A method for surface active agent induced modification of zeolites for hydrogen sulfide valorization

Abstract

The application discloses a method for hydrogen sulfide resource utilization by using surfactant-induced modified zeolite to catalyze butene and hydrogen sulfide to synthesize butyl mercaptan. The surfactant-induced modified zeolite is prepared by the following steps: dissolving 0.3-0.4g of cetyl tripropyl ammonium bromide in 0.06-0.1mol / L of NaOH aqueous solution, then adding 1-1.2g of FAU type zeolite, stirring for 1-2h at room temperature, transferring the mixture into a high-pressure reaction kettle, heating for 30-90h at 150-170 DEG C, performing solid-liquid separation, calcining the solid at 500-700 DEG C for 3-5h, and then using an equal-volume impregnation method to place the calcined solid in a molybdate solution, standing, and drying to obtain the surfactant-induced modified zeolite. The catalyst has the advantages of good stability, good sulfur resistance and high selectivity, and the service life of the catalyst is greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of butanethiol catalytic synthesis technology, specifically relating to a method for the resource utilization of hydrogen sulfide by surfactant-induced modification of zeolite. Background Technology

[0002] Hydrogen sulfide, a typical toxic and malodorous gas, not only harms the atmospheric environment but also poses a significant threat to human health. Currently, the mainstream method for treating hydrogen sulfide is the Claus process, but its main drawbacks are low added value and less than ideal treatment efficiency. However, the synthesis of butanethiol offers a more attractive pathway for the resource utilization of hydrogen sulfide.

[0003] Butanethiol is slightly soluble in water but readily soluble in ethanol, diethyl ether, etc., and is mainly used as a solvent and organic synthesis intermediate, making it an important chemical raw material. Currently, research on the industrial-scale preparation of butanethiol is still largely lacking. Existing synthetic methods mainly involve the reaction of bromobutane with thiourea, or the catalytic reaction of butene with hydrogen sulfide. The latter has greater application potential, but the development of catalysts for this reaction is a major obstacle. The quality of the catalyst determines the efficiency of the catalytic reaction; therefore, catalysts for the efficient synthesis of butanethiol from butene and hydrogen sulfide have significant research and development value.

[0004] Zeolite is widely used in industry, agriculture, science and technology, plastics, fillers, feed, fertilizer, rubber, electronics and other sectors. The current annual output of natural zeolite in the world is about 4 million tons, and this number will increase with industrial development. In the chemical field, zeolite is often used to make catalysts because of its low price and easy availability. The modification of natural zeolite for catalytic reactions has been extensively studied. If its properties can be utilized to modify the catalytic reaction of butene and hydrogen sulfide, a catalyst with great application potential in this field will be obtained. Summary of the Invention

[0005] This invention provides a method for surfactant-induced modification of zeolite for hydrogen sulfide resource recovery. The method employs surfactant-induced modified zeolite to catalyze the reaction of butene and hydrogen sulfide at 290-320℃, 0.2-0.3 MPa, and a gas hourly space velocity of 270-290 h⁻¹. -1 The synthesis of butanethiol was carried out below;

[0006] The surfactant-induced modified zeolite is prepared by dissolving 0.3-0.4g of hexadecyltripropylammonium bromide in a 0.06-0.1mol / L NaOH aqueous solution, then adding 1-1.2g of FAU type zeolite, stirring at room temperature for 1-2h, transferring the mixture to a high-pressure reactor, heating at 150-170℃ for 30-90h, and calcining at 500-700℃ for 3-5h.

[0007] Surfactant-induced modified zeolite can also be prepared by equal-volume impregnation, in which the above-mentioned calcined solid is placed in ammonium molybdate solution, allowed to stand for 24-36 hours, and then dried at 70-80℃.

[0008] The molybdenum loading is 5wt%-15wt%;

[0009] This invention improves the catalyst, enhancing its catalytic activity and increasing its lifetime. Furthermore, the raw materials for preparing the catalyst are readily available and the preparation process is simple. The modified zeolite exhibits advantages such as good stability, good sulfur resistance, and high selectivity in the synthesis of butanethiol, while also significantly improving the catalyst lifetime. Attached Figure Description

[0010] Figure 1 This illustrates the effect of different hydrothermal times on the synthesis of butanethiol in Example 1.

[0011] Figure 2 This illustrates the effect of different Mo loading levels on the synthesis of butanethiol in Example 2.

[0012] Figure 3 The effect of Mo loading on the selectivity of butanethiol in Example 2. Detailed Implementation

[0013] The present invention will be further described in detail below through examples, but the scope of protection of the present invention is not limited to the content described.

