Method for preparing fatty acid methyl ester from olefin and / or alcohol

Abstract

The present application belongs to the field of catalytic chemistry. Disclosed is a method for preparing a fatty acid methyl ester from an olefin and / or an alcohol. A raw material containing an olefin and / or an alcohol and carbon monoxide reacts with a raw material containing methanol by means of a reactor loaded with a solid acid catalyst, so as to obtain a fatty acid methyl ester, wherein the solid acid catalyst is an acidic molecular sieve. The present application provides a new method for preparing a fatty acid methyl ester by means of the carbonylation of an olefin and an alcohol thereof that is catalyzed by a solid acid. The method for preparing a fatty acid methyl ester in the present application does not require any noble metal catalyst, the reaction raw materials therefor do not contain water, the system has low corrosiveness, the product is easy to separate, the emission of three wastes is low, the fixed-bed process is easy to industrialize, and the method is suitable for single-set large-scale production.

Description

A method for preparing fatty acid methyl esters from olefins and / or alcohols Technical Field

[0001] This application relates to a method for preparing fatty acid methyl esters from olefins and / or alcohols, belonging to the field of catalytic chemistry. Background Technology

[0002] Methyl fatty acids (methyl propionate, methyl isobutyrate, methyl valerate, etc.) are important chemical intermediates widely used in the food, cosmetics, coatings, and organic synthesis industries. Currently, the main industrial method for producing these methyl fatty acids is the esterification reaction of carboxylic acids with methanol. This reaction uses sulfuric acid as a homogeneous catalyst, is simple to operate, but is environmentally harmful and hinders product separation. In addition, researchers have developed homogeneous synthesis processes based on olefin carbonylation. For example, BASF in Germany developed a method using ethylene, methanol, and CO as raw materials, under conditions of 250–320℃ and 10–30 MPa, employing a rhodium, ruthenium, and palladium complex catalyst for a one-step carbonylation synthesis reaction to produce methyl propionate. This method involves high reaction pressure, extremely demanding equipment, and the expensive precious metal catalysts pose potential safety risks to human health and the environment. In addition, there are some methods for the carbonylation of ethylene by coupling noble metals with molecular sieves. For example, CN114621089A discloses a carbonylation reaction using ethylene, CO, and methanol as reactants, catalyzed by a Ru-modified molecular sieve, to produce methyl propionate. This technology requires the use of the noble metal Ru and is synthesized in a batch reactor, making continuous large-scale production difficult. Similarly, for methyl isobutyrate, propylene, CO, and methanol can be synthesized under homogeneous reaction conditions of high temperature, high pressure, and strong acids (such as concentrated sulfuric acid and hydrofluoric acid) based on the carbonylation mechanism. Although the homogeneous Koch carbonylation method uses inexpensive and readily available raw materials, it suffers from harsh reaction conditions, extremely high requirements for reactor materials, difficulties in product separation, and significant challenges in industrialization. Furthermore, only carbonylation processes for low-carbon olefins have been developed. Therefore, developing new routes for the production of fatty acid methyl esters, especially hydrogen-form molecular sieve catalysis processes without noble metals, has important application potential. Summary of the Invention

[0003] This application provides a method for producing fatty acid methyl esters from olefins and their alcohols. The method involves passing a feedstock containing olefins and / or alcohols and carbon monoxide, along with a feedstock containing methanol, through a reactor supported by a solid acid catalyst. Under predetermined reaction conditions, the product containing fatty acid methyl esters is directly obtained. This is a novel method for producing fatty acid methyl esters using solid acid-catalyzed carbonylation of olefins and their alcohols. The fatty acid methyl ester preparation method of this application does not require precious metal catalysts, the reactants are water-free, the system has low corrosivity, the products are easily separated, waste emissions are low, the fixed-bed process is easily engineered, and it is suitable for large-scale single-unit production.

