Heterogeneous catalyst and preparation method of mercaptan

Abstract

The invention relates to the technical field of chemical engineering, and discloses a heterogeneous catalyst and a preparation method of mercaptan. The heterogeneous catalyst comprises an active component and an organic phosphine polymer ligand, wherein the organic phosphine polymer ligand and the active component form a coordinate bond through a P element in a chemical structure of the organic phosphine polymer ligand; the active component comprises at least one of Co and Rh elements, the organic phosphine polymer ligand is formed by polymerizing and vulcanizing an organic phosphine monomer comprising a carbon-carbon double bond, and the content of the sulfur element is 1-20% by taking the mass of the heterogeneous catalyst as a reference. According to the heterogeneous catalyst, the utilization rate of active components is high, the active components are not prone to loss, the phosphine ligand has a remarkable stereo effect, the stereo selectivity of a target product can be improved, meanwhile, the binding force of the catalyst and H2S can be increased through a certain content of sulfur element, and therefore the thiol yield is increased.

Description

Technical Field

[0001] The present application relates to the field of chemical technology, and in particular to a method for preparing a heterogeneous catalyst and a thiol. Background Art

[0002] Mercaptan refers to a class of non-aromatic compounds containing a thiol functional group (-SH), which can be used as a rubber vulcanization accelerator, a conditioning agent, a surfactant, etc. The industrial production method of mercaptan is usually obtained by the addition of olefins and hydrogen sulfide or the reaction of corresponding alcohols and hydrogen sulfide. Among them, the addition reaction of olefins and hydrogen sulfide generally adopts photocatalysis, free radical catalysis or acid catalysis, and the reaction conditions are harsh, the raw material purity is required to be high, the technical difficulty is high, and the reaction yield is not good. As for the reaction of alcohol and hydrogen sulfide, since the boiling point of mercaptan is close to that of the corresponding alcohol, it is difficult to separate the product when the raw material alcohol conversion rate is insufficient. Therefore, it is urgent to develop a method for preparing mercaptan with high industrial possibility to solve the problems existing in the above two production processes. Summary of the invention

[0003] In view of this, the present application provides a heterogeneous catalyst and a method for preparing thiols using the heterogeneous catalyst to solve the problems of harsh reaction conditions, difficult product separation and poor reaction yield in existing thiol production processes.

[0004] According to an embodiment of the present application, in a first aspect, a heterogeneous catalyst is provided, comprising an active component and an organic phosphine polymer ligand, wherein the organic phosphine polymer ligand forms a coordination bond with the active component through a P element in its chemical structure;

[0005] The active component includes at least one of Co and Rh elements;

[0006] The organic phosphine polymer ligand is prepared by polymerization and sulfurization of an organic phosphine monomer including a carbon-carbon double bond, and the content of sulfur element is 1%-20% based on the mass of the heterogeneous catalyst.

[0007] The heterogeneous catalyst provided by the present application utilizes the polymerization reaction between the carbon-carbon double bonds in the organic phosphine monomer to form an organic phosphine polymer with a multi-level pore structure, and the organic phosphine polymer skeleton contains a large number of P elements with lone electron pairs, which can form multiple coordination bonds with the empty orbits of the metal elements of the active component, so that the active component can be evenly dispersed in the organic phosphine polymer carrier, which not only greatly improves the utilization rate of the active component, but also ensures that the active component is not easy to lose, prolongs the service life of the catalyst, and the phosphine ligand also has a significant stereo effect, which can improve the stereoselectivity of the target product. In addition, the heterogeneous catalyst of the present application also pre-sulfurizes the organic phosphine polymer ligand so that the organic phosphine polymer ligand contains a certain amount of sulfur, thereby increasing the binding force between the catalyst and H2S, thereby improving the yield of mercaptan. The present application has found that if the sulfur content in the organic phosphine polymer ligand is too high, it will cause excessive sulfur content around the active component, inhibiting the combination of the active component and olefins, and vice versa, if the sulfur content is too low, it will not help much to improve the yield of mercaptan.

