Micro-tubular reactor for preparing mercaptan and process method

Abstract

The invention relates to the technical field of mercaptan preparation, in particular to a microtubular reactor for preparing mercaptan and a process method.The microtubular reactor comprises a microreaction tube, the microreaction tube is provided with a high-carbon olefin feeding port and a plurality of hydrogen sulfide feeding ports, and multiple sections of catalyst layers containing solid acid are arranged in the microreaction tube; the plurality of hydrogen sulfide feed ports and the plurality of sections of catalyst layers are arranged at intervals along the length direction of the micro reaction tube; the high-carbon olefin storage tank is communicated with the high-carbon olefin feeding hole; the hydrogen sulfide storage tank is communicated with the plurality of hydrogen sulfide feed ports so as to progressively supplement hydrogen sulfide gas in the length direction of the micro-reaction tube; the flash tank is communicated with the outlet of the micro reaction tube, is used for recovering hydrogen sulfide gas after the reaction is finished, and is communicated with the hydrogen sulfide storage tank; the product storage tank is communicated with the bottom of the flash tank and is used for collecting mercaptan prepared after reaction; through the arrangement, the technical problems of low efficiency and high cost during preparation of mercaptan are effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of mercaptan preparation, and in particular to a micro-tubular reactor and a process method for preparing mercaptan. Background Art

[0002] The reaction of higher olefins with hydrogen sulfide to synthesize higher thiols is an important chemical raw material used in pharmaceuticals, antidotes, and rubber vulcanization accelerators. The addition reaction of higher olefins with hydrogen sulfide is a three-phase gas-liquid-solid reaction. Traditional synthesis processes typically utilize batch reactors with high-speed stirring to enhance the dispersion of the various phases within the reaction system. Batch reactors require alternating cycles of operation, which is highly detrimental to product stability.

[0003] In typical gas-liquid-solid three-phase reactions, increasing the effective contact area between the reactants is crucial. While mechanical stirring can break the reactant gas into small bubbles, it can also easily cause back-mixing during the stirring process, leading to reduced reaction conversion. Therefore, improving the mass transfer efficiency of the gas-liquid-solid three-phase reaction of higher olefins with hydrogen sulfide has long been a key research topic.

[0004] Patent application publication number CN116745262A discloses a method for preparing mercaptan compounds using a nickel-molybdenum catalyst. This method involves reacting olefins with hydrogen sulfide gas over the nickel-molybdenum catalyst to synthesize mercaptan compounds. The reaction is carried out at 235°C and 3.5 MPa. While this method can achieve the addition reaction of hydrogen sulfide to olefins, it requires relatively high reaction conditions due to insufficient contact between the various phases during the reaction, and it cannot achieve a continuous reaction.

[0005] Patent application publication number CN118022637A discloses a process and apparatus for producing tert-dodecyl mercaptan. This process uses dodecene and hydrogen sulfide as raw materials, employs Fe / Na-loaded Al2O3 as a catalyst, and employs a fixed-bed reactor as the primary reaction device. While this method achieves continuous production, the gas-liquid phases in the fixed-bed reactor tend to aggregate and diverge, resulting in a reduced contact area, which affects mass transfer efficiency between the reactants and reduces conversion.

[0006] Therefore, how to provide an efficient and low-cost device and process for preparing thiols has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0007] The present invention provides a micro-tubular reactor for preparing mercaptan, so as to solve the technical problems of low efficiency and high cost in the prior art for preparing mercaptan; the present invention also provides a process for preparing mercaptan using the micro-tubular reactor.

[0008] To solve the above problems, the micro-tubular reactor for preparing mercaptans provided by the present invention adopts the following technical solutions: A microtubular reactor for preparing mercaptans, comprising: A micro-reactor tube having a higher olefin feed port and multiple hydrogen sulfide feed ports, wherein multiple catalyst layers containing a solid acid are arranged in the micro-reactor tube, and the multiple hydrogen sulfide feed ports and the multiple catalyst layers are spaced apart along the length of the micro-reactor tube to allow multiple reactions between the higher olefins and hydrogen sulfide; a higher carbon olefin storage tank connected to the higher carbon olefin feed port; A hydrogen sulfide storage tank is connected to the plurality of hydrogen sulfide feed ports to achieve progressive replenishment of hydrogen sulfide gas along the length direction of the micro-reaction tube; A flash tank connected to the outlet of the micro-reaction tube is used to recover the hydrogen sulfide gas after the reaction is completed. The flash tank is connected to the hydrogen sulfide storage tank; The product storage tank is connected to the bottom of the flash tank and is used to collect the mercaptan produced after the reaction.

