A tert-nonylthiol and its synthesis method

Abstract

This invention provides a tert-nonylthiol and its synthesis method. The synthesis steps are as follows: nonene and hydrogen sulfide are preheated separately, then the preheated nonene and hydrogen sulfide are mixed, and the mixture is reacted under the action of a catalyst to obtain tert-nonylthiol. The preheating temperature of nonene is 40-50℃, and the preheating temperature of hydrogen sulfide is 50-60℃. This invention provides mild reaction conditions and precise preheating of nonene and hydrogen chloride separately. The product prepared by this method has a purity of over 99.0%, meeting the requirements of high-end industrial applications for high-purity tert-nonylthiol.

Description

Technical Field

[0001] This invention relates to the field of chemical synthesis technology, specifically to a tert-nonylthiol and its synthesis method. Background Technology

[0002] Tertiary nonylthiol is an important fine chemical, mainly used as a highly efficient chain transfer agent and regulator in the polymerization of polymer materials (such as styrene-butadiene rubber and ABS resin). The thio group at the tertiary carbon position in its molecular structure endows it with superior regulating activity and efficiency. In addition, it also has applications in the synthesis of lubricating oil additives, surfactants, and certain specialty chemicals.

[0003] Traditional tert-nonylthiol synthesis processes typically involve the direct addition of nonene and hydrogen sulfide in the presence of an acidic catalyst (such as sulfuric acid, phosphoric acid, or a solid acid). However, this addition reaction is susceptible to fluctuations in reaction conditions (temperature, pressure, and material ratio), leading to increased side reactions (such as the formation of disulfides and thioethers), low selectivity for the target product, and a slow reaction rate, thus limiting production efficiency. Furthermore, the reaction usually requires high temperatures and pressures to ensure conversion rates, resulting in significant energy consumption. Therefore, the existing technology requires further development. Summary of the Invention

[0004] To address the shortcomings of existing technologies and solve the aforementioned problems, a tert-nonylthiol and its synthesis method are proposed, and the following technical solution is provided: A method for synthesizing tert-nonylthiol, comprising the following steps: preheating nonene and hydrogen sulfide feedstocks separately, mixing the preheated nonene and hydrogen sulfide feedstocks, and reacting the mixture under the action of a catalyst to obtain tert-nonylthiol, wherein the preheating temperature of nonene is 40-50℃ and the preheating temperature of hydrogen sulfide is 50-60℃.

[0005] Furthermore, after the reaction of nonene and hydrogen sulfide, unreacted nonene and hydrogen sulfide are recovered to obtain recovered nonene and recovered hydrogen sulfide. The recovered nonene is mixed with nonene raw material in a mass ratio of 1-3:8 and then preheated to participate in the reaction of nonene and hydrogen sulfide. The recovered hydrogen sulfide is mixed with hydrogen sulfide raw material in a mass ratio of 1-2:5 and then preheated to participate in the reaction of nonene and hydrogen sulfide.

[0006] Furthermore, the catalyst uses phosphoric acid as the active host, silicotungstic acid as the co-catalyst, and the support is spherical silica gel modified with 3-aminopropyltriethoxysilane.

[0007] Furthermore, the mass ratio of phosphoric acid to silicotungstic acid is 20:1.

[0008] Furthermore, the catalyst preparation steps include: S1: Support modification: Take spherical silica gel with a particle size of 2-3 mm, immerse it in 3-aminopropyltriethoxysilane ethanol solution, stir and dry to obtain modified support; S2: Impregnation and calcination: The modified support is placed in a phosphate-silicotungstic acid mixed solution, vacuum impregnated, dried, and calcined to obtain the catalyst.

[0009] Furthermore, in step S1, the specific surface area of ​​the spherical silica gel is ≥450m² / g, the concentration of the 3-aminopropyltriethoxysilane ethanol solution is 4%-6%, the stirring time is 3-5 hours, the temperature is controlled at 70-90℃ during stirring, the drying time in step S1 is 5-7 hours, and the drying temperature in step S1 is 110-130℃.

[0010] Furthermore, in step S2, the solid-liquid ratio of the modified carrier to the phosphate-silicotungstic acid mixed solution is 1:3, the vacuum impregnation time is 5-7 hours, the drying time in step S2 is 2-4 hours, the drying temperature in step S2 is 110-130℃, and after drying, it is calcined twice. The first calcination time is 1-3 hours, the first calcination temperature is 190-210℃, and the second calcination time is 3-4 hours, the second calcination temperature is 340-360℃.

