Method for resource utilization of hydrogen sulfide by using modified molecular sieve of kaolin

Abstract

The application discloses a method for hydrogen sulfide resource utilization by using kaolin modified molecular sieve, wherein the kaolin modified molecular sieve is prepared by the following steps: calcining kaolin at 700-800 DEG C, stirring and reacting the calcined kaolin in 3-5 mol / L H2SO4 solution, performing solid-liquid separation, washing the solid to neutral, drying, placing the dried product, tetrapropylammonium hydroxide and high fructose corn syrup in a high-pressure reaction kettle, adding ammonia water to adjust the pH to 9-10, and then reacting at 180-190 DEG C, performing solid-liquid separation, washing the solid, and then calcining the solid at 500-700 DEG C; the kaolin modified molecular sieve is applied to the synthesis of butyl mercaptan from butene and hydrogen sulfide, can simultaneously improve the conversion rate of isobutene and the selectivity of butyl mercaptan, and has good stability, still has good catalytic effect after being used for 53 h, and the service life of the catalyst is greatly improved, and the application provides a new way for the efficient synthesis of butyl mercaptan.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of preparation of kaolin modified molecular sieve and its method for synthesizing butyl mercaptan with hydrogen sulfide as raw material, belong to the field of hydrogen sulfide resource synthesis high value-added. BACKGROUND

[0002] Kaolin belongs to a non-metallic mineral, pure kaolin has the physical and chemical properties such as soft texture, high whiteness, easy to disperse and suspend in water, good plasticity, excellent fire resistance, which makes it widely used in papermaking, ceramics and refractory materials, and also can see the figure of kaolin in pigment, grinding wheel, plastic, paint, pencil, soap, pesticide, medicine, textile, daily cosmetic, petroleum, chemical industry, building material, national defense and other industries. And because it is composed of aluminum silicate, sodium silicate, magnesium silicate, iron oxide, titanium oxide and other chemical components, it is often modified for the preparation of catalyst, and high proportion of silicon and aluminum makes it possible to be used as silicon source and aluminum source for molecular sieve production.

[0003] Butyl mercaptan is used as an intermediate of rubber synthesis and an intermediate of various pesticides, and also participates in perfume, solvent, polymerization regulator, stabilizer, surfactant, which is an important chemical raw material. However, the most promising method of butene plus hydrogen sulfide gas phase catalytic preparation of butyl mercaptan requires that the catalyst has certain acidity and excellent mass transfer rate, and kaolin has high acidity due to its high silicon-aluminum ratio. If a suitable modification method can be found to improve its mass transfer rate, kaolin will have wider application potential in butyl mercaptan synthesis field. SUMMARY

[0004] The present application provides a kind of preparation of kaolin modified molecular sieve and its application in butyl mercaptan synthesis;Wherein the kaolin modified molecular sieve is placed at 700-800 ℃ for 3-5h after calcination, stirring reaction in 3-5mol / L H2SO4 solution, solid-liquid separation, solid washing to neutral, drying, the dry material, tetrapropylammonium hydroxide (TPAOH), high fructose corn syrup is placed in high pressure reactor, after adding ammonia water to adjust pH to 9-10, reaction is carried out at 180-190 ℃ for 24-36h, solid-liquid separation, after washing the solid, calcination is carried out at 500-700 ℃ for 5-7h;

[0005] The mass ratio of the dry material to tetrapropylammonium hydroxide is 12-13:1, and the mass ratio of the dry material to high fructose corn syrup is 7-8:1.

[0006] The kaolin in the present application is from Yangshan in Suzhou.

[0007] The application of the kaolin modified molecular sieve in the synthesis of butanethiol from butene and hydrogen sulfide can improve the butene conversion rate and the selectivity of butanethiol, and the catalyst has good stability and good catalytic effect after being used for 53h, and the service life of the catalyst is greatly improved, and the application provides a new way for the efficient synthesis of butanethiol. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 The figure is a comparison of the activity of the kaolin modified molecular sieve and the H-ZSM5 catalyst in the synthesis of butanethiol in Example 1. DETAILED DESCRIPTION

[0009] The application will be further described in detail through examples, but the protection scope of the application is not limited to the content.

[0010] Example 1: Preparation of the kaolin modified molecular sieve and its application in the synthesis of butanethiol

[0011] 1. Preparation of the kaolin modified molecular sieve

[0012] After the kaolin is calcined at 800℃ for 3h, it is stirred in a 3mol / L H2SO4 solution, and then solid-liquid separation is performed, the solid is washed with water until neutral, and then dried at 70℃, the dried material, tetrapropylammonium hydroxide and high-fructose corn syrup are placed in a high-pressure reaction kettle, the mass ratio of the dried material to tetrapropylammonium hydroxide is 12:1, the mass ratio of the dried material to high-fructose corn syrup is 7:1, ammonia water is added to adjust the pH to 9, and then reaction is performed at 180℃ for 24h, solid-liquid separation is performed, and the solid is washed with deionized water and ethanol alternately during the separation process, and then the solid is calcined at 550℃ for 7h to obtain the kaolin modified molecular sieve;

