Method for preparing acrylic acid and methyl acrylate

Abstract

The present invention provides a method for preparing acrylic acid and methyl acrylate. The method comprises passing the feed gas containing dimethoxymethane and carbon monoxide through a solid acid catalyst to generate acrylic acid and methyl acrylate with a high conversion rate and selectivity at a reaction temperature in a range from 180 to 400 and a reaction pressure in a range from 0.1 MPa to 15.0 MPa, the mass space velocity of dimethoxymethane in the feed gas is in a range from 0.05 h.sup.−1 to 10.0 h.sup.−1, and the volume percentage of dimethoxymethane in the feed gas is in a range from 0.1% to 95%.

Claims

1. A method, for preparing acrylic acid and methyl acrylate, the method comprising passing a feed gas containing dimethoxymethane and carbon monoxide through a reactor loaded with a molecular sieve catalyst to carry out a reaction, to generate acrylic acid and methyl acrylate, methyl acetate and acetic acid; wherein the esters produced by the method are further hydrolyzed to produce the corresponding carboxylic acids, including the hydrolysis of the methyl acrylate to produce the corresponding acrylic acid, and the hydrolysis of the methyl acetate to produce the corresponding acetic acid.

2. The method according to claim 1, wherein the esters and carboxylic acids produced by the method are further hydrogenated to produce the corresponding alcohols, including the hydrogenation of the methyl acrylate and acrylic acid to produce the corresponding propanol, and the hydrogenation of the methyl acetate and acetic acid to produce the corresponding ethanol.

3. The method according to claim 1, wherein the molecular sieve catalyst contains a binder, the binder is any one or more selected from the group consisting of alumina, silica and magnesia, and the binder content is in a range from 0 wt % to 70 wt % of the total weight of the catalyst.

4. The method according to claim 1, wherein the feed gas includes hydrogen and an inactive gas in addition to dimethoxymethane and carbon monoxide, wherein the volume content of carbon monoxide is in a range from 50% to 95%, the volume content of hydrogen is in a range from 0% to 50%, and the volume content of the inactive gas is in a range from 0% to 50%; and the inactive gas includes any one or more selected from the group consisting of nitrogen, helium, argon, carbon dioxide, methane and ethane.

5. The method according to claim 1, wherein the reactor is a fixed bed reactor, a fluidized bed reactor or a tank reactor.

6. The method according to claim 1, wherein the reaction is carried out at a reaction temperature in a range from 180° C. to 400° C. and a reaction pressure in a range from 0.1 MPa to 15.0 MPa, the mass space velocity of dimethoxymethane in the feed gas is in a range from 0.05 h.sup.−1 to 10.0 h.sup.−1, and the volume percentage of dimethoxymethane in the feed gas is in a range from 0.1% to 95%.

7. The method according to claim 1, wherein the molecular sieve catalyst is any one or more selected from the group consisting of a ZSM-35 molecular sieve, a ZSM-5 molecular sieve, a MOR mordenite molecular sieve and a EMT molecular sieve.

8. The method according to claim 7, wherein the atomic ratio of silicon to aluminum in the molecular sieve catalyst is Si/Al=3 to 100.

9. The method according to claim 7, wherein the atomic ratio of silicon to aluminum in the ZSM-35 molecular sieve is Si/Al=20 to 50; the atomic ratio of silicon to aluminum in the ZSM-5 molecular sieve is Si/Al=20 to 60; the atomic ratio of silicon to aluminum in the mordenite is Si/Al=10 to 30; and the atomic ratio of silicon to aluminum in the EMT zeolite is Si/Al=5 to 20.

10. The method according to claim 7, wherein the molecular sieve catalyst is obtained by heat treatment, hydrothermal treatment, inorganic acid treatment, organic acid treatment, F treatment, chelate treatment, or gas-solid phase dealuminization and silicon supplementation treatment.

11. The method according to claim 7, wherein the molecular sieve catalyst comprises one or more selected from the group consisting of gallium, iron, copper and silver; introduction methods comprise in-situ synthesis, metal ion exchange or impregnation loading; and the metal content is in a range from 0.01 wt % to 10.0 wt % of the total weight of the catalyst, calculated by metal elementary substance.

12. The method according to claim 11, wherein the metal content is in a range from 0.05 wt % to 1.0 wt % of the total weight of the catalyst.