[0011] Furthermore, the preheated nonene and hydrogen sulfide feedstocks are statically mixed. The reaction temperature of nonene and hydrogen sulfide is 60-90℃, the reaction pressure is 0.5-1.5MPa, and the total molar ratio of nonene to hydrogen sulfide is 1:3-5.

[0012] Furthermore, the reaction products after the reaction of nonene and hydrogen sulfide feedstocks are post-processed. The reaction products are separated into gas and liquid phases by a gas-liquid separator. The gas phase is freeze-dried and desulfurized to recover recovered hydrogen sulfide. The liquid phase is split at a mass ratio of 10:1. The reflux material is filtered and reused. The stored material is sent to a vacuum distillation column. The light components at the top of the vacuum distillation column are recovered to obtain recovered nonene. Tert-nonyl mercaptan is collected at the bottom of the vacuum distillation column.

[0013] In addition, the present invention also provides a tert-nonylthiol, which is prepared by the above-described tert-nonylthiol synthesis method.

[0014] Beneficial effects: 1. The present invention provides a method for synthesizing tert-nonylthiol by precisely preheating nonene and hydrogen chloride separately and in conjunction with a static mixing process, thereby achieving efficient and uniform mixing of gaseous and liquid raw materials. Combined with the high directional selectivity of the catalyst, the generation of by-products is effectively reduced, and the product purity reaches more than 99.0%, meeting the demand of high-end industrial applications for high-purity tert-nonylthiol.

[0015] 2. The reaction conditions of this invention are mild, the conversion rate of nonene is increased to over 93%, the utilization rate of hydrogen sulfide reaches over 90%, the raw material conversion is more complete, and resource waste is reduced.

[0016] 3. The modification of the catalyst support and the synergistic design of the co-catalyst significantly extend the catalyst lifetime.

[0017] 4. Unreacted gases are recovered, compressed, and recycled, allowing most of the hydrogen sulfide to be recycled, reducing the consumption and leakage risk of hydrogen sulfide. At the same time, the three wastes generated by the process can be treated harmlessly, and the solid waste (waste catalyst) is incinerated at high temperature and then landfilled harmlessly, with no waste liquid generated, achieving clean production control and efficient recycling of resources in the industrial process. Attached Figure Description

[0018] Figure 1 This is a flowchart of the method for synthesizing tert-nonylthiol according to the present invention; Figure 2 This is an image of the tert-nonylthiol prepared in Example 1 of this invention; Figure 3 This is the gas chromatographic spectrum of the crude tert-nonylthiol prepared in Example 1; Figure 4 The gas chromatogram of the crude tert-nonylthiol prepared in Comparative Example 2 is shown. Figure 5 This is the gas chromatographic spectrum of the crude tert-nonylthiol prepared in Comparative Example 1. Detailed Implementation

[0019] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Based on the embodiments in this application, other similar embodiments obtained by those skilled in the art without creative effort should all fall within the scope of protection of this application.

[0020] According to embodiments of the present invention, a method for synthesizing tert-nonylthiol is provided, comprising the following steps: nonene and hydrogen sulfide feedstocks are preheated separately; the preheated nonene and hydrogen sulfide feedstocks are mixed; and the mixture is reacted under the action of a catalyst to obtain tert-nonylthiol. The preheating temperature of nonene is 40-50°C, and the preheating temperature of hydrogen sulfide is 50-60°C. The reaction conditions of this invention are mild, and nonene and hydrogen chloride are precisely preheated separately. The product prepared by this method has a purity of over 99.0%, meeting the requirements of high-end industrial applications for high-purity tert-nonylthiol.

[0021] Specifically, the method for producing tert-nonylthiol provided by this invention is as follows: Figure 1 As shown.

[0022] Example 1 (1) Raw material preparation: 1) Fresh nonene: purity ≥ 99.0%; 2) Fresh hydrogen sulfide: purity 99.9%, sulfur content <5ppm; 3) Nonene recovery: After distillation recovery, the purity is ≥99.0%; 4) Recovered hydrogen sulfide: purity 99.9%, sulfur content <5ppm.

