A method for modifying h-beta zeolite and application of the modified h-beta zeolite
By modifying Hβ zeolite to change its silicon-to-aluminum ratio and loading it with molybdenum and nickel active components, the problem of low mesitylene formation efficiency in reformed C9 aromatics was solved, achieving a highly efficient catalytic isomerization reaction and improving the mesitylene formation rate.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SINOPEC YANGZI PETROCHEMICAL CO LTD
- Filing Date
- 2022-05-30
- Publication Date
- 2026-05-12
AI Technical Summary
In existing technologies, the formation efficiency of mesitylene in reformed C9 aromatics is low, making it difficult to effectively utilize it as an important raw material for the production of mesitylene.
By subjecting Hβ zeolite to high-temperature calcination, alkali treatment, ammonium chloride treatment, and loading with molybdenum and nickel active components, the silica-alumina ratio of the zeolite is altered, providing active centers and improving catalytic performance.
Under conditions of 200℃-300℃, the conversion rate of pseudotrimethylbenzene is greater than 40%, the conversion rate of o-toluene is greater than 30%, and the selectivity of mesitylene is greater than 30%, which increases the resource quantity of mesitylene in reformed C9.
Abstract
Description
Technical Field
[0001] This invention relates to a method for reforming C9 isomerization, specifically, to a method for modifying Hβ zeolite and a method for generating mesitylene from modified Hβ zeolite through a catalytic isomerization reaction of pseudotrimethylbenzene and o-ethylbenzene. Background Technology
[0002] my country has abundant C9 aromatics resources, accounting for approximately 10% of total oil refining output. Mesitylene accounts for 8% of C9 aromatics in reformed oil, and most refineries use it as a gasoline blending component or as a feedstock for the disproportionation of aromatics to xylene. In recent years, with the in-depth development and utilization of C9 aromatics, mesitylene has become an important raw material for the production of mesitylenetrimethylaniline, the antioxidant Ethanox 330, herbicides, and ultraviolet absorbers for plastics and rubber. Demand has increased significantly in recent years due to the successful development of many downstream products.
[0003] Related research includes: Zhang Pengfei et al., in their study on the non-hydroisomerization process of pseudotrimethylbenzene to mesitylene in Petrochemicals, 2005, Issue 5, used M-2 type composite mordenite zeolite to catalyze the liquid-phase non-hydroisomerization of pseudotrimethylbenzene to mesitylene, at a reaction temperature of 310–320℃, a reaction pressure of 1.5–2.0 MPa, and a liquid hourly space velocity of 1.0–1.5 h⁻¹. -1 Under certain conditions, the single-pass conversion rate of pseudotrimethylbenzene can reach 39%, and the selectivity of mesitylene reaches 66.29%. Zhang Weijiang et al., in the Journal of Chemical Industry and Engineering, 2002, Issue 3, reported that the optimal process conditions for the isomerization reaction in the production of mesitylene from pseudotrimethylbenzene were: using mixed aromatics as raw materials, the composition of which was controlled as follows: xylene approximately 21.8%, pseudotrimethylbenzene approximately 50.3%, mesitylene approximately 0.4%, methyl-xylene approximately 0.2%, and tetramethylbenzene (including 3 isomers) approximately 24.3% (other components are light components brought in by the raw materials, such as benzene and toluene); the reaction conditions were: reaction temperature 110℃, reaction time 5h, and catalyst (aluminum trichloride) to aromatics mass ratio of 3%. More methods for generating mesitylene from pseudotrimethylbenzene and o-ethylbenzene through isomerization reactions need to be developed. Summary of the Invention
[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a method for modifying Hβ and its application in the preparation of mesitylene via Hβ zeolite catalytic isomerization reaction.
[0005] The technical solution of this invention is as follows:
[0006] A method for modifying Hβ zeolite includes sequential steps of high-temperature calcination, alkali treatment, ammonium chloride treatment, and loading of molybdenum and nickel active components. In the alkali treatment, mordenite is mixed with NaOH solution and reacted at 50℃-80℃. In the active component loading step, Hβ zeolite is placed in a mixed solution of soluble salts of molybdenum and nickel and reacted at 50℃-80℃. The mixture of molybdenum and nickel is beneficial to the interaction between active centers.
[0007] As a further improvement to the technical solution, in order to improve the loading effect, the concentration of the molybdenum soluble salt solution is 0.2-1M, the concentration of the nickel soluble salt solution is 0.2-1M, and 1g of Hβ zeolite is placed in 20-50ml of soluble salt mixed solution. The soluble salt of each metal can be one or a mixture of ammonium salt and nitrate.