13. The method according to claim 6, wherein the reaction temperature is in a range from 220° C. to 300° C.

14. The method according to claim 6, wherein the reaction pressure is in a range from 5 MPa to 10 MPa.

15. The method according to claim 6, wherein the mass space velocity of dimethoxymethane in the feed gas is in a range from 0.3 h.sup.−1 to 2.0 h.sup.−1.

16. The method according to claim 6, wherein the volume percentage of dimethoxymethane in the feed gas is in a range from 0.5% to 30%.

17. The method according to claim 8, wherein the atomic ratio of silicon to aluminum in the ZSM-35 molecular sieve is Si/Al=20 to 50; the atomic ratio of silicon to aluminum in the ZSM-5 molecular sieve is Si/Al=20 to 60; the atomic ratio of silicon to aluminum in the mordenite is Si/Al=10 to 30; and the atomic ratio of silicon to aluminum in the EMT zeolite is Si/Al=5 to 20.

Description

DESCRIPTION OF THE FIGURES

(1) FIG. 1 is a graph showing the conversion rate of the raw material DMM and the selectivity to products with temperature at a total pressure of 5.0 MPa, a CO partial pressure of 2.5 MPa and a DMM partial pressure of 1.25×10.sup.−2 MPa on the H-MOR molecular sieve in Example 1.

(2) FIG. 2 is a graph showing the relationship between the total reaction pressure and the selectivity to the products of acetic acid and acrylic acid as a function of reaction temperature on the H-MOR molecular sieve in Example 3.

DETAILED DESCRIPTION OF THE EMBODIMENT

(3) The present application will be further described below with reference to the examples. It is to be understood that the examples are for illustrative purposes only and are not intended to limit the scope of the present application.

(4) The raw materials and catalysts in the examples of the present application are all commercially purchased, unless otherwise stated.

(5) The analytical methods in the examples of the present application are as follows:

(6) The raw materials and products were tested by Agilent's Agilent 7890A gas chromatograph using Agilent's FFAP capillary column.

(7) According to an embodiment of the present application, a fixed bed reactor was used, the packing mass of catalyst was in a range from 0.5 g to 3.0 g, the reaction temperature was in a range from 180 to 350, and the reaction pressure was in a range from 0.1 MPa to 10 MPa. The raw material of dimethoxymethane was entered into the reactor by two ways of feeding:

(8) In the first way, the saturated vapor of dimethoxymethane was carried by carbon monoxide at different water bath temperatures (0 to 50) to enter into the fixed bed reactor, to obtain feed gases of dimethoxymethane with different volume contents. The calculation method of the saturated vapor pressure of the raw material ethylene glycol dimethyl ether under different temperature conditions is as shown in Formula II:
ln(p.sub.1*/p.sub.2*)=−Δ.sub.vapH.sub.mΔVapH/8.3145×(1/T.sub.1−1/T.sub.2)  Formula II

(9) wherein p.sub.1* and p.sub.2* represent the saturated vapor pressures of dimethoxymethane at different temperatures (T.sub.1, T.sub.2), respectively. It is known that dimethoxymethane has a molar enthalpy of vaporization Δ.sub.vapH.sub.m of 43.99 KJ/mol and a boiling point of 42.3, so that the saturated vapor pressure of dimethoxymethane at any temperature can be calculated. The amount of substance of the raw material dimethoxymethane entered into the reactor per unit time can be calculated by the saturated vapor pressure.

(10) In the second way, the liquid raw material of dimethoxymethane was pumped directly into the fixed bed reactor by a constant flow pump at a flow rate in a range from 0.1 mL/min to 10 mL/min. In this way, the volume content of dimethoxymethane in the feed gas entering into the reactor to contact with the catalyst was in a range from 0.1% to 100%.