[0013] Meanwhile, the H-ZSM5 catalyst is prepared as a control, specifically, aluminum sulfate octadecahydrate and silica sol are dissolved in deionized water, NaOH is added to adjust the pH to 12, then TPAOH is added, the molar ratio of TPAOH to silica sol is 0.25:1, after stirring and mixing, the mixture is transferred to a high-pressure reaction kettle, and then reaction is performed at 120℃ for 4 days, solid-liquid separation is performed, and then the solid is washed, dried and calcined at 550℃ for 5h, then the solid is placed in a 1mol / L ammonium chloride solution, and then exchanged at 80℃ for 2 times, solid-liquid separation is performed, the solid is washed with water, and then dried at 100℃ for 12h to obtain the H-ZSM5 catalyst;

[0014] 2. The kaolin modified molecular sieve 0.4g and the H-ZSM5 catalyst 0.4g are respectively placed in a tubular furnace reactor, a mixture of butene and hydrogen sulfide (volume ratio 1:8) is introduced into the tubular furnace reactor, the flow rate is 10mL / min, the reaction is performed at 290℃, 0.3MPa and gas hourly space velocity 260h -1The reaction product was analyzed by a gas chromatograph. After 3 h of reaction, under the action of the kaolin-modified molecular sieve, the conversion rate of butene was 92.36%, and the selectivity of butyl mercaptan was 93.15%. After 53 h of continuous operation, the catalyst still had high activity, the conversion rate of butene was 89.23%, and the selectivity of butyl mercaptan was 92.89%.

[0015] Under the action of the H-ZSM5 catalyst, the conversion rate of butene was 76.58%, and the selectivity of butyl mercaptan was 72.96%. After 13 h of reaction, the catalyst was deactivated, as shown in FIG. 1.

[0016] Example 2: Preparation of a kaolin-modified molecular sieve catalyst and its application in the synthesis of butyl mercaptan

[0017] 1. Kaolin was calcined at 700°C for 5 h, then stirred in a 5 mol / L H2SO4 solution, and then solid-liquid separation was performed. The solid was washed with water until neutral, and then dried at 80°C. The dried material, tetrapropylammonium hydroxide, and high-fructose corn syrup were placed in a high-pressure reaction kettle. The mass ratio of the dried material to tetrapropylammonium hydroxide was 13:1, and the mass ratio of the dried material to high-fructose corn syrup was 8:1. After adjusting the pH to 10 by adding ammonia water, the mixture was reacted at 190°C for 36 h. Solid-liquid separation was performed, and deionized water and ethanol were used for alternative washing during the separation process. The solid was calcined at 650°C for 5 h to obtain the kaolin-modified molecular sieve.

[0018] 2. 0.4 g of the kaolin-modified molecular sieve was placed in a tubular furnace reactor, and a mixed gas of ethylene and hydrogen sulfide (volume ratio 1:3) was introduced into the tubular furnace reactor at a flow rate of 10 mL / min. The reaction was carried out at 280°C, 0.2 MPa, and a gas hourly space velocity of 280 h -1 The reaction product was analyzed by a gas chromatograph. After 3 h of reaction, under the action of the kaolin-modified molecular sieve, the conversion rate of butene was 91.87%, and the selectivity of ethyl mercaptan was 92.91%. After 53 h of continuous operation, the conversion rate of butene was 89.35%, and the selectivity of butyl mercaptan was 92.72%.

Claims

1. A method for the resource recovery of hydrogen sulfide from kaolin-modified molecular sieves, characterized in that: Butyl mercaptan was synthesized from butene and hydrogen sulfide using kaolin-modified molecular sieve catalysis. The modified kaolin molecular sieve is prepared by calcining kaolin at 700-800℃ for 3-5 hours, then stirring it in a 3-5 mol / L H2SO4 solution, separating the solid and liquid, washing the solid until neutral, drying it, placing the dried material, tetrapropylammonium hydroxide, and high fructose corn syrup in a high-pressure reactor, adding ammonia to adjust the pH to 9-10, reacting it at 180-190℃, separating the solid and liquid, washing the solid, and calcining it at 500-700℃ for 5-7 hours.

2. The method for using kaolin-modified molecular sieves for hydrogen sulfide resource recovery according to claim 1, characterized in that: The mass ratio of the dried product to tetrapropylammonium hydroxide is 12-13:1, and the mass ratio of the dried product to high fructose corn syrup is 7-8:

1.

3. The method for using kaolin-modified molecular sieves for hydrogen sulfide resource recovery according to claim 1, characterized in that: The gas-phase catalytic reaction for the synthesis of butanethiol was carried out at 280-300℃, 0.2-0.3MPa, and a gas hourly space velocity of 260-280h⁻¹. -1 It is carried out under the following conditions.

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