[0008] As a further improvement to the technical solution, in order to improve the desilication effect, the concentration of NaOH solution during alkali treatment is 0.1-0.3M, and 1g of Hβ zeolite is placed in 15-50ml of NaOH solution.
[0009] As a further improvement to the technical solution, during alkali treatment, Hβ zeolite reacts with NaOH solution to obtain a suspension. The suspension is then filtered, washed with water until pH=7, and then dried.
[0010] As a further improvement to the technical solution, in order to convert sodium-type zeolite into hydrogen-type zeolite, during ammonium chloride treatment, the alkali-treated Hβ zeolite is mixed with ammonium chloride solution to obtain a suspension, the suspension is filtered and washed with water until it is free of chloride ions, and then dried.
[0011] As a further improvement to the technical solution, the concentration of ammonium chloride solution is 0.2-1M, and it is mixed according to the ratio of 1g Hβ zeolite to 15-50ml of ammonium chloride solution.
[0012] As a further improvement to the technical solution, the Hβ zeolite treated with ammonium chloride was calcined for 4 hours at a calcination temperature of 400℃-600℃ to obtain modified Hβ zeolite.
[0013] As a further improvement to the technical solution, in order to enhance the activation effect, the activation conditions are 400℃-500℃ and activation in a hydrogen atmosphere for 3-5 hours.
[0014] An application of Hβ zeolite, specifically the preparation of mesitylene via the catalytic isomerization reaction of the modified Hβ zeolite, is disclosed. The reaction temperature is 200℃-300℃, the reaction pressure is 1.0-1.5 MPa, and the reaction space velocity is 0.5-1.5 h⁻¹. -1 The hydrogen-to-oil molar ratio is 5-10.
[0015] This invention represents a significant advancement and substantial improvement over existing technologies. Specifically, it provides a novel modification method for Hβ zeolite. This modification involves alkali desilication, altering the silica-alumina ratio of the zeolite, and loading nickel and molybdenum to provide active centers, thereby enhancing the catalytic effect of Hβ zeolite. This invention also provides an application of Hβ zeolite in increasing the amount of mesitylene resources in C9 reforming during catalytic isomerization to obtain mesitylene. This method can achieve a mesitylene conversion rate greater than 40%, an o-toluene conversion rate greater than 30%, and a mesitylene selectivity greater than 30% at 200℃-300℃. Detailed Implementation
[0016] The technical solution of the present invention will be further described in detail below through specific embodiments.
[0017] The instrument used to detect the content of ortho-, meta-, and para-methylethylbenzene was an SP6890 gas chromatograph from Lunan Ruihong Chemical Instrument Co., Ltd. The analytical conditions were: nitrogen as carrier gas, carrier gas pressure 0.04 MPa, column temperature 200℃, detector temperature 300℃, and injector temperature 300℃.
[0018] Example 1
[0019] Alkali treatment: 10g of Hβ zeolite was calcined at 500℃ for 4h. The calcined 10g of mordenite was placed in 300ml of 0.2M NaOH solution and stirred for 1h at 60℃ and a stirring speed of 100 rpm. The mixture was then filtered, and the filter residue was washed with water until the pH reached 7. Finally, it was dried at 110℃ for 10h.
[0020] Ammonium chloride modification: 10g of alkali-treated Hβ zeolite was placed in 300ml of 0.5M ammonium chloride solution and stirred for 1h at 60℃ and a stirring speed of 100 rpm. The mixture was then washed with water until chloride ions were removed and dried at 110℃ for 10h. The ammonium chloride-treated 10g of Hβ zeolite was then calcined at 450℃ for 4h to obtain modified Hβ zeolite.
[0021] Acid treatment: 10g of modified Hβ zeolite was placed in 150ml of a mixed solution of ammonium molybdate and nickel nitrate, with the concentrations of both being 0.5M. The mixture was stirred at 60℃ and a stirring speed of 100 rpm for 12h, then allowed to stand for 4h, and dried at 110℃ for 4h to obtain the isomerization catalyst.
[0022] Using reformed C9 as feedstock after the removal of light and heavy components, the molar composition was as follows: 1% n-propylbenzene, 11% m-toluene, 5% p-toluene, 11% o-toluene, 14% mesitylene, 49% pseudotrimethylbenzene, and 9% terephthalene. The isomerization reaction was carried out in a continuous tubular reactor at a temperature of 260℃, a reaction pressure of 1.4 MPa, and a space velocity of 1 h⁻¹. -1 Under the condition of a hydrogen-to-oil ratio of 5, the conversion rate of pseudotrimethylbenzene after the reaction was 46.1%, the conversion rate of o-toluene was 38.3%, and the selectivity of mesitylene was 41.1%.