(11) The conversion rate and selectivity in the examples of the present application are calculated as follows:
The conversion rate of dimethoxymethane=[(mole number of dimethoxymethane in the feed)−(mole number of dimethoxymethane in the discharge)]÷(mole number of dimethoxymethane in the feed)×(100%)
The selectivity to acrylic acid=⅔ (mole number of carbon in acrylic acid in the discharge)÷[(mole number of carbon in dimethoxymethane in the feed)−(mole number of carbon in dimethoxymethane in the discharge)]×(100%)
The selectivity to methyl acrylate=¾ (mole number of carbon in methyl acrylate in the discharge)÷[(mole number of carbon in dimethoxymethane in the feed)−(mole number of carbon in dimethoxymethane in the discharge)]×(100%)
The selectivity to acetic acid=½ (mole number of carbon in acetic acid in the discharge)÷[(mole number of carbon in dimethoxymethane in the feed)−(mole number of carbon in dimethoxymethane in the discharge)]×(100%)
The selectivity to methyl acetate=⅔ (mole number of carbon in methyl acetate in the discharge)÷[(mole number of carbon in dimethoxymethane in the feed)−(mole number of carbon in dimethoxymethane in the discharge)]×(100%)

(12) Preparation of Catalyst

(13) H-Mordenite Catalyst

(14) 100 g of calcined Na-mordenite zeolite molecular sieves, with an aluminum atomic molar ratio of 5, 6.5, 25 and 50 respectively, were each exchanged three times with 0.5 mol/L ammonium nitrate (2 hours for each time), washed with deionized water, dried, calcined at 550 for 4 hours, and extruded to prepare catalysts of 20-40 mesh.

(15) Ga-Mordenite Catalyst

(16) 100 g of calcined gallium-containing Na-mordenite (silicon-aluminum atomic molar ratio of 5) zeolite molecular sieve was exchanged three times with 0.5 mol/L ammonium nitrate (2 hours for each time), washed with deionized water, dried, calcined at 550 for 4 hours, and extruded to prepare a catalyst of 20-40 mesh.

(17) Fe-Mordenite Catalyst

(18) 100 g of calcined iron-containing Na-mordenite (silicon-aluminum atomic molar ratio of 6.5) zeolite molecular sieve was exchanged three times with 0.5 mol/L ammonium nitrate (2 hours for each time), washed with deionized water, dried, calcined at 550 for 4 hours, and extruded to prepare a catalyst of 20-40 mesh.

(19) Loaded Type M/H-Mordenite Catalyst

(20) The loaded type catalyst was prepared by the equal volume impregnation method. 4.32 g of Fe(NO.sub.3).sub.3, 4.32 g of Cu(NO.sub.3).sub.2.3H.sub.2O and 3.04 g of AgNO.sub.3.3H.sub.2O were each dissolved in 18 ml of deionized water to prepare the corresponding aqueous nitrate solutions. 20 g of H-mordenite zeolite molecular sieve with a silicon-aluminum ratio of 25 was placed in the aqueous ferric nitrate solution, and stood for 24 hours. The obtained sample was dried in an oven at 120 for 12 hours. After drying, the sample was placed in a muffle furnace, heated to 550 at a heating rate of 2/min and then calcined for 4 hours to prepare a catalyst.

(21) Ion exchange type M-mordenite catalyst

(22) g of H-mordenite and 300 ml of an aqueous ferric nitrate solution (0.15 mol) were placed in a flask, and stirred under cooling and refluxing at 80 for 2 hours, with the solid-liquid ratio being 1:15. The resultant was separated by filtration, washed with deionized water, treated by repeating the above steps twice, and dried at 120 for 12 hours. After drying, the sample was placed in a muffle furnace, heated to 550 at a heating rate of 2/min, and calcined for 4 hours to obtain a catalyst.

(23) Molding of H-Mordenite Catalyst

(24) 80 g of Na-mordenite with a silicon-aluminum atomic molar ratio of 6.5, g of pseudo-boehmite and 10% dilute nitric acid were mixed homogeneously and extruded for molding, then calcined, exchanged with 0.5 mol/L ammonium nitrate for three times (2 hours for each time), washed with deionized water, dried, and calcined at 550 for 4 hours to obtain a catalyst.

(25) 80 g of Na-mordenite with a silicon-aluminum atomic molar ratio of 4, 20 g of magnesia and 10% dilute nitric acid were mixed homogeneously and extruded for molding, then calcined, exchanged with 0.5 mol/L ammonium nitrate for three times (2 hours for each time), washed with deionized water, dried, and calcined at 550 for 4 hours to obtain a catalyst.