[0008] In some optional embodiments, the vulcanization step includes: reacting the polymer product of the organic phosphine monomer with sulfur at 110° C.-150° C. for 4 h-10 h. This allows the hydrogen on the skeleton of the polymer product of the organic phosphine monomer to undergo a substitution reaction with sulfur to form an organic phosphine polymer doped with a certain amount of sulfur. If the reaction temperature is too low or the time is too short, there are too few thio sites, which has little effect on improving the thiol yield. If the reaction temperature is too high or the time is too long, the thiol sulfhydryl group will be broken, affecting the sulfidation reaction yield.

[0009] It is understood that in some optional embodiments, based on the mass of the heterogeneous catalyst, the content of the active component is 0.001%-3%, and / or the content of the organic phosphine polymer ligand is 97%-99.999%, thereby ensuring that the active component can be well combined with the polymer ligand, thereby ensuring higher catalytic activity and selectivity.

[0010] Exemplarily, the organic phosphine monomer includes at least one of the following compounds:

[0011]

[0012] The present application study found that, compared with triphenylphosphine, the organic phosphine monomers introduced with nitrogen-containing aromatic groups, such as those shown in formula (3) and formula (4), can enhance the coordination ability of the P element, thereby improving the stability of the catalyst; the organic phosphine monomers of the structures shown in formula (5) to formula (12) can improve the chelation ratio of the organic phosphorus polymer ligand and the active component due to their bidentate coordination ability, thereby increasing the ratio of olefins binding to the active component with terminal double bonds, and improving the selectivity of primary mercaptans. Different from the PC bond in other organic phosphorus monomers, the phosphate bidentate monomers formed by constructing PO bonds in formula (11) and formula (12) have better coordination activity, can better bind to internal olefins, and allow the double bonds of internal olefins to migrate to the terminal positions to react with CO, H2 and H2S, thereby improving the conversion rate of internal olefins and the selectivity of primary mercaptans.

[0013] It is understood that internal olefins refer to olefins whose carbon-carbon double bonds are not at the ends of the molecular chain, whereas terminal olefins refer to olefins whose carbon-carbon double bonds are located at the ends of the molecular chain.

[0014] It should be noted that the heterogeneous catalyst can be prepared by a commonly used solvent thermal polymerization method. In some optional embodiments, the preparation method of the heterogeneous catalyst comprises the following steps:

[0015] S1: mixing an organic phosphine monomer, a free radical initiator and a solvent at 20°C-60°C and in an inert gas atmosphere, and stirring the mixture for a reaction of 0.5-20 hours;

[0016] S2: transferring the suspension obtained in S1 to an autoclave for solvent thermal polymerization at 80°C-150°C and in an inert gas atmosphere for 0.5-20 hours;

[0017] S3: removing the solvent from the suspension obtained in S2 under vacuum at 40°C-100°C to obtain a polymerization product of the organic phosphine monomer;

[0018] S4: subjecting the polymer product obtained in S3 to a vulcanization reaction with sulfur at 110° C. to 150° C. for 4 to 10 hours to obtain an organic phosphine polymer ligand;

[0019] S5: placing the organic phosphine polymer ligand obtained in S4 in a solvent containing an active metal salt, stirring at 10°C-100°C in an inert gas protective atmosphere for 0.5-40 hours, and then removing the solvent in vacuo at 40°C-100°C to obtain a heterogeneous catalyst.

[0020] Exemplarily, the solvent includes one or more of benzene, toluene, xylene, cyclohexane, tetrahydrofuran, methanol, ethanol, dichloromethane, and dichloroethane; the free radical initiator includes one or more of dibenzoyl peroxide, tert-butyl hydroperoxide, and azobisisobutyronitrile, and the amount of the free radical initiator is 0.1%-5% of the mass of the organic phosphine monomer; the amount of sulfur is 1%-40% of the mass of the polymer product obtained by S3; the active metal salt includes inorganic salts and / or organic salts of cobalt and / or rhodium, preferably in the form of acetate, isooctanoate, cyclopentaneate, and acetylacetonate. The chemical structure of the organic phosphine monomer is as described above, so it is not repeated here.

[0021] According to an embodiment of the present application, in a second aspect, a use of the heterogeneous catalyst described in the first aspect in a thiol preparation process is provided.