[0009] The beneficial effects of the above scheme are as follows: hydrogen sulfide gas and higher olefins are added to the microtubular reactor from different angles, mixed in the micro-mixing section to form a mixed liquid containing microbubbles. The mixed liquid passes through the catalyst layer of the microreactor, where the higher olefins react with hydrogen sulfide under the action of acid active sites to produce mercaptans. After the reaction, the hydrogen sulfide gas is recovered in a flash tank and reused as a raw material, and the mercaptans are obtained at the bottom. The entire device changes the traditional mixing method and optimizes mass transfer within the reactor by reducing the tube diameter to achieve sufficient mixing between the reactants. After being fully mixed at a certain angle, higher carbon olefins and hydrogen sulfide pass through the catalyst layer and undergo catalytic reaction on the catalyst surface. The multiple catalyst layers constitute a multi-stage reaction unit, allowing the reactants to undergo multiple reactions. After the reaction is completed, the products are collected at the tail of the reactor. Solid acids are used as catalysts to activate the carbon-carbon double bonds in higher olefins through π-bond activation, making them susceptible to addition reactions with hydrogen sulfide. Furthermore, the prepared acidic catalyst effectively adsorbs hydrogen sulfide molecules, making it easier for them to come into contact with and react with higher olefins. Therefore, the present invention can be carried out under relatively mild conditions, significantly reducing the reaction requirements.

[0010] Furthermore, the micro-reaction tube includes a horizontal tube, one end of which forms a high-carbon olefin feed port connected to the high-carbon olefin storage tank, and the other end forms an outlet connected to the flash tank. A plurality of inclined tubes are also arranged on the horizontal tube, and the end of each inclined tube forms a hydrogen sulfide feed port connected to the hydrogen sulfide storage tank.

[0011] Furthermore, a catalyst layer is arranged at the connection point between each inclined tube and the horizontal tube, and the number of the catalyst layers is the same as the number of the inclined tubes.

[0012] The beneficial effect of the above solution is that hydrogen sulfide can react with higher carbon olefins on the surface of the catalyst layer immediately after entering the horizontal tube, thereby improving the reaction efficiency.

[0013] Furthermore, the angle between each hydrogen sulfide feed port and each higher olefin feed port ranges from 1 to 80 degrees.

[0014] Furthermore, the catalyst layer is perpendicular to the midline of the angle between the hydrogen sulfide feed port and the higher olefin feed port.

[0015] The beneficial effect of the above solution is that the catalyst layer faces hydrogen sulfide and higher carbon olefins, so that the two can react directly in the catalyst layer, further improving the reaction efficiency.

[0016] The beneficial effects of the micro-tubular reactor for preparing mercaptans provided by the present invention are: 1) The entire device changes the traditional mixing method and optimizes the mass transfer inside the reactor by reducing the tube diameter, achieving sufficient mixing between the reactants; 2) The multi-stage catalyst layer constitutes a multi-stage reaction unit, which allows the reactants to undergo multiple reactions. After the reaction is completed, the product is collected at the tail of the reactor; 3) The use of a solid acid as a catalyst activates the carbon-carbon double bonds in higher olefins through π-bond activation, facilitating an addition reaction with hydrogen sulfide. Furthermore, the prepared acidic catalyst effectively adsorbs hydrogen sulfide molecules, facilitating contact and reaction with higher olefins. Therefore, the present invention can be carried out under relatively mild conditions, significantly reducing the reaction requirements.

[0017] In summary, through the above-mentioned configuration, the present invention effectively solves the technical problems of low efficiency and high cost in the preparation of thiols in the prior art.

[0018] To solve the above problems, the process for preparing mercaptan provided by the present invention adopts the following technical solution: A process for preparing mercaptan is implemented by means of the above-mentioned microtubular reactor for preparing mercaptan, comprising the following steps: S1: Prepare the catalyst layer and place it at different positions in the microreactor; S2: adding hydrogen sulfide gas and higher olefins from different angles; S3: Control the reaction temperature, molar ratio, reaction pressure and reaction time of hydrogen sulfide gas and higher carbon olefins to meet the set standards; S4: collecting the produced thiol.