[0014] Example 1: Preparation of surfactant-induced modified zeolite and its application in the synthesis of butanethiol

[0015] 1. Dissolve 0.3g of hexadecyltripropylammonium bromide in 0.08mol / L NaOH aqueous solution, then add 1g of FAU type zeolite, stir at room temperature for 1h, transfer the mixture to a high-pressure reactor, heat at 150℃ for 30h, 60h and 90h respectively, and calcine at 550℃ for 5h to obtain surfactant-induced modified zeolite;

[0016] 2. Place 0.4 g of the catalyst and 0.4 g of FAU-type zeolite prepared under different hydrothermal times in step 1 into tubular furnace reactors respectively. Introduce a mixed gas of butene and hydrogen sulfide (volume ratio 1:8) into the tubular furnace reactor at a flow rate of 10 mL / min. Maintain the reactor at 300℃, 0.3 MPa, and a gas hourly space velocity of 280 h⁻¹. -1 The synthesis of butanethiol was carried out under hydrothermal conditions. Within a 7-hour reaction time, the modified zeolites prepared at different hydrothermal times all exhibited superior catalytic performance compared to FAU-type natural zeolites. The modified zeolite with a hydrothermal time of 60 minutes showed the best activity, achieving a butene conversion rate of 78.12%. (See attached image). Figure 1 .

[0017] Example 2: Preparation of surfactant-induced modified zeolite and its application in the synthesis of butanethiol

[0018] 1. Dissolve 0.3 g of hexadecyltripropylammonium bromide in a 0.08 mol / L NaOH aqueous solution, then add 1 g of FAU type zeolite. After stirring at room temperature for 1 h, transfer the mixture to a high-pressure reactor, heat at 150 °C for 60 h, calcine at 550 °C for 5 h, and then place the calcined solid in an aqueous solution containing 0.0102 g of ammonium molybdate using an equal-volume impregnation method. After standing for 24 h, dry at 80 °C for 12 h to obtain 5Mo modified zeolite with a theoretical Mo loading of 5 wt%. Then, use the same method to prepare 10Mo modified zeolite and 15Mo modified zeolite with Mo loadings of 10 wt% and 15 wt%, respectively.

[0019] 2. 0.4 g of 5Mo zeolite modified catalyst, 0.4 g of 10Mo zeolite modified catalyst, 0.4 g of 15Mo zeolite modified catalyst, and 0.4 g of Mo-free modified zeolite catalyst were placed in tubular furnace reactors respectively. A mixture of butene and hydrogen sulfide (volume ratio 1:8) was introduced into the tubular furnace reactor at a flow rate of 10 mL / min. The reactor was operated at 300℃, 0.3 MPa, and a gas hourly space velocity of 280 h⁻¹. -1 The synthesis of butanethiol was carried out. After loading different amounts of Mo, the conversion rate of butene by the catalyst was improved to some extent. With the increase of Mo loading, the catalyst lifetime also increased. This may be because the MoO3 on the catalyst underwent oxygen-sulfur exchange during the reaction, improving the catalyst's sulfur resistance and thus affecting its lifetime. At the same time, the addition of Mo provided more active sites, thereby improving the selectivity of butanethiol. (See...) Figure 2 , Figure 3 .

Claims

1. A method for surfactant-induced modification of zeolite for hydrogen sulfide resource recovery, characterized in that: The synthesis of butanethiol from butene and hydrogen sulfide was achieved by using surfactant-induced modified zeolite catalysis. The surfactant-induced modified zeolite is prepared by dissolving 0.3-0.4 g of hexadecyltripropylammonium bromide in a 0.06-0.1 mol / L NaOH aqueous solution, then adding 1-1.2 g of FAU type zeolite, stirring at room temperature for 1-2 h, transferring the mixture to a high-pressure reactor, heating at 150-170℃ for 30-90 min, separating the solid and liquid after heating, and calcining the solid at 500-700℃ for 3-5 h. Surfactant-induced modified zeolite was prepared by placing the calcined solid in a molybdate solution, allowing it to stand, and then drying it using an equal-volume impregnation method.

2. The method according to claim 1, characterized in that: The Mo loading is 5-15 wt%.

3. The method according to claim 1, characterized in that: The gas-phase catalytic reaction for the synthesis of butanethiol was carried out at 290-320℃, 0.2-0.3MPa, and a gas hourly space velocity of 270-290h⁻¹. -1 This was carried out below.

4. The method according to claim 1, characterized in that: The molybdate is ammonium molybdate.

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