[0022] According to an embodiment of the present application, in a third aspect, a method for preparing thiol is also provided, comprising the following steps:

[0023] In the presence of the heterogeneous catalyst described in the first aspect, olefins react with CO, H2 and H2S, and the volume space velocity of the mixed gas of CO, H2 and H2S is controlled to be 0.1h -1 -50h -1 , the reaction temperature is 80℃-150℃, the reaction pressure is 0.5MPa-10MPa, and mercaptan is obtained.

[0024] The present application adopts a new process flow under the catalytic action of the heterogeneous catalyst described in the first aspect, and by controlling the reaction temperature, pressure and gas distribution, the olefin can directly react with carbon monoxide, hydrogen sulfide and hydrogen, so as to achieve the introduction of olefin terminal mercaptomethyl, and generate a mercaptan with a carbon number of one more than the olefin. The preparation method of the mercaptan provided by the present application simplifies the synthesis process, and the heterogeneous catalyst used is not only easy to separate, but also can avoid the harsh conditions of photocatalysis, peroxide catalysis or acid catalysis. Moreover, the boiling point difference between the raw material olefin and the target product mercaptan is large, even if the raw material conversion is incomplete, it does not affect the product separation, reduces the energy consumption of raw material and product separation, and significantly reduces the product production cost.

[0025] In some optional embodiments, the volume space velocity of the mixed gas of CO, H2 and H2S is 1h -1 -30h -1 The gas space velocity is adjusted according to the reaction activity of different olefins so that the reaction efficiency and the removal of reaction heat can be better taken into account within the above range.

[0026] In some optional embodiments, the reaction temperature is 100°C-130°C, which can better balance the reaction rate and the stability of the catalyst. The present application found that if the reaction temperature is too low (less than 80°C), the reaction rate is too slow, affecting the efficiency, while if the temperature is too high (greater than 150°C), the effective components of the catalyst are easily separated, affecting the service life.

[0027] In some optional embodiments, the reaction pressure is 1.5MPa-5MPa to ensure a more suitable reaction rate. The present application has found that if the reaction pressure is too low (less than 0.5MPa), it is difficult for the gas to combine with the active component, affecting the raw material conversion rate, while if the reaction pressure is too high (greater than 10MPa), the binding force between the gas such as CO and the ligand of the active metal is too strong to be separated, thereby inhibiting the reaction rate.

[0028] In some optional embodiments, when C2-C4 olefins are used, the mass flow rate of the olefins is 0.01-0.5 g / (h·mL catalyst), thereby adjusting the feed rate according to the reaction rates of different olefins, adjusting the conversion rate and the exothermic power, thereby maintaining the stability of the reaction temperature and the selectivity of the target product.

[0029] In some optional embodiments, at least one of the following conditions is met: a. the molar ratio of H2S to H2 is 0.4-2.5:1; b. the molar ratio of CO to H2 is 0.4-1.2:1; c. the molar ratio of olefin to CO is 1.0-5.0:1. In this way, the selectivity of mercaptans in the reaction can be better controlled to avoid excessive selectivity of by-products such as aldehydes, alcohols, and alkanes.

[0030] In some optional embodiments, the olefin is a C2-C20 monoolefin, illustratively, it can be at least one of propylene, 1-butene, 2-butene, 1-pentene, 1-hexene, 1-heptene, 2-heptene, 1-octene, 1-undecene, 2-methyl-1-decene, 5-methyl-5-decene, 8-methyl-1-decene, and 2,4,4,6-tetramethyl-2-heptene.

[0031] It is understood that the reaction for preparing mercaptan is carried out in a reactor. For example, the reactor may be a fixed bed reactor or a bubbling bed reactor.

[0032] The technical solution of this application has the following advantages:

[0033] The heterogeneous catalyst provided by the present application comprises an active component and an organic phosphine polymer ligand, wherein the organic phosphine polymer ligand forms a coordination bond with the active component through the P element in its chemical structure; the active component comprises at least one of Co and Rh elements, the organic phosphine polymer ligand is polymerized and vulcanized by an organic phosphine monomer comprising a carbon-carbon double bond, and the content of sulfur element is 1%-20% based on the mass of the organic phosphine polymer ligand. The utilization rate of the active component in the heterogeneous catalyst of the present application is high and it is not easy to lose, the phosphine ligand has a significant stereo effect, and can improve the stereoselectivity of the target product, and at the same time, a certain content of sulfur element can increase the binding force between the catalyst and H2S, thereby improving the yield of mercaptan.

