Bifunctional catalyst for synthesizing saturated acid ester through esterification-hydrogenation coupling reaction of unsaturated acid or / and anhydride and application of bifunctional catalyst

Abstract

The invention provides a bifunctional catalyst for synthesizing saturated acid ester through unsaturated acid / anhydride esterification-hydrogenation coupling reaction and application of the bifunctional catalyst. The catalyst is composed of a solid acid carrier with an esterification function and an active metal with a hydrogenation function or an active metal and metal oxide auxiliary agent, and the solid acid comprises an acidic oxide, a hydrogen-type zeolite molecular sieve or a supported solid acid. The active metal comprises one or two of Ni, Ru, Pd or Pt or bimetallic or multi-metal composed of Ni, Ru, Pd or Pt and at least one of Mn, Fe, Co or Cu, and the auxiliary agent comprises one or more of oxides of Mg, Ca, Sn, Pb, Y, La, Ce, Sm, Nd, B, P, Mo, W or Zn. The catalyst is used for unsaturated acid / anhydride and alcohol one-step esterification-hydrogenation coupling reaction to synthesize saturated acid ester and has excellent catalytic activity.

Description

Technical Field

[0001] The present invention relates to the technical field of catalysts and their preparation, and particularly relates to a bifunctional catalyst for the synthesis of saturated acid esters by the coupling reaction of esterification - hydrogenation of unsaturated acids or / and acid anhydrides and its application. Background Art

[0002] Organic carboxylic acid esters are a type of green biodiesel, polyester and polyurethane monomers, as well as excellent non - ionic surfactants, and are widely used as high - grade lubricants, additives, emulsifiers, solvents and intermediates, etc., mainly in the fields of fuels, plastics, oils, cosmetics, foods, spices, medicines and dyes, etc. In addition, about 60% of fatty alcohols globally are produced from fatty acid esters as raw materials. Organic carboxylic acid esters such as saturated carboxylic acid esters, fatty acid polyol esters and ester oils have extensive applications in various fields of industrial production.

[0003] Chinese Patent CN107686760B provides a synthetic ester lubricating oil base oil with a high viscosity index and its preparation method. This synthetic ester lubricating oil base oil is prepared by a step - by - step esterification reaction using pyromellitic acid, triethanolamine, dihydroxypolyether, 1,10 - decanediol, tetraethylene glycol, n - octanoic acid, cyclohexanecarboxylic acid, and an organic solvent as the main raw materials; the obtained synthetic ester lubricating oil base oil has a very high viscosity index and a low pour point, and can meet the requirements of high - viscosity lubricants without the need to additionally add a viscosity index modifier. CN104845699B discloses a dibasic acid ester - type lubricating oil base oil and its preparation method. Using dibasic acid and monohydric alcohol as raw materials, and using H x A y M z O n -type heteropolyacid as a catalyst to synthesize diesters, with an esterification rate reaching over 99%; the diesters are refined and purified by an adsorption decolorization - neutralization - distillation process, and the product has a high purity, a pour point below - 70 °C, a viscosity index greater than 150, a flash point above 250 °C, and an acid value below 0.05 mgKOH / g. CN104845700B provides a lubricating oil base oil with a long - carbon - chain dibasic acid complex ester structure and its preparation method. The chemical general formula of the long - carbon - chain dibasic acid complex ester is: (R 2 COO) n -R 1 -OOC - R - COO - R 3 -(OOCR 2 ) n , where: R is a straight - chain alkylene group of C 9 ~C 12 , R 1 , R 3 are saturated hydrocarbon groups of C 1 ~C 6 , and R 2 is C 3 ~C18 alkyl group, and n is an integer from 1 to 6; this complex ester base oil has the advantages of low pour point, high viscosity index, high flash point, good biodegradability, etc., and the kinematic viscosity at 40 °C is 100 - 1000 mm 2 / s, which is suitable as a lubricating oil base oil with medium to high viscosity. In the preparation method of the above fatty acid ester, the preparation process has many steps and is complex.

[0004] Saturated carboxylic acid anhydride is esterified to prepare saturated carboxylic acid ester, for example, succinic anhydride is esterified to prepare succinic mono- or diester. CN104557536B discloses a preparation method of monomethyl succinate. Succinic anhydride and methanol are introduced into a static mixer for monoesterification reaction, and the reaction effluent then enters a high-gravity reactor for reaction. At the same time, water vapor is introduced into the high-gravity reactor. After the reaction, the liquid-phase material is cooled and separated to obtain monomethyl succinate. The optimized process conditions are that the molar ratio of succinic anhydride to methanol is 1:1.5 - 2.5, the reaction temperature is 90 - 120 °C, the reaction pressure is 0.2 - 2.0 MPa (to ensure that the reaction materials are in the liquid phase), the residence time is 1 - 2 h, and the material cooling temperature is 10 - 15 °C. CN110256244B discloses a synthesis method of diisopropyl succinate. Using succinic anhydride and isopropyl alcohol as raw materials, acidic resin and solid superacid are used as catalysts for segmented catalytic continuous production of diisopropyl succinate.

[0005] Unsaturated carboxylic acid ester is hydrogenated to prepare saturated carboxylic acid ester, for example, maleic diester is hydrogenated to prepare succinic diester. CN101979139B provides a catalyst and its preparation method for hydrogenating maleic dicarboxylic ester to prepare succinic dicarboxylic ester. The nickel content of the active component of the catalyst is 5 - 25 wt%, and the content of the promoters Na, K, Ca, Mg, Mn, Ba or Cu is 0.5 - 8 wt%. The rest is the carrier alumina, silica, silica-alumina composite oxide or activated carbon; the maleic dicarboxylic ester suitable for hydrogenation by the catalyst is C 1 -C 5 carboxylic acid ester. Using a fixed-bed reaction process, the conversion rate of maleic dicarboxylic ester is 100%, and the selectivity of succinic dicarboxylic ester is more than 99.6%. CN101745396B discloses a method and catalyst for hydrogenating maleic dialkyl ester (C 1 -C 5 alkyl ester) to prepare succinic dialkyl ester. The CuZnAl catalyst is prepared by the co-precipitation method, in which the main active component copper oxide accounts for 40 - 60%, the promoter zinc oxide accounts for 20 - 50%, and alumina accounts for 10 - 20%; before use, the catalyst is reduced in a hydrogen stream at 230 - 300 °C for 4 - 12 hours, and then hydrogenation reaction is carried out at a reaction temperature of 80 - 120 °C, a hydrogen pressure of 0.1 - 7.0 MPa, a hydrogen-ester molar ratio of 5 - 250, and a liquid hourly space velocity of 0.1 - 10 h -1 .

[0006] The two-step reaction of esterification and hydrogenation of unsaturated acid anhydride is used to prepare saturated acid esters. For example, maleic anhydride is esterified and hydrogenated to prepare dimethyl succinate. For example, CN102070448B discloses a method for preparing dimethyl succinate. Using maleic anhydride and methanol as raw materials, an acidic cation exchange resin catalyst and a fixed bed catalytic distillation process are used to synthesize dimethyl maleate, and then through Al 2 O 3 , SiO 2 , TiO 2 , ZrO 2 or activated carbon as the carrier to load Pd catalyst and the fixed bed reaction process to hydrogenate dimethyl maleate to prepare dimethyl succinate. The esterification conversion rate of maleic anhydride is 100% and the selectivity of dimethyl maleate is greater than 99%. The hydrogenation conversion rate of dimethyl maleate and the selectivity of dimethyl succinate are both greater than 99.8%. CN115745772A synthesizes diester succinate through two-step reactions of maleic anhydride esterification and hydrogenation of dimaleate. The esterification conversion rate of maleic anhydride is greater than 99.5%, the hydrogenation conversion rate of dimaleate is greater than 99.5%, and the selectivity of diester succinate exceeds 99.7%.

[0007] At present, the synthesis methods of saturated carboxylic acid esters mainly include the esterification method of saturated acids or acid anhydrides and alcohols, the transesterification method of saturated acid lower alkyl esters, the hydrogenation method of unsaturated acid esters, the two-step method of esterification and hydrogenation of unsaturated acids or acid anhydrides, etc. However, there are few reports on the one-step preparation of saturated acid esters through the esterification-hydrogenation coupling reaction of unsaturated acids or acid anhydrides. Summary of the Invention

[0008] Aiming at the above deficiencies in the prior art, the purpose of the present invention is to provide a bifunctional catalyst for the synthesis of saturated acid esters by the esterification-hydrogenation coupling reaction of unsaturated acids or / and acid anhydrides and its application, so as to realize the one-step synthesis of saturated acid esters from unsaturated acids or / and acid anhydrides and alcohols through the esterification-hydrogenation coupling reaction.