[0019] Furthermore, in step S1, the catalyst layer is prepared, including the following steps: a) mixing and dissolving sodium silicate, aluminum chloride, sodium hydroxide, and tetrapropylammonium hydroxide to prepare a precursor solution; b) placing the precursor solution in a hydrothermal autoclave and crystallizing it under certain temperature conditions, filtering and drying it to obtain a catalyst support precursor; c) The obtained precursor was ion exchanged in an ammonium salt solution, filtered, dried, and calcined to obtain a catalyst support; d) the catalyst support is impregnated in an acidic solution, dried and calcined; e) The catalyst is pressed into a circular catalytic sheet according to the diameter of the microtubular reaction. The catalytic sheet is the catalyst layer.

[0020] Furthermore, the molar ratio of each substance in the precursor solution is n(Na):n(Al):n(Si):n(H2O) is X:1:Y:200, wherein X=5-20, Y=15-50.

[0021] Furthermore, in step b), the hydrothermal temperature is 100° C., and the crystallization time is 8-24 hours.

[0022] Furthermore, in step d), the acidic solution includes one or more of H2SO4, H3PO4, and H3BO3.

[0023] The beneficial effects of the process for preparing mercaptan provided by the present invention are: 1) The entire device changes the traditional mixing method and optimizes the mass transfer inside the reactor by reducing the tube diameter, achieving sufficient mixing between the reactants; 2) The multi-stage catalyst layer constitutes a multi-stage reaction unit, which allows the reactants to undergo multiple reactions. After the reaction is completed, the product is collected at the tail of the reactor; 3) The use of a solid acid as a catalyst activates the carbon-carbon double bonds in higher olefins through π-bond activation, facilitating an addition reaction with hydrogen sulfide. Furthermore, the prepared acidic catalyst effectively adsorbs hydrogen sulfide molecules, facilitating contact and reaction with higher olefins. Therefore, the present invention can be carried out under relatively mild conditions, significantly reducing the reaction requirements.

[0024] In summary, through the above-mentioned configuration, the present invention effectively solves the technical problems of low efficiency and high cost in the preparation of thiols in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and other objects, features and advantages of the exemplary embodiments of the present invention will become readily understood by reading the following detailed description with reference to the accompanying drawings. In the accompanying drawings, several embodiments of the present invention are shown in an illustrative and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein: Figure 1 This is a schematic diagram of a micro-tubular reactor for preparing mercaptans provided by the present invention; Figure 2 This is a flow chart of the process for preparing mercaptan provided by the present invention; Figure 3 This is the XRD pattern of the catalyst layer in the present invention.

[0026] Description of reference numerals: 1. Micro-reactor tube; 101. Horizontal tube; 102. Inclined tube; 2. Higher olefin feed port; 3. Hydrogen sulfide feed port; 4. Catalyst layer; 5. Higher olefin storage tank; 6. Hydrogen sulfide storage tank; 7. Flash tank; 8. Product storage tank; 9. Export. DETAILED DESCRIPTION

[0027] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Those skilled in the art should know that the embodiments described below are part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0028] The principles and spirit of the present invention are explained in detail below with reference to several representative embodiments of the present invention.

[0029] Examples of the micro-tubular reactor for preparing mercaptans provided by the present invention: like Figure 1 As shown, the microtubular reactor for preparing mercaptans includes a microreaction tube 1, a higher olefin storage tank 5, a hydrogen sulfide storage tank 6, a flash tank 7, and a product storage tank 8. The microreaction tube 1 has a higher olefin feed port 2 and multiple hydrogen sulfide feed ports 3. Multiple catalyst layers 4 containing solid acid are arranged inside the microreaction tube 1. The multiple hydrogen sulfide feed ports 3 and the multiple catalyst layers 4 are spaced apart along the length of the microreaction tube 1 to allow multiple reactions between the higher olefins and hydrogen sulfide.

[0030] The high-carbon olefin storage tank 5 is connected to the high-carbon olefin feed port 2; the hydrogen sulfide storage tank 6 is connected to multiple hydrogen sulfide feed ports 3 to achieve progressive replenishment of hydrogen sulfide gas in the length direction of the micro-reaction tube 1; the flash tank 7 is connected to the outlet 9 of the micro-reaction tube 1, and is used to recover the hydrogen sulfide gas after the reaction is completed. The flash tank 7 is connected to the hydrogen sulfide storage tank 6, and is used to continue to inject the recovered hydrogen sulfide gas into the hydrogen sulfide storage tank 6 to achieve recycling.

[0031] The product storage tank 8 is connected to the bottom of the flash tank 7 and is used to collect the mercaptan produced after the reaction.