[0034] The preparation method of the mercaptan provided by the present application adopts a new process flow under the catalytic action of the heterogeneous catalyst, and by controlling the reaction temperature, pressure and gas distribution, the olefin can directly react with carbon monoxide, hydrogen sulfide and hydrogen to achieve the introduction of olefin terminal mercaptomethyl to obtain the mercaptan. The preparation method of the present application has a short process route, mild reaction conditions, simple operation, and easy product separation, which significantly reduces the production cost of the mercaptan.

[0035] Additional aspects and advantages of the embodiments of the present application will be described and shown in part in the subsequent description, or explained through the implementation of the embodiments of the present application. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0037] In the following examples and comparative examples, if no specific experimental steps or conditions are specified, the conventional experimental steps or conditions described in the literature in the art can be used. If no manufacturer is specified for the reagents or instruments used, they are all conventional reagent products that can be purchased commercially.

[0038] In the examples and comparative examples of the present application, the reagents used are as follows:

[0039] Propylene, carbon monoxide, hydrogen sulfide and hydrogen mixture were purchased from Air Products and Chemicals;

[0040] 2-Heptene, 1-undecene, and vinyl monomer were purchased from Beijing Inokai Technology Co., Ltd.;

[0041] Rhodium acetylacetonate, cobalt acetate, rhodium acetate, and triphenylphosphine were purchased from Aladdin Reagent Co., Ltd.

[0042] In the examples and comparative examples of the present application, the main test methods are described as follows:

[0043] The raw material conversion rate and product selectivity were calibrated by gas chromatography internal standard method, wherein the raw material conversion rate = (moles of reaction raw materials - moles remaining after the reaction) / moles of reaction raw materials × 100%, product selectivity = moles of product after the reaction / (moles of reaction raw materials - moles of remaining raw materials after the reaction) × 100%. The gas chromatograph was Agilent Technologies GC-7820, the gas chromatograph column was a 0.25 mm × 30 m DB-5 capillary column, the column box temperature was programmed from 40 ° C to 280 ° C at a rate of 15 ° C / min and maintained for 5 min, an FID detector was used, the vaporization chamber temperature was 280 ° C, the detector temperature was 300 ° C, the argon carrier flow was 2.1 mL / min, the hydrogen flow was 30 mL / min, the air flow was 400 mL / min, and the injection volume was 1.0 μL.

[0044] Unless otherwise specified, the conversion rate and selectivity percentage used in the examples and comparative examples of the present invention are all molar percentages, and the purity content of the substances are all mass percentages. The unit barA represents absolute pressure, which refers to the actual pressure directly acting on the surface of a container or an object, and its zero point is absolute vacuum. The unit MPaG represents gauge pressure, which refers to the pressure value relative to atmospheric pressure, excluding the atmospheric pressure itself.

[0045] Preparation Example 1: Preparation of Catalyst A

[0046] In a nitrogen atmosphere, add 1000g of tetrahydrofuran, 190g of the monomer of formula (4), and 5g of azobisisobutyronitrile to a 2L pressure-resistant stirred reactor with a heat transfer inner coil, and stir at 50°C for 3h. Then heat to 120°C for thermal polymerization and react for 10h. Transfer the resulting reaction solution to a rotary evaporator and remove tetrahydrofuran at 50°C and 0.5barA. The resulting polymer is reacted with 2g of sulfur at 120°C for 6h to obtain 176g of an organic phosphine polymer ligand. Take 14g of cobalt acetate and dissolve it in 200g of ethanol to prepare a solution. Immerse the resulting organic phosphine polymer ligand in the solution, stir at 10°C for 8h under a nitrogen atmosphere, filter and remove residual dichloromethane from the resulting solid at 40°C and 0.9barA to obtain catalyst A.

[0047] After testing, based on the total mass of Catalyst A, the cobalt content in Catalyst A is 2.4%, and the sulfur content is 1.1%.