[0023] 5) Catalyst preparation: Support modification: 100g of silica gel balls with a particle size of 2-3mm were immersed in 500mL of 5% 3-aminopropyltriethoxysilane ethanol solution, stirred in a constant temperature water bath at 80℃ for 4h, and dried in a forced air at 120℃ for 6h to obtain a modified support; the modified support was placed in a phosphate-silicotungstic acid mixed solution (the mass ratio of phosphate to silicotungstic acid was 20:1, and the solid-liquid ratio of the modified support to the mixed solution was 1:3), and impregnated under a vacuum of -0.08MPa for 6h, with stirring for 10min every 2h during the process; then dried at 120℃ for 3h, calcined at 200℃ for 2h, calcined at 350℃ for 4h, and naturally cooled to room temperature to obtain the catalyst.

[0024] (2) Operating steps: Pretreatment stage: Fresh nonene and recycled nonene are fed into the nonene mixing tank at a mass ratio of 8:2 and filtered through a 0.05μm filter before entering the preheating stage; fresh hydrogen sulfide and recycled hydrogen sulfide are treated by a zinc oxide desulfurization tower and then fed into the hydrogen sulfide mixing tank at a volume ratio of 5:2 and filtered through a precision filter before entering the compressor. Preheating and mixing stage: Nonene mixture is heated to 45°C by a tube preheater, hydrogen sulfide mixture is heated to 55°C by a coil preheater, and the two materials are simultaneously fed into the static mixer at a mixing pressure of 2.0 MPa and a mixing time of 1.8 s. Reaction stage: The mixed raw materials are fed into a fixed-bed reactor, and the reaction temperature is controlled at 80℃, the pressure at 1MPa, and the space velocity at 1h. -1 The catalyst loading ratio to reactor volume ratio is 1:6, and the total molar ratio of nonene to hydrogen sulfide is 1:4, to obtain the reaction product; Recycling stage: The reaction products are separated by a vertical gas-liquid separator. The gas phase is freeze-dried at -10℃, finely filtered and desulfurized using a 0.01μm polytetrafluoroethylene filter element, and then recovered to the hydrogen sulfide recovery storage tank. The crude liquid phase is split at a ratio of 10:1. The reflux is filtered through a 0.05μm ceramic membrane (operating pressure 0.4MPa) and then reused. The stored material is sent to a distillation column. The light components at the top of the column are recovered to the nonene recovery storage tank. The tail gas is treated by a first-stage 15% alkali wash and a second-stage 30% alkali wash + activated carbon adsorption. Tert-nonyl mercaptan is collected at the bottom of the vacuum distillation column.

[0025] Example 2 (1) Raw material preparation: 1) Fresh nonene: purity ≥ 99.0%; 2) Fresh hydrogen sulfide: purity 99.9%, sulfur content <5ppm; 3) Nonene recovery: After distillation recovery, the purity is ≥99.0%; 4) Recovered hydrogen sulfide: purity 99.9%, sulfur content <5ppm.

[0026] 5) Catalyst preparation: Support modification: 100g of silica gel balls with a particle size of 2-3mm were immersed in 500mL of 5% 3-aminopropyltriethoxysilane ethanol solution, stirred in a constant temperature water bath at 80℃ for 4h, and dried in a forced air at 120℃ for 6h to obtain a modified support; the modified support was placed in a phosphate-silicotungstic acid mixed solution (phosphate to silicotungstic acid mass ratio 20:1, solid-liquid ratio 1:3), and impregnated under a vacuum of -0.08MPa for 6h, with stirring for 10min every 2h during the process; then dried at 120℃ for 3h, calcined at 200℃ for 2h, calcined at 350℃ for 4h, and naturally cooled to room temperature to obtain the catalyst.

[0027] (2) Operating steps: Pretreatment stage: Fresh nonene and recycled nonene are fed into the nonene mixing tank at a mass ratio of 8:2 and filtered through a 0.05μm filter before entering the preheating stage; fresh hydrogen sulfide and recycled hydrogen sulfide are treated by a zinc oxide desulfurization tower and then fed into the hydrogen sulfide mixing tank at a volume ratio of 5:2 and filtered through a precision filter before entering the compressor. Preheating and mixing stage: Nonene mixture is heated to 50°C by a tube preheater, hydrogen sulfide mixture is heated to 60°C by a coil preheater, and the two materials are simultaneously fed into the static mixer at a mixing pressure of 2.0 MPa and a mixing time of 1.8 s. Reaction stage: The mixed raw materials are fed into a fixed-bed reactor, and the reaction temperature is controlled at 80℃, the pressure at 1MPa, and the space velocity at 1h. -1 The catalyst loading ratio to reactor volume ratio is 1:6, and the total molar ratio of nonene to hydrogen sulfide is 1:4, to obtain the reaction product; Recycling stage: The reaction products are separated by a vertical gas-liquid separator. The gas phase is freeze-dried at -10℃, finely filtered and desulfurized using a 0.01μm polytetrafluoroethylene filter element, and then recovered to the hydrogen sulfide recovery storage tank. The crude liquid phase is split at a ratio of 10:1. The reflux is filtered through a 0.05μm ceramic membrane (operating pressure 0.4MPa) and then reused. The stored material is sent to a distillation column. The light components at the top of the column are recovered to the nonene recovery storage tank. The tail gas is treated by a first-stage 15% alkali wash and a second-stage 30% alkali wash + activated carbon adsorption. Tert-nonyl mercaptan is collected at the bottom of the vacuum distillation column.