[0004] A method for preparing fatty acid methyl esters from olefins and / or alcohols involves passing a raw material containing olefins and / or alcohols and carbon monoxide with a raw material containing methanol through a reactor supported by a solid acid catalyst to obtain fatty acid methyl esters.

[0005] The solid acid catalyst is an acidic molecular sieve;

[0006] The olefin is selected from at least one of ethylene, propylene, butene, pentene, hexene, hepten, and octene and their corresponding isomers;

[0007] The alcohol is selected from at least one of ethanol, propanol, butanol, pentanol, hexanol, heptanol, and octanol corresponding to alkenes and their corresponding isomers;

[0008] The fatty acid methyl ester is selected from at least one of methyl propionate, methyl butyrate, methyl valerate, methyl hexanoate, methyl heptanoate, methyl octanoate, methyl nonanoate, and their corresponding isomers.

[0009] Optionally, the structure of the acidic molecular sieve is selected from at least one of the following structures: EUO, FER, FAU, BEA, MEL, MFI, MFS, MTT, and TON.

[0010] Optionally, the acidic molecule is screened from at least one of H-ZSM-35, H-ZSM-11, H-ZSM-5, H-ZSM-57, H-ZSM-23, H-ZSM-22, H-ZSM-50, H-MCM-22, HY, and H-Beta molecular sieves.

[0011] Optionally, the silicon-aluminum molecular ratio (SiO2 / Al2O3) of the acidic molecular sieve is 10–200.

[0012] Optionally, the silicon-aluminum molecular ratio of the acidic molecular sieve is SiO2 / Al2O3 = 20 to 80.

[0013] Optionally, the SiO2 / Al2O3 ratio of the acidic molecular sieve can be independently selected from any value of 10, 20, 50, 75, 100, 125, 150, 175, 200 or any range between two.

[0014] Optionally, the acidic molecular sieve is modified with a metal; the modified metal element is selected from at least one of Fe, Cu, Zr, Cr, In, Cd, Zn, and Ni.

[0015] In this application, the acidic molecular sieve can be used alone or modified with transition metal elements. The transition metal elements are selected from those other than the constituent elements of the zeolite molecular sieve framework. Preferred transition metals are Fe, Cu, Zr, Cr, In, Cd, Zn, and Ni, all of which are non-precious metals and do not require the use of precious metals.

[0016] Optionally, the solid acid catalyst further includes a matrix; the matrix is ​​selected from at least one of alumina, silicon dioxide, magnesium oxide, and kaolin.

[0017] Optionally, olefins and / or alcohols, carbon monoxide, and methanol are reacted in a reactor supported by a solid acid catalyst to obtain fatty acid methyl esters.

[0018] In this application, the reaction raw materials do not contain water.

[0019] Optionally, the molar ratio of carbon monoxide to olefins and / or alcohols is 5:1 to 200:1;

[0020] The molar ratio of methanol to olefins and / or corresponding alcohols is 0.1:1 to 20:1.

[0021] Optionally, the molar ratio of carbon monoxide to olefins and / or alcohols is 30:1 to 100:1;

[0022] The molar ratio of methanol to olefins and / or alcohols is 0.1:1 to 5:1.

[0023] Optionally, the molar ratio of carbon monoxide to olefins and / or alcohols may be independently selected from any value or a range between 5:1, 10:1, 20:1, 50:1, 75:1, 100:1, 125:1, 150:1, 175:1, and 200:1.

[0024] Optionally, the molar ratio of methanol to olefins and / or alcohols may be independently selected from any value or a range between 0.1:1, 0.5:1, 1.0:1, 2.0:1, 3.0:1, 4.0:1, 5.0:1, 6.0:1, 7.0:1, 8.0:1, 9.0:1, 10.0:1, 12.0:1, 15.0:1, 17.5:1, and 20:1.

[0025] Optionally, the mass hourly space velocity (WHSV) of the olefin and / or alcohol is 0.01–1.0 h⁻¹. -1 .