[0048] Preparation Example 2: Preparation of Catalyst B

[0049] In a nitrogen atmosphere, add 1000g toluene, 200g monomer of formula (6), and 2g dibenzoyl peroxide to a 2L pressure-resistant stirred reactor with a heat transfer inner coil, and stir at 40°C for 2h. Then heat to 100°C for thermal polymerization and react for 6h. Transfer the resulting reaction solution to a rotary evaporator and remove toluene at 60°C and 0.2barA. The resulting polymer is reacted with 26g sulfur at 110°C for 8h to obtain 183g of an organic phosphine polymer ligand. Take 0.1g of rhodium acetylacetonate and dissolve it in 200g of toluene to prepare a solution, immerse the resulting organic phosphine polymer ligand in the solution, stir at 70°C for 6h under a nitrogen atmosphere, filter and remove toluene from the resulting solid at 60°C and 0.2barA to obtain catalyst B.

[0050] After testing, based on the total mass of Catalyst B, the rhodium content in Catalyst B is 0.007%, and the sulfur content is 12.1%.

[0051] Preparation Example 3: Preparation of Catalyst C

[0052] In a nitrogen atmosphere, add 1000g of ethanol, 200g of the monomer of formula (12), and 10g of tert-butyl hydroperoxide to a 2L pressure-resistant stirred reactor with a heat transfer inner coil, and stir at 60°C for 2h. Then heat to 110°C for thermal polymerization and react for 8h. Transfer the resulting reaction solution to a rotary evaporator and remove ethanol at 60°C and 0.3barA. The resulting polymer is reacted with 30g of sulfur at 150°C for 4h to obtain 147g of an organic phosphine polymer ligand. Take 6.5g of rhodium acetate and dissolve it in 200g of methanol to prepare a solution. Immerse the resulting organic phosphine polymer ligand in the solution, stir at 70°C for 6h under a nitrogen atmosphere, and remove ethanol from the resulting solid at 70°C and 0.3barA after filtration to obtain catalyst C.

[0053] After testing, based on the total mass of Catalyst C, the rhodium content in Catalyst C is 1.3%, and the sulfur content is 17%.

[0054] Preparation Example 4: Preparation of Catalyst D

[0055] Catalyst D was prepared by a method substantially the same as that in Preparation Example 3, except that the vinyl monomer used was trivinylphenylphosphine represented by formula (1).

[0056] After testing, based on the total mass of catalyst D, the rhodium content in catalyst C is 1.3%, and the sulfur content is 17%.

[0057] Example 1: Synthesis of n-butyl mercaptan

[0058] A 100mL fixed bed reactor with an outer jacket was used, filled with 80mL of catalyst A, carbon monoxide + hydrogen sulfide + hydrogen atmosphere, reaction pressure of 2MPaG, temperature of 100°C. Propylene was 3.38g / h flow rate, carbon monoxide + hydrogen sulfide + hydrogen mixture (carbon monoxide accounted for 25.00%, hydrogen sulfide accounted for 25.00%, hydrogen accounted for 50.00%, all molar percentages) was 40mL / min (gas volume space velocity was 30h -1 ) flows through the fixed bed from bottom to top. Samples were taken at the outlet for analysis, and the propylene conversion was 91.1% and the n-butyl mercaptan selectivity was 95.7%.

[0059] Example 1-1

[0060] The method is basically the same as that in Example 1, except that the reaction pressure is 3.5 MPaG and the temperature is 120°C.

[0061] Sampling and analysis at the reactor outlet showed that the propylene conversion rate was 92.4% and the n-butyl mercaptan selectivity was 95.4%.

[0062] Example 1-2

[0063] The method is basically the same as that in Example 1, except that the reaction pressure is 5 MPaG and the temperature is 130°C.

[0064] Sampling and analysis at the reactor outlet showed that the propylene conversion rate was 92.8% and the n-butyl mercaptan selectivity was 94.8%.

[0065] Examples 1-3

[0066] The method is basically the same as that in Example 1, except that the reaction pressure is 10 MPaG and the temperature is 150°C.

[0067] Sampling and analysis at the reactor outlet showed that the propylene conversion rate was 76.4% and the n-butyl mercaptan selectivity was 83.4%.

[0068] Examples 1-4

[0069] The method is basically the same as that in Example 1, except that the reaction pressure is 0.5 MPaG and the temperature is 80°C.

[0070] Sampling and analysis at the reactor outlet showed that the propylene conversion rate was 64.8% and the n-butyl mercaptan selectivity was 93.6%.

[0071] Examples 1-5

[0072] The method is basically the same as that in Example 1, except that the volumetric space velocity of the mixed gas is 15h -1 .