[0028] Example 3 (1) Raw material preparation: 1) Fresh nonene: purity ≥ 99.0%; 2) Fresh hydrogen sulfide: purity 99.9%, sulfur content <5ppm; 3) Nonene recovery: After distillation recovery, the purity is ≥99.0%; 4) Recovered hydrogen sulfide: purity 99.9%, sulfur content <5ppm.

[0029] 5) Catalyst preparation: Support modification: 100g of silica gel balls with a particle size of 2-3mm were immersed in 500mL of 5% 3-aminopropyltriethoxysilane ethanol solution, stirred in a constant temperature water bath at 80℃ for 4h, and dried in a forced air at 120℃ for 6h to obtain a modified support; the modified support was placed in a phosphate-silicotungstic acid mixed solution (phosphate to silicotungstic acid mass ratio 20:1, solid-liquid ratio 1:3), and impregnated under a vacuum of -0.08MPa for 6h, with stirring for 10min every 2h during the process; then dried at 120℃ for 3h, calcined at 200℃ for 2h, calcined at 350℃ for 4h, and naturally cooled to room temperature to obtain the catalyst.

[0030] (2) Operating steps: Pretreatment stage: Fresh nonene and recycled nonene are fed into the nonene mixing tank at a mass ratio of 8:2 and filtered through a 0.05μm filter before entering the preheating stage; fresh hydrogen sulfide and recycled hydrogen sulfide are treated by a zinc oxide desulfurization tower and then fed into the hydrogen sulfide mixing tank at a volume ratio of 5:2 and filtered through a precision filter before entering the compressor. Preheating and mixing stage: Nonene mixture is heated to 40°C by a tube preheater, hydrogen sulfide mixture is heated to 50°C by a coil preheater, and the two materials are simultaneously fed into the static mixer at a mixing pressure of 2.0 MPa and a mixing time of 1.8 s. Reaction stage: The mixed raw materials are fed into a fixed-bed reactor, and the reaction temperature is controlled at 80℃, the pressure at 1MPa, and the space velocity at 1h. -1 The catalyst loading ratio to reactor volume ratio is 1:6, and the total molar ratio of nonene to hydrogen sulfide is 1:4, to obtain the reaction product; Recycling stage: The reaction products are separated by a vertical gas-liquid separator. The gas phase is freeze-dried at -10℃, finely filtered and desulfurized using a 0.01μm polytetrafluoroethylene filter element, and then recovered to the hydrogen sulfide recovery storage tank. The crude liquid phase is split at a ratio of 10:1. The reflux is filtered through a 0.05μm ceramic membrane (operating pressure 0.4MPa) and then reused. The stored material is sent to a distillation column. The light components at the top of the column are recovered to the nonene recovery storage tank. The tail gas is treated by a first-stage 15% alkali wash and a second-stage 30% alkali wash + activated carbon adsorption. Tert-nonyl mercaptan is collected at the bottom of the vacuum distillation column.

[0031] Example 4 (1) Raw material preparation: 1) Fresh nonene: purity ≥ 99.0%; 2) Fresh hydrogen sulfide: purity 99.9%, sulfur content <5ppm; 3) Nonene recovery: After distillation recovery, the purity is ≥99.0%; 4) Recovered hydrogen sulfide: purity 99.9%, sulfur content <5ppm.

[0032] 5) Catalyst preparation: Support modification: 100g of silica gel balls with a particle size of 2-3mm were immersed in 500mL of 4% 3-aminopropyltriethoxysilane ethanol solution, stirred in a constant temperature water bath at 90℃ for 3h, and dried in a forced air at 110℃ for 7h to obtain a modified support; the modified support was placed in a phosphate-silicotungstic acid mixed solution (phosphate to silicotungstic acid mass ratio 20:1, solid-liquid ratio 1:3), and impregnated under a vacuum of -0.08MPa for 7h, with stirring for 10min every 2h; then dried at 130℃ for 4h, calcined at 210℃ for 1h, calcined at 360℃ for 3h, and naturally cooled to room temperature to obtain the catalyst.

[0033] (2) Operating steps: Pretreatment stage: Fresh nonene and recycled nonene are fed into the nonene mixing tank at a mass ratio of 8:2 and filtered through a 0.05μm filter before entering the preheating stage; fresh hydrogen sulfide and recycled hydrogen sulfide are treated by a zinc oxide desulfurization tower and then fed into the hydrogen sulfide mixing tank at a volume ratio of 5:2 and filtered through a precision filter before entering the compressor. Preheating and mixing stage: Nonene mixture is heated to 45°C by a tube preheater, hydrogen sulfide mixture is heated to 55°C by a coil preheater, and the two materials are simultaneously fed into the static mixer at a mixing pressure of 2.0 MPa and a mixing time of 1.8 s. Reaction stage: The mixed raw materials are fed into a fixed-bed reactor, and the reaction temperature is controlled at 80℃, the pressure at 1MPa, and the space velocity at 1h. -1 The catalyst loading ratio to reactor volume ratio is 1:6, and the total molar ratio of nonene to hydrogen sulfide is 1:4, to obtain the reaction product; Recycling stage: The reaction products are separated by a vertical gas-liquid separator. The gas phase is freeze-dried at -10℃, finely filtered and desulfurized using a 0.01μm polytetrafluoroethylene filter element, and then recovered to the hydrogen sulfide recovery storage tank. The crude liquid phase is split at a ratio of 10:1. The reflux is filtered through a 0.05μm ceramic membrane (operating pressure 0.4MPa) and then reused. The stored material is sent to a distillation column. The light components at the top of the column are recovered to the nonene recovery storage tank. The tail gas is treated by a first-stage 15% alkali wash and a second-stage 30% alkali wash + activated carbon adsorption. Tert-nonyl mercaptan is collected at the bottom of the vacuum distillation column.

[0034] Example 5 (1) Raw material preparation: 1) Fresh nonene: purity ≥ 99.0%; 2) Fresh hydrogen sulfide: purity 99.9%, sulfur content <5ppm; 3) Nonene recovery: After distillation recovery, the purity is ≥99.0%; 4) Recovered hydrogen sulfide: purity 99.9%, sulfur content <5ppm.

[0035] 5) Catalyst preparation: Support modification: 100g of silica gel balls with a particle size of 2-3mm were immersed in 500mL of 6% 3-aminopropyltriethoxysilane ethanol solution, stirred in a constant temperature water bath at 70℃ for 5h, and dried in a forced air at 130℃ for 5h to obtain a modified support; the modified support was placed in a phosphate-silicotungstic acid mixed solution (phosphate to silicotungstic acid mass ratio 20:1, solid-liquid ratio 1:3), and impregnated under a vacuum of -0.08MPa for 5h, with stirring for 10min every 2h; then dried at 110℃ for 2h, calcined at 190℃ for 3h, calcined at 340℃ for 4h, and naturally cooled to room temperature to obtain the catalyst.

[0036] (2) Operating steps: Pretreatment stage: Fresh nonene and recycled nonene are fed into the nonene mixing tank at a mass ratio of 8:2 and filtered through a 0.05μm filter before entering the preheating stage; fresh hydrogen sulfide and recycled hydrogen sulfide are treated by a zinc oxide desulfurization tower and then fed into the hydrogen sulfide mixing tank at a volume ratio of 5:2 and filtered through a precision filter before entering the compressor. Preheating and mixing stage: Nonene mixture is heated to 45°C by a tube preheater, hydrogen sulfide mixture is heated to 55°C by a coil preheater, and the two materials are simultaneously fed into the static mixer at a mixing pressure of 2.0 MPa and a mixing time of 1.8 s. Reaction stage: The mixed raw materials are fed into a fixed-bed reactor, and the reaction temperature is controlled at 80℃, the pressure at 1MPa, and the space velocity at 1h. -1 The catalyst loading ratio to reactor volume ratio is 1:6, and the total molar ratio of nonene to hydrogen sulfide is 1:4, to obtain the reaction product; Recycling stage: The reaction products are separated by a vertical gas-liquid separator. The gas phase is freeze-dried at -10℃, finely filtered and desulfurized using a 0.01μm polytetrafluoroethylene filter element, and then recovered to the hydrogen sulfide recovery storage tank. The crude liquid phase is split at a ratio of 10:1. The reflux is filtered through a 0.05μm ceramic membrane (operating pressure 0.4MPa) and then reused. The stored material is sent to a distillation column. The light components at the top of the column are recovered to the nonene recovery storage tank. The tail gas is treated by a first-stage 15% alkali wash and a second-stage 30% alkali wash + activated carbon adsorption. Tert-nonyl mercaptan is collected at the bottom of the vacuum distillation column.

[0037] Example 6 (1) Raw material preparation: 1) Fresh nonene: purity ≥ 99.0%; 2) Fresh hydrogen sulfide: purity 99.9%, sulfur content <5ppm; 3) Nonene recovery: After distillation recovery, the purity is ≥99.0%; 4) Recovered hydrogen sulfide: purity 99.9%, sulfur content <5ppm.

[0038] 5) Catalyst preparation: Support modification: 100g of silica gel balls with a particle size of 2-3mm were immersed in 500mL of 5% 3-aminopropyltriethoxysilane ethanol solution, stirred in a constant temperature water bath at 80℃ for 4h, and dried in a forced air at 120℃ for 6h to obtain a modified support; the modified support was placed in a phosphate-silicotungstic acid mixed solution (phosphate to silicotungstic acid mass ratio 20:1, solid-liquid ratio 1:3), and impregnated under a vacuum of -0.08MPa for 6h, with stirring for 10min every 2h during the process; then dried at 120℃ for 3h, calcined at 200℃ for 2h, calcined at 350℃ for 4h, and naturally cooled to room temperature to obtain the catalyst.

[0039] (2) Operating steps: Pretreatment stage: Fresh nonene and recycled nonene are fed into the nonene mixing tank at a ratio of 8:3 (mass ratio), filtered through a 0.05μm filter, and then enter the preheating stage; fresh hydrogen sulfide and recycled hydrogen sulfide are treated by a zinc oxide desulfurization tower, fed into the hydrogen sulfide mixing tank at a ratio of 5:1 (volume ratio), filtered through a precision filter, and then enter the compressor. Preheating and mixing stage: Nonene mixture is heated to 45°C by a tube preheater, hydrogen sulfide mixture is heated to 55°C by a coil preheater, and the two materials are simultaneously fed into the static mixer at a mixing pressure of 2.0 MPa and a mixing time of 1.8 s. Reaction stage: The mixed raw materials are fed into a fixed-bed reactor, and the reaction temperature is controlled at 90℃, the pressure at 0.5MPa, and the space velocity at 1h. -1 The catalyst loading ratio to reactor volume ratio is 1:6, and the total molar ratio of nonene to hydrogen sulfide is 1:5, to obtain the reaction product; Recycling stage: The reaction products are separated by a vertical gas-liquid separator. The gas phase is freeze-dried at -10℃, finely filtered and desulfurized using a 0.01μm polytetrafluoroethylene filter element, and then recovered to the hydrogen sulfide recovery storage tank. The crude liquid phase is split at a ratio of 10:1. The reflux is filtered through a 0.05μm ceramic membrane (operating pressure 0.4MPa) and then reused. The stored material is sent to a distillation column. The light components at the top of the column are recovered to the nonene recovery storage tank. The tail gas is treated by a first-stage 15% alkali wash and a second-stage 30% alkali wash + activated carbon adsorption. Tert-nonyl mercaptan is collected at the bottom of the vacuum distillation column.

[0040] Example 7 (1) Raw material preparation: 1) Fresh nonene: purity ≥ 99.0%; 2) Fresh hydrogen sulfide: purity 99.9%, sulfur content <5ppm; 3) Nonene recovery: After distillation recovery, the purity is ≥99.0%; 4) Recovered hydrogen sulfide: purity 99.9%, sulfur content <5ppm.

[0041] 5) Catalyst preparation: Support modification: 100g of silica gel balls with a particle size of 2-3mm were immersed in 500mL of 5% 3-aminopropyltriethoxysilane ethanol solution, stirred in a constant temperature water bath at 80℃ for 4h, and dried in a forced air at 120℃ for 6h to obtain a modified support; the modified support was placed in a phosphate-silicotungstic acid mixed solution (phosphate to silicotungstic acid mass ratio 20:1, solid-liquid ratio 1:3), and impregnated under a vacuum of -0.08MPa for 6h, with stirring for 10min every 2h during the process; then dried at 120℃ for 3h, calcined at 200℃ for 2h, calcined at 350℃ for 4h, and naturally cooled to room temperature to obtain the catalyst.

[0042] (2) Operating steps: Pretreatment stage: Fresh nonene and recycled nonene are fed into the nonene mixing tank at a ratio of 8:1 (mass ratio), filtered through a 0.05μm filter, and then enter the preheating stage; fresh hydrogen sulfide and recycled hydrogen sulfide are treated by a zinc oxide desulfurization tower, fed into the hydrogen sulfide mixing tank at a ratio of 5:1 (volume ratio), filtered through a precision filter, and then enter the compressor. Preheating and mixing stage: Nonene mixture is heated to 45°C by a tube preheater, hydrogen sulfide mixture is heated to 55°C by a coil preheater, and the two materials are simultaneously fed into the static mixer at a mixing pressure of 2.0 MPa and a mixing time of 1.8 s. Reaction stage: The mixed raw materials are fed into a fixed-bed reactor, and the reaction temperature is controlled at 60℃, the pressure at 1.5MPa, and the space velocity at 1h. -1 The catalyst loading ratio to reactor volume ratio is 1:6, and the total molar ratio of nonene to hydrogen sulfide is 1:3, to obtain the reaction product; Recycling stage: The reaction products are separated by a vertical gas-liquid separator. The gas phase is freeze-dried at -10℃, finely filtered and desulfurized using a 0.01μm polytetrafluoroethylene filter element, and then recovered to the hydrogen sulfide recovery storage tank. The crude liquid phase is split at a ratio of 10:1. The reflux is filtered through a 0.05μm ceramic membrane (operating pressure 0.4MPa) and then reused. The stored material is sent to a distillation column. The light components at the top of the column are recovered to the nonene recovery storage tank. The tail gas is treated by a first-stage 15% alkali wash and a second-stage 30% alkali wash + activated carbon adsorption. Tert-nonyl mercaptan is collected at the bottom of the vacuum distillation column.

[0043] Comparative Example 1 The nonene mixture and hydrogen sulfide mixture were both kept at room temperature and directly introduced into the static mixer, while the rest of the process was the same as in Example 1.

[0044] Comparative Example 2 The catalyst did not use silicotungstic acid or a modified support; instead, the same amount of phosphoric acid was directly loaded onto original spherical silica gel of the same size, and dried and calcined under the same conditions. The other parts were the same as in Example 1.

[0045] Comparative Example 3 The gas phase separated after the reaction (containing a large amount of unreacted H2S) is directly sent to the alkali washing tower for treatment and is not recovered. After distillation, the light component at the top of the liquid phase (unreacted nonene) is discharged from the system as a byproduct and is not refluxed. Fresh feedstock is used throughout, and the molar ratio of nonene to hydrogen sulfide remains 1:4. Other aspects are the same as in Example 1.

[0046] Relevant tests were performed on Examples 1-7 and Comparative Examples 1-3: Quantitative analysis was performed using gas chromatography, and the relative content of each component was calculated using the area normalization method.

[0047] The tert-nonylthiol prepared in Example 1 of this invention is as follows: Figure 2 As shown. The gas chromatographic detection spectrum of the crude tert-nonylthiol prepared in Example 1 is shown below. Figure 3 As shown, the gas chromatogram of the crude tert-nonylthiol prepared in Comparative Example 2 is as follows. Figure 4 As shown, the gas chromatogram of the crude tert-nonylthiol prepared in Comparative Example 1 is as follows. Figure 5 As shown.

[0048] 2. Run continuously for 1000 hours, monitor the pressure difference and hot spot temperature of the reactor bed, and observe the catalyst morphology and whether the catalyst particles are pulverized after the operation is completed.

[0049] The specific test results are shown in Table 1.