(26) 80 g of Na-mordenite with a silicon-aluminum atomic molar ratio of 4, 50 g of silica sol and 10% dilute nitric acid were mixed homogeneously and extruded for molding, then calcined, exchanged with 0.5 mol/L ammonium nitrate for three times (2 hours for each time), washed with deionized water, dried, and calcined at 550 for 4 hours to obtain a catalyst.

(27) H-ZSM-35 Catalyst 100 g of calcined Na-ZSM-35 molecular sieves, with a silicon-aluminum atomic molar ratio of 20, 35 and 50 respectively, were each exchanged with 0.5 mol/L ammonium nitrate for three times (2 hours for each time), washed with deionized water, dried, calcined at 550 for 4 hours, and extruded to prepare catalysts of 20-40 mesh.

(28) H-ZSM-5 Catalyst

(29) 100 g of calcined Na-ZSM-5 molecular sieves, with a silicon-aluminum atomic molar ratio of 20, 40 and 60 respectively, were each exchanged with 0.5 mol/L ammonium nitrate for three times (2 hours for each time), washed with deionized water, dried, calcined at 550 for 4 hours, and extruded to prepare catalysts of 20-40 mesh.

(30) H-EMT Catalyst

(31) The synthetic H-EMT molecular sieves, with a silicon-aluminum atomic molar ratio of 5, 10 and 20 respectively, were each extruded to prepare catalysts of 20-40 mesh.

Example 1

(32) The H-MOR molecular sieve with a silicon-aluminum ratio Si/Al=6.5 was tableted under a pressure of 40 MPa, and crushed to 20-40 mesh to obtain a catalyst. 0.4 g of the catalyst was packed into a fixed bed reactor for pretreatment. The pretreatment conditions for the catalyst were as follows: the N.sub.2 flow rate was 30 mL/min, and the temperature was raised from 25° C. to 500 for 150 min and maintained at 500° C. for 180 min

(33) The reaction gas was consisted of three gas streams, and a total flow rate of 100 mL/min was ensured. The raw material of dimethoxymethane was carried into the reactor by CO at a flow rate of 10 ml/min under a water bath temperature of 30° C.; the flow rates of another stream of pure CO were 0 mL/min, 10 mL/min, 40 mL/min and 90 mL/min respectively; the flow rates of the third stream of N.sub.2 were 90 mL/min, 80 mL/min, 50 mL/min and 0 mL/min respectively. The total pressure of reaction was 5.0 MPa. The reaction temperature was maintained at 190° C. for 300 min, then increased to 200° C. in 5 min, maintained at 200° C. for another 300 min, and then increased to 210° C. in 5 min. According to the above rule, the temperature was maintained for 300 min for each increase by 10° C., until it was increased to 270° C. and then maintained for 300 min. The raw material of DMM had a partial pressure of about 1.25×10.sup.−2 MPa (0.0125 atm), and the total CO partial pressures were approximately 0.5, 1.0, 2.5 and 5.0 MPa.

(34) When the partial pressure of CO is 2.5 MPa, the graph of the conversion rate of the raw material DMM and the selectivity to the products with temperature is shown in FIG. 1. As can be seen from FIG. 1, on the H-MOR (Si/Al=6.5) catalyst, when the reaction temperature is higher than 190, the conversion rate of the raw material DMM is close to 100%. Five products are substantially generated, namely dimethyl ether (DME), methyl acetate (MAc), acetic acid (AA), methyl acrylate (MA) and acrylic acid (CA). The selectivities to the products of dimethyl ether and methyl acetate decrease gradually with increase in the reaction temperature. When the reaction temperature reaches to 240° C., almost no dimethyl ether is generated; when the reaction temperature reaches to 270° C., the selectivity to methyl acetate is reduced to 40%. When the reaction temperature is higher than 200, a small amount of acrylic acid is generated in the products, the selectivity of which increases as the reaction temperature increases, and the highest selectivity reaches to 35% as the reaction temperature reaches to 270. The product of methyl acrylate is accompanied by the generation of acrylic acid, and its selectivity is stabilized constantly at around 3%. The selectivity to the product of acetic acid also increases gradually as the reaction temperature increases, but the change is not obvious, and the selectivity increases from 10% at the initial 190° C. to 23% at 270° C.