[0073] Sampling and analysis at the reactor outlet showed that the propylene conversion rate was 93.2% and the n-butyl mercaptan selectivity was 94.5%.

[0074] Examples 1-6

[0075] The method is basically the same as that in Example 1, except that the volumetric space velocity of the mixed gas is 1h -1 .

[0076] Sampling and analysis at the reactor outlet showed that the propylene conversion rate was 93.7% and the n-butyl mercaptan selectivity was 94.0%.

[0077] Examples 1-7

[0078] The method is basically the same as that in Example 1, except that the volumetric space velocity of the mixed gas is 0.1h -1 .

[0079] Sampling and analysis at the reactor outlet showed that the propylene conversion rate was 96.1% and the n-butyl mercaptan selectivity was 87.5%.

[0080] Examples 1-8

[0081] The method is basically the same as that in Example 1, except that the volumetric space velocity of the mixed gas is 50h -1 .

[0082] Sampling and analysis at the reactor outlet showed that the propylene conversion rate was 72.1% and the n-butyl mercaptan selectivity was 95.8%.

[0083] Examples 1-9

[0084] The method is basically the same as that of Example 1, except that the molar ratios of the mixed gas composition of CO, H2 and H2S are 25.64%, 23.08% and 51.28%.

[0085] Sampling and analysis at the reactor outlet showed that the propylene conversion rate was 90.5% and the n-butyl mercaptan selectivity was 93.2%.

[0086] Examples 1-10

[0087] The method is basically the same as that of Example 1, except that the molar ratios of the mixed gas composition of CO, H2 and H2S are 23.26%, 30.23% and 46.51%.

[0088] Sampling and analysis at the reactor outlet showed that the propylene conversion rate was 91.0% and the n-butyl mercaptan selectivity was 95.3%.

[0089] Examples 1-11

[0090] The method is basically the same as that of Example 1, except that the molar ratios of the mixed gas composition of CO, H2 and H2S are 22.22%, 22.22% and 55.56%.

[0091] Sampling and analysis at the reactor outlet showed that the propylene conversion rate was 92.3% and the n-butyl mercaptan selectivity was 93.9%.

[0092] Examples 1-12

[0093] The method is basically the same as that of Example 1, except that the molar ratios of the mixed gas composition of CO, H2 and H2S are 23.26%, 23.26% and 53.48%.

[0094] Sampling and analysis at the reactor outlet showed that the propylene conversion rate was 92.0% and the n-butyl mercaptan selectivity was 94.2%.

[0095] Examples 1-13

[0096] The method is basically the same as that of Example 1, except that the flow rate of propylene is 1.13 g / h.

[0097] Sampling and analysis at the reactor outlet showed that the propylene conversion rate was 93.7% and the n-butyl mercaptan selectivity was 92.9%.

[0098] Examples 1-14

[0099] The method is basically the same as that of Example 1, except that the flow rate of propylene is 2.51 g / h.

[0100] Sampling and analysis at the reactor outlet showed that the propylene conversion rate was 93.2% and the n-butyl mercaptan selectivity was 93.3%.

[0101] Examples 1-15

[0102] The method is basically the same as that of Example 1, except that the flow rate of propylene is 5.63 g / h.

[0103] Sampling and analysis at the reactor outlet showed that the propylene conversion rate was 85.4% and the n-butyl mercaptan selectivity was 95.5%.

[0104] Examples 1-16

[0105] The method is basically the same as that in Example 1, except that catalyst D is used instead of catalyst A.

[0106] Sampling and analysis at the reactor outlet showed that the propylene conversion rate was 81.3% and the n-butyl mercaptan selectivity was 91.2%.

[0107] Example 2: Synthesis of n-octyl mercaptan

[0108] A 100mL fixed bed reactor with an outer jacket was used, filled with 80mL of catalyst C, carbon monoxide + hydrogen sulfide + hydrogen atmosphere, reaction pressure of 4MPaG, and temperature of 110°C. 2-heptene was flowed from top to bottom through the fixed bed at a flow rate of 76.1g / h, and a mixture of carbon monoxide + hydrogen sulfide + hydrogen (wherein carbon monoxide accounted for 21.74%, hydrogen sulfide accounted for 28.26%, and hydrogen accounted for 50.00%, all in volume percentage) at a flow rate of 266.7mL / min. Samples were taken at the outlet for analysis, and the conversion rate of 2-heptene was 88.1%, and the selectivity of n-octanol was 97.8%.