[0023] Example 2
[0024] Alkali treatment: 10g of Hβ zeolite was calcined at 600℃ for 6h. The calcined 10g of mordenite was placed in 500ml of 0.1M NaOH solution and stirred at 70℃ and 100 rpm for 2h. The mixture was then filtered, and the filter residue was washed with water until pH=7. Finally, it was dried at 110℃ for 10h.
[0025] Ammonium chloride modification: 10g of alkali-treated Hβ zeolite was placed in 500ml of 0.2M ammonium chloride solution and stirred for 2h at 70℃ and a stirring speed of 100 rpm. The mixture was then washed with water until no chloride ions were present, and then dried at 110℃ for 10h. 10g of the ammonium chloride-treated mixture was calcined at 600℃ for 4h to obtain modified Hβ zeolite.
[0026] Acid treatment: 10g of modified Hβ zeolite was placed in a 250ml mixed solution of ammonium molybdate and nickel nitrate, with the concentrations of both being 0.2M. The mixture was stirred and mixed at 80℃ and a stirring speed of 100 rpm for 12h, allowed to stand for 4h, and then dried at 110℃ for 4h to obtain the isomerization catalyst.
[0027] Using reformed C9 as feedstock, after the removal of light and heavy components, the molar composition was as follows: 1% n-propylbenzene, 11% m-toluene, 5% p-toluene, 11% o-toluene, 14% mesitylene, 49% pseudotrimethylbenzene, and 9% terephthalene. The isomerization reaction was carried out in a continuous tubular reactor at 300℃, 1.5 MPa, and a space velocity of 1.5 h⁻¹. -1 Under the condition of a hydrogen-to-oil ratio of 10, the conversion rate of pseudotrimethylbenzene was 51.3%, the conversion rate of o-toluene was 20.3%, and the selectivity of mesitylene was 31.8%.
[0028] Example 3
[0029] 10g of Hβ zeolite was calcined at 400℃ for 3h. The calcined 10g of mordenite was placed in 150ml of 0.3M NaOH solution and stirred at 50℃ and 100 rpm for 0.5h. The mixture was then filtered, and the filter residue was washed with water until pH=7. The residue was then dried at 110℃ for 10h.
[0030] Ammonium chloride modification: 10g of alkali-treated Hβ zeolite was placed in 150ml of 1M ammonium chloride solution and stirred for 0.5h at 40℃ and a stirring speed of 100 rpm. The mixture was then washed with water until no chloride ions were present, and then dried at 110℃ for 10h. 10g of the ammonium chloride-treated mixture was calcined at 400℃ for 4h to obtain modified Hβ zeolite.
[0031] Acid treatment: 10g of modified Hβ zeolite was placed in 100ml of a mixed solution of ammonium molybdate and nickel nitrate, with the concentrations of both being 1M. The mixture was stirred and mixed at 50℃ and a stirring speed of 100 rpm for 12h, allowed to stand for 4h, and then dried at 110℃ for 4h to obtain the isomerization catalyst.
[0032] Using reformed C9 as feedstock, after the removal of light and heavy components, the molar composition was as follows: 1% n-propylbenzene, 11% m-toluene, 5% p-toluene, 11% o-toluene, 14% mesitylene, 49% pseudotrimethylbenzene, and 9% terephthalene. The isomerization reaction was carried out in a continuous tubular reactor at a temperature of 240℃, a reaction pressure of 1.0 MPa, and a space velocity of 0.5 h⁻¹. -1 Under the condition of a hydrogen-to-oil ratio of 7, the conversion rate of pseudotrimethylbenzene was 45.8%, the conversion rate of o-toluene was 41.0%, and the selectivity of mesitylene was 39.7%.
[0033] Example 4
[0034] 10g of Hβ zeolite was calcined at 500℃ for 4h. The calcined 10g of mordenite was placed in 300ml of 0.2M NaOH solution and stirred for 1h at 60℃ and a stirring speed of 100 rpm. The mixture was then filtered, and the filter residue was washed with water until the pH reached 7. Finally, it was dried at 110℃ for 10h.
[0035] Ammonium chloride modification: 10g of alkali-treated Hβ zeolite was placed in 300ml of 0.5M ammonium chloride solution and stirred for 1h at 60℃ and a stirring speed of 100 rpm. The mixture was then washed with water until no chloride ions were present, and then dried at 110℃ for 10h. 10g of the ammonium chloride-treated mixture was calcined at 450℃ for 4h to obtain modified Hβ zeolite.
[0036] Acid treatment: 10g of modified Hβ zeolite was placed in 150ml of a mixed solution of ammonium molybdate and nickel nitrate, with the concentrations of both being 0.5M. The mixture was stirred and mixed at 60℃ and a stirring speed of 100 rpm for 12h, allowed to stand for 4h, and then dried at 110℃ for 4h to obtain the isomerization catalyst.