(35) Table 1 shows the distribution of product as a function of the reaction temperature at a DMM partial pressure of 1.25×10.sup.−2 MPa (0.0125 atm) and CO partial pressures of 0.5 MPa, 1.0 MPa and 5.0 MPa respectively. It can be known from Table 1 that under all conditions, the conversion rate of the raw material DMM is close to 100%, and the selectivity to the product of acrylic acid is higher at the same reaction temperature as the CO partial pressure increases. When the partial pressure of CO is 5.0 MPa, the selectivity to acrylic acid reaches to 37% at 240° C. The partial pressure of CO has little effect on the selectivity to acetic acid, and the selectivity to acetic acid is basically stabilized at 20-25%.

Example 2

(36) The H-MOR molecular sieve with a silicon-aluminum ratio Si/Al=6.5 was tableted under a pressure of 40 MPa, and crushed to 20-40 mesh to obtain a catalyst. 0.4 g of the catalyst was packed into a fixed bed reactor for pretreatment. The pretreatment conditions for the catalyst were as follows: the N.sub.2 flow rate was 30 mL/min, and the temperature was raised from 25° C. to 500 for 150 min and maintained at 500° C. for 180 min

(37) The reaction gas was consisted of two gas streams, and a total flow rate of 100 mL/min was ensured. The raw material of dimethoxymethane was carried into the reactor by CO at flow rates of 2 mL/min, 5 mL/min, 10 mL/min, 25 mL/min, 50 mL/min and 100 mL/min under water bath temperatures of 0° C. and 30° C.; the flow rates of another stream of pure CO were 98 mL/min, 95 mL/min, 90 mL/min, 75 mL/min, 50 mL/min and 0 mL/min respectively. The total reaction pressure was 5.0 MPa. The reaction temperature was maintained at 190° C. for 300 min, then increased to 200° C. in 5 min, maintained at 200° C. for another 300 min, and then increased to 210° C. in 5 min. According to the above rule, the temperature was maintained for 300 min for each increase by 10° C., until it was increased to 270° C. and then maintained for 300 min. The partial pressures of the raw material DMM were 0.21×10.sup.−2 MPa (0.0021 atm), 0.416×10.sup.−2 MPa (0.00416 atm), 1.25×10.sup.−2 MPa (0.0125 atm), 3.125×10.sup.−2 MPa (0.3125 atm), 6.25×10.sup.−2 MPa (0.625 atm) and 12.5×10.sup.−2 MPa (0.125 atm) respectively. Among them, the reaction data at the partial pressure of 1.25×10.sup.−2 MPa (0.0125 atm) for the raw material DMM is shown in FIG. 1, and other reaction data is shown in Table 2. When the partial pressure of DMM is lower than 3.125×10.sup.−2 MPa, the conversion rate of DMM is close to 100% under any reaction temperature. When the partial pressure of DMM is higher than 3.125×10.sup.−2 MPa, the conversion rate of DMM increases gradually as the reaction temperature increases. When the partial pressure of DMM is 0.21×10.sup.−2 MPa and the reaction temperature is 190, the products are methyl acetate and acetic acid, with selectivities of 56% and 44%, respectively. As the reaction temperature increases, the selectivities to methyl acetate and acetic acid are gradually reduced, accompanied by the generation of acrylic acid and methyl acrylate, and the selectivity to acrylic acid increases as the reaction temperature increases. When the reaction temperature is higher than or equal to 250, the selectivity to acrylic acid reaches to a maximum of 48%, and remains substantially unchanged as the reaction temperature increases thereafter. When the reaction temperature is higher than 250, with the partial pressure of DMM being increased to 0.416×10.sup.−2 MPa, the selectivity to acrylic acid is stabilized at around 40%. As the partial pressure of DMM increases, the selectivity to acrylic acid gradually decreases under the same reaction temperature conditions. When the partial pressure of DMM is 12.5×10.sup.−2 MPa and the reaction temperature is 270, the selectivity to acrylic acid is only 4%.