[0032] Specifically, refer to Figure 1 The micro-reactor tube 1 includes a horizontal tube 101, one end of which forms a higher olefin feed port 2 connected to the higher olefin storage tank 5, and the other end forms an outlet 9 connected to the flash tank 7. The horizontal tube 101 is also provided with a plurality of inclined tubes 102, each end of which forms a hydrogen sulfide feed port 3 connected to the hydrogen sulfide storage tank 6. In this embodiment, the diameter of the micro-reactor tube 1 is 0.1-10 mm. In other embodiments, the diameter of the micro-reactor tube 1 can also be adjusted according to actual needs.

[0033] A catalyst layer 4 is arranged at the connection point between each inclined tube 102 and the horizontal tube 101. The number of catalyst layers 4 is the same as the number of inclined tubes 102, and the outer circumference of the catalyst layer 4 is adapted to the inner diameter of the horizontal tube 101. This arrangement has the advantage that hydrogen sulfide can immediately react with higher carbon olefins on the surface of the catalyst layer 4 after entering the horizontal tube 101, thereby improving the reaction efficiency.

[0034] In this embodiment, the number of catalyst layers 4 is 10-20 layers ( Figure 1 Only three layers are shown, and the remaining catalyst layers are not shown). In other embodiments, the number of catalyst layers can also be adjusted according to actual needs. In addition, in this embodiment, the length of a single catalyst layer is 5 cm, and the thickness of the catalyst filler is 1 cm.

[0035] In a specific configuration, the angle between each hydrogen sulfide feed port 3 and each higher olefin feed port 2 ranges from 1 to 80 degrees. The catalyst layer is perpendicular to the midline of the angle between the hydrogen sulfide feed port 3 and the higher olefin feed port 2. This configuration has the advantage of facing the hydrogen sulfide and higher olefins directly in the catalyst layer, allowing them to react directly, further improving reaction efficiency.

[0036] Examples of the process for preparing mercaptan provided by the present invention: like Figure 2 As shown, the process for preparing mercaptan is realized by means of the above-mentioned micro-tubular reactor for preparing mercaptan, comprising the following steps: S1: Prepare the catalyst layer and place it at different positions in the microreactor; S2: adding hydrogen sulfide gas and higher olefins from different angles; S3: Control the reaction temperature, molar ratio, reaction pressure and reaction time of hydrogen sulfide gas and higher carbon olefins to meet the set standards; S4: collecting the produced thiol.

[0037] The setting standards in step S3 are: the molar ratio of higher carbon olefins to hydrogen sulfide is 1:(2-20), the reaction temperature is 60-150° C., the reaction pressure is 0.1-0.5 MPa, and the reaction time is 1-20 min.

[0038] As a highlight of this process, in step S1, when preparing the catalyst layer, the following steps are included: a) mixing and dissolving sodium silicate, aluminum chloride, sodium hydroxide, and tetrapropylammonium hydroxide to prepare a precursor solution; b) placing the precursor solution in a hydrothermal autoclave and crystallizing it under certain temperature conditions, filtering and drying it to obtain a catalyst support precursor; c) The obtained precursor was ion exchanged in an ammonium salt solution, filtered, dried, and calcined to obtain a catalyst support; d) the catalyst support is impregnated in an acidic solution, dried and calcined; e) The catalyst is pressed into a circular catalytic sheet according to the diameter of the microtubular reaction. The catalytic sheet is the catalyst layer.

[0039] Specifically, the molar ratio of each substance in the precursor solution is n(Na):n(Al):n(Si):n(H2O) is X:1:Y:200, wherein X=5-20, Y=15-50.

[0040] In step b), the hydrothermal temperature is 100° C. and the crystallization time is 8-24 hours. In step d), the acidic solution includes one or more of H 2 SO 4 , H 3 PO 4 , and H 3 BO 3 .

[0041] In addition, in step c) and step d), the calcination temperatures are 400-600° C. and 250-400° C., respectively, and the calcination times are 2-6 hours and 1-3 hours, respectively.

[0042] Below, the mercaptan conversion rate obtained by this process is analyzed through several groups of examples: The first group of examples (the acidic solution is H2SO4): (1) Sodium silicate, aluminum chloride, sodium hydroxide and tetrapropylammonium hydroxide were mixed and dissolved in a molar ratio of n(Na):n(Al):n(Si):n(H2O) of 15:1:50:200 to prepare a precursor solution, the solution was placed in a hydrothermal autoclave and crystallized at a reaction temperature of 100°C for 12 hours, filtered, dried and then calcined at 500°C for 4 hours to obtain a carrier; the obtained carrier was immersed in H2SO4 solution for 12 hours, filtered, dried and then calcined at 300°C for 2 hours to obtain a catalyst; the catalyst flakes were obtained by tableting.

