Method for Preparing Halohydrin and Epoxide

Abstract

Provided is a method for preparing an epoxide by halohydrination, the method comprising: (1) halohydrination: adding H.sub.2O, a halogen(s) and an olefin compound to a reaction device for reaction to obtain a halohydrin; (2) saponification: saponificating the halohydrin with an alkali metal hydroxide to obtain an epoxide and an alkali metal halide; (3) performing a bipolar membrane electrodialysis of the alkali metal halide to obtain an alkali metal hydroxide and a halogen hydride. Also provided is a method for preparing an epoxide by halohydrination, the method comprising: (1) halohydrination: halohydrinating a halogen hydride, an H.sub.2O.sub.2 and an olefin compound to obtain a halohydrin; optionally, (2) saponification: saponificating the halohydrin with an alkali metal hydroxide to obtain an epoxide and an alkali metal halide; optionally, (3) performing a bipolar membrane electrodialysis of the alkali metal halide to obtain an alkali metal hydroxide and a halogen hydride. The method according to the present invention can prepare a halohydrin or an epoxide at very high selectivity and yield, and greatly reduce the amount of waste water and waste slag discharges.

Claims

1-15. (canceled)

16. A method for preparing a halohydrin, said method comprising the step of: (1) halohydrination: adding a hydrogen halide, H.sub.2O.sub.2, and an ethylenically unsaturated compound or an olefin compound having one or more CC double bonds to a reaction device, and performing halohydrination reaction, so as to obtain a halohydrin, wherein molar ratio of the ethylenically unsaturated compound or the olefin compound to the hydrogen halide is from 1:0.9-20, wherein in said step (1), a catalyst is used, which is one, two or more selected from the group consisting of solid acids, molecular sieves, vanadium phosphorus oxide composites, molybdenum-vanadium composite metal oxides, molybdenum-bismuth composite metal oxides, molybdenum-tungsten composite metal oxides, Salen transition metal catalysts or heteropolyacids.

17. The method according to claim 16, wherein said method further comprising (2) saponification: saponificating of the halohydrin obtained in the step (1) with an alkali metal hydroxide (preferably, sodium hydroxide, potassium hydroxide or lithium hydroxide) and then performing a separation, so as to obtain an epoxide and an alkali metal halide, wherein molar ratio of the halohydrin to the alkali metal hydroxide is from 1:0.8-20, wherein in step (1), a catalyst is used, which is one, two or more selected from the group consisting of solid acids, molecular sieves, vanadium phosphorus oxide composites, molybdenum-vanadium composite metal oxides, molybdenum-bismuth composite metal oxides, molybdenum-tungsten composite metal oxides, Salen transition metal catalysts or heteropolyacids.

18. The method according to claim 17, wherein said method further comprising: (3) electrodialysis: subjecting the alkali metal halide obtained in the step (2) to electrodialysis through a bipolar membrane to obtain an alkali metal hydroxide and hydrogen halide.

19. The method according to claim 18, wherein the method further comprising: (4) refining the epoxide to obtain a refined epoxide.

20. The method according to claim 16, wherein the catalyst is one, two or more selected from the group consisting of tungstic acid, niobic acid and Ti-molecular sieves.

21. The method according to claim 16, wherein the ethylenically unsaturated compound or olefin compound having one or more CC double bonds is a C.sub.2-C.sub.50 ethylenically unsaturated compound having one or more CC double bonds; and/or the hydrogen halide is one or more of hydrogen chloride, hydrogen bromide or hydrogen iodide, and the concentration of the hydrogen halide is from 5 to 40%.

22. The method according to claim 21, wherein the ethylenically unsaturated compound or olefin compound having one or more CC double bonds is a C.sub.3-C.sub.20 ethylenically unsaturated compound having one or more CC double bonds; and/or the concentration of the hydrogen halide is from 10 to 40%.

23. The method according to claim 22, wherein the ethylenically unsaturated compound or olefin compound having one or more CC double bonds is: ethylene, propylene, butylene, butadiene, pentene, pentadiene, hexene, hexadiene, heptene, heptadiene, octene, octadiene, decene, decadiene, nonene, nonadiene, undecene, dodecene, dodecadiene, dodecatriene, docosatriene, styrene, methyl styrene or divinyl benzene; and/or the concentration of the hydrogen halide is from 20 to 40%.

24. The method according to claim 16, wherein the molar ratio of the ethylenically unsaturated compound or the olefin compound to the hydrogen halide in the step (1) is from 1:1.0-10.

25. The method according to claim 16, wherein the molar ratio of the ethylenically unsaturated compound or the olefin compound to H.sub.2O.sub.2 in the step (1) is 1:0.9-20; and/or the concentration (wt %) of the H.sub.2O.sub.2 is 8-90%.

26. The method according to claim 25, wherein the molar ratio of the ethylenically unsaturated compound or the olefin compound to H.sub.2O.sub.2 in the step (1) is from 1:1.0-10; and/or the concentration (wt %) of the H.sub.2O.sub.2 is 10-80%.

27. The method according to claim 26, wherein the molar ratio of the ethylenically unsaturated compound or the olefin compound to H.sub.2O.sub.2 in the step (1) is from 1:1.1-5; and/or the concentration (wt %) of the H.sub.2O.sub.2 is 15-70%.

28. The method according to claim 2, wherein the molar ratio of the halohydrin to the alkali metal hydroxide in the step (2) is 1:1.0-10.

29. The method according to claim 17, wherein the reaction temperature in the step (1) is from 10 to 60 C., and/or, the reaction temperature in the step (2) is 5-100 C.