Example 3

(38) The H-MOR molecular sieve with a silicon-aluminum ratio Si/Al=6.5 was tableted under a pressure of 40 MPa, and crushed to 20-40 mesh to obtain a catalyst. 0.4 g of the catalyst was packed into a fixed bed reactor for pretreatment. The pretreatment conditions for the catalyst were as follows: the N.sub.2 flow rate was 30 mL/min, and the temperature was raised from 25° C. to 500 for 150 min and maintained at 500° C. for 180 min

(39) The reaction gas was consisted of two gas streams, and a total flow rate of 100 mL/min was ensured. The molar ratio of CO to DMM was maintained at 400:1 (that is, to ensure the peak area of the raw material DMM in the chromatogram was kept constant) by adjusting the water bath temperature of the raw material DMM and the flow rate of the CO carrier gas. The total reaction pressures were adjusted to be 1.25 MPa, 2.50 MPa and 5.0 MPa, respectively. The reaction temperature was maintained at 190° C. for 90 min, then increased to 200° C. in 5 min, maintained at 200° C. for another 90 min, and then increased to 210° C. in 5 min According to the above rule, the temperature was maintained for 90 min for each increase by 10° C., until it was increased to 270° C. and then maintained for 90 min. The graph of the conversion rate of the raw material DMM and the selectivity to the products of acetic acid and acrylic acid as a function of temperature is shown in FIG. 2. In the case that the ratio of CO to DMM is kept constant, the selectivity to acetic acid remains basically unchanged as the total reaction pressure is increased gradually. However, when the total reaction pressure is 5.0 MPa, the selectivity to the product of acrylic acid is significantly higher than the selectivities to acrylic acid at the total pressures of 1.25 MPa and 2.50 MPa at the same temperature. This is because the aldol condensation reaction is a reaction in which the number of molecules is reduced, and an increased reaction pressure is favorable for the reaction to proceed in the positive direction.

Example 4

(40) A fixed bed reactor was used, and the packing mass of catalyst was in a range from 0.1 g to 5.0 g. The molecular sieves having different silicon-aluminum ratios with topologies of MWW, FER, MFI, MOR, FAU and BEA, including H-MCM-22, H-ZSM-35, H-ZSM-5, H-MOR, H-Y, H-Beta and the metal modified Ga-mordenite, Fe-mordenite, Cu-mordenite as well as the molded catalysts of H-mordenite-Al.sub.2O.sub.3, H-mordenite-SiO.sub.2 and H-mordenite-MgO, were tableted at a pressure of 40 MPa, and crushed to 20-40 mesh to obtain catalysts. The reaction results of acidic resin catalysts and solid sulfonic acid catalysts at the conditions of a reaction temperature in a range from 180 to 350, a reaction pressure in a range from 0.1 MPa to 10 MPa, a mass space velocity of raw material DMM in a range from 0.05 h.sup.−1 to 10 h.sup.−1 and a volume percentage in a range from 0.1% to 100% are shown in Table 3.

(41) TABLE-US-00001 TABLE 1 Reaction results of dimethoxymethane under different temperatures and CO partial pressures Conversion Selectivity to product/% Reaction CO partial rate/% Dimethyl Methyl Methyl Acetic acrylic temperature/ pressure/MPa Dimethoxymethane ether acetate acrylate acid acid 190 0.5 100 90 10 0 0 0 1.0 100 75 25 0 0 0 5.0 100 14 70 0 16 0 200 0.5 100 75 25 0 0 0 1.0 100 60 35 0 5 0 5.0 100 9 64 2 16 9 210 0.5 100 40 56 0 4 0 1.0 100 28 59 1 9 3 5.0 100 3 62 3 16 16 220 0.5 100 16 72 2 10 0 1.0 100 10 63 3 12 12 5.0 100 2 50 3 17 28 230 0.5 100 6 64 6 15 9 1.0 100 4 55 5 19 17 5.0 100 1 42 3 20 34 240 0.5 100 2 52 9 19 18 1.0 100 1 50 7 21 21 5.0 100 0 37 4 22 37 250 0.5 100 1 42 9 22 26 1.0 100 0 41 7 23 29 5.0 100 0 34 4 23 39 260 0.5 100 0 36 9 23 32 1.0 100 0 37 7 23 34 5.0 100 0 33 4 24 39 270 0.5 100 0 34 9 24 33 1.0 100 0 36 7 24 35 5.0 100 0 32 4 25 39