[0043] (2) Hydrogen sulfide gas and higher olefins were fed from different angles and mixed in the micro-mixing section to form a mixed liquid containing microbubbles. The diameter of the microreactor tube was 0.8 mm, and the angle of gas and liquid two-phase feeding was 60°. The number of catalyst layers was 15. The length of a single catalyst layer was 5 cm, and the thickness of the catalyst packing was 1 cm. The molar ratio of higher olefins to hydrogen sulfide was 1:10, the reaction temperature was 100°C, the reaction pressure was 0.3 MPa, and the reaction time was 10 min. When the mixed liquid passed through the catalyst layer of the microreactor, the higher olefins reacted with hydrogen sulfide under the action of the acid active sites to produce mercaptans. The final mercaptan conversion rate was 62.3%, and the selectivity was 99.5%.

[0044] The second group of examples (the acidic solution is H3PO4) (1) Sodium silicate, aluminum chloride, sodium hydroxide, and tetrapropylammonium hydroxide were mixed and dissolved in a molar ratio of n(Na):n(AL):n(Si):n(H2O) of 15:1:50:200 to prepare a precursor solution, the solution was placed in a hydrothermal autoclave and crystallized at a reaction temperature of 100°C for 12 hours, filtered, dried, and then calcined at 500°C for 4 hours to obtain a carrier; the obtained carrier was immersed in H3PO4 solution for 2 hours, filtered, dried, and then calcined at 300°C for 2 hours to obtain a catalyst; and the catalyst flakes were obtained by tableting.

[0045] (2) Hydrogen sulfide gas and higher carbon olefins were fed from different angles and mixed in the micro-mixing section to form a mixed liquid containing microbubbles. The diameter of the micro-reactor tube was 0.8 mm, and the angle of gas and liquid two-phase feeding was 60°. The number of catalyst layers was 15. The length of a single catalyst layer was 5 cm, and the thickness of the catalyst packing was 1 cm. The molar ratio of higher carbon olefins to hydrogen sulfide was 1:10, the reaction temperature was 100 °C, the reaction pressure was 0.3 MPa, and the reaction time was 10 min. The mixed liquid passed through the catalyst layer of the microreactor, and under the action of the acid active sites, the higher carbon olefins reacted with hydrogen sulfide to produce mercaptans. The final mercaptan conversion rate was 57.3%, and the selectivity was 99.6%.

[0046] The third group of examples (the acidic solution is H3BO3) (1) Sodium silicate, aluminum chloride, sodium hydroxide, and tetrapropylammonium hydroxide were mixed and dissolved in a molar ratio of n(Na):n(AL):n(Si):n(H2O) of 15:1:50:200 to prepare a precursor solution. The solution was placed in a hydrothermal autoclave and crystallized at a reaction temperature of 100°C for 12 hours. After filtering and drying, the solution was calcined at 500°C for 4 hours to obtain a carrier. The obtained carrier was immersed in H3BO3 solution for 2 hours, filtered, dried, and calcined at 300°C for 2 hours to obtain a catalyst. The catalyst flakes were obtained by tableting.

[0047] (2) Hydrogen sulfide gas and higher olefins were fed from different angles and mixed in the micro-mixing section to form a mixed liquid containing microbubbles. The diameter of the microreactor tube was 0.8 mm, and the angle of gas and liquid two-phase feeding was 60°. The number of catalyst layers was 15. The length of a single catalyst layer was 5 cm, and the thickness of the catalyst packing was 1 cm. The molar ratio of higher olefins to hydrogen sulfide was 1:10, the reaction temperature was 100°C, the reaction pressure was 0.3 MPa, and the reaction time was 10 min. The mixed liquid passed through the catalyst layer of the microreactor, and under the action of the acid active sites, the higher olefins reacted with hydrogen sulfide to produce mercaptans. The final mercaptan conversion rate was 59.3%, and the selectivity was 98.7%.

[0048] Example 4 (the acidic solution is H2SO4, the number of catalyst layers is changed to 5, the immersion time of the carrier in the H2SO4 solution is changed to 2 hours, and the other conditions remain unchanged) (1) Sodium silicate, aluminum chloride, sodium hydroxide, and tetrapropylammonium hydroxide were mixed and dissolved in a molar ratio of n(Na):n(AL):n(Si):n(H2O) of 15:1:50:200 to prepare a precursor solution. The solution was placed in a hydrothermal autoclave and crystallized at a reaction temperature of 100°C for 12 hours. After filtering and drying, the solution was calcined at 500°C for 4 hours to obtain a carrier. The obtained carrier was immersed in H2SO4 solution for 2 hours, filtered, dried, and calcined at 300°C for 2 hours to obtain a catalyst. The catalyst flakes were obtained by tableting.