[0009] To achieve the above purpose, the technical solution of the present invention is specifically: a bifunctional catalyst for the synthesis of saturated acid esters by the esterification-hydrogenation coupling reaction of unsaturated acids or / and acid anhydrides. The catalyst is composed of a solid acid carrier, a metal active component and a metal oxide promoter with or without. Among them: the solid acid carrier is selected from acidic oxides, hydrogen-type zeolite molecular sieves, porous materials loaded with acidic oxides or supported acids of solid superacids; the metal active component is one or two of Ni, Ru, Pd or Pt, or a bimetal or polymetal composed of at least one of them and Mn, Fe, Co or Cu, and the metal oxide promoter is one or more of the oxides of Mg, Ca, Sn, Pb, Y, La, Ce, Sm, Nd, Mo, W or Zn; the mass percentages of each component are: the solid acid carrier is 65-99.9wt%, the metal active component is 0.1-25wt%, and the metal oxide promoter is 0-10wt%.

[0010] The present invention is further configured such that, in the solid acid support, the acidic oxide is selected from γ-Al 2 O 3 , SiO 2 -Al 2 O 3 , Fe 2 O 3 , Nb 2 O 5 , MoO 3 or WO 3 ; the hydrogen-type zeolite molecular sieve is selected from at least one of HM, HHEU, HY, Hβ, HZSM-5, HZSM-11, HZSM-12, HZSM-18, HZSM-22, HZSM-23, HZSM-35, HZSM-48, HMCM-22, HMCM-49 or HMCM-56;

[0011] The porous material in the supported acid is selected from activated carbon, mesoporous carbon, carbon nanotubes, graphene, γ-Al 2 O 3 , θ-Al 2 O 3 , mesoporous Al 2 O 3 , SiO 2 , mesoporous SiO 2 , SiO 2 -Al 2 O 3 , TiO 2 , mesoporous TiO 2 , ZrO 2 , HM, HHEU, Hβ, HZSM-5, HZSM-22, HMCM-22, HMCM-41, HMCM-48, HMCM-49, HMCM-56, AlPO 4 -11, SAPO-11, SAPO-34, Silicalite-1 (S-1), Silicalite-2 (S-2), TS-1, TS-2, SBA-15, ZEO-1, ZEO-3, KIT-6, SCM-14, montmorillonite, diatomite, bentonite or attapulgite; the solid superacid in the supported acid is selected from at least one of SO 4 2- / M x O y type or AO 3 / MO 2 type solid superacids; the acidic oxide in the supported acid is selected from at least one of oxides of phosphorus, arsenic, selenium, tellurium, antimony, vanadium, niobium, molybdenum or tungsten, isopolyacids, heteropolyacids or their salts; the SO4 2- / M x O y type solid superacids include SO 4 2- / ZrO 2 、SO 4 2- / TiO 2 、SO 4 2- / Fe 2 O 3 、SO 4 2- / ZrO 2 -La 2 O 3 、SO 4 2- / ZrO 2 -CeO 2 、SO 4 2- / TiO 2 -ZrO 2 ,wherein the AO 3 / MO 2 type solid superacids include WO 3 / ZrO 2 or MoO 3 / TiO 2 ,and the acidic oxides include Nb 2 O 5 、H 3 PO 4 、H 6 TeO 6 、H 2 WO 4 、Al(H 2 PO 4 ) 3 、AlPO 4 、Zr(HPO 4 ) 2 、VPO x 、H 3 PW 12 O 40 、H 3 PMo 12 O 40 、H 4 SiW 12 O 40 、H 4 SiMo 12 O 40 or Cs 2.5 H 0.5 PW 12 O40 .

[0012] The present invention is further configured such that the supported acid is selected from one of activated carbon (AC), SiO 2 , γ-Al 2 O 3 , SiO 2 -Al 2 O 3 , TiO 2 , ZrO 2 , HM, Hβ, HZSM-5, HMCM-22, HMCM-41, HMCM-48, S-1, TS-1 or SBA-15 supported with SO 4 2- / TiO 2 -ZrO 2 , SO 4 2- / ZrO 2 -CeO 2 -Fe 2 O 3 , WO 3 / ZrO 2 , Nb 2 O 5 , H 3 PO 4 , Zr(HPO 4 ) 2 , H 3 PW 12 O 40 or Cs 2.5 H 0.5 PW 12 O 40 of one kind.

[0013] The present invention is further configured such that the metal active component is single metal Ni, Ru, Pd, or bimetal Ni-Cu, Ni-Co, Ru-Ni, Pd-Ni, Pd-Fe, Pd-Ru, Pt-Co, Ru-Cu, Pd-Cu, Pt-Cu, or polymetal Ni-Cu-Mn, Ni-Co-Mn or Ru-Ni-Mn, and the metal oxide promoter is MgO, La 2 O 3 , CeO 2 , SnO, PbO, MoO 3 , WO 3 or ZnO or their combination; preferably the metal active component is Ni, Pd, Ni-Cu, Ru-Ni, Pd-Ni or Ni-Cu-Mn, and the promoter is MgO, La 2 O 3 , CeO 2, MoO 3 , WO 3 or ZnO.

[0014] The present invention is further configured such that when the metal active component is selected from one or two of Ru, Pd or Pt, the content of the metal active component is 0.1-7.5 wt%; preferably, the content of Ru is 1.0-5.0 wt%, and the content of Pd or Pt is 0.2-1.0 wt%; or,

[0015] when the metal active component is selected from Ni or one of Ni and noble metals Ru, Pd or Pt, wherein the content of Ni is 1.0-20.0 wt%, and the content of the noble metal is 0-1.5 wt%; preferably, the Ni content is 5.0-15.0 wt%, or the Ni content is 2.0-7.5 wt% and the Ru content is 0.5-1.0 wt%, or the Ni content is 2.0-5.0 wt% and the Pd or Pt content is 0.1-0.5 wt%; or,

[0016] when the metal active component is selected from one or two of Ni, Ru, Pd or Pt and at least one of Mn, Fe, Co or Cu to form a bimetal or polymetal, the content of at least one or two metals selected from Mn, Fe, Co or Cu is 2.0-25.0 wt%, and the content of one or two metals selected from Ni, Ru, Pd or Pt is 0.1-7.5 wt%; preferably, the content of one or two metals selected from Mn, Fe, Co or Cu is 5.0-15.0 wt%, and the Ni content is 2.0-5.0 wt%, or the Ru content is 0.5-2.0 wt%, or the Pd or Pt content is 0.1-0.5 wt%.

[0017] The present invention is further configured such that when the solid acid carrier is a supported acid, when the supported acid is a porous material loaded with an acidic oxide, the content of the acidic oxide is 10-25 wt%, and when the supported acid is a porous material loaded with a solid superacid, the content of the solid superacid is 15-45 wt%.

[0018] The present invention is further configured such that the preparation steps of the catalyst are as follows:

[0019] S1. Preparation of the solid acid powder carrier:

[0020] S11. Preparation of the hydrogen-type zeolite molecular sieve: The molecular sieve raw powder is calcined in an air stream at 350 °C for 1-3 h, and then calcined at 550 °C for 3-5 h, and cooled to room temperature to obtain the molecular sieve powder from which the template agent is removed; then the molecular sieve from which the template agent is removed is placed in an exchange kettle, and 0.1-1.0 mol / L NH 4The Cl solution is refluxed and exchanged with stirring at 75-85 °C for 2-3 h, filtered or centrifuged, and washed with deionized water until the pH value is 6-8; after repeating the exchange 2-4 times, the cake is dried at 120-200 °C for 1-3 h, then the cake is pulverized and calcined in an air stream at 300-350 °C for 1-3 h and at 500-550 °C for 3-5 h, and cooled to room temperature to obtain a hydrogen-form molecular sieve powder carrier;