[0026] Optionally, the mass hourly space velocity (MSV) of the olefin and / or alcohol can be independently selected from 0.01 h⁻¹. -1 0.03h -1 0.05h -1 0.1h -1 0.15h -1 0.2h -1 0.25h -1 0.3h -1 0.35h -1 0.4h -1 0.45h-1 0.5h -1 0.55h -1 0.6h -1 0.65h -1 0.7h -1 0.75h -1 0.8h -1 0.85h -1 0.9h -1 0.95h -1 1.0h -1 Any value in the range or any value between the two.

[0027] Optionally, the reaction temperature is 150–320℃ and the reaction pressure is 2–10 MPa.

[0028] Optionally, the temperature of the reaction can be independently selected from any value or a range between 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C, 300°C, 310°C, and 320°C.

[0029] Optionally, the pressure of the reaction can be independently selected from any value of 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa, 10 MPa, or any range between the two.

[0030] Optionally, the reactor is selected from at least one of a fixed-bed reactor, a fluidized-bed reactor, and a moving-bed reactor.

[0031] The beneficial effects that this application can produce include:

[0032] The method for preparing fatty acid methyl esters from olefins and / or alcohols provided in this application is a novel method for producing fatty acid methyl esters by carbonylation of olefins and / or alcohols catalyzed by acidic molecular sieves / metal-modified molecular sieves. It does not require precious metal catalysts, the reaction raw materials do not contain water, the system has low corrosivity, the products are easy to separate, and the emissions of waste are low. The fixed-bed process is easy to engineer and suitable for large-scale single-unit production. Detailed Implementation

[0033] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0034] Unless otherwise specified, the raw materials and catalysts used in the embodiments of this application were all purchased commercially.

[0035] Unless otherwise specified, all test methods are standard and all instrument settings are those recommended by the manufacturer.

[0036] The analysis method in the embodiments of this application is as follows:

[0037] The products and unreacted raw materials were analyzed online using an Agilent 7890B gas chromatograph. The FID detector was connected to a PLOT-Q capillary column, and the TCD detector was connected to a Porapak Q packed column.

[0038] Since the alcohols corresponding to alkenes readily undergo dehydration reactions in the reaction system to form the corresponding alkenes, the conversion rates of alkenes and their alcohols, as well as the selectivity of fatty acid methyl esters, in carbonylation reactions are calculated based on the number of carbon moles, as shown in the following formula:

[0039] Olefin and alcohol conversion rate = [(number of carbon moles of olefins and / or corresponding alcohols in feed) - (number of carbon moles of olefins and / or corresponding alcohols in discharge)] ÷ (number of carbon moles of olefins and / or corresponding alcohols in feed) × 100%

[0040] Fatty acid methyl ester selectivity = (number of carbon moles of fatty acid methyl esters in the discharge) ÷ (number of carbon moles of all products) × 100%.

[0041] Example 1 Catalyst Preparation

[0042] Preparation of metal-modified zeolite molecular sieves

[0043] The purchased hydrogen-type molecular sieve was subjected to impregnation, drying, and calcination to obtain metal-modified zeolite molecular sieve.

[0044] This embodiment uses the H-ZSM-35 (SiO2 / Al2O3=20) sample as an example to prepare metal-modified molecular sieves. The preparation methods of other hydrogen-type molecular sieves in Table 1 for preparing metal-modified catalysts are similar to those of the H-ZSM-35 (SiO2 / Al2O3=20) sample, and will not be described in detail here.

[0045] Preparation of 5% Zn / ZSM-35: A pre-prepared Zn(NO3)2 solution was added dropwise to H-ZSM-35 molecular sieve powder, with a Zn / H-ZSM-35 (mass ratio) of 0.05. The mixture was stirred at room temperature for 15 min, sonicated for 15 min, allowed to stand at room temperature for 12 h, dried in an oven at 80 °C for 24 h, and finally calcined at 550 °C in air atmosphere for 4 h to obtain the desired catalyst sample 5% Zn / ZSM-35.

[0046] Preparation of matrix-containing samples

[0047] The matrix-containing molded hydrogen form sample was prepared by extrusion molding.

[0048] This embodiment uses the H-ZSM-35 (SiO2 / Al2O3=20) sample as an example to prepare a hydrogen form sample containing a matrix. The preparation methods of other hydrogen form molecular sieves in Table 1 are similar to those of the H-ZSM-35 (SiO2 / Al2O3=20) sample, and will not be described in detail here.

[0049] Preparation of H-ZSM-35 molecular sieve containing an alumina matrix: 50g of raw material sample H-ZSM-35 and 50g of alumina were thoroughly mixed, and 10% wt nitric acid was added and kneaded. The kneaded sample was formed into lumps and extruded using an extruder. The extruded sample was dried at 120℃ and calcined at 550℃ for 4h to obtain an acidic zeolite molecular sieve containing a matrix, labeled as ZSM-35 / Al2O3.

[0050] For other acidic zeolite molecular sieves used to prepare matrix samples, the above method can be followed as needed. Typical samples prepared are shown in Table 1.

[0051] Table 1 Sample Names and Compositions

[0052] Example 2: Preparation of Methyl Isobutyrate from Propylene Using Different Catalysts

[0053] 1g of the solid acid catalyst (20-40 mesh particles) from Table 1 was loaded into a container with an inner diameter of [missing information]. In a fixed-bed reactor, propylene and carbon monoxide were fed via mass flow meters, while methanol was fed via a horizontal flow pump. The feedstock was mixed and preheated before entering the catalyst bed for reaction. The product was heated and analyzed online using gas chromatography. Reaction conditions included a reaction temperature (T) of 230°C, a reaction pressure (P) of 6 MPa, a carbon monoxide to propylene molar ratio (CO:C3H6) of 200, a methanol to propylene molar ratio (CH3OH:C3H6) of 5, and a propylene mass hourly space velocity (WHSV) of 0.2 h⁻¹. -1 The results of the reaction after 10 hours of operation are shown in Table 2.

[0054] Table 2 Reaction results on different catalysts

[0055] As shown in Table 2, solid acid catalysts based on acidic zeolite molecular sieves can achieve the purpose of producing methyl isobutyrate from propylene.

[0056] Example 3: Preparation of Methyl Isobutyrate from Propylene at Different Reaction Temperatures

[0057] Catalyst H-1 was used as the sample, and the reaction temperatures were 150℃, 210℃, 270℃, and 320℃, respectively. Other reaction conditions were the same as in Example 2. The results of the catalytic reaction after 10 hours are shown in Table 3.

[0058] Table 3. Reaction results at different reaction temperatures.

[0059] As shown in Table 3, the reaction temperature has a significant impact on the preparation of methyl isobutyrate from propylene. As the temperature increases, the propylene conversion rate increases. However, when the reaction temperature exceeds 210℃, it promotes the formation of a large number of polymeric hydrocarbons, which leads to a decrease in product selectivity.

[0060] Example 4: Preparation of Methyl Isobutyrate from Propylene under Different Reaction Pressures

[0061] Catalyst H-1 was used as the sample, and the reaction pressures were 2 MPa, 5 MPa, 8 MPa, and 10 MPa, respectively. Other conditions were the same as in Example 2. The reaction was run for 10 hours, and the results are shown in Table 4.

[0062] Table 4. Reaction results under different reaction pressures.

[0063] As shown in Table 4, increasing the reaction pressure helps to promote the reaction of propylene to prepare methyl isobutyrate. The reaction pressure is directly proportional to the propylene conversion rate, and increasing the pressure is beneficial to the product selectivity.

[0064] Example 5: Preparation of Methyl Isobutyrate from Propylene at Different Mass Hourly velocities

[0065] Using catalyst H-1 as the sample, the mass hourly space velocities (MHVs) of propylene were 0.01, 0.1, 0.5, and 1 h⁻¹. -1 Other conditions were the same as in Example 2, and the results after 10 hours of reaction are shown in Table 5.

[0066] Table 5. Reaction results at different propylene mass space velocities.

[0067] As shown in Table 5, the higher the reaction space velocity, the lower the propylene conversion rate, while the selectivity of methyl isobutyrate is basically unaffected.

[0068] Example 6: Preparation of Methyl Isobutyrate from Propylene under Different Molar Ratios of Carbon Monoxide and Propylene

[0069] Catalyst H-1 was used as the sample, and the molar ratios of CO and propylene were 5, 60, 120, and 200, respectively. Other conditions were the same as in Example 2. The results of the reaction running for 8 hours are shown in Table 6.

[0070] Table 6. Reaction results with different molar ratios of carbon monoxide and propylene.

[0071] As shown in Table 6, the ratio of carbon monoxide to propylene has a significant impact on propylene conversion; the higher the ratio, the higher the product selectivity.

[0072] Example 7: Preparation of Methyl Isobutyrate from Propylene under Different Molar Ratios of Methanol and Propylene

[0073] Catalyst H-1 was used as the sample, and the molar ratios of methanol and propylene were 0.1, 1, 5, 10, and 20, respectively. Other conditions were the same as in Example 2. The results of the reaction running for 10 hours are shown in Table 7.

[0074] Table 7. Reaction results at different methanol and propylene molar ratios.

[0075] As shown in Table 7, the ratio of methanol to propylene has a significant impact on propylene conversion. An appropriate ratio is beneficial to improving catalyst activity; however, if the ratio is too high, the catalyst activity will be significantly reduced.

[0076] Example 8: Preparation of Methyl Isobutyrate from Propylene in Different Reactors

[0077] Using catalyst H-1 as a sample, different reactors were selected to carry out the reaction of propylene to produce methyl isobutyrate. Since fluidized bed, moving bed and fixed bed are different, catalyst H-1 needs to be processed to be suitable for use in fluidized bed and moving bed. Other conditions are the same as in Example 2. The results after 10 hours of reaction are shown in Table 8.

[0078] Table 8. Reaction results in different reactors

[0079] Example 9: Ethylene to Methyl Propionate on Different Catalysts

[0080] 1g of the solid acid catalyst (20-40 mesh particles) from Table 1 was loaded into a container with an inner diameter of [missing information]. In a fixed-bed reactor, ethylene and carbon monoxide were fed using mass flow meters, while methanol was fed using a horizontal flow pump. The feedstock was mixed, preheated, and then introduced into the catalyst bed for reaction. The products were heated and analyzed online using gas chromatography. Reaction conditions, including reaction temperature (T), reaction pressure (P), the molar ratio of carbon monoxide to ethylene (CO:C2H4), the molar ratio of methanol to ethylene (CH3OH:C2H4), the ethylene mass hourly space velocity (WHSV), and the reaction results after 10 hours of operation are shown in Table 9.

[0081] Table 9. Results of the production of methyl propionate from ethylene using different catalysts.

[0082] Example 10: Preparation of methyl valerate from butene using different catalysts

[0083] 1g of the solid acid catalyst (20-40 mesh particles) from Table 1 was loaded into a container with an inner diameter of [missing information]. In a fixed-bed reactor, butene and carbon monoxide were fed using mass flow meters, while methanol was fed using a horizontal flow pump. The feedstock was mixed, preheated, and then introduced into the catalyst bed for reaction. The product was heated and analyzed online using gas chromatography. Reaction conditions, including reaction temperature (T), reaction pressure (P), the molar ratio of carbon monoxide to butene (CO:C4H8), the molar ratio of methanol to butene (CH3OH:C4H8), the butene mass hourly space velocity (WHSV), and the reaction results after 10 hours of operation are shown in Table 10.

[0084] Table 10 Results of the production of methyl valerate from butene using different catalysts

[0085] Example 11: Preparation of Methyl Hexanoate from Pentene using Different Catalysts

[0086] 1g of the solid acid catalyst (20-40 mesh particles) from Table 1 was loaded into a container with an inner diameter of [missing information]. In a fixed-bed reactor, pentene and carbon monoxide are fed via mass flow meters, while methanol is fed via a horizontal flow pump. The raw materials are mixed and preheated before entering the catalyst bed for reaction. The products are heated and analyzed online using gas chromatography. Reaction conditions include a reaction temperature (T) of 200℃, a reaction pressure (P) of 5MPa, and a carbon monoxide to pentene molar ratio (CO:C5H2O). 10 =100, Molar ratio of methanol to pentene (CH3OH:C5H) 10 =3, pentene mass hourly space velocity (WHSV) = 0.4h -1 The results of the reaction after 10 hours of operation are shown in Table 11.

[0087] Table 11 Reaction results of pentene to methyl hexanoate using different catalysts

[0088] Example 12 Preparation of Methyl Heptanoate from Hexene using Different Catalysts

[0089] 1g of the solid acid catalyst (20-40 mesh particles) from Table 1 was loaded into a container with an inner diameter of [missing information]. In a fixed-bed reactor, hexene and carbon monoxide are fed via mass flow meters, while methanol is fed via a horizontal flow pump. The raw materials are mixed, preheated, and then fed into the catalyst bed for reaction. The products are heated and analyzed online using gas chromatography. Reaction conditions include a reaction temperature (T) of 200℃, a reaction pressure (P) of 5MPa, and a carbon monoxide to hexene molar ratio (CO:C5H2O). 10 =70, Molar ratio of methanol to hexene (CH3OH:C5H) 10 =1, Hexene mass hourly space velocity (WHSV) = 0.3h -1 The results of the reaction after 10 hours of operation are shown in Table 12.

[0090] Table 12 Results of the preparation of methyl heptaate from hexene using different catalysts

[0091] Example 13 Preparation of Methyl Octanoate from Hepten on Different Catalysts

[0092] 1g of the solid acid catalyst (20-40 mesh particles) from Table 1 was loaded into a container with an inner diameter of [missing information]. In a fixed-bed reactor, heptene and carbon monoxide are fed via mass flow meters, while methanol is fed via a horizontal flow pump. The feedstock is mixed, preheated, and then introduced into the catalyst bed for reaction. The product is heated and analyzed online using gas chromatography. Reaction conditions include a reaction temperature (T) of 200°C, a reaction pressure (P) of 5 MPa, and a carbon monoxide to heptene molar ratio (CO:C7H2O). 14 =70, Molar ratio of methanol to heptene (CH3OH:C7H) 14 =1, heptaene mass hourly space velocity (WHSV) = 0.3h -1 The results of the reaction after 10 hours of operation are shown in Table 13.

[0093] Table 13 Results of the preparation of methyl heptanoate from heptene using different catalysts

[0094] Example 14: Octenene to Methyl Nonanoate on Different Catalysts

[0095] 1g of the solid acid catalyst (20-40 mesh particles) from Table 1 was loaded into a container with an inner diameter of [missing information]. In a fixed-bed reactor, octene and carbon monoxide are fed via mass flow meters, while methanol is fed via a horizontal flow pump. The feedstock is mixed, preheated, and then introduced into the catalyst bed for reaction. The product is heated and analyzed online using gas chromatography. Reaction conditions include a reaction temperature (T) of 200°C, a reaction pressure (P) of 6 MPa, and a carbon monoxide to octene molar ratio (CO:C5H2O). 10 =80, Molar ratio of methanol to octene (CH3OH:C5H) 10 =3, octene mass hourly space velocity (WHSV) = 0.3h -1 The results of the reaction after 10 hours of operation are shown in Table 14.

[0096] Table 14 Results of the preparation of methyl nonanoate from octene using different catalysts

[0097] Example 15: Preparation of Methyl Propionate from Ethanol on Different Catalysts

[0098] 1g of the solid acid (20-40 mesh particles) catalyst from Table 1 was loaded into a container with an inner diameter of [missing information]. In a fixed-bed reactor, ethanol and carbon monoxide were fed using mass flow meters, while methanol was fed using a horizontal flow pump. The feedstocks were mixed, preheated, and then introduced into the catalyst bed for reaction. The products were heated and analyzed online using gas chromatography. Reaction conditions, including reaction temperature (T), reaction pressure (P), the molar ratio of carbon monoxide to ethanol (CO:C2H4), the molar ratio of methanol to ethanol (CH3OH:C2H4), the ethanol mass hourly space velocity (WHSV), and the reaction results after 10 hours of operation are shown in Table 9.

[0099] Table 15 Results of the preparation of methyl propionate from ethanol using different catalysts

[0100] Example 16 Preparation of Methyl Hexanoate from Pentanol using Different Catalysts

[0101] 1g of the solid acid catalyst (20-40 mesh particles) from Table 1 was loaded into a container with an inner diameter of [missing information]. In a fixed-bed reactor, pentanol (2,2-dimethylpropanol, 2-methyl-2-butanol) and carbon monoxide were fed via mass flow meters, while methanol was fed via a horizontal flow pump. The feedstock was mixed and preheated before entering the catalyst bed for reaction. The product was heated and analyzed online using gas chromatography. Reaction conditions included a reaction temperature (T) of 200℃, a reaction pressure (P) of 5 MPa, and a molar ratio of carbon monoxide to pentanol (2,2-dimethylpropanol, 2-methyl-2-butanol) of (CO:C5H2O). 12 O) = 100, molar ratio of methanol to pentanol (2,2-dimethylpropanol, 2-methyl-2-butanol) (CH3OH:C5H) 12 O) = 3, and the mass hourly space velocity (WHSV) of pentanol (2,2-dimethylpropanol, 2-methyl-2-butanol) is 0.4 h. -1 The results of the reaction after 10 hours of operation are shown in Table 16.

[0102] Table 16 Results of the preparation of methyl hexanoate from pentanol using different catalysts

[0103] Example 17 Preparation of methyl nonanoate from octanol using different catalysts

[0104] 1g of the solid acid catalyst (20-40 mesh particles) from Table 1 was loaded into a container with an inner diameter of [missing information]. In a fixed-bed reactor, octanol (2,2,3-trimethyl-3-pentanol, 2,2,3,3-tetramethyl-1-butanol) and carbon monoxide were fed via mass flow meters, while methanol was fed via a horizontal flow pump. The feedstock was mixed and preheated before entering the catalyst bed for reaction. The product was heated and analyzed online using gas chromatography. Reaction conditions included a reaction temperature (T) of 200℃, a reaction pressure (P) of 6 MPa, and a molar ratio of carbon monoxide to octanol (2,2,3-trimethyl-3-pentanol, 2,2,3,3-tetramethyl-1-butanol) of (CO:C8H2O). 18 O) = 80, molar ratio of methanol to octanol (2,2,3-trimethyl-3-pentanol, 2,2,3,3-tetramethyl-1-butanol) (CH3OH:C8H) 18 O) = 3, octanol (2,2,3-trimethyl-3-pentanol, 2,2,3,3-tetramethyl-1-butanol) mass hourly space velocity (WHSV) = 0.3 h. -1 The results of the reaction after 10 hours of operation are shown in Table 17.

[0105] Table 17 Results of the reaction for the preparation of methyl nonanoate from octanol

[0106] Example 18 Preparation of carboxylic acid esters from mixtures of olefins and alcohols on different catalysts

[0107] 1g of the solid acid catalyst (20-40 mesh particles) from Table 1 was loaded into a container with an inner diameter of [missing information]. In a fixed-bed reactor, olefins, alcohols, and carbon monoxide are fed via mass flow meters, while methanol is fed via a horizontal flow pump. The feedstock is mixed, preheated, and then introduced into the catalyst bed for reaction. The products are heated and analyzed online using gas chromatography. The ratio of olefins to their corresponding alcohol mixtures (C0) is... x H 2x :C x H 2x+2 The reaction results after running for 10 hours and the ratio of O to 1:1 are shown in Table 18.

[0108] Table 18 Results of the reaction to prepare carboxylic acid esters from mixtures of alkenes and their corresponding alcohols.

[0109] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for preparing fatty acid methyl esters from olefins and / or alcohols, characterized in that, A raw material containing olefins and / or alcohols and carbon monoxide is reacted with a raw material containing methanol in a reactor supported by a solid acid catalyst to obtain fatty acid methyl esters. The solid acid catalyst is an acidic molecular sieve; The olefin is selected from at least one of ethylene, propylene, butene, pentene, hexene, hepten, and octene and their corresponding isomers; The alcohol is selected from at least one of ethanol, propanol, butanol, pentanol, hexanol, heptanol, and octanol corresponding to alkenes and their corresponding isomers; The fatty acid methyl ester is selected from at least one of methyl propionate, methyl butyrate, methyl valerate, methyl hexanoate, methyl heptanoate, methyl octanoate, methyl nonanoate, and their corresponding isomers.

2. The method according to claim 1, characterized in that, The structure of the acidic molecular sieve is selected from at least one of the following structures: EUO, FER, FAU, BEA, MEL, MFI, MFS, MTT, and TON.

3. The method according to claim 1 or 2, characterized in that, The acidic molecular sieve is selected from at least one of H-ZSM-35, H-ZSM-11, H-ZSM-5, H-ZSM-57, H-ZSM-23, H-ZSM-22, H-ZSM-50, H-MCM-22, HY, and H-Beta molecular sieves.

4. The method according to any one of claims 1 to 3, characterized in that, The silicon-aluminum molecular ratio of the acidic molecular sieve is SiO2 / Al2O3 = 10-200.

5. The method according to any one of claims 1 to 4, characterized in that, The silicon-aluminum molecular ratio of the acidic molecular sieve is SiO2 / Al2O3 = 20 to 80.

6. The method according to any one of claims 1 to 5, characterized in that, The acidic molecular sieve is modified with metal; the modified metal element is selected from at least one of Fe, Cu, Zr, Cr, In, Cd, Zn, and Ni.

7. The method according to any one of claims 1 to 6, characterized in that, The solid acid catalyst further includes a matrix; the matrix is ​​selected from at least one of alumina, silicon dioxide, magnesium oxide, and kaolin.

8. The method according to any one of claims 1 to 7, characterized in that, The molar ratio of carbon monoxide to olefins and / or alcohols is 5:1 to 200:1; The molar ratio of methanol to olefins and / or corresponding alcohols is 0.1:1 to 20:

1.

9. The method according to any one of claims 1 to 8, characterized in that, The molar ratio of carbon monoxide to olefins and / or alcohols is 30:1 to 100:1; The molar ratio of methanol to olefins and / or alcohols is 0.1:1 to 5:

1.

10. The method according to any one of claims 1 to 9, characterized in that, The mass hourly space velocity (MSV) of olefins and / or alcohols is 0.01–1.0 h⁻¹. -1 .

11. The method according to any one of claims 1 to 10, characterized in that, The reaction temperature is 150–320℃, and the reaction pressure is 2–10 MPa.

12. The method according to any one of claims 1 to 11, characterized in that, The reactor is selected from at least one of a fixed-bed reactor, a fluidized-bed reactor, and a moving-bed reactor.

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