[0049] (2) Hydrogen sulfide gas and higher olefins were fed from different angles and mixed in the micro-mixing section to form a mixed liquid containing microbubbles. The diameter of the microreactor tube was 0.8 mm, and the angle of gas and liquid two-phase feeding was 60°. The number of catalyst layers was 5 layers. The length of a single catalyst layer was 5 cm, and the thickness of the catalyst packing was 1 cm. The molar ratio of higher olefins to hydrogen sulfide was 1:10, the reaction temperature was 100°C, the reaction pressure was 0.3 MPa, and the reaction time was 10 min. When the mixed liquid passed through the catalyst layer of the microreactor, the higher olefins reacted with hydrogen sulfide under the action of the acid active sites to produce mercaptans. The final mercaptan conversion rate was 54.1%, and the selectivity was 99.7%.

[0050] The fifth group of examples (the acidic solution is H2SO4, the number of catalyst layers remains 15, the immersion time of the carrier in the H2SO4 solution is changed to 2 hours, and the other conditions remain unchanged) (1) Sodium silicate, aluminum chloride, sodium hydroxide, and tetrapropylammonium hydroxide were mixed and dissolved in a molar ratio of n(Na):n(AL):n(Si):n(H2O) of 15:1:50:200 to prepare a precursor solution. The solution was placed in a hydrothermal autoclave and crystallized at a reaction temperature of 100°C for 12 hours. After filtering and drying, the solution was calcined at 500°C for 4 hours to obtain a carrier. The obtained carrier was immersed in H2SO4 solution for 2 hours, filtered, dried, and calcined at 300°C for 2 hours to obtain a catalyst. The catalyst flakes were obtained by tableting.

[0051] (2) Hydrogen sulfide gas and higher olefins were fed from different angles and mixed in the micro-mixing section to form a mixed liquid containing microbubbles. The diameter of the microreactor tube was 0.8 mm, and the angle of gas and liquid two-phase feeding was 60°. The number of catalyst layers was 15. The length of a single catalyst layer was 5 cm, and the thickness of the catalyst packing was 1 cm. The molar ratio of higher olefins to hydrogen sulfide was 1:10, the reaction temperature was 100°C, the reaction pressure was 0.3 MPa, and the reaction time was 10 min. When the mixed liquid passed through the catalyst layer of the microreactor, the higher olefins reacted with hydrogen sulfide under the action of the acid active sites to produce mercaptans. The final mercaptan conversion rate was 58.8%, and the selectivity was 99.3%.

[0052] Example 6 (the acidic solution is H2SO4, the number of catalyst layers remains 15, the immersion time of the support in the H2SO4 solution is changed to 2 hours, the reaction time of higher olefins and hydrogen sulfide is changed to 8 minutes, and the other conditions remain unchanged) (1) Sodium silicate, aluminum chloride, sodium hydroxide, and tetrapropylammonium hydroxide were mixed and dissolved in a molar ratio of n(Na):n(AL):n(Si):n(H2O) of 15:1:50:200 to prepare a precursor solution. The solution was placed in a hydrothermal autoclave and crystallized at a reaction temperature of 100°C for 12 hours. After filtering and drying, the solution was calcined at 500°C for 4 hours to obtain a carrier. The obtained carrier was immersed in H2SO4 solution for 2 hours, filtered, dried, and calcined at 300°C for 2 hours to obtain a catalyst. The catalyst flakes were obtained by tableting.

[0053] (2) Hydrogen sulfide gas and higher olefins were fed from different angles and mixed in the micro-mixing section to form a mixed liquid containing microbubbles. The diameter of the microreactor tube was 0.8 mm, and the angle of gas and liquid two-phase feeding was 60°. The number of catalyst layers was 15. The length of a single catalyst layer was 5 cm, and the thickness of the catalyst packing was 1 cm. The molar ratio of higher olefins to hydrogen sulfide was 1:10, the reaction temperature was 100°C, the reaction pressure was 0.3 MPa, and the reaction time was 8 min. When the mixed liquid passed through the catalyst layer of the microreactor, the higher olefins reacted with hydrogen sulfide under the action of the acid active sites to produce mercaptans. The final mercaptan conversion rate was 55.7%, and the selectivity was 99.1%.