[0109] Example 3: Synthesis of n-octyl mercaptan

[0110] The method is basically the same as that of Example 2, except that catalyst D is used instead of catalyst C.

[0111] Sampling and analysis at the outlet showed that the conversion rate of 2-heptene was 73.2% and the selectivity of n-octanol was 32.1%.

[0112] Example 4: Synthesis of n-dodecyl mercaptan

[0113] A 100mL fixed bed reactor with an outer jacket was used, filled with 80mL of catalyst B, carbon monoxide + hydrogen sulfide + hydrogen atmosphere, reaction pressure of 3MPaG, and temperature of 100°C. 1-undecene was flowed from top to bottom through the fixed bed at a flow rate of 100g / h, and a mixture of carbon monoxide + hydrogen sulfide + hydrogen (wherein carbon monoxide accounted for 22.72%, hydrogen sulfide accounted for 20.45%, and hydrogen accounted for 56.83%, all in volume percentage) at a flow rate of 1066.7mL / min. Samples were taken at the outlet for analysis, and the conversion rate of 1-undecene was 67.4%, and the selectivity of n-dodecyl mercaptan was 86.1%.

[0114] Example 5: Synthesis of n-dodecyl mercaptan

[0115] The method is basically the same as that of Example 4, except that catalyst D is used instead of catalyst B.

[0116] Sampling and analysis at the outlet showed that the conversion rate of 1-undecene was 53.2% and the selectivity of n-dodecyl mercaptan was 75.9%.

[0117] Comparative Example 1

[0118] The method is basically the same as that of Example 1, except that catalyst DA is used. The preparation method of catalyst DA is as follows:

[0119] In a nitrogen atmosphere, 1000 g of tetrahydrofuran, 190 g of the monomer of formula (4), and 5 g of azobisisobutyronitrile were added to a 2L pressure-resistant stirred reactor with a heat transfer inner coil, and the mixture was stirred at 50°C for 3 h. Then the temperature was raised to 120°C for thermal polymerization and the reaction was continued for 10 h. The resulting reaction solution was transferred to a rotary evaporator, and tetrahydrofuran was removed at 50°C and 0.5 barA to obtain a polymer. 14 g of cobalt acetate was dissolved in 200 g of dichloromethane to prepare a solution, and the obtained polymer was immersed in the solution, stirred at 10°C for 8 h under a nitrogen atmosphere, and then dichloromethane was removed at 40°C and 0.9 barA to obtain catalyst DA. After testing, the cobalt content in catalyst DA was 2.4% based on the total mass of catalyst DA.

[0120] Sampling and analysis at the reactor outlet showed that the propylene conversion rate was 36.2% and the n-butyl mercaptan selectivity was 0.002%.

[0121] Comparative Example 2

[0122] The method is basically the same as that of Example 1, except that the fixed bed reactor is filled with 80 mL of catalyst DA (prepared by the same method as in Comparative Example 1) and 2 mL of sulfur uniformly dispersed around the catalyst DA.

[0123] Sampling and analysis at the reactor outlet showed that the propylene conversion rate was 2.4% and the n-butyl mercaptan selectivity was 0.001%.

[0124] Comparative Example 3

[0125] The method is basically the same as that in Example 1, except that the reaction temperature is 160°C.

[0126] Sampling and analysis at the reactor outlet showed that the propylene conversion rate was 52.6% and the n-butyl mercaptan selectivity was 10.1%.

[0127] Comparative Example 4

[0128] The method is basically the same as that in Example 1, except that the reaction temperature is 70°C.

[0129] Sampling and analysis at the reactor outlet showed that the propylene conversion rate was 5.7% and the n-butyl mercaptan selectivity was 93.3%.

[0130] Comparative Example 5

[0131] The method is basically the same as that in Example 1, except that the reaction pressure is 0.4 MPa.

[0132] Sampling and analysis at the reactor outlet showed that the propylene conversion rate was 34.4% and the n-butyl mercaptan selectivity was 92.5%.