[0037] Using reformed C9 as feedstock after the removal of light and heavy components, the molar composition was as follows: 1% n-propylbenzene, 11% m-toluene, 5% p-toluene, 11% o-toluene, 14% mesitylene, 49% pseudotrimethylbenzene, and 9% terephthalene. The isomerization reaction was carried out in a continuous tubular reactor at a temperature of 280℃, a reaction pressure of 1.3 MPa, and a space velocity of 1 h⁻¹. -1 Under the condition of a hydrogen-to-oil ratio of 5, the conversion rate of pseudotrimethylbenzene was 47.2%, the conversion rate of o-toluene was 32.4%, and the selectivity of mesitylene was 36.8%.
[0038] Example 5
[0039] 10g of Hβ zeolite was calcined at 500℃ for 4h. The calcined 10g of mordenite was placed in 300ml of 0.2M NaOH solution and stirred for 1h at 60℃ and a stirring speed of 100 rpm. The mixture was filtered and the filter residue was washed with water until pH=7. Then it was dried at 110℃ for 10h.
[0040] Ammonium chloride modification: 10g of alkali-treated Hβ zeolite was placed in 300ml of 0.5M ammonium chloride solution and stirred for 1h at 60℃ and a stirring speed of 100 rpm. The mixture was then washed with water until no chloride ions were present, and then dried at 110℃ for 10h. 10g of the ammonium chloride-treated mixture was calcined at 450℃ for 4h to obtain modified Hβ zeolite.
[0041] Acid treatment: 10g of modified Hβ zeolite was placed in 150ml of a mixed solution of ammonium molybdate and nickel nitrate, with the concentrations of both being 0.5M. The mixture was stirred and mixed at 60℃ and a stirring speed of 100 rpm for 12h, allowed to stand for 4h, and then dried at 110℃ for 4h to obtain the isomerization catalyst.
[0042] Using reformed C9 as raw material after light and heavy element removal, its molar composition is as follows: n-propylbenzene 1%, m-toluene 11%, p-toluene 5%, o-toluene 11%, mesitylene 14%, pseudotrimethylbenzene 49%, and thionylbenzene 9%. The isomerization reaction is carried out in a continuous tubular reactor at a temperature of 200℃, a reaction pressure of 1.1 MPa, and a space velocity of 1 h⁻¹. -1Under the condition of a hydrogen-to-oil ratio of 5, the conversion rate of pseudotrimethylbenzene was 40.7%, the conversion rate of o-toluene was 48.6%, and the selectivity of mesitylene was 39.7%.
[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.
Claims
1. The application of an isomerization catalyst in the catalytic isomerization reaction of pseudotrimethylbenzene and o-toluene to prepare mesitylene, characterized in that, The isomerization catalyst is obtained by sequentially processing Hβ zeolite through high-temperature calcination, alkali treatment, ammonium chloride treatment, and loading of molybdenum and nickel active components. During alkali treatment, Hβ zeolite is mixed with NaOH solution and reacted at 50℃-80℃. The active component loading step involves placing Hβ zeolite in a mixed solution of soluble salts of molybdenum and nickel and reacting it at 50℃-80℃. The concentration of the molybdenum soluble salt solution is 0.2-1M, the concentration of the nickel soluble salt solution is 0.2-1M, and 1g of Hβ zeolite is placed in 20-50mL of soluble salt mixed solution. During the alkali treatment, the concentration of the NaOH solution is 0.1-0.3M, and 1g of Hβ zeolite is placed in 15-50mL of NaOH solution; In this application, the reaction temperature is 200℃-300℃, the reaction pressure is 1.0-1.5MPa, and the reaction space velocity is 0.5-1.5h. -1 The hydrogen-to-oil molar ratio is 5-10.
2. The application according to claim 1, characterized in that, During alkali treatment, Hβ zeolite reacts with NaOH solution to obtain a suspension. The suspension is filtered and washed with water until pH=7, and then dried.
3. The application according to claim 2, characterized in that, During ammonium chloride treatment, the alkali-treated Hβ zeolite is mixed with an ammonium chloride solution to obtain a suspension. The suspension is filtered and washed with water until it is free of chloride ions, and then dried.
4. The application according to claim 3, characterized in that, The ammonium chloride solution concentration is 0.2-1M, and it is mixed according to the ratio of 1g Hβ zeolite per 15-50mL of ammonium chloride solution.
5. The application according to claim 4, characterized in that, The modified Hβ zeolite was obtained by calcining the ammonium chloride-treated Hβ zeolite for 4 hours at a calcination temperature of 400℃-600℃.