[0054] Example 7 (the acidic solution is H2SO4, the number of catalyst layers remains 15, the immersion time of the support in the H2SO4 solution is changed to 2 hours, the reaction temperature of higher olefins and hydrogen sulfide is changed to 120°C, and the other conditions remain unchanged) (1) Sodium silicate, aluminum chloride, sodium hydroxide, and tetrapropylammonium hydroxide were mixed and dissolved in a molar ratio of n(Na):n(AL):n(Si):n(H2O) of 15:1:50:200 to prepare a precursor solution. The solution was placed in a hydrothermal autoclave and crystallized at a reaction temperature of 100°C for 12 hours. After filtering and drying, the solution was calcined at 500°C for 4 hours to obtain a carrier. The obtained carrier was immersed in H2SO4 solution for 2 hours, filtered, dried, and calcined at 300°C for 2 hours to obtain a catalyst. The catalyst flakes were obtained by tableting.

[0055] (2) Hydrogen sulfide gas and higher olefins were fed from different angles and mixed in the micro-mixing section to form a mixed liquid containing microbubbles. The diameter of the microreactor tube was 0.8 mm, and the angle of gas and liquid two-phase feeding was 60°. The number of catalyst layers was 15. The length of a single catalyst layer was 5 cm, and the thickness of the catalyst packing was 1 cm. The molar ratio of higher olefins to hydrogen sulfide was 1:10, the reaction temperature was 120°C, the reaction pressure was 0.3 MPa, and the reaction time was 10 min. When the mixed liquid passed through the catalyst layer of the microreactor, the higher olefins reacted with hydrogen sulfide under the action of the acid active sites to produce mercaptans. The final mercaptan conversion rate was 61.3%, and the selectivity was 97.2%.

[0056] Example 8 (the acidic solution is H2SO4, the number of catalyst layers remains 15, the immersion time of the carrier in the H2SO4 solution is changed to 2 hours, the diameter of the microreactor tube is changed to 1.2 mm, and the other conditions remain unchanged) (1) Sodium silicate, aluminum chloride, sodium hydroxide, and tetrapropylammonium hydroxide were mixed and dissolved in a molar ratio of n(Na):n(AL):n(Si):n(H2O) of 15:1:50:200 to prepare a precursor solution. The solution was placed in a hydrothermal autoclave and crystallized at a reaction temperature of 100°C for 12 hours. After filtering and drying, the solution was calcined at 500°C for 4 hours to obtain a carrier. The obtained carrier was immersed in H2SO4 solution for 2 hours, filtered, dried, and calcined at 300°C for 2 hours to obtain a catalyst. The catalyst flakes were obtained by tableting.

[0057] (2) Hydrogen sulfide gas and higher olefins were fed from different angles and mixed in the micro-mixing section to form a mixed liquid containing microbubbles. The diameter of the microreactor tube was 1.2 mm, and the angle of gas and liquid two-phase feeding was 60°. The number of catalyst layers was 15. The length of a single catalyst layer was 5 cm, and the thickness of the catalyst packing was 1 cm. The molar ratio of higher olefins to hydrogen sulfide was 1:10, the reaction temperature was 100 °C, the reaction pressure was 0.3 MPa, and the reaction time was 10 min. When the mixed liquid passed through the catalyst layer of the microreactor, the higher olefins reacted with hydrogen sulfide under the action of the acid active sites to produce mercaptans. The final mercaptan conversion rate was 57.7%, and the selectivity was 96.7%.

[0058] like Figure 3 As shown in the figure, the diffraction peaks at 2θ=2.28°, 15.68°, 18.79°, 20.46°, 23.67°, 27.04°, 31.39° and 34.07° on the XRD pattern are the characteristic crystal plane diffraction peaks of this type of molecular sieve. These characteristic diffraction peaks indicate that the molecular sieve on the catalyst layer has good crystallinity and uniform crystal structure, proving that this type of molecular sieve has been successfully synthesized.

[0059] In summary, this process demonstrates that high mercaptan conversion and selectivity can be achieved. The conversion reflects the degree to which the raw materials are converted into the target mercaptan product during the reaction. A higher conversion indicates greater utilization of the raw materials and a more thorough reaction toward mercaptan production. High selectivity means that the mercaptan-producing reaction pathway predominates during the reaction, with relatively fewer side reactions, resulting in a higher purity of the target mercaptan product.