(42) TABLE-US-00002 TABLE 2 Reaction results under different temperatures and partial pressures of dimethoxymethane Partial pressure of Conversion Selectivity to product/% Reaction DMM/10.sup.−2 rate/% Dimethyl Methyl Methyl Acetic acrylic temperature/ MPa Dimethoxymethane ether acetate acrylate acid acid 190 0.210 100 0 56 0 44 0 0.416 100 0 60 0 40 0 3.125 100 67 24 0 9 0 6.250 57 81 17 0 2 0 12.500 36 76 9 0 0 0 200 0.210 100 0 50 0 50 0 0.416 100 0 62 0 48 0 3.125 100 18 68 0 12 2 6.250 61 66 32 0 2 0 12.500 49 74 16 0 0 0 210 0.210 100 0 46 0 54 0 0.416 100 0 60 0 40 0 3.125 100 8 64 2 14 12 6.250 78 57 37 0 6 0 12.500 64 69 21 0 2 0 220 0.210 100 0 33 0 38 29 0.416 100 0 40 0 36 24 3.125 100 2 59 2 17 20 6.250 89 48 41 1 8 2 12.500 79 63 29 0 1 0 230 0.210 100 0 27 0 34 39 0.416 100 0 41 2 30 27 3.125 100 0 52 3 20 25 6.250 93 41 46 2 9 2 12.500 85 54 33 2 4 2 240 0.210 100 0 23 0 34 43 0.416 100 0 33 2 32 33 3.125 100 0 44 3 21 32 6.250 94 30 50 2 11 7 12.500 89 49 40 3 4 3 250 0.210 100 0 17 0 35 48 0.416 100 0 29 2 33 36 3.125 100 0 42 3 20 35 6.250 94 24 51 3 12 10 12.500 92 45 40 3 4 3 260 0.210 100 0 16 0 36 48 0.416 100 0 23 2 35 39 3.125 100 0 40 3 21 36 6.250 94 20 51 3 13 13 12.500 92 43 42 3 5 4 270 0.210 100 0 14 0 38 48 0.416 100 0 22 2 37 39 3.125 100 0 39 3 21 37 6.250 94 18 52 3 13 14 12.500 92 43 42 3 5 4

(43) TABLE-US-00003 TABLE 3 Catalytic reaction results of dimethoxymethane on surfaces and in pores of different solid acid catalysts Reaction condition Reaction result Mass space Volume Conversion velocity of content of rate of Reaction Reaction dimethoxy- dimethoxy- dimethoxy- Selectivity Catalyst temperature pressure methane methane methane to acrylic No. Type Si/Al ( ) (MPa) (h.sup.−1) (%) (%) acid (%) 1 H-mordenite 5 250 5 0.25 0.1 100 50 2 H-mordenite 6.5 350 8 1.00 1.0 100 50 3 H-mordenite 25 240 10 0.50 0.5 100 40 4 H-mordenite 50 240 10 0.50 0.5 100 40 6 H-ZSM-35 5 270 10 0.25 1.0 100 9 7 H-ZSM-35 25 280 10 0.25 0.25 100 15 8 H-ZSM-35 50 290 10 0.25 0.5 100 16 9 H-ZSM-35 100 300 10 0.25 0.5 100 20 10 H-ZSM-5 25 260 5 0.5 0.1 100 4 11 H-ZSM-5 50 260 5 0.5 0.1 100 4 12 Benzenesulfonic — 170 10 0.1 0.5 38 28 acid 13 p-Methylbenzene — 170 10 0.1 0.5 46 31 sulfonic acid 14 Perfluorinated — 170 10 0.1 0.5 80 32 sulfonic acid resin 15 Ga-mordenite 5 250 3 1.00 1.0 100 36 16 Fe-mordenite 6.5 250 3 1.00 1.0 100 50 17 Cu-mordenite 25 250 3 1.00 1.0 100 43 18 H-mordenite-Al.sub.2O.sub.3 6.5 240 5 3.0 5.0 86 50 19 H-mordenite-SiO.sub.2 6.5 240 5 3.0 5.0 88 50 20 H-mordenite-MgO 6.5 240 5 3.0 5.0 96 50

(44) The above are only a few embodiments of the present application, and are not intended to limit the present application in any form. Although the present application is disclosed by the preferred embodiments as above, they are however not used to limit the present application. A slight change or modification utilizing the technical content disclosed above made by the person skilled in art, without departing from the technical solution of the present application, is equivalent to the equivalent embodiment, and falls within the scope of the technical solution.