30. The method according to claim 29, wherein the reaction temperature in the step (1) is from 10 to 50 C., and/or, the reaction temperature in the step (2) is 10 to 90 C.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0078] FIG. 1 is a schematic diagram of a bipolar membrane electrodialysis process of the present invention.

[0079] FIG. 2 is a schematic view showing the operation of the bipolar membrane of the present invention.

[0080] Reference numerals: 1, 2, 3: mixing containers.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

[0081] The invention is further illustrated by the following examples, which do not limit the scope of the invention.

[0082] The product was qualitatively analyzed by Agilent 7890/5975C-GC/MSD gas chromatography mass spectrometer. The product was quantitatively analyzed by Agilent 6890N gas chromatograph and external standard method.

[0083] Based on the results of the analysis, the following objective function is defined as an indicator.

[0084] Olefin conversion rate:

[00001]$C_{\mathrm{olefin}}=\frac{n_{0-\mathrm{olefin}}-n_{\mathrm{olefin}}}{n_{0-\mathrm{olefin}}}100.Math.\%$

[0085] Halohydrin selectivity:

[00002]$S_{\mathrm{halohydrin}}=\frac{n_{\mathrm{halohydrin}}}{n_{0-\mathrm{olefin}}-n_{\mathrm{olefin}}}100.Math.\%$

[0086] Halohydrin yield: Y.sub.halohydrin=C.sub.olefinS.sub.olefin

[0087] Epoxide yield:

[00003]$Y_{\mathrm{epoxide}}=\frac{n_{\mathrm{epoxide}}}{n_{0-\mathrm{olefin}}}100.Math.\%$

[0088] In the formula, C is a conversion ratio, S is a selectivity, Y is a yield, n is the amount of the substance after the reaction, and n0 is the amount of the starting material.

[0089] The bipolar membrane electrodialysis device is shown in FIGS. 1 and 2.

[0090] A bipolar membrane electrodialysis apparatus comprises: 1) a membrane stack composed of a bipolar membrane, an anion membrane, a cation membrane, a separator, and a plate as core components, and 2) auxiliary devices including a water tank, flow meters, pumps, pipes, etc. The auxiliary devices further include a rectifier cabinet. A stainless steel frame is used in the core components. The number of membranes and separators can vary depending on the particular amount of treatment (the volume of the salt solution).

[0091] Bipolar membrane, one of the electro-driven membranes, mainly provides H+ ions and OH-ions under electric field force. One side of the membrane is an anion surface, the other side is a cation surface, and the middle layer between the anion surface and the cation surface is an aqueous layer. Under the action of the applied DC electric field force, the H.sub.2O in the aqueous layer splits into H+ ions and OH ions, and H+ ions and OH ions migrates respectively through the anion surface and the cation surface to the corresponding solutions on both sides, so the role of the bipolar membrane is to provide H+ ion and OH ion source by the electric field force.

[0092] The performances of the bipolar membrane are as follows:

TABLE-US-00001 exchange capacity Membrane (milli-equivalents per water Trans-membrane bursting thickness gram of dry content Voltage* strength Appearance (mm) membrane) (%) (V) (MPa) brownish black on 0.16-0.23 1.4-1.8 through the 35-40 0.6-1.6 >0.25 the cation surface; cation surface light grey on the 0.7-1.1 through the anion surface anion surface *Measured in a 0.5 Mol Na.sub.2SO.sub.4 solution at 25 C., under current density of 10-100 mA/cm.sup.2.

Example A

[0093] 1) Halohydrination: water, chlorine (Cl.sub.2) and propylene are added to a tubular reactor in which a fixed tungstic acid catalyst bed is packed in the tube, and chlorohydrination reaction is carried out at a temperature of 45 C. The residence time in the tubular reactor was 30 minutes, wherein the flow rates of chlorine (Cl.sub.2) and propylene respectively are such that the molar ratio of liquid chlorine (Cl.sub.2) to propylene was 3.4:1, and the amount of water introduced was 99 times the mass of propylene. Halohydrin (a mixture of 2-chloropropan-1-ol and 1-chloropropan-2-ol) is obtained, which contains 9 wt % of a halogenated hydrocarbon by-product.

[0094] 2) Saponification: The halohydrin obtained in the step 1) is subjected to a saponification reaction with sodium hydroxide, and the resulting mixture is performed a separation to obtain a propylene oxide organic phase and a sodium chloride solution. The saponification reaction is carried out in a steel column reactor, and the upper part is designed as a sieve tray column. Steam enters the bottom of the column and the resulting crude propylene oxide is blown out from the top of the column. The saponification temperature is controlled at 90 to 105 C.

[0095] 3) Electrodialysis: The sodium chloride solution obtained in the step 2) was subjected to bipolar membrane electrodialysis to obtain sodium hydroxide and HCl.

[0096] 4) Refining of propylene oxide:

[0097] The crude propylene oxide obtained in the step 2 was subjected to rectification to obtain propylene oxide of high purity (99.0 wt %).

[0098] The presence of halogenated hydrocarbon by-products has little or no effect on the effect of bipolar membrane electrodialysis.

[0099] After analysis, it is found that bipolar membrane electrodialysis produces acid and base. In the bipolar membrane electrodialysis process, when the olefin compound encounters acid, the olefin mixture reacts with the acid to form a halohydrin, which is an intermediate product of the present invention. Therefore, it can be directly utilized. When the olefin compound encounters a base, they do not react and do not affect bipolar membrane electrodialysis. When the halohydrin encounters the acid, it does not change and does not affect the bipolar membrane electrodialysis. When the halohydrin encