A catalyst for synthesizing a mercaptan compound, a preparation method thereof, and an application thereof

Abstract

The application provides a catalyst for synthesizing a mercaptan compound, comprising a biomass nitrogen-containing carrier and a transition metal oxide loaded on the biomass nitrogen-containing carrier; the biomass nitrogen-containing carrier comprises chitosan; and the transition metal element in the transition metal oxide comprises a VIB group element and a VIII group element. The chitosan is used as the carrier, the chitosan has a unique chelating capacity for metals, and due to the presence of N atoms, the chitosan can better improve the electronic conductivity, charge transfer at the interface and stability of the transition metal, thereby improving the agglomeration of metal particles, making the metal particles more uniformly dispersed on the surface of the carrier, and improving the activity of the catalyst, so that the conversion rate of an olefin compound and the selectivity of the mercaptan compound are improved, and the yield of the mercaptan compound is further improved. The application also provides a preparation method and application of the catalyst for synthesizing the mercaptan compound.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of fine chemical synthesis, and particularly relates to a catalyst for synthesizing mercaptan compounds, a preparation method and application thereof. BACKGROUND

[0002] Mercaptan compounds are very important chemical raw materials and reaction intermediates, and are widely used in the industrial production of various fine chemicals. For example, methyl mercaptan is used as an important organic intermediate for synthesizing fenthion, benzoximate and methionine; ethyl mercaptan is often used in the synthesis of the pesticide fenclorim, the synthesis of sulfonamides in the pharmaceutical field, and as a chain transfer agent for the synthesis of butyl acrylate and styrene copolymer; tert-butyl mercaptan is used as a rubber vulcanization accelerator and a partial drug intermediate; n-dodecyl mercaptan is used as a rubber polymerization regulator and a surfactant, and the like. In particular, low-carbon mercaptans have attracted more and more attention from researchers in recent years. Among low-carbon mercaptans, ethyl mercaptan plays a crucial role in industrial applications.

[0003] There are various preparation processes for ethyl mercaptan, mainly including a thiourea method, a chloroethane method, an ethanol method and an ethylene sulfuration method. The ethylene sulfuration method for synthesizing ethyl mercaptan, as an atom economy route, has attracted important attention from researchers. China has abundant low-carbon olefin resources, but the utilization rate of low-carbon olefin resources is relatively low. At the same time, hydrogen sulfide, as a kind of pollutant that poses a great threat to the atmospheric environment, is mainly produced in processes such as petroleum refining, natural gas desulfurization and coking metallurgy. Current methods for treating hydrogen sulfide waste gas are mostly to recover sulfur, which has low economic benefits and sulfur products still cause harm to the environment. Using low-cost and readily available low-carbon olefins (ethylene, propylene, butene or its isomers) and hydrogen sulfide resources to prepare mercaptans, which have high added value, can achieve both economic and environmental benefits.

[0004] In the process of synthesizing ethanethiol by ethylene sulfuration, the key technology is the research of high-efficiency catalyst. Since the 1950s, foreign countries have begun to research catalysts for the synthesis of mercaptans by olefin sulfuration, and have developed a variety of catalysts with high activity, long service life and high selectivity. Among these catalysts, supported transition metal oxide or sulfide catalysts are widely used in the addition reaction of olefins and hydrogen sulfide. In the existing technology, many catalysts have been proposed, specifically, supported phosphoric acid (US2950324), silicon dioxide containing a small amount of alumina (US2951875), synthetic zeolite (US4102931 and US5453544) or ion exchange resin (US4102931), wherein the ion exchange resin as a catalyst has attracted people's attention in terms of olefin conversion rate and mercaptan selectivity, but these resins have poor thermal stability and begin to degrade at 100°C and completely decompose at 140°C, so in the high-temperature olefin sulfuration reaction, such catalysts cannot well play a catalytic role and their application is limited.

[0005] Patent US3036133 describes a method for preparing ethanethiol and ethyl sulfide by the addition of H2S and ethylene in the presence of a catalyst, the catalyst involved contains silica or alumina activated with a heteropoly acid, or one of the salts of alkali metal or alkaline earth metal, but when this catalyst is used for other olefins in addition to ethylene, such as propylene or butene, the conversion rate of the olefin compound is very low, and the selectivity and yield of mercaptans are not high enough. SUMMARY

[0006] The present application provides a catalyst for synthesizing mercaptan compounds, a preparation method thereof and an application, the catalyst in the present application has high activity and high yield of mercaptan compounds.

[0007] The present application provides a catalyst for synthesizing mercaptan compounds, which comprises a biomass nitrogen-containing carrier and a transition metal oxide supported on the biomass nitrogen-containing carrier.

[0008] The biomass nitrogen-containing carrier comprises chitosan; and the transition metal element in the transition metal oxide comprises one or more of elements in Group VIB and elements in Group VIII.

[0009] Preferably, the elements in Group VIII include one or more of cobalt, nickel, ruthenium, palladium and platinum; and the elements in Group VIB include one or more of chromium, molybdenum and tungsten.

[0010] Preferably, the loading amount of the elements in Group VIB is 3-25% and the loading amount of the elements in Group VIII is 3-20% based on the mass of the transition metal oxide.

[0011] The present application provides a preparation method of the catalyst for synthesizing mercaptan compounds as described above, which comprises the following steps:

[0012] A) immersing the biomass nitrogen-containing carrier into a transition metal salt solution to perform impregnation;

[0013] B) drying the impregnated carrier to obtain a catalyst intermediate;

[0014] C) calcining the catalyst intermediate under a protective atmosphere to obtain a catalyst for synthesizing mercaptan compounds.

[0015] Preferably, the concentration of the transition metal salt solution is 5.0% to 70.0%; and the impregnation time is 6 to 12 hours.

[0016] Preferably, the drying temperature in step B) is 50 to 120°C, and the drying time is 6 to 10 hours.

[0017] Preferably, the calcining temperature in step C) is 400 to 600°C, and the calcining time is 3 to 8 hours.

[0018] The application provides an application of the catalyst for synthesizing mercaptan compounds as described above in preparing mercaptan compounds.

[0019] The catalyst for synthesizing mercaptan compounds is sulfided, and is used to catalyze the reaction of hydrogen sulfide and olefins to prepare mercaptan compounds.

[0020] Preferably, the catalyst is sulfided by using H2S, the sulfiding temperature is 50 to 300°C, the sulfiding pressure is 0 to 2 MPa, and the sulfiding time is 1 to 6 hours.

[0021] Preferably, the catalytic reaction temperature is 80 to 300°C, the catalytic reaction pressure is 0.2 to 5 MPa, the catalytic reaction space velocity is 100 to 600 h-1, and the catalytic reaction time is 1 to 10 hours. -1 .

[0022] The application provides a catalyst for synthesizing mercaptan compounds, comprising a biomass nitrogen-containing carrier and a transition metal oxide loaded on the biomass nitrogen-containing carrier; the biomass nitrogen-containing carrier comprises chitosan; and the transition metal element in the transition metal oxide comprises a VIB group element and a VIII group element. The application uses chitosan as a carrier, which has a unique chelating capacity for metals due to the large number of amino groups and hydroxyl groups in the structure, and can more easily prepare a supported metal catalyst with good properties; in addition, high-temperature calcination in a tube furnace is more conducive to preparing a nitrogen-doped carbon-based material with a high specific surface area and good mechanical properties, because the presence of N atoms can better improve the electronic conductivity, charge transfer at the interface and the stability of the transition metal, thereby improving the agglomeration of metal particles, making the metal particles more uniformly dispersed on the surface of the carrier, and improving the activity of the catalyst, thereby improving the conversion rate of olefin compounds and the selectivity of mercaptan compounds, and further improving the yield of mercaptan compounds. In addition, the basic carrier can effectively inhibit ethylene self-polymerization and carbonization, effectively improve the service life of the catalyst, and has high economic and social benefits. DETAILED DESCRIPTION

[0023] The application provides a catalyst for synthesizing mercaptan compounds, comprising a biomass nitrogen-containing carrier and a transition metal oxide loaded on the biomass nitrogen-containing carrier;

[0024] The biomass nitrogen-containing carrier comprises chitosan; and the transition metal element in the transition metal oxide comprises a VIB group element and a VIII group element.

[0025] In the application, the VIII group element comprises one or more of cobalt, nickel, ruthenium, palladium and platinum, and is more preferably cobalt and / or nickel; and the VIB group element comprises one or more of chromium, molybdenum and tungsten, and is more preferably molybdenum.

[0026] In the catalyst in the application, the loading amount of the VIB group element is preferably 3-25% by mass of the transition metal oxide, and is more preferably 5-20%, such as 3%, 5%, 10%, 15%, 20% or 25%, and is preferably a range value with any of the above values as the upper limit or the lower limit; and the loading amount of the VIII group element is preferably 3-20%, and is more preferably 5-15%, such as 3%, 5%, 10% or 15%, and is preferably a range value with any of the above values as the upper limit or the lower limit. If the loading amount of the transition metal element is too low, the catalytic activity of the catalyst is low; and if the loading amount is too high, the activity of the catalyst is too high, which can easily cause a side reaction and reduce the performance of the catalyst.

[0027] The application further provides a preparation method of the catalyst for synthesizing mercaptan compounds.

[0028] A) immersing the biomass nitrogen-containing carrier into a transition metal salt solution to perform impregnation;

[0029] B) drying the impregnated carrier to obtain a catalyst intermediate;

[0030] C) calcining the catalyst intermediate under a protective atmosphere to obtain a catalyst for synthesizing mercaptan compounds.

[0031] In the present application, the biomass nitrogen-containing carrier is chitosan, the transition metal salt solution is an aqueous solution of the salt of the transition metal as described above, and the concentration of the transition metal salt solution is preferably 5-70%, more preferably 7-40%, such as 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, preferably a range value with any of the above-mentioned values as the upper or lower limit.

[0032] In the present application, the impregnation time is preferably 6-8h, and the impregnation temperature is preferably 15-35℃, more preferably 20-30℃.

[0033] After the impregnation is completed, the impregnated carrier is dried in the present application to obtain a catalyst intermediate.

[0034] In the present application, the drying is preferably performed in a vacuum drying box, the drying temperature is preferably 70-110℃, more preferably 80-100℃, such as 70℃, 80℃, 90℃, 100℃, 110℃, preferably a range value with any of the above-mentioned values as the upper or lower limit, and the drying time is preferably 6-10h, more preferably 8-9h.

[0035] The catalyst intermediate is then calcined under a protective atmosphere to obtain a catalyst for synthesizing mercaptan compounds.

[0036] In the present application, the protective atmosphere is preferably nitrogen and / or argon, the calcination temperature is preferably 450-550℃, more preferably 500-520℃, such as 450℃, 460℃, 470℃, 480℃, 490℃, 500℃, 510℃, 520℃, 530℃, 540℃, 550℃, preferably a range value with any of the above-mentioned values as the upper or lower limit, and the calcination time is preferably 3-8h, more preferably 5-6h.

[0037] The present application also provides a use of the above-mentioned catalyst in the preparation of mercaptan compounds.

[0038] In the present application, olefin and hydrogen sulfide are used as raw materials, and the reaction is performed under the catalysis of the above-mentioned catalyst to synthesize mercaptan compounds.

[0039] In the present application, the olefin has the general formula R2-CH=CH2, R2 is a hydrogen atom or a linear or branched alkyl group with 1-20 carbon atoms, preferably a linear or branched alkyl group with 1-12 carbon atoms, and in the embodiments of the present application, the synthesis of ethanethiol is preferably exemplified.

[0040] In the present application, the catalyst is first sulfided and then used to catalytically synthesize mercaptan compounds.

[0041] In the present application, the catalyst is placed in a reactor, and hydrogen sulfide gas is introduced to sulfide the catalyst.

[0042] In the present application, the flow rate of the hydrogen sulfide gas is preferably 50-500 mL / min, more preferably 100-400 mL / min, such as 50 mL / min, 100 mL / min, 150 mL / min, 200 mL / min, 250 mL / min, 300 mL / min, 350 mL / min, 400 mL / min, 450 mL / min, 500 mL / min, and preferably a range value with any of the above values as the upper or lower limit; the sulfidation temperature is preferably 50-300°C, more preferably 100-250°C, such as 50°C, 100°C, 150°C, 200°C, 250°C, 300°C, and preferably a range value with any of the above values as the upper or lower limit; a sulfidation temperature that is too low results in incomplete sulfidation of the supported catalyst, and a sulfidation temperature that is too high results in wasted energy consumption; the sulfidation time is preferably 2-5 hours, more preferably 3-4 hours; and the sulfidation pressure is preferably 0-2 MPa, more preferably 0.2-1 MPa, such as 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 1 MPa, 1.5 MPa, 2 MPa, and preferably a range value with any of the above values as the upper or lower limit; a sulfidation pressure that is too low results in incomplete sulfidation of the supported catalyst, and a sulfidation pressure that is too high requires higher pressure resistance of the equipment, and on the other hand, a sulfidation pressure that is too high does not significantly improve the performance of the catalyst.

[0043] After the sulfidation is completed, hydrogen sulfide and an olefin are introduced into the reactor to perform a catalytic reaction to obtain a mercaptan compound.

[0044] In the present application, the molar ratio of the hydrogen sulfide to the olefin is preferably (1-100):1, more preferably (2-50):1, and most preferably (10-30):1, such as 1:1, 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, 50:1, 60:1, 70:1, 80:1, 90:1, 100:1, and preferably a range value with any of the above values as the upper or lower limit.

[0045] In the present application, the temperature of the catalytic reaction is preferably 80-300°C, more preferably 100-250°C, such as 80°C, 100°C, 150°C, 200°C, 250°C, 300°C, preferably a range with any of the above values as upper or lower limit, the pressure of the catalytic reaction is preferably 0.2-5 MPa, more preferably 0.5-4 MPa, such as 0.2 MPa, 0.5 MPa, 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, preferably a range with any of the above values as upper or lower limit; the space velocity of the catalytic reaction is preferably 100-600 h -1 , more preferably 200-500 h -1 , such as 100 h -1 , 200 h -1 , 300 h -1 , 400 h -1 , 500 h -1 , 600 h -1 , preferably a range with any of the above values as upper or lower limit.

[0046] The reaction gas is subjected to gas-liquid separation after cooling, and the liquid phase is subjected to rectification to obtain the ethanethiol product;

[0047] (iv) The reaction gas is subjected to on-line gas phase detection, the contents of ethylene, ethanethiol and diethyl sulfide in the reaction gas are detected, and the selectivity and yield of the catalyst are calculated according to the contents of the above components. The calculation formula is as follows:

[0048] Selectivity X C2H4 = (A 乙硫醇 / M 乙硫醇 + 2*A 乙硫醚 / M 乙硫醚 ) / (A 乙烯 / M 乙烯 + A 乙硫醇 / M 乙硫醇 + 2*A 乙硫醚 / M 乙硫醚 ) * 100%

[0049] Yield S C2H5SH = (A 乙硫醇 / M 乙硫醇 ) / (A 乙硫醇 / M 乙硫醇 + 2*A 乙硫醚 / M 乙硫醚 ) * 100%

[0050] Wherein, A i is the area corresponding to each component in the chromatogram, and M i is the molar mass of each component.

[0051] In the present application, the catalytic reaction can be a batch reaction or a continuous reaction.

[0052] The present application provides a catalyst for synthesizing mercaptan compounds, comprising a biomass nitrogen-containing carrier and a transition metal supported on the biomass nitrogen-containing carrier; the biomass nitrogen-containing carrier comprises chitosan; and the transition metal comprises two or more than two elements in Group VIB and Group VIII. The present application uses chitosan as a carrier. On the one hand, the structure of chitosan contains a large number of amino groups and hydroxyl groups, which have a unique chelating ability for metals, and it is easier to prepare a supported metal catalyst with good properties. On the other hand, high-temperature calcination in a tube furnace is more conducive to preparing a nitrogen-doped carbon-based material with a high specific surface area and good mechanical properties. The presence of N atoms can better improve the electronic conductivity, charge transfer at the interface and the stability of the transition metal, thereby improving the agglomeration of metal particles and making the metal particles more uniformly dispersed on the surface of the carrier, so that the activity of the catalyst is improved, thereby improving the conversion rate of olefin compounds and the selectivity of mercaptan compounds, and further improving the yield of mercaptan compounds. In addition, the basic carrier can effectively inhibit ethylene self-polymerization and carbonization, effectively improve the service life of the catalyst, and has high economic and social benefits.

[0053] In order to further illustrate the present application, the catalyst for synthesizing mercaptan compounds, the preparation method and application thereof provided by the present application are described in detail below in conjunction with examples, but it should not be understood as limiting the scope of protection of the present application.

[0054] Example 1

[0055] 1. Catalyst preparation process:

[0056] (1) According to the mass fraction of the oxides obtained by calcination, the mass of ammonium heptamolybdate is 12.24 g, the mass of cobalt nitrate hexahydrate is 76.42 g, and the mass of water is 154.22 g. A wine red clear transparent salt solution is prepared, and there is no other insoluble substance.

[0057] (2) The mass of the carrier chitosan is 100.00 g. The above prepared salt solution is fully immersed into the carrier, and is placed for more than 10 h to ensure that the immersion liquid is fully absorbed.

[0058] (3) The loaded catalyst after immersion is placed in a vacuum drying box, and the temperature is controlled at 50℃ for more than 5 h.

[0059] (4) After vacuum drying, the loaded catalyst is placed in a tube furnace, calcined at 550℃ for more than 3 h under nitrogen atmosphere, and then cooled to obtain the loaded catalyst.

[0060] 2. Catalyst application performance evaluation process: a fixed bed reactor is used as a reaction device

[0061] (1) Take the prepared supported catalyst 50 ml, according to the filling requirements, and load it into the reactor;

[0062] (2) At 160℃, hydrogen sulfide is introduced at 100ml / min, and the sulfidation pressure is 0.2MPa. The catalyst is sulfided for 3h;

[0063] (3) After the catalyst is sulfided, hydrogen sulfide and ethylene are introduced:

[0064] Adjust the molar ratio of H2S / ethylene: 3:1

[0065] Reaction temperature control: 200℃

[0066] Reaction pressure: 1.0MPa

[0067] (4) The reaction process is detected by gas phase online chromatography:

[0068] Gas phase detection is performed every 2h, and data analysis is performed:

[0069] Table 1 Catalyst performance of Example 1

[0070] Reaction time / h 2 4 6 8 Ethylene conversion / % 85.62 86.43 85.32 85.55 Ethane thiol selectivity / % 90.14 90.08 89.97 90.21

[0071] Example 2

[0072] 1. Catalyst preparation process:

[0073] (1) According to the mass fraction of the oxide obtained by calcination, the mass of ammonium heptamolybdate is 18.12g, the mass of cobalt nitrate hexahydrate is 50.30g, and the mass of water is 165.84g. A wine red clear transparent salt solution is prepared, and there is no other insoluble substance;

[0074] (2) Take the carrier chitosan 100.00g, and fully immerse the above prepared salt solution into the carrier, and stand for more than 10h to ensure that the immersion liquid is fully absorbed;

[0075] (3) The impregnated supported catalyst is placed in a vacuum drying box, and the temperature is controlled at 50℃, and dried for more than 5h;

[0076] (4) After vacuum drying, the supported catalyst is placed in a tube furnace, calcined at 550℃ for more than 3h under nitrogen atmosphere, and cooled to obtain the supported catalyst.

[0077] 2. Catalyst application performance evaluation process: The self-designed fixed bed reactor is used as the reaction device

[0078] (1) Take 50 ml of the prepared supported catalyst, and fill it into the reactor according to the filling requirements;

[0079] (2) At 200°C, pass 50 ml / min of hydrogen sulfide, and sulfidize the catalyst at a pressure of 0.1 MPa. The sulfidization process lasts for 2 h;

[0080] (3) After the sulfidization of the catalyst is completed, pass hydrogen sulfide and ethylene:

[0081] Adjust the molar ratio of H2S / ethylene: 4:1

[0082] Reaction temperature control: 220°C

[0083] Reaction pressure: 1.2 MPa

[0084] (4) The reaction process is detected by gas phase online chromatography:

[0085] Gas phase detection is performed every 2 h, and the data analysis is as follows:

[0086] Table 2 Catalyst performance of Example 2

[0087] Reaction time / h 2 4 6 8 Ethylene conversion / % 88.56 88.68 89.14 87.99 Ethane thiol selectivity / % 91.45 92.31 91.78 91.83

[0088] Example 3

[0089] 1. Catalyst preparation process:

[0090] (1) According to the mass fraction of the oxides obtained by calcination, the mass of ammonium heptamolybdate is 31.42 g, the mass of cobalt nitrate hexahydrate is 26.16 g, and the mass of water is 173.44 g. A wine red clear transparent salt solution is prepared, and there is no other insoluble substance;

[0091] (2) Take 100.00 g of the carrier chitosan, and fully immerse the above prepared salt solution into the carrier, and stand for more than 10 h to ensure sufficient absorption of the immersion liquid;

[0092] (3) The immersed supported catalyst is placed in a vacuum drying box, and the temperature is controlled at 50°C for more than 5 h;

[0093] (4) After vacuum drying is completed, the supported catalyst is placed in a tube furnace, and calcined at 550°C for more than 3 h under a nitrogen atmosphere. After calcination is completed, the supported catalyst is cooled.

[0094] 2. Catalyst application performance evaluation process: a fixed bed reactor designed independently is used as the reaction device

[0095] (1) Take 50 ml of the prepared supported catalyst, and fill it into the reactor according to the filling requirements;

[0096] (2) at 260℃, hydrogen sulfide was passed at 150 ml / min, sulfidation pressure was 0.3 MPa, the catalyst was sulfided, and the sulfidation process lasted for 4 h;

[0097] (3) after the catalyst was sulfided, hydrogen sulfide and ethylene were passed:

[0098] Adjust the molar ratio of H2S / ethylene: 5:1

[0099] Reaction temperature control: 240℃

[0100] Reaction pressure: 1.5 MPa

[0101] (4) The reaction process was detected by gas phase online chromatography:

[0102] Gas phase detection was performed every 2 h, and data analysis was performed:

[0103] Table 3 Catalyst performance of Example 3

[0104] Reaction time / h 2 4 6 8 Ethylene conversion / % 86.37 86.02 86.78 87.03 Ethane thiol selectivity / % 90.56 90.36 90.16 90.45

[0105] Example 4

[0106] 1. Catalyst preparation process:

[0107] (1) According to the mass fraction of molybdenum oxide / nickel oxide: 8% / 15%, 12.24 g of ammonium heptamolybdate, 77.40 g of nickel nitrate hexahydrate, and 157.34 g of water were weighed, and a wine red clear transparent salt solution was prepared, without other insoluble substances;

[0108] (2) 100.00 g of carrier chitosan was weighed, and the above prepared salt solution was fully immersed into the carrier and was placed for more than 10 h to ensure sufficient absorption of the immersion liquid;

[0109] (3) The impregnated supported catalyst was placed in a vacuum drying box, and the temperature was controlled at 50℃ for more than 5 h;

[0110] (4) After vacuum drying, the supported catalyst was placed in a tube furnace, calcined at 550℃ for more than 3 h under nitrogen atmosphere, and then the supported catalyst was cooled.

[0111] 2. Catalyst application performance evaluation process: a self-designed fixed bed reactor was used as the reaction device

[0112] (1) 50 ml of the above prepared supported catalyst was weighed and loaded into the reactor according to the filling requirements;

[0113] (2) at 120℃, hydrogen sulfide was passed at 200 ml / min, sulfidation pressure was 0.5 MPa, the catalyst was sulfided, and the sulfidation process lasted for 5 h;

[0114] (3) After the catalyst is sulfided, hydrogen sulfide and ethylene are introduced:

[0115] The molar ratio of H2S / ethylene is adjusted to 6:1

[0116] The reaction temperature is controlled at 160°C

[0117] The reaction pressure is 1.2 MPa

[0118] (4) The reaction process is detected by gas phase online chromatography:

[0119] Gas phase detection is performed every 2 h, and data analysis is performed:

[0120] Table 4 Catalyst performance of Example 4

[0121] Reaction time / h 2 4 6 8 Ethylene conversion / % 85.37 86.10 85.88 86.45 Ethane thiol selectivity / % 89.75 90.36 90.16 90.45

[0122] Example 5

[0123] 1. Catalyst preparation process:

[0124] (1) According to the mass fraction of molybdenum oxide / nickel oxide: 15% / 9%, 23.26 g of ammonium heptamolybdate, 47.04 g of nickel nitrate hexahydrate, and 167.74 g of water are weighed, and a wine red clear transparent salt solution is prepared, without other insoluble substances;

[0125] (2) 100.00 g of the carrier chitosan is weighed, the above prepared salt solution is fully immersed into the carrier, and is placed for more than 10 h to ensure sufficient absorption of the immersion liquid;

[0126] (3) The impregnated supported catalyst is placed in a vacuum drying box, and the temperature is controlled at 50°C for more than 5 h;

[0127] (4) After vacuum drying is completed, the supported catalyst is placed in a tube furnace, and is calcined at 550°C for more than 3 h under a nitrogen atmosphere. After calcination is completed, the supported catalyst is cooled.

[0128] 2. Catalyst application performance evaluation process: a fixed bed reactor designed independently is used as the reaction device

[0129] (1) 50 ml of the prepared supported catalyst is measured and loaded into the reactor according to the filling requirements;

[0130] (2) The catalyst is sulfided by introducing 300 ml / min of hydrogen sulfide at 180°C and a sulfidation pressure of 1.0 MPa, and the sulfidation process lasts for 3 h;

[0131] (3) After the catalyst is sulfided, hydrogen sulfide and ethylene are introduced:

[0132] Adjusting the molar ratio of H2S / ethylene: 10:1

[0133] Reaction temperature control: 180℃

[0134] Reaction pressure: 1.8MPa

[0135] (4) Reaction process detection by gas phase online chromatography:

[0136] Gas phase detection every 2h interval, data analysis:

[0137] Table 5 Catalyst performance of Example 5

[0138] Reaction time / h 2 4 6 8 Ethylene conversion / % 88.76 89.25 88.67 89.56 Ethane thiol selectivity / % 92.23 92.86 92.10 93.24

[0139] Example 6

[0140] 1. Catalyst preparation process:

[0141] (1) According to the mass fraction of molybdenum oxide / nickel oxide: 18% / 5%, 27.54g of ammonium heptamolybdate, 25.80g of nickel nitrate hexahydrate, and 176.40g of water were weighed, and a wine red clear transparent salt solution was prepared, without other insoluble substances;

[0142] (2) 100.00g of carrier chitosan was weighed, and the above prepared salt solution was fully immersed into the carrier and statically placed for more than 10h to ensure sufficient absorption of the immersion liquid;

[0143] (3) The impregnated supported catalyst was placed in a vacuum drying box, and the temperature was controlled at 50℃ for more than 5h;

[0144] (4) After vacuum drying, the supported catalyst was placed in a tube furnace and calcined at 550℃ for more than 3h under nitrogen atmosphere. After calcination, the supported catalyst was cooled.

[0145] 2. Catalyst application performance evaluation process: a self-designed fixed bed reactor was used as the reaction device

[0146] (1) 50ml of the above prepared supported catalyst was weighed and filled into the reactor according to the filling requirements;

[0147] (2) At 240℃, 100ml / min of hydrogen sulfide was introduced, and the sulfidation pressure was 0.3MPa. The catalyst was sulfided for 2h;

[0148] (3) After the catalyst was sulfided, hydrogen sulfide and ethylene were introduced:

[0149] Adjusting the molar ratio of H2S / ethylene: 8:1

[0150] Reaction temperature control: 220°C

[0151] Reaction pressure: 2.2 MPa

[0152] (4) Reaction process detection by gas phase online chromatography:

[0153] Gas phase detection was performed every 2 h, and data analysis was performed:

[0154] Table 6 Catalyst performance of Example 6

[0155]

[0156]

[0157] Comparative Example 1

[0158] 1. Catalyst preparation process:

[0159] (1) According to the mass fraction of molybdenum oxide / cobalt oxide: 12% / 10%, 18.12 g of ammonium heptamolybdate, 50.30 g of cobalt nitrate hexahydrate, and 111.12 g of water were weighed, and a wine red clear transparent salt solution was prepared, without other insoluble substances;

[0160] (2) 100.00 g of the carrier alumina was weighed, the above prepared salt solution was fully impregnated into the carrier, and was allowed to stand for more than 10 h to ensure sufficient absorption of the impregnation solution;

[0161] (3) The impregnated supported catalyst was placed in a vacuum drying box, and the temperature was controlled at 50°C for more than 5 h;

[0162] (4) After vacuum drying, the supported catalyst was placed in a tube furnace and calcined at 550°C for more than 3 h under a nitrogen atmosphere. After calcination, the supported catalyst was obtained by cooling.

[0163] 2. Catalyst application performance evaluation process: a fixed bed reactor designed independently was used as the reaction device

[0164] (1) 50 ml of the above prepared supported catalyst was weighed and loaded into the reactor according to the filling requirements;

[0165] (2) The catalyst was sulfided by passing 50 ml / min of hydrogen sulfide at 200°C and a sulfidation pressure of 0.1 MPa, and the sulfidation process lasted for 2 h;

[0166] (3) After the catalyst was sulfided, hydrogen sulfide and ethylene were passed in:

[0167] The molar ratio of H2S / ethylene was adjusted to 4:1

[0168] Reaction temperature control: 220°C

[0169] Reaction pressure: 1.2 MPa

[0170] (4) The reaction process was detected by gas phase online chromatography:

[0171] Gas phase detection was performed every 2 h, and data analysis was performed:

[0172] Table 7 Catalyst performance of Comparative Example 1

[0173] Reaction time / h 2 4 6 8 Ethylene conversion / % 82.36 82.69 83.12 82.67 Ethane thiol selectivity / % 87.35 88.23 88.54 87.86

[0174] Comparative Example 2

[0175] 1. Catalyst preparation process:

[0176] (1) According to the mass fraction of molybdenum oxide / nickel oxide: 18% / 5%, 27.54 g of ammonium heptamolybdate, 25.80 g of nickel nitrate hexahydrate, and 118.19 g of water were weighed, and a wine red clear transparent salt solution was prepared, without other insoluble substances;

[0177] (2) 100.00 g of the carrier alumina was weighed, the above prepared salt solution was fully impregnated into the carrier, and was statically placed for more than 10 h to ensure sufficient absorption of the impregnation solution;

[0178] (3) The impregnated supported catalyst was placed in a vacuum drying box, and the temperature was controlled at 50°C for more than 5 h;

[0179] (4) After vacuum drying, the supported catalyst was placed in a tube furnace, calcined at 550°C for more than 3 h under nitrogen atmosphere, and then the supported catalyst was cooled.

[0180] 2. Catalyst application performance evaluation process: a fixed bed reactor designed independently was used as the reaction device

[0181] (1) 50 ml of the prepared supported catalyst was weighed and filled into the reactor according to the filling requirements;

[0182] (2) The catalyst was sulfided by passing 100 ml / min of hydrogen sulfide at 240°C and a sulfidation pressure of 0.3 MPa, and the sulfidation process lasted for 2 h;

[0183] (3) After the catalyst was sulfided, hydrogen sulfide and ethylene were passed in:

[0184] The molar ratio of H2S / ethylene was adjusted to 8:1

[0185] Reaction temperature control: 220°C

[0186] Reaction pressure: 2.2 MPa

[0187] (4) Reaction process detection by gas phase on-line chromatography:

[0188] Gas phase detection was performed every 2 h, and data analysis was performed:

[0189] Table 8 Catalyst performance of Comparative Example 2

[0190] Reaction time / h 2 4 6 8 Ethylene conversion / % 83.26 82.88 83.15 83.56 Ethane thiol selectivity / % Reaction time / h Ethylene conversion / % Ethane thiol selectivity / % 87.66 88.14 87.89 88.25

[0191] The above only describes the preferred embodiments of the present application, and it should be noted that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. Use of a catalyst for synthesizing mercaptan compounds in preparing mercaptan compounds; the catalyst for synthesizing mercaptan compounds is sulfided and used to catalyze the reaction of hydrogen sulfide and olefins to prepare mercaptan compounds; the catalyst for synthesizing mercaptan compounds comprises a calcined biomass nitrogen-containing carrier and a transition metal oxide supported on the biomass nitrogen-containing carrier; the biomass nitrogen-containing carrier comprises chitosan; the transition metal elements in the transition metal oxide comprise elements in Group VIB and elements in Group VIII; in the catalyst, the loading of the elements in Group VIB is 3-25% by mass of the transition metal oxide, and the loading of the elements in Group VIII is 3-20% by mass of the transition metal oxide; the method for preparing the catalyst for synthesizing mercaptan compounds comprises the following steps: A) immersing a biomass nitrogen-containing carrier in a transition metal salt solution for impregnation; B) drying the impregnated carrier to obtain a catalyst intermediate; C) calcining the catalyst intermediate under a protective atmosphere to obtain the catalyst for synthesizing mercaptan compounds; the calcination temperature in step C) is 400-600°C, and the calcination time is 3-8 h.

2. Use according to claim 1, characterized in that, the elements in Group VIII include one or more of cobalt, nickel, ruthenium, palladium and platinum; and the elements in Group VIB include one or more of chromium, molybdenum and tungsten.

3. Use according to claim 1, characterized in that, the concentration of the transition metal salt solution is 5.0%-70.0%; and the impregnation time is 6-12 h.

4. Use according to claim 1, characterized in that, the drying temperature in step B) is 50-120°C, and the drying time is 6-10 h.

5. The use according to claim 1, characterized in that, the catalyst is sulfided using H2S, the sulfiding temperature is 50-300°C, the sulfiding pressure is 0-2 MPa, and the sulfiding time is 1-6 h.

6. Use according to claim 1, characterized in that, The temperature of the catalytic reaction is 80-300℃, the pressure of the catalytic reaction is 0.2-5MPa, and the space velocity of the catalytic reaction is 100-600h -1 .

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