[0021] S12. Preparation of the supported solid acid: Use an aqueous solution of a heteropolyacid, heteropolyacid salt, or isopolyacid of phosphorus, arsenic, selenium, tellurium, antimony, vanadium, niobium, molybdenum, or tungsten, or an aqueous solution of a nitrate or ammonium salt of other metals, and impregnate the large specific surface area porous material powder at 50-85 °C with stirring for 20-60 min, then heat to evaporate to dryness, and then calcine at 300-550 °C for 3-5 h to obtain a solid acid powder supported with an acidic oxide; or, use sulfuric acid and an aqueous solution of a nitrate, sulfate, or ammonium salt of the corresponding metal, or an aqueous solution of an ammonium salt and a nitrate or an alcohol solution of an alkoxide of the corresponding metal, and impregnate the large specific surface area porous material powder at 50-85 °C with stirring for 20-60 min, heat to evaporate to dryness and then calcine at 300-350 °C for 2-3 h and at 500-650 °C for 3-5 h to obtain a solid acid powder carrier of supported SO 4 2- / M x O y type or AO 3 / MO 2 type solid superacid (M is a +2 to +4 valence metal element, A is a +6 valence metal element, x = 1 or 2, y = 1-3);

[0022] S2. Preparation of the solid acid particle carrier: Mix the commercial solid acid powder or the solid acid powder carrier prepared in step S1 with water, an extrusion aid, and a pore-forming agent, and form it by rolling, extrusion, or tableting, and then dry it in an air stream at 120-200 °C for 0.5-2.0 h and calcine it at 450-500 °C for 3-5 h to obtain a solid acid particle carrier;

[0023] S3. Loading of the metal oxide promoter: Use an aqueous solution of a soluble nitrate, acetate, chloride, or ammonium salt of the corresponding promoter metal element, impregnate the commercial solid acid particle carrier or the solid acid particle carrier prepared in step S2 at 50-85 °C for 20-60 min, dry it at 120-200 °C for 1-3 h and then calcine it at 450-550 °C for 3-5 h to obtain a solid acid particle supported with a metal oxide promoter;

[0024] S4. Preparation of bifunctional catalyst particles: An aqueous solution of one, two or more of soluble compounds of metals Ru, Pd, Pt, Mn, Fe, Co, Ni or Cu is impregnated on a commercial solid acid particle support, or the solid acid particle support prepared in step S2, or the solid acid particle loaded with a metal oxide promoter prepared in step S3 at 50 - 85°C for 20 - 60 min, dried at 120 - 200°C for 1 - 3 h, and then calcined at 450 - 600°C for 3 - 6 h to obtain bifunctional catalyst particles with solid acid supported single metal, bimetal or multi-metal.

[0025] The present invention is further configured such that the extrusion aid (also a pore-forming agent) in step S2 is selected from at least one of ammonia water, nitric acid, acetic acid, oxalic acid, tartaric acid, citric acid, sesbania powder, paraffin, stearic acid, glycerol, starch, polyethylene glycol, polyoxypropylene ether, polytetrahydrofuran, polyvinyl alcohol, polyacrylamide, cellulose, methyl cellulose and graphite, and the addition amount is 2.0 - 15.0 wt%; preferably, the extrusion aid is selected from at least one of nitric acid, acetic acid, sesbania powder, glycerol, starch, polyethylene glycol, polyvinyl alcohol, methyl cellulose and graphite, and the addition amount is 5.0 - 10.0 wt%.

[0026] The present invention is further configured such that the morphology of the catalyst particles is a sphere with a diameter of 1.0 - 5.0 mm, a cylinder with a length of 1 - 5 mm, a clover with a length of 1 - 8 mm or a strip with a length of 1 - 8 mm, preferably a sphere with a diameter of 1.6 - 3.0 mm, a cylinder with a length of 2 - 3 mm, a clover with a length of 2 - 5 mm or a strip with a length of 2 - 5 mm.

[0027] The present invention also provides an application of the above-mentioned catalyst in the reaction of synthesizing saturated acid esters by the esterification-hydrogenation coupling reaction of unsaturated acids or / and acid anhydrides.

[0028] The present invention is further configured such that the process of the esterification-hydrogenation coupling reaction is as follows: An unsaturated acid or / and acid anhydride is mixed with an alcohol and preheated to the reaction temperature, and then fed into a fixed-bed reactor filled with a bifunctional catalyst that has been pre-reduced and activated in advance to carry out the esterification-hydrogenation coupling reaction to prepare saturated acid esters.

[0029] The present invention is further configured such that the reduction and activation of the catalyst are carried out on a fixed-bed reaction device by an in-situ pressurized reduction method, and the reduction and activation conditions are: a reduction temperature of 100 - 400°C, a hydrogen gas volume space velocity of 5 - 100 h -1 and a pressure of 0.2 - 3.5 MPa; preferably a reduction temperature of 150 - 350°C, a hydrogen gas volume space velocity of 10 - 50 h -1 and a pressure of 0.5 - 3.0 MPa; more preferably a reduction temperature of 180 - 250°C, a hydrogen gas volume space velocity of 15 - 30 h -1 and a pressure of 1.0 - 2.5 MPa.

[0030] The present invention is further configured such that the esterification-hydrogenation coupling reaction process conditions are as follows: temperature 45 to 200 °C, hydrogen pressure 0.2 to 3.0 MPa, weight hourly space velocity of the liquid raw materials 0.05 to 2.00 h -1 , molar ratio of alcohol to acid or / and acid anhydride in the raw materials 0.25 to 5.00, molar ratio of hydrogen to acid or / and acid anhydride 5 to 50; preferably, temperature 55 to 180 °C, hydrogen pressure 0.5 to 2.5 MPa, weight hourly space velocity of the liquid raw materials 0.10 to 1.50 h -1 , molar ratio of alcohol to acid or / and acid anhydride 0.35 to 3.00, molar ratio of hydrogen to acid / and acid anhydride 7.5 to 40; more preferably, temperature 65 to 150 °C, hydrogen pressure 1.0 to 2.0 MPa, weight hourly space velocity of the liquid raw materials 0.2 to 1.0 h -1 , molar ratio of alcohol to acid or acid anhydride 0.45 to 2.50, molar ratio of hydrogen to acid or / and acid anhydride 10 to 30.

[0031] The present invention is further configured such that the unsaturated acid or acid anhydride includes acrylic acid, propiolic acid, methacrylic acid, 2-butenoic acid (crotonic acid), 2-butynoic acid, 4-pentenoic acid, 2,4-pentadienoic acid, 2,4-hexadienoic acid (sorbic acid), 3-cyclohexylacrylic acid, 3-phenylacrylic acid (cinnamic acid), furylacrylic acid, myristoleic acid, palmitoleic acid, ricinoleic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid, butynedioic acid, maleic acid, fumaric acid, maleic anhydride, methylenemalonic acid, glutaconic acid, glutaconic anhydride, methylenesuccinic acid (itaconic acid), methylenesuccinic anhydride (itaconic anhydride), norbornene dianhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexenedioic acid, cis-hexenedioic acid, heptenedioic acid, octenedioic acid, nonenedioic acid, decenedioic acid, cis-aconitic acid, trans-aconitic acid or aconitic anhydride;

[0032] Preferably, the unsaturated acid or acid anhydride is acrylic acid, methacrylic acid, crotonic acid, sorbic acid, cinnamic acid, furylacrylic acid, myristoleic acid, palmitoleic acid, ricinoleic acid, oleic acid, maleic acid, fumaric acid, maleic anhydride, glutaconic acid, glutaconic anhydride, itaconic acid, itaconic anhydride, norbornene dianhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, cis-aconitic acid or aconitic anhydride;

[0033] More preferably, the unsaturated acid or acid anhydride is acrylic acid, methacrylic acid, crotonic acid, sorbic acid, cinnamic acid, ricinoleic acid, oleic acid, maleic acid, fumaric acid, maleic anhydride, itaconic acid, itaconic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride or aconitic anhydride.

