hydroxide (SB powder) according to the weight ratio of 80: 20, uniformly mixing the components in a dry basis mass ratio, and adding the mixture in a volume ratio of 1: 1, kneading the nitric acid solution, wherein the volume ratio of the added nitric acid solution to the solid powder is 1: 1.6, extruding and molding, drying for 2 hours at 120 ℃, and roasting for 4 hours at 540 ℃ in air to obtain the composite carrier.

20 g of the composite carrier is taken, dipped in 7.5mL of chloroplatinic acid solution with the concentration of 8.6 mol/L for 24 hours at normal temperature, dried at 120 ℃ for 4 hours, and roasted at 550 ℃ in air for 4 hours to prepare the hydroisomerization catalyst E, wherein the platinum content is 0.32 percent by mass based on the composite carrier.

Example 6

By using Na₂O0.05 mass%, SiO₂/Al₂O₃The hydroisomerization catalyst is prepared from conventional mordenite c with the molar ratio of 25 and the grain size of 0.5-5 microns, the pore volume and pore diameter data of the conventional mordenite c are shown in a table 1, and a scanning electron microscope image is shown in a figure 4.

A hydroisomerization catalyst M was prepared from conventional mordenite c by the method of example 5 (step 2), in which the platinum content was 0.32 mass% based on the composite carrier.

Example 7

According to the method of the invention₅/C₆Rectifying and separating alkane raw material

According to the flow shown in FIG. 1, the composition is C shown in Table 2₅/C₆The alkane raw material (light naphtha) is sent into the middle part of a rectifying tower 2 from a pipeline 1, and the operating conditions of the rectifying tower are as follows: the tower top temperature is 40 ℃, the tower top pressure is 0.6MPa, and the tower top reflux ratio is 12: 1; the side-draw temperature of the tower is 75 ℃, and the bottom temperature of the tower is 100 ℃. Said C is₅/C₆The alkane raw material is subjected to hydrofining treatment, wherein the water content is less than 0.1ppm, the sulfur, nitrogen and oxygen contents are less than 0.1ppm, and the arsenic, lead and copper contents are respectively less than 2ng/g, 20ng/g and 20 ng/g. The temperature of the hydrofining treatment is 300 ℃, the pressure is 3.0MPa, the hydrogen/hydrocarbon molar ratio is 2, and the feed mass space velocity is 5 hours^-1. The hydrorefining catalyst contained 2.8 mass% of NiO and 25 mass% of WO₃And the balance of alumina carrier.

After rectification, the top components rich in isopentane are discharged from a pipeline 3, the side components are discharged from a pipeline 4, and the bottom components are discharged from a pipeline 5. The top component discharged from the pipeline 3 is mainly isopentane, the research octane number RON is 92, the side component discharged from the pipeline 4 is rich in n-pentane and n-hexane, and the bottom component discharged from the pipeline 5 mainly contains methylcyclopentane, benzene and cyclohexane. The various hydrocarbon contents of the overhead, side and bottoms components are shown in Table 2.

Example 8

The following examples were run for the isomerization of paraffins for the side stream component to examine the performance of the isomerization catalyst.

Using the chlorided alumina catalyst A prepared in example 1 as an isomerization catalyst and the side stream component of the rectification column shown in Table 2 (line 4) as a raw material, at 130 ℃ and 3.1MPa, a hydrogen/hydrocarbon mole ratio of 0.3 and a mass space velocity of the raw material of 1.5 hours^-1The isomerization reaction is carried out under the reaction condition, the isomerization product adopts a liquid phase simulated moving bed to adsorb and separate normal paraffin and isoparaffin in the isomerization reaction, the used adsorbent is a 5A molecular sieve, the desorbent is normal nonane, the adsorption and separation operation temperature is 120 ℃, and the pressure is 0.8 MPa. Returning the normal paraffin obtained by adsorption separation to carry out isomerization reaction again until the normal paraffin is completely converted into isoparaffin with high octane value, and obtaining the final C₅/C₆The isomerized product is withdrawn from line 8 as shown in figure 1. The composition and octane number of the single pass isomerized product and the final isomerized product are shown in table 3.

Example 9

The isomerization was carried out as in example 8 starting from the side stream of the rectification column (line 4) indicated in Table 2, except that the catalyst used was the catalyst B prepared in example 2, under the isomerization conditions: 260 ℃, 3.1MPa, hydrogen/hydrocarbon molar ratio of 2 and mass space velocity of raw material of 1.0 hour^-1. The single pass isomerization product and final isomerization product compositions and octane numbers are shown in table 3.

Example 10

The isomerization was carried out as in example 8 starting from the side stream of the rectification column (line 4) indicated in Table 2, except that the catalyst used was catalyst C prepared in example 3, under the isomerization conditions: 150 ℃, 3.1MPa, hydrogen/hydrocarbon molar ratio of 2 and mass space velocity of raw material of 1.5 hours^-1. The single pass isomerization product and final isomerization product compositions and octane numbers are shown in table 3.

Examples 11 to 13

The following example was conducted to conduct the hydroisomerization of the bottoms component and examine the performance of the hydroisomerization catalyst.