[0133] Comparative Example 6

[0134] The method is basically the same as that in Example 1, except that the reaction pressure is 11 MPa.

[0135] Sampling and analysis at the reactor outlet showed that the propylene conversion rate was 57.1% and the n-butyl mercaptan selectivity was 87.7%.

[0136] Comparative Example 7

[0137] The method is basically the same as that in Example 1, except that the volumetric space velocity of the mixed gas is 0.05h -1 .

[0138] Sampling and analysis at the reactor outlet showed that the propylene conversion rate was 96.7% and the n-butyl mercaptan selectivity was 49.2%.

[0139] Comparative Example 8

[0140] The method is basically the same as that in Example 1, except that the volumetric space velocity of the mixed gas is 52h -1 .

[0141] Sampling and analysis at the reactor outlet showed that the propylene conversion rate was 63.7% and the n-butyl mercaptan selectivity was 91.3%.

[0142] It can be seen from the above embodiments and comparative examples that when sulfurization treatment is not performed during the catalyst preparation process, the selectivity of mercaptans in the final product is very low; when sulfur is dispersed around the catalyst in the form of a single substance, it becomes an inhibitor of the reaction, not only the reaction rate is low, but also the mercaptan selectivity is low; when process conditions such as temperature, pressure or feed rate deviate from the appropriate range, the reaction can occur, but the reaction rate or selectivity is difficult to reach a better index.

[0143] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection created by this application.

Claims

1. A heterogeneous catalyst, characterized in that The invention comprises an active component and an organic phosphine polymer ligand, wherein the organic phosphine polymer ligand forms a coordination bond with the active component through a P element in its chemical structure; The active component includes at least one of Co and Rh elements; The organic phosphine polymer ligand is prepared by polymerization and vulcanization of an organic phosphine monomer including a carbon-carbon double bond; The content of sulfur element is 1%-20% based on the mass of the heterogeneous catalyst.

2. The heterogeneous catalyst according to claim 1, characterized in that The vulcanization step comprises: reacting the polymerization product of the organic phosphine monomer with sulfur at 110° C.-150° C. for 4 h-10 h.

3. The heterogeneous catalyst according to claim 1 or 2, characterized in that Based on the mass of the heterogeneous catalyst, the content of the active component is 0.001%-3%, and / or the content of the organic phosphine polymer ligand is 97%-99.999%.

4. The heterogeneous catalyst according to claim 1 or 2, characterized in that The organic phosphine monomer comprises at least one of the following compounds:

5. Use of the heterogeneous catalyst according to any one of claims 1 to 4 in a process for preparing mercaptans.

6. A method for preparing mercaptan, characterized in that: The steps include: In the presence of the heterogeneous catalyst according to any one of claims 1 to 4, olefins react with CO, H2 and H2S, and the volume space velocity of the mixed gas of CO, H2 and H2S is controlled to be 0.1h -1 -50h -1 , the reaction temperature is 80℃-150℃, the reaction pressure is 0.5MPa-10MPa, and mercaptan is obtained.

7. The method for preparing mercaptan according to claim 6, characterized in that: The volumetric space velocity of a mixture of CO, H2 and H2S is 1h -1 -30h -1 ; and / or, the reaction temperature is 100°C-130°C; And / or, the reaction pressure is 1.5 MPa-5 MPa.

8. The method for preparing mercaptan according to claim 6 or 7, characterized in that: When C2-C4 olefin is used, the mass flow rate of the olefin is 0.01 g / (h·mL catalyst)-0.5 g / (h·mL catalyst).

9. The method for preparing mercaptan according to claim 6 or 7, characterized in that: At least one of the following conditions is met: a. The molar ratio of H2S to H2 is 0.4-2.5:1; b. The molar ratio of CO to H2 is 0.4-1.2:1; c. The molar ratio of olefin to CO is 1.0-5.0:

1.

10. The method for preparing mercaptan according to claim 6 or 7, characterized in that: The olefin is a C2-C20 monoolefin, preferably at least one of propylene, 1-butene, 2-butene, 1-pentene, 1-hexene, 1-heptene, 2-heptene, 1-octene, 1-undecene, 2-methyl-1-decene, 5-methyl-5-decene, 8-methyl-1-decene, and 2,4,4,6-tetramethyl-2-heptene.

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