[0060] Based on the above description of this specification, those skilled in the art may also understand that the terms used below, such as "upper", "lower", "front", "back", "left", "right", "width", "horizontal", "top", "bottom", "inner", "outer" (and the like) indicating orientation or positional relationships are based on the orientation or positional relationships shown in the drawings of this specification, and are only for the purpose of facilitating the explanation of the solutions of the present invention and simplifying the description, rather than explicitly or implicitly indicating that the devices or elements involved must have the specific orientation, be constructed and operate in the specific orientation. Therefore, the above-mentioned orientation or positional relationship terms should not be understood or interpreted as limiting the solutions of the present invention.

[0061] In addition, in the description of this specification, “a plurality of” means at least two, for example, two, three or more, etc., unless otherwise clearly and specifically defined.

Claims

1. A microtubular reactor for preparing mercaptans, characterized in that: include: A micro-reactor tube having a higher olefin feed port and multiple hydrogen sulfide feed ports, wherein multiple catalyst layers containing a solid acid are arranged in the micro-reactor tube, and the multiple hydrogen sulfide feed ports and the multiple catalyst layers are spaced apart along the length of the micro-reactor tube to allow multiple reactions between the higher olefins and hydrogen sulfide; a higher carbon olefin storage tank connected to the higher carbon olefin feed port; A hydrogen sulfide storage tank is connected to the plurality of hydrogen sulfide feed ports to achieve progressive replenishment of hydrogen sulfide gas along the length direction of the micro-reaction tube; A flash tank connected to the outlet of the micro-reaction tube is used to recover the hydrogen sulfide gas after the reaction is completed. The flash tank is connected to the hydrogen sulfide storage tank; The product storage tank is connected to the bottom of the flash tank and is used to collect the mercaptan produced after the reaction.

2. The microtubular reactor for preparing mercaptans according to claim 1, wherein: The micro-reaction tube includes a horizontal tube, one end of which forms a high-carbon olefin feed port connected to the high-carbon olefin storage tank, and the other end forms an outlet connected to the flash tank. A plurality of inclined tubes are also arranged on the horizontal tube, and the end of each inclined tube forms a hydrogen sulfide feed port connected to the hydrogen sulfide storage tank.

3. The microtubular reactor for preparing mercaptans according to claim 2, wherein: A catalyst layer is arranged at the connection point between each inclined tube and the horizontal tube, and the number of the catalyst layers is the same as the number of the inclined tubes.

4. The microtubular reactor for preparing mercaptans according to claim 3, wherein: The angle between each hydrogen sulfide feed port and each higher olefin feed port ranges from 1 to 80 degrees.

5. The microtubular reactor for preparing mercaptans according to claim 4, wherein: The catalyst layer is perpendicular to the midline of the angle between the hydrogen sulfide feed port and the higher olefin feed port.

6. A process for preparing mercaptan, characterized in that: The method is realized by using the micro-tubular reactor for preparing mercaptans according to any one of claims 1 to 5, comprising the following steps: S1: Prepare the catalyst layer and place it at different positions in the microreactor; S2: adding hydrogen sulfide gas and higher olefins from different angles; S3: Control the reaction temperature, molar ratio, reaction pressure and reaction time of hydrogen sulfide gas and higher carbon olefins to meet the set standards; S4: collecting the produced thiol.

7. The process for preparing mercaptan according to claim 6, characterized in that: In step S1, the catalyst layer is prepared, including the following steps: a) mixing and dissolving sodium silicate, aluminum chloride, sodium hydroxide, and tetrapropylammonium hydroxide to prepare a precursor solution; b) placing the precursor solution in a hydrothermal autoclave and crystallizing it under certain temperature conditions, filtering and drying it to obtain a precursor of the catalyst support; c) The obtained precursor was ion exchanged in an ammonium salt solution, filtered, dried, and calcined to obtain a catalyst support; d) the catalyst support is impregnated in an acidic solution, dried and calcined; e) The catalyst is pressed into a circular catalytic sheet according to the diameter of the microtubular reaction. The catalytic sheet is the catalyst layer.

8. The process for preparing mercaptan according to claim 7, wherein: The molar ratio of each substance in the precursor solution is n(Na):n(Al):n(Si):n(H2O), which is X:1:Y:200, wherein X=5-20 and Y=15-50.

9. The process for preparing mercaptan according to claim 7 or 8, characterized in that: In step b), the hydrothermal temperature is 100° C. and the crystallization time is 8-24 hours.

10. The process for preparing mercaptan according to claim 7 or 8, characterized in that: In step d), the acidic solution includes one or more of H2SO4, H3PO4, and H3BO3.

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