[0050] Table 1 Performance test results of Examples 1-7 and Comparative Examples 1-3 As shown in Table 1 above, the dual-temperature zone preheating in this application significantly improves both conversion rate and selectivity compared to room temperature feed in Comparative Example 1. Preheating ensures ideal mixing of H2S in a gaseous state with liquid nonene, optimizing gas-liquid mass transfer and making the reaction more efficient and selective on the catalyst surface. Furthermore, the catalyst used in this application is significantly superior to the catalyst in Comparative Example 2 in terms of activity, selectivity, and long-term stability; the catalyst in Comparative Example 2 rapidly deactivated and pulverized. Examples 6 and 7 adjusted the recovery ratio and reaction conditions, further optimizing feedstock consumption while maintaining high performance.

[0051] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for synthesizing tert-nonylthiol, characterized in that, The synthesis steps are as follows: Nonene and hydrogen sulfide raw materials are preheated separately, and the preheated nonene and hydrogen sulfide raw materials are mixed. After mixing, the mixture is reacted under the action of a catalyst to obtain tert-nonyl mercaptan. The preheating temperature of nonene is 40-50℃, and the preheating temperature of hydrogen sulfide is 50-60℃.

2. The method for synthesizing tert-nonylthiol according to claim 1, characterized in that, After the nonene and hydrogen sulfide react, the unreacted nonene and hydrogen sulfide are recovered to obtain recovered nonene and recovered hydrogen sulfide. The recovered nonene is mixed with the nonene raw material in a mass ratio of 1-3:8 and then preheated to participate in the reaction of nonene and hydrogen sulfide. The recovered hydrogen sulfide is mixed with the hydrogen sulfide raw material in a mass ratio of 1-2:5 and then preheated to participate in the reaction of nonene and hydrogen sulfide.

3. The method for synthesizing tert-nonylthiol according to claim 1, characterized in that, The catalyst uses phosphoric acid as the active component and silicotungstic acid as the co-catalyst, with spherical silica gel modified by 3-aminopropyltriethoxysilane as the support.

4. The method for synthesizing tert-nonylthiol according to claim 3, characterized in that, The mass ratio of phosphoric acid to silicotungstic acid is 20:

1.

5. The method for synthesizing tert-nonylthiol according to claim 3, characterized in that, The catalyst preparation steps include: S1: Support modification: Take spherical silica gel with a particle size of 2-3 mm, immerse it in 3-aminopropyltriethoxysilane ethanol solution, stir and dry to obtain modified support; S2: Impregnation and calcination: The modified support is placed in a phosphate-silicotungstic acid mixed solution, vacuum impregnated, dried, and calcined to obtain the catalyst.

6. The method for synthesizing tert-nonylthiol according to claim 5, characterized in that, In step S1, the specific surface area of ​​the spherical silica gel is ≥450m² / g, the concentration of the 3-aminopropyltriethoxysilane ethanol solution is 4%-6%, the stirring time is 3-5 hours, the temperature is controlled at 70-90℃ during stirring, the drying time in step S1 is 5-7 hours, and the drying temperature in step S1 is 110-130℃.

7. The method for synthesizing tert-nonylthiol according to claim 5, characterized in that, In step S2, the solid-liquid ratio of the modified carrier to the phosphate-silicotungstic acid mixed solution is 1:3, the vacuum impregnation time is 5-7 hours, the drying time in step S2 is 2-4 hours, the drying temperature in step S2 is 110-130℃, and after drying, it is calcined twice. The first calcination time is 1-3 hours, the first calcination temperature is 190-210℃, and the second calcination time is 3-4 hours, the second calcination temperature is 340-360℃.

8. The method for synthesizing tert-nonylthiol according to claim 1, characterized in that, The preheated nonene and hydrogen sulfide feedstocks are statically mixed. The reaction temperature of nonene and hydrogen sulfide is 60-90℃, the reaction pressure is 0.5-1.5MPa, and the total molar ratio of nonene to hydrogen sulfide is 1:3-5.

9. The method for synthesizing tert-nonylthiol according to claim 1, characterized in that, The reaction products from the reaction of nonene and hydrogen sulfide feedstocks undergo post-processing. The reaction products are separated into gas and liquid phases by a gas-liquid separator. The gas phase is freeze-dried and desulfurized to recover recovered hydrogen sulfide. The liquid phase is split at a mass ratio of 10:

1. The reflux material is filtered and reused. The stored material is sent to a vacuum distillation column. The light components at the top of the vacuum distillation column are recovered to obtain recovered nonene. Tert-nonyl mercaptan is collected at the bottom of the vacuum distillation column.

10. A tert-nonylthiol, characterized in that, It was prepared by the method of tert-nonylthiol synthesis according to any one of claims 1-9.

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