[0034] The present invention is further configured such that in the esterification-hydrogenation coupling reaction, the alcohol substances in the raw materials include saturated monohydric alcohols, unsaturated monohydric alcohols, saturated polyhydric alcohols, unsaturated polyhydric alcohols, saturated polyether polyols, unsaturated polyether polyols, saturated polyester polyols or unsaturated polyester polyols;

[0035] Preferably, the alcohol substances are methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol, isopentanol, neopentanol, n-hexanol, n-heptanol, n-octanol, isooctanol, n-nonanol, isononanol, n-decanol, cyclopentanol, cyclohexanol, methylcyclohexanol, benzyl alcohol, α-phenylethyl alcohol, β-phenylethyl alcohol, α,α-dimethylbenzyl alcohol, 1-phenylpropanol (hydrocinnamyl alcohol), 2-tetrahydrofurfuryl alcohol, 2-furfuryl alcohol, tetrahydropyranol, 4-pyridinemethanol (nicotinyl alcohol), 4-piperidinemethanol, 3-thiophenemethanol, 2-thiopheneethanol, 5-pyrimidinemethanol, allyl alcohol, propargyl alcohol, 2-butenol (crotyl alcohol), methallyl alcohol, butynediol, 2-pentenol, isopentenol, 2-cyclohexenol, cinnamyl alcohol, 3-(2-furyl)allyl alcohol; ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 2-ethyl-2-methyl-1,3-propanediol, 2-isopropyl-2-methyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-n-butyl-2-ethyl-1,3-propanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1-phenyl-1,3-propanediol, 2-phenyl-1,3-propanediol, 1-phenyl-1,4-butanediol, m-xylene glycol, p-xylene glycol, 2,6-naphthalenedimethanol, 2,2'-biphenyldimethanol, 4,4'-biphenyldimethanol, 2,5-furandimethanol, 2,6-pyridinedimethanol, glycerol, trimethylolethane, 1,2,6-hexanetriol, trimethylolpropane, erythritol, pentaerythritol, xylitol, sorbitol, mannitol, inositol, butenediol, butynediol; bis(3-hydroxy-2,2-dimethylpropyl) ether, diglycerol, triglycerol, bis(trimethylolethane), bis(trimethylolpropane), dipentaerythritol, tripentaerythritol, polyethylene glycol, polypropylene glycol, polybutylene glycol with a polymerization degree of 2 to 100, and polybutylene succinate diol, polyethylene terephthalate diol or polybutylene maleate diol with a polymerization degree of 2 to 50;

[0036] More preferably, the alcohol is methanol, ethanol, isopropanol, isobutanol, neopentyl alcohol, isooctyl alcohol, cyclohexanol, benzyl alcohol, α-phenylethyl alcohol, tetrahydrofurfuryl alcohol, furfuryl alcohol, allyl alcohol, crotyl alcohol, methallyl alcohol, isoprenol, cinnamyl alcohol; ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 2-ethyl-2-methyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, p-xylene glycol, 2,5-furandimethanol, glycerol, trimethylolethane, 1,2,6-hexanetriol, trimethylolpropane, pentaerythritol, sorbitol, butenediol, butynediol, diglycerol, triglycerol, ditrimethylolethane, ditrimethylolpropane, dipentaerythritol, tripentaerythritol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol with a polymerization degree of 5-50, polypropylene glycol with a polymerization degree of 4-40, polybutylene glycol with a polymerization degree of 2-30, poly(butylene succinate) diol with a polymerization degree of 2-20, and polyethylene terephthalate diol with a polymerization degree of 2-20.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] (1) The present invention provides a bifunctional catalyst for synthesizing saturated acid esters by the esterification-hydrogenation coupling reaction of unsaturated acids or / and acid anhydrides, which is composed of a solid acid support with esterification function and an active metal with hydrogenation function or an active metal and a metal oxide promoter; it is used for the one-step preparation of saturated acid esters by the esterification-hydrogenation coupling reaction of unsaturated acids or / and acid anhydrides with alcohols, and a fixed-bed reaction process and relatively mild reaction process conditions are adopted. Compared with the prior art that uses two-step reaction processes of esterification and hydrogenation, and two catalysts of inorganic liquid acid or solid acid esterification catalyst and hydrogenation catalyst, the process flow is shortened, the device investment is saved, the process is clean and efficient, and there is no need to separate the catalyst.

[0039] (2) The catalyst of the present invention has excellent catalytic activity for the one-step esterification-hydrogenation coupling reaction of unsaturated acids or acid anhydrides with alcohols to synthesize saturated acid esters. Especially for the ring-opening esterification of unsaturated acid anhydrides to prepare saturated acid esters, the esterification rate of unsaturated acid anhydrides, the double bond hydrogenation rate and the selectivity of saturated acid esters are all close to 100%. Detailed implementation mode

[0040] The following will further illustrate the present invention in combination with specific embodiments. It should be noted that the embodiments described in this part are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the scope of protection of the present invention.

[0041] Examples 1 - 12

[0042] Preparation of Metal Bifunctional Catalysts Supported on Acidic Oxides or Hydrogen-Type Molecular Sieves

[0043] S1. Preparation of hydrogen-type molecular sieve powder carriers: The original powders of NaM, NaZSM-5 or NaMCM-22 molecular sieves are calcined in an air stream at 350 °C for 2 h, then at 550 °C for 5 h, and cooled to room temperature to obtain molecular sieve powders without template agents; then, they are refluxed and exchanged with 1.0 mol / L NH 4 Cl solution under stirring at 85 °C for 2 h, filtered, and washed with deionized water until the pH value is < 8; after repeating the exchange 2 times, the cake is dried at 200 °C for 2 h, and then the cake is crushed and calcined in an air stream at 350 °C for 2 h and 550 °C for 5 h to obtain HM, HZSM-5 or HMCM-22 molecular sieve powder carriers.

[0044] S2. Preparation of hydrogen-type molecular sieve particle carriers: 10 wt% of water, 8 wt% of sesbania powder and 2 wt% of graphite are added to the hydrogen-type molecular sieve powder carriers prepared in step S1, mixed evenly and then extruded into shapes, and then dried in an air stream at 200 °C for 2.0 h and calcined at 500 °C for 5 h to obtain clover-shaped HM, HZSM-5 or HMCM-22 molecular sieve particle carriers with a particle size of 2.2 mm and a length of 3 - 5 mm.

[0045] S3. Loading of metal oxide promoters: An aqueous solution of ammonium heptamolybdate or cerium nitrate is prepared, and the HM molecular sieve particle carriers prepared in step S2 are impregnated at 50 °C for 30 min, dried at 200 °C for 2 h and calcined at 550 °C for 3 h to obtain HM molecular sieve particles loaded with promoters MoO 3 or CeO 2 .

[0046] S4. Loading of metal active components: Aqueous solutions or dilute hydrochloric acid solutions of RuCl 3 , PdCl 2 , H 2 PtCl 6 , Ni(NO 3 ) 2 , Co(NO 3 ) 2 , Cu(NO 3 ) 2 or Mn(AcO) 2 are prepared, and γ-Al 2 O 3 , the molecular sieve particle carriers prepared in step S2 or the molecular sieve particles loaded with promoters prepared in step S3 are impregnated at 50 °C for 30 min, dried at 200 °C for 2 h and then calcined at 600 °C for 5 h to obtain γ-Al 2 O3 , HM, HZSM-5 or HMCM-22 supported metal bifunctional particulate catalysts.

[0047] Corresponding to Examples 1 to 12, the prepared porous material γ-Al 2 O 3 , HM, HZSM-5 or HMCM-22 supported metal bifunctional particulate catalysts are listed in Table 1 respectively.

[0048] Examples 13 to 18

[0049] Preparation of supported solid acid supported metal bifunctional catalysts

[0050] S1. Preparation of supported solid acid powder carriers: Use an aqueous solution of H 3 PW 12 O 40 or Cs 2.5 H 0.5 PW 12 O 40 to impregnate porous material AC, HMCM-48 or SBA-15 powder for 45 min at 80 °C under stirring, then heat to evaporate to dryness, and then calcine at 350 °C for 5 h to obtain supported heteropolyacid solid acid powder carriers; or use an aqueous solution of concentrated sulfuric acid and cerium nitrate, zirconium oxysulfate, or an aqueous solution of concentrated sulfuric acid and zirconium oxysulfate, tetrabutyl titanate, or an aqueous solution of zirconium nitrate and ammonium tungstate to impregnate porous material SiO 2 , HMCM-22, diatomite powder for 60 min at 85 °C under stirring, heat to evaporate to dryness and then calcine at 350 °C for 2 h and 550 °C for 5 h to obtain supported solid superacid solid acid powder carriers.

[0051] S2. Preparation of supported solid acid particulate carriers: Add 8 wt% water, 5 wt% methylcellulose and 1 wt% graphite to the supported solid acid powder carriers prepared in step S1, mix well and extrude into shape, then dry in an air stream at 200 °C for 2.0 h and calcine at 500 °C for 5 h to obtain clover-shaped supported solid acid particulate carriers with a particle size of 2.2 mm and a length of 3 - 5 mm.

[0052] S4. Preparation of bifunctional catalyst particles: Prepare a dilute hydrochloric acid solution of PdCl 2 or PdCl 2 and RuCl 3 , impregnate the supported solid acid particulate carriers prepared in step S2 at room temperature for 30 min, dry at 150 °C for 2 h and then calcine at 550 °C for 5 h to obtain supported solid acid supported metal bifunctional particulate catalysts.