The bottom component (line 5) of the rectifying column shown in Table 2 was used as a raw material, and the reaction pressure was 1.7MPa, the hydrogen/hydrocarbon molar ratio was 2, and the mass space velocity of the raw material was 1 hour^-1Hydroisomerization at 230 ℃ and 250 ℃ respectively, the reaction temperature being as defined in the examplesThe hydrocarbon content of the hydroisomerization catalyst, and of the hydroisomerization reaction product obtained at different reaction temperatures (line 9) are shown in table 4.

Example 14

According to the scheme of FIG. 1, C shown in Table 2₅/C₆After the paraffin raw material is subjected to fractional distillation and cutting of the tower top component, the side line component and the tower bottom component, the paraffin isomerization reaction and the hydroisomerization reaction are respectively carried out.

C of the composition shown in Table 2₅/C₆The alkane raw material is sent to the middle part of a rectifying tower 2 through a pipeline 1, after rectification, the tower top component which is rich in isopentane and has the boiling point not more than that of the isopentane is discharged from the top of the rectifying tower and enters a pipeline 3, the side line component which is rich in n-pentane and n-hexane is discharged from a side line 4 of the rectifying tower and enters a pipeline C₅/C₆A paraffin isomerization reaction unit 6 which is contacted with the isomerization catalyst A prepared in the example 1 in a paraffin isomerization reactor (not shown in the figure) to carry out normal paraffin isomerization reaction, an isomerization product is discharged from the isomerization reactor and enters a normal paraffin and isoparaffin adsorption separation device, and normal paraffin obtained by adsorption separation returns to the isomerization reactor to carry out re-reaction until all normal paraffin is converted into isoparaffin, and the isoparaffin is discharged from a pipeline 8; the bottom component with the boiling point not less than that of methylcyclopentane is discharged from the bottom of the rectification column, enters a hydroisomerization reactor 7 through a line 5 and contacts with the hydroisomerization catalyst D prepared in example 4, the bottom component mainly contains Methylcyclopentane (MCP), benzene (B) and Cyclohexane (CH), the benzene is hydrogenated and converted into cyclohexane, the contained cyclohexane is isomerized into methylcyclopentane to the maximum extent, and thus the octane number loss caused by the hydrogenation of the benzene to form cyclohexane is compensated, and the hydroisomerization product is discharged through a line 9.

The operating conditions of the rectifying tower are as follows: the tower top temperature is 40 ℃, the tower top pressure is 0.60MPa, and the tower top reflux ratio is 12: 1; the side-draw temperature of the tower is 75 ℃, and the bottom temperature of the tower is 100 ℃. C entering the rectifying tower from a pipeline 1₅/C₆The paraffin feed flow rate was 100ml/h, and the discharge flow rates of the overhead component, the side stream component and the bottom component were 14.5ml/h, 65.6ml/h and 19.9ml/h, respectively.

The isomerization reaction condition of the alkane is 130 ℃, 3.1MPa and hydrogen/hydrocarbon molThe molar ratio is 0.3, the mass space velocity of the raw materials is 1.5 hours^-1。

The conditions of the hydroisomerization reaction are 250 ℃, 1.7MPa, the hydrogen/hydrocarbon molar ratio is 2 and the mass space velocity of the raw material is 1 hour^-1。

The alkane isomerization product adopts a liquid phase simulated moving bed to adsorb and separate normal alkane and isoparaffin in the product, the adsorbent is a 5A molecular sieve, the desorbent is n-nonane, the adsorption and separation operation temperature is 120 ℃, and the pressure is 0.8 MPa.

The three streams, line 3, line 8 and line 9, were combined to obtain the high octane gasoline blending component of the present invention and discharged via line 10, having the hydrocarbon composition shown in table 5.

Comparative example 1

C of the composition shown in Table 2₅/C₆The alkane raw material is directly sent into an alkane isomerization reactor without being separated by a rectifying tower to contact with the catalyst A prepared in the example 1 for normal alkane isomerization reaction, the reaction conditions are 130 ℃, 3.1MPa, hydrogen/hydrocarbon mol 0.3 and raw material mass space velocity of 1.5 hours^-1The isomerization product is discharged from the isomerization reactor and enters a normal paraffin and isoparaffin adsorption separation device, normal paraffin obtained by adsorption separation returns to the isomerization reactor for re-reaction until the normal paraffin is completely converted into isoparaffin and discharged, the hydrocarbon composition is shown in table 5, wherein the normal paraffin and isoparaffin adsorption separation operation is the same as that in example 14.

TABLE 1

TABLE 2

The meanings of the symbols in table 2 are: iC₄Isobutane, nC₄N-butane, iC₅Isopentane, nC₅N-pentane, CP-cyclopentane, 22 DMB-2, 2-dimethylbutane, 23 DMB-2, 3-dimethylbutane, 2 MP-2-methylpentane, 3MP-3-methylpentane, nC₆N-hexane, MCP-methylcyclopentane, B-benzene, CH-cyclohexane and C₇ ⁺-alkanes of seven and more carbons. The symbols in the other tables have the same meanings as in Table 2. TABLE 3

TABLE 4

TABLE 5