[0053] Corresponding to Examples 13 to 18, the prepared supported solid acid supported metal bifunctional catalysts are listed in Table 1.

[0054] Table 1 Solid acid supported metal bifunctional catalysts prepared in Examples 1-18 and labels

[0055] Examples Bifunctional Catalysts and Compositions Labels 1 <![CDATA[0.5wt% Pd / γ-Al 2 O 3 > Cat-01 2 <![CDATA[20wt% Ni / γ - Al 2 O 3 > Cat-02 3 0.5 wt% Pd / HM Cat-03 4 <![CDATA[0.3 wt% Pd - 3.0 wt% CeO 2 / HM]]> Cat-04 5 0.2 wt% Pd - 5.0 wt% Ni / HM Cat-05 6 <![CDATA[15wt% Ni - 5wt% MoO 3 / HM]]> Cat-06 7 5 wt% Ni - 5 wt% Cu / HZSM-5 Cat-07 8 2 wt% Ru / HZSM-5 Cat-08 9 0.5 wt% Pd / HZSM-5 Cat-09 10 0.2 wt% Pd - 0.5 wt% Ru / HMCM-22 Cat-10 11 <![CDATA[3 wt% Ni - 2 wt% Co - 2 wt% Mn / γ - Al 2 O 3 > Cat-11 12 1.0 wt% Ru - 2.0 wt% Ni - 2 wt% Mn / HMCM-22 Cat-12 13 <![CDATA[0.5 wt% Pd / (15 wt% H 3 PW 12 O 40 / SBA-15)]]> Cat-13 14 <![CDATA[0.5 wt% Pd / (20 wt% H 3 PW 12 O 40 / AC)]]> Cat-14 15 <![CDATA[0.5 wt% Pd / (10 wt% Cs 2.5 H 0.5 PW 12 O 40 / HMCM-48)]]> Cat-15 16 <![CDATA[0.5 wt% Pd / [40 wt% (SO 4 2- / ZrO 2 -CeO 2 ) / SiO 2 > Cat-16 17 <![CDATA[0.5 wt% Pd / [35 wt% (SO 4 2- / ZrO 2 -TiO 2 ) / HMCM-22]]]> Cat-17 18 <![CDATA[0.2 wt% Pd - 0.5 wt% Ru / [45 wt% (WO 3 / ZrO 2 ) / diatomaceous earth]]]> Cat-18

[0056] Examples 19-31

[0057] Esterification and hydrogenation of unsaturated monocarboxylic acids with alcohols to prepare saturated monocarboxylic acid esters

[0058] The preparation process is as follows:

[0059] Load the catalyst into a fixed-bed reactor, and carry out in-situ pressure reduction and activation at a temperature of 200 °C, a hydrogen gas hourly space velocity of 20 h -1 and a pressure of 1.5 MPa for 5 h; then adjust the reaction process conditions to a temperature of 65-120 °C, a hydrogen pressure of 1.0-2.0 MPa, a raw material weight hourly space velocity of 0.2-1.0 h -1 , an alcohol-acid molar ratio of 0.45-1.50, and a hydrogen-acid molar ratio of 10-30. Mix the unsaturated acid and alcohol and preheat them to the reaction temperature, and then feed them into the reactor for esterification-hydrogenation coupling reaction to prepare saturated acid esters. Among them, the corresponding unsaturated acids and alcohols in each example are acrylic acid and n-butanol, ethylene glycol, polyethylene glycol (PEG 200), trimethylolpropane (TMP), methacrylic acid (MAA) and isobutanol, 1,2-propanediol (PG), glycerol, crotonic acid and ethanol, 1,4-cyclohexanedimethanol (CHDM), cinnamic acid and benzyl alcohol, sorbic acid and pentanol, ricinoleic acid (BMYA) and methanol, oleic acid and methanol.

[0060] The specific reaction conditions (temperature, hydrogen pressure, raw material space velocity, alcohol-acid molar ratio, hydrogen-acid molar ratio), catalysts and reaction results corresponding to each example are shown in Table 2. It can be seen that the esterification rate of unsaturated acids is 87.6-99.5%, the hydrogenation rate of the double bond of unsaturated acids is 100%, and the selectivity of saturated acid esters is 98.5-100%.

[0061] Comparative Example 1 Synthesis of methyl stearate from oleic acid and methanol through two-step reactions of esterification and hydrogenation

[0062] Refer to the catalyst preparation method and reaction process conditions of Example 31. Feed the mixture of oleic acid and methanol into a fixed-bed esterification reactor filled with a supported solid superacid (SO 4 2- / ZrO 2 -TiO 2 ) / HMCM-22 particle catalyst, at an alcohol-acid molar ratio of 1.35, a temperature of 90 °C and a raw material weight hourly space velocity of 0.5 h -1React under the following conditions to prepare methyl oleate; then send the esterification reaction product into a fixed-bed hydrogenation reactor filled with 0.5 wt% Pd / HMCM-22 particulate catalyst, and carry out a double-bond hydrogenation reaction at a hydrogen-to-ester molar ratio of 20 (based on oleic acid), a weight hourly space velocity of the esterification liquid of 0.5 h -1 ⁻¹, a temperature of 90 °C, and a hydrogen pressure of 1.5 MPa to prepare methyl stearate. The esterification rate of oleic acid is 90.5%, the double-bond hydrogenation rate of methyl oleate is 100%, and the selectivity of methyl stearate is 98.5%.

[0063] Comparing Example 31 and Comparative Example 1, it can be seen that when using the same reaction process conditions and the corresponding catalyst to synthesize methyl stearate from oleic acid and methanol, the esterification rate and selectivity of the esterification-hydrogenation one-step coupling reaction process are higher than those of the two-step series reaction process of esterification and hydrogenation. The esterification rate of oleic acid in the coupling reaction is 91.8% and the double-bond hydrogenation rate is 100%, and the selectivity of methyl stearate is 99.3%.

[0064] Examples 32 - 40

[0065] Esterification and hydrogenation of unsaturated polyacids with alcohols to prepare saturated polyacid esters

[0066] The preparation process is as follows:

[0067] Load the catalyst into a fixed-bed reactor, and carry out in-situ pressure reduction and activation at a temperature of 220 °C, a hydrogen volumetric hourly space velocity of 30 h -1 ⁻¹, and a pressure of 1.0 MPa for 3 h; then adjust the reaction process conditions to a temperature of 90 - 150 °C, a hydrogen pressure of 1.0 - 2.0 MPa, a weight hourly space velocity of the raw materials of 0.20 - 0.50 h -1 ⁻¹, an alcohol-to-acid molar ratio of 0.75 - 2.50, and a hydrogen-to-acid molar ratio of 10 - 30. Mix the unsaturated polyacid and the alcohol and preheat them to the reaction temperature, and send them into the reactor to carry out an esterification-hydrogenation coupling reaction to prepare saturated polyacid esters. Among them, the corresponding unsaturated polyacids and alcohols in each example are maleic acid, fumaric acid, or itaconic acid and methanol, 2-ethylhexanol (EH), ethylene glycol, 1,4-butanediol (BDO), 1,4-cyclohexanedimethanol (CHDM), 2,5-furandimethanol (BHMF), tetraethylene glycol, or pentaerythritol (THME).

[0068] The specific reaction conditions (temperature, hydrogen pressure, raw material space velocity, alcohol-to-acid molar ratio, hydrogen-to-acid molar ratio), catalyst, and reaction results corresponding to each example are shown in Table 2. Obviously, the esterification rate of the unsaturated acid is 85.8 - 95.6%, the double-bond hydrogenation rate of the unsaturated acid is 100%, and the selectivity of the saturated acid ester is 99.4 - 100%.

[0069] Comparative Example 2 Preparation of hydroxybutyl succinate by two-step reaction of esterification and hydrogenation of maleic acid and 1,4-butanediol

[0070] Refer to the catalyst preparation method and reaction process conditions of Example 34. Feed the mixture of maleic acid and 1,4-butanediol (BDO) into a fixed-bed esterification reactor filled with solid acid HM granular catalyst, and carry out the reaction at an alcohol-acid molar ratio of 1.50, a temperature of 135 °C, and a weight hourly space velocity of 0.25 h -1 to prepare hydroxybutyl maleate; then feed the esterification reaction product into a fixed-bed hydrogenation reactor filled with 0.5 wt% Pd / HM granular catalyst, and carry out the double bond hydrogenation reaction at a hydrogen-ester molar ratio of 20 (calculated based on maleic acid), an esterification liquid weight hourly space velocity of 0.25 h -1 , a temperature of 135 °C, and a hydrogen pressure of 1.5 MPa to prepare hydroxybutyl succinate. The esterification rate of succinic acid is 95.5%, the double bond hydrogenation rate of hydroxybutyl maleate is 100%, and the selectivity of hydroxybutyl succinate is 98.3%.

[0071] Comparing Example 34 and Comparative Example 2, it can be seen that using the same reaction process conditions and catalyst, when synthesizing hydroxybutyl succinate from maleic acid and BDO as raw materials, the esterification rate of the esterification-hydrogenation one-step coupling reaction process is lower than that of the two-step series reaction process of esterification and hydrogenation, but the selectivity is higher. The esterification rate of maleic acid in the coupling reaction is 94.6% and the double bond hydrogenation rate is 100%, and the selectivity of hydroxybutyl succinate is 99.9%.

[0072] Table 2 Catalysts, reaction process conditions, and results for the esterification and hydrogenation of unsaturated acids with saturated alcohols to prepare saturated acid esters

[0073]

[0074]

[0075] Examples 41 - 50 Esterification and hydrogenation of unsaturated acid anhydrides with saturated monohydric alcohols to prepare saturated acid esters

[0076] Load the catalyst into a fixed-bed reactor. Catalysts Cat-01, 03 - 05, 08 are in-situ pressure-reducingly reduced and activated at a temperature of 230 °C, a hydrogen volumetric space velocity of 20 h -1 and a pressure of 1.0 MPa for 3 h. Catalysts Cat-02, 06, 07, 11, and 12 are in-situ pressure-reducingly reduced and activated at a temperature of 350 °C, a hydrogen volumetric space velocity of 50 h -1 and a pressure of 2.5 MPa for 3 h; then adjust the reaction process conditions to a temperature of 65 - 120 °C, a hydrogen pressure of 1.0 - 2.0 MPa, and a raw material weight hourly space velocity of 0.50 - 1.00 h -1, with the molar ratio of alcohol to anhydride being 1.05 - 2.20 and the molar ratio of hydrogen to anhydride being 10 - 30, the unsaturated anhydride and alcohol are mixed and preheated to the reaction temperature, and then fed into the reactor for esterification-hydrogenation coupling reaction to prepare saturated acid esters. Among them, the corresponding unsaturated anhydrides and alcohols in each example are maleic anhydride and methanol, butanol, benzyl alcohol, tetrahydrofurfuryl alcohol (THFA), itaconic anhydride (ICA), tetrahydrophthalic anhydride (THPA), methyltetrahydrophthalic anhydride (THMPA), aconitic anhydride (CANA) and methanol.

[0077] The specific reaction conditions (temperature, hydrogen pressure, raw material space velocity, molar ratio of alcohol to anhydride, molar ratio of hydrogen to anhydride), catalysts and reaction results corresponding to each example are shown in Table 3. It can be seen from Table 3 that the esterification rate of the unsaturated anhydride is 99.8 - 100%, the double bond hydrogenation rate of the unsaturated anhydride is 100%, and the selectivity of the saturated acid ester is 100%.

[0078] Comparative Example 3: Preparation of monomethyl succinate by monoesterification of maleic anhydride and methanol followed by hydrogenation

[0079] Referring to the catalyst preparation method and reaction process conditions of Example 43. The mixture of maleic anhydride and methanol is fed into a fixed-bed esterification reactor filled with solid acid γ-Al 2 O 3 particle catalyst, and the reaction is carried out at a molar ratio of alcohol to anhydride of 1.05, a temperature of 65 °C and a weight hourly space velocity of 1.00 h -1 to prepare monomethyl maleate; then the esterification reaction product is fed into a fixed-bed hydrogenation reactor filled with 0.5 wt% Pd / γ-Al 2 O 3 particle catalyst, and the double bond hydrogenation reaction is carried out at a molar ratio of hydrogen to ester of 10 (calculated based on maleic anhydride), a weight hourly space velocity of the esterification liquid of 1.00 h -1 , a temperature of 65 °C and a hydrogen pressure of 1.0 MPa to prepare monomethyl succinate. The esterification rate of maleic anhydride is 100%, the double bond hydrogenation rate of monomethyl maleate is 100%, and the selectivity of monomethyl succinate is 96.6%.

[0080] Comparing Example 43 and Comparative Example 3, it can be seen that using the same reaction process conditions and catalyst, when synthesizing monomethyl succinate from maleic anhydride and methanol, the esterification rate of the esterification-hydrogenation one-step coupling reaction process is slightly lower than that of the esterification and hydrogenation two-step series reaction process, while the selectivity of the monoester is higher. The esterification rate of maleic anhydride in the coupling reaction is 99.8% and the hydrogenation rate is 100%, and the selectivity of monomethyl succinate is 100%.

[0081] Examples 51 - 62

[0082] Esterification and hydrogenation of unsaturated anhydride and saturated polyol to prepare saturated acid ester

[0083] The preparation process is as follows:

[0084] The catalyst was loaded into a fixed-bed reactor and in-situ reduced and activated under pressure for 3 h at a temperature of 210 °C, a hydrogen volumetric space velocity of 30 h -1 and a pressure of 1.5 MPa; then the reaction process conditions were adjusted to a temperature of 120 - 150 °C, a hydrogen pressure of 1.0 - 1.5 MPa, a feed weight hourly space velocity of 0.50 - 1.00 h -1 an alcohol-to-anhydride molar ratio of 1.05 - 1.75, and a hydrogen-to-anhydride molar ratio of 10 - 20. The unsaturated anhydride and alcohol were mixed and preheated to the reaction temperature and then fed into the reactor for an esterification-hydrogenation coupling reaction to prepare a saturated acid ester. Among them, the corresponding unsaturated anhydrides and alcohols in each example were maleic anhydride and ethylene glycol, 1,4-butanediol (BDO), 1,6-hexanediol (HDO), 1,4-cyclohexanedimethanol (CHDM), 2,5-furandimethanol (BHMF), triethylene glycol, trimethylolpropane (TMP), itaconic anhydride (ICA), tetrahydrophthalic anhydride (THPA), methyltetrahydrophthalic anhydride (THMPA), aconitic anhydride (CANA) and BDO.

[0085] The specific reaction conditions (temperature, hydrogen pressure, feed space velocity, alcohol-to-anhydride molar ratio, hydrogen-to-anhydride molar ratio), catalyst and reaction results corresponding to each example are shown in Table 3. The data in Table 3 show that the esterification rate of the unsaturated anhydride is 100%, the double bond hydrogenation rate of the unsaturated anhydride is 100%, and the selectivity of the saturated acid ester is 98.2 - 100%.

[0086] Comparative Example 4

[0087] Preparation of hydroxybutyl succinate by two-step esterification and hydrogenation of maleic anhydride and 1,4-butanediol

[0088] The preparation process was as follows:

[0089] Referring to the catalyst preparation method and reaction process conditions of Example 52. A mixture of maleic anhydride and 1,4-butanediol (BDO) was fed into a fixed-bed esterification reactor filled with solid acid HMCM-22 particle catalyst, and the reaction was carried out at an alcohol-to-anhydride molar ratio of 1.35, a temperature of 120 °C and a feed weight hourly space velocity of 0.75 h -1 to prepare hydroxybutyl maleate; then the esterification reaction product was fed into a fixed-bed hydrogenation reactor filled with 0.2 wt% Pd - 0.5 wt% Ru / HMCM-22 particle catalyst, and at a hydrogen-to-ester molar ratio of 10 (calculated based on maleic anhydride), an esterification liquid weight hourly space velocity of 0.75 h -1 a temperature of 120 °C and a hydrogen pressure of 1.5 MPa, for double bond hydrogenation reaction to prepare hydroxybutyl succinate. The esterification rate of maleic anhydride was 100%, the double bond hydrogenation rate of hydroxybutyl maleate was 100%, and the selectivity of hydroxybutyl succinate was 98.3%.

[0090] Comparing Example 52 with Comparative Example 4, it can be seen that when synthesizing hydroxybutyl succinate using maleic anhydride and BDO as raw materials under the same reaction process conditions and catalyst, the selectivity of the esterification-hydrogenation one-step coupling reaction process is higher than that of the two-step series reaction process of esterification and hydrogenation. For the coupling reaction, the maleic anhydride esterification rate and double bond hydrogenation rate are both 100%, and the selectivity of hydroxybutyl succinate is 99.6%.

[0091] Table 3 Catalysts, reaction process conditions and results for the esterification and hydrogenation of unsaturated acid anhydrides with saturated polyols to prepare saturated acid esters

[0092]

[0093]

[0094] Examples 63 - 78

[0095] Esterification and hydrogenation of unsaturated acids / anhydrides with unsaturated alcohols to prepare saturated acid esters

[0096] The preparation process is as follows:

[0097] Load the catalyst into a fixed-bed reactor and in-situ reduce and activate it under pressure at a temperature of 200 °C, a hydrogen volumetric space velocity of 50 h -1 and a pressure of 1.5 MPa for 3 h; then adjust the reaction process conditions to a temperature of 65 - 120 °C, a hydrogen pressure of 1.0 - 2.0 MPa, a raw material weight hourly space velocity of 0.25 - 1.00 h -1 , an alcohol-acid or alcohol-anhydride molar ratio of 1.05 - 1.35, and a hydrogen-acid or hydrogen-anhydride molar ratio of 10 - 15. Mix the unsaturated acid and the unsaturated alcohol and preheat them to the reaction temperature, and then feed them into the reactor for the esterification-hydrogenation coupling reaction to prepare the saturated acid ester. Among them, the corresponding unsaturated acids and unsaturated alcohols in each example are acrylic acid, methacrylic acid (MAA), cinnamic acid, oleic acid, maleic acid, fumaric acid and allyl alcohol, methallyl alcohol (MAO) or butenediol (BEDO), maleic anhydride and allyl alcohol, MAO, isopentenol (IPA), crotyl alcohol, cinnamyl alcohol, BEDO, BOZ, and itaconic anhydride (ICA) and MAO or BEDO.

[0098] The specific reaction conditions (temperature, hydrogen pressure, raw material space velocity, alcohol-acid or alcohol-anhydride molar ratio, hydrogen-acid or hydrogen-anhydride molar ratio), catalyst and reaction results corresponding to each example are shown in Table 4. It can be seen from Table 4 that the esterification rate of the unsaturated acid or acid anhydride is 82.4 - 100%, the double bond hydrogenation rate of the unsaturated acid or acid anhydride is 100%, and the selectivity of the saturated acid ester is 99.1 - 100%.

[0099] Table 4 Catalysts, reaction process conditions and results for the esterification and hydrogenation of unsaturated acids / anhydrides with unsaturated alcohols to prepare saturated acid esters

[0100]

[0101]

[0102] Comparative Example 5

[0103] Synthesis of allyl propionate by two-step reaction of acrylic acid esterification and hydrogenation

[0104] Refer to the catalyst preparation method and reaction process conditions of Example 63. Feed the mixture of acrylic acid and allyl alcohol into a fixed-bed esterification reactor filled with solid acid HZSM-5 particle catalyst, and carry out the reaction to prepare allyl acrylate at an alcohol-acid molar ratio of 1.10, a temperature of 80 °C, and a weight hourly space velocity of the raw materials of 0.50 h -1 Then feed the esterification reaction product into a fixed-bed hydrogenation reactor filled with 0.5 wt% Pd / HZSM-5 particle catalyst, and carry out the double-bond hydrogenation reaction to prepare allyl propionate at a hydrogen-ester molar ratio of 15 (calculated based on acrylic acid), a weight hourly space velocity of the esterification liquid of 0.50 h -1 , a temperature of 80 °C, and a hydrogen pressure of 1.0 MPa. The esterification rate of acrylic acid is 90.5%, the hydrogenation rate is 100%, the selectivity of propionate is 100%, and the selectivity of allyl propionate is 95.5%.

[0105] Comparing Example 63 and Comparative Example 5, it can be seen that when using the same reaction process conditions and catalyst to synthesize allyl propionate from acrylic acid and allyl alcohol, the esterification rate of the esterification-hydrogenation one-step coupling reaction process is lower than that of the two-step series reaction process of esterification and hydrogenation, while the selectivity of allyl ester is higher. The esterification rate of acrylic acid in the coupling reaction is 86.8%, the hydrogenation rate is 100%, the selectivity of propionate is 100%, and the selectivity of allyl propionate is 98.6%.

[0106] In summary, the catalyst with both esterification and hydrogenation functions provided by the present invention is used for the one-step preparation of saturated acid esters by the esterification-hydrogenation coupling reaction of unsaturated acids or / and acid anhydrides with alcohols. Using a fixed-bed reaction process, the reaction conditions are relatively mild, and the catalytic performance is excellent. Especially for the ring-opening esterification of unsaturated acid anhydrides to prepare saturated acid esters, the esterification rate of unsaturated acid anhydrides, the double-bond hydrogenation rate, and the selectivity of saturated acid esters are all close to 100%. Compared with the prior art using two catalysts, an inorganic liquid acid or solid acid esterification catalyst and a hydrogenation catalyst, and a two-step reaction process of esterification and hydrogenation, the process flow is short, the device investment is saved, the process is clean and efficient, the catalyst does not need to be separated, and the equipment is not corroded.

[0107] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A bifunctional catalyst for synthesizing saturated acid esters by esterification-hydrogenation coupling reaction of unsaturated acids or / and acid anhydrides, characterized in that: The catalyst is composed of a solid acid carrier, a metal active component and a metal oxide additive with or without a metal oxide additive, wherein: the solid acid carrier is selected from acidic oxides, hydrogen-type zeolite molecular sieves, porous material-supported acidic oxides or supported acids of solid superacids; the metal active component is one or two of Ni, Ru, Pd or Pt, or a bimetal or polymetal composed of them and at least one of Mn, Fe, Co or Cu; the metal oxide additive is one or more of the oxides of Mg, Ca, Sn, Pb, Y, La, Ce, Sm, Nd, Mo, W or Zn; the mass percentage of each component is: the solid acid carrier is 65-99.9wt%, the metal active component is 0.1-25wt%, and the metal oxide additive is 0-10wt%.

2. The catalyst according to claim 1, characterized in that The acidic oxide is selected from γ-Al2O3, SiO2-Al2O3, Fe2O3, Nb2O5, MoO3 or WO3; The hydrogen-type zeolite molecular sieve is selected from at least one of HM, HHEU, HY, Hβ, HZSM-5, HZSM-11, HZSM-12, HZSM-18, HZSM-22, HZSM-23, HZSM-35, HZSM-48, HMCM-22, HMCM-49 or HMCM-56; The porous material in the supported acid is selected from one of activated carbon, mesoporous carbon, carbon nanotubes, graphene, γ-Al2O3, θ-Al2O3, mesoporous Al2O3, SiO2, mesoporous SiO2, SiO2-Al2O3, TiO2, mesoporous TiO2, ZrO2, HM, HHEU, Hβ, HZSM-5, HZSM-22, HMCM-22, HMCM-41, HMCM-48, HMCM-49, HMCM-56, AlPO4-11, SAPO-11, SAPO-34, Silicalite-1, Silicalite-2, TS-1, TS-2, SBA-15, ZEO-1, ZEO-3, KIT-6, SCM-14, montmorillonite, diatomaceous earth, bentonite or attapulgite; the solid superacid in the supported acid is selected from one of SO4 2- / M x O y The acidic oxide in the supported acid is selected from at least one of an oxide, isopoly acid, heteropoly acid or salt thereof of phosphorus, arsenic, selenium, tellurium, antimony, vanadium, niobium, molybdenum or tungsten; the SO4 2- / M x O y Type solid superacids including SO4 2- / ZrO2、SO4 2- / TiO2、SO4 2- / Fe2O3、SO4 2- / ZrO2-La2O3, SO4 2- / ZrO2-CeO2, SO4 2- / TiO2-ZrO2, the AO3 / MO2 type solid superacid includes WO3 / ZrO2 or MoO3 / TiO2, and the acidic oxide includes Nb2O5, H3PO4, H6TeO6, H2WO4, Al(H2PO4)3, AlPO4, Zr(HPO4)2, VPO x 、H3PW 12 O 40 、H3PMo 12 O 40 、H4SiW 12 O 40 、H4SiMo 12 O 40 or Cs 2.5 H 0.5 PW 12 O 40 .

3. The catalyst according to claim 1, characterized in that The loaded acid is selected from activated carbon, SiO2, γ-Al2O3, SiO2-Al2O3, TiO2, ZrO2, HM, Hβ, HZSM-5, HMCM-22, HMCM-41, HMCM-48, S-1, TS-1 or SBA-15. 2- / TiO2-ZrO2, SO4 2- / ZrO2-CeO2-Fe2O3, WO3 / ZrO2, Nb2O5, H3PO4, Zr(HPO4)2, H3PW 12 O 40 or Cs 2.5 H 0.5 PW 12 O 40 One of them.

4. The catalyst according to claim 1, characterized in that The metal active component is a single metal Ni, Ru, Pd, or a bimetallic Ni-Cu, Ni-Co, Ru-Ni, Pd-Ni, Pd-Fe, Pd-Ru, Pt-Co, Ru-Cu, Pd-Cu, Pt-Cu, or a multimetallic Ni-Cu-Mn, Ni-Co-Mn or Ru-Ni-Mn, and the metal oxide additive is MgO, La2O3, CeO2, SnO, PbO, MoO3, WO3 or ZnO or a combination thereof; preferably, the metal active component is Ni, Pd, Ni-Cu, Ru-Ni, Pd-Ni or Ni-Cu-Mn, and the additive is MgO, La2O3, CeO2, MoO3, WO3 or ZnO.

5. The catalyst according to claim 1, characterized in that When the metal active component is one or two of Ru, Pd or Pt, the content of the metal active component is 0.1 to 7.5 wt %; or, When the metal active component is selected from Ni or Ni and one of the noble metals Ru, Pd or Pt, the content of Ni is 1.0-20.0wt% and the content of the noble metal is 0-1.5wt%; or When the metal active component is selected from a bimetallic or multimetallic composed of one or two of Ni, Ru, Pd or Pt and at least one of Mn, Fe, Co or Cu, the content of at least one or two metals selected from Mn, Fe, Co or Cu is 2.0-25.0wt%, and the content of one or two metals selected from Ni, Ru, Pd or Pt is 0.1-7.5wt%.

6. The catalyst according to claim 5, characterized in that When the solid acid carrier is a loaded acid, when the loaded acid is an acidic oxide loaded on a porous material, the content of the acidic oxide is 10-25wt%; when the loaded acid is a solid superacid loaded on a porous material, the content of the solid superacid is 15-45wt%.

7. Use of the catalyst as claimed in any one of claims 1 to 6 in the synthesis of saturated acid esters by esterification-hydrogenation coupling reaction of unsaturated acids or / and acid anhydrides.

8. The use according to claim 7, characterized in that: The process conditions of the esterification-hydrogenation coupling reaction are: temperature 45-200°C, hydrogen pressure 0.2-3.0 MPa, liquid raw material weight hourly space velocity 0.05-2.00 h -1 , the molar ratio of alcohol to acid or / and anhydride in the raw material is 0.25-5.00, and the molar ratio of hydrogen to acid or / and anhydride is 5-50; preferably, the temperature is 55-180°C, the hydrogen pressure is 0.5-2.5MPa, and the weight hourly space velocity of the liquid raw material is 0.10-1.50h -1 , alcohol to acid or / and anhydride molar ratio of 0.35 to 3.00, hydrogen to acid / and anhydride molar ratio of 7.5 to 40; more preferably, temperature 65 to 150 ° C, hydrogen pressure 1.0 to 2.0 MPa, liquid raw material weight hourly space velocity 0.2 to 1.0 h -1 , the molar ratio of alcohol to acid or acid anhydride is 0.45-2.50, and the molar ratio of hydrogen to acid or / and acid anhydride is 10-30.

9. The use of the catalyst according to claim 7, characterized in that: The unsaturated acid or anhydride includes acrylic acid, propiolic acid, methacrylic acid, crotonic acid, 2-butynoic acid, 4-pentenoic acid, 2,4-pentadienoic acid, sorbic acid, 3-cyclohexyl acrylic acid, cinnamic acid, furanyl acrylic acid, myristic acid, palmitoleic acid, ricinoleic acid, oleic acid, linoleic acid, octadecatrienoic acid, arachidonic acid, butynedioic acid, maleic acid, fumaric acid, maleic anhydride, methylenemalonic acid, glutaconic acid, glutaconic anhydride, itaconic acid itaconic anhydride, nadic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexenedioic acid, cis-hexadienedioic acid, heptenedioic acid, octenedioic acid, nonenedioic acid, decanedioic acid, cis-aconitic acid, trans-aconitic acid or aconitic anhydride; Preferably, the unsaturated acid or anhydride is acrylic acid, methacrylic acid, crotonic acid, sorbic acid, cinnamic acid, furanyl acrylic acid, myristic acid, palmitic acid, ricinoleic acid, oleic acid, maleic acid, fumaric acid, maleic anhydride, glutaconic acid, glutaconic anhydride, itaconic acid, itaconic anhydride, nadic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, cis-aconitic acid or aconitic anhydride; More preferably, the unsaturated acid or anhydride is acrylic acid, methacrylic acid, crotonic acid, sorbic acid, cinnamic acid, ricinoleic acid, oleic acid, maleic acid, fumaric acid, maleic anhydride, itaconic acid, itaconic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride or aconitic anhydride.

10. The use of the catalyst according to claim 7, characterized in that: In the esterification-hydrogenation coupling reaction, the alcohol substance in the raw material includes saturated monohydric alcohol, unsaturated monohydric alcohol, saturated polyhydric alcohol, unsaturated polyhydric alcohol, saturated polyether polyol, unsaturated polyether polyol, saturated polyester polyol or unsaturated polyester polyol; Preferably, the alcohol substance is methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol, isopentanol, neopentyl alcohol, n-hexanol, n-heptanol, n-octanol, isooctyl alcohol, n-nonanol, isononanol, n-decanol, cyclopentanol, cyclohexanol, methylcyclohexanol, benzyl alcohol, α-phenylethyl alcohol, β-phenylethyl alcohol, α,α-dimethylbenzyl alcohol, 1-phenylpropanol, tetrahydrofurfuryl alcohol, furfuryl alcohol, tetrahydropyranol, 4-pyridinemethanol, 4-piperidinemethanol, 3-thiophenemethanol, 2-thiopheneethanol, 5-pyrimidinemethanol, allyl alcohol, propanol, Alkynol, crotyl alcohol, methyl allyl alcohol, butynol, 2-pentenol, isopentenol, 2-cyclohexenol, cinnamyl alcohol, 3-(2-furan)propenol; ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 2-ethyl-2-methyl-1,3-propanediol, 2-isopropyl-2-methyl-1,3-propanediol diol, 2,2-diethyl-1,3-propanediol, 2-n-butyl-2-ethyl-1,3-propanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1-phenyl-1,3-propanediol, 2-phenyl-1,3-propanediol, 1-phenyl-1,4-butanediol, isophthalic acid methanol, p-phthalic acid methanol, 2,6-naphthalene dimethanol, 2,2′-biphenyl dimethanol, 4,4′-biphenyl dimethanol, 2,5-furan dimethanol, 2,6-pyridine dimethanol, glycerol, trimethylolethane, 1, 2,6-hexanetriol, trimethylolpropane, erythritol, pentaerythritol, xylitol, sorbitol, mannitol, inositol, butylene glycol, butynediol; di(3-hydroxy-2,2-dimethylpropyl) ether, diglycerol, triglycerol, ditrimethylolethane, ditrimethylolpropane, dipentaerythritol, tripentaerythritol, polyethylene glycol, polypropylene glycol, polybutylene glycol with a polymerization degree of 2 to 100, polybutylene succinate diol, polyethylene terephthalate diol or polybutylene butenediol diol with a polymerization degree of 2 to 50; More preferably, the alcohol is methanol, ethanol, isopropanol, isobutanol, neopentyl alcohol, isooctyl alcohol, cyclohexanol, benzyl alcohol, α-phenylethanol, tetrahydrofurfuryl alcohol, furfuryl alcohol, allyl alcohol, crotyl alcohol, methylallyl alcohol, isopentenol, cinnamyl alcohol; ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 2-ethyl-2-methyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, Benzenediol, 2,5-furan dimethanol, glycerol, trimethylolethane, 1,2,6-hexanetriol, trimethylolpropane, pentaerythritol, sorbitol, butylene glycol, butynediol, diglycerol, triglycerol, ditrimethylolethane, ditrimethylolpropane, dipentaerythritol, tripentaerythritol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol with a polymerization degree of 5-50, polypropylene glycol with a polymerization degree of 4-40, polybutylene glycol with a polymerization degree of 2-30, polybutylene succinate glycol with a polymerization degree of 2-20, and polyethylene terephthalate glycol with a polymerization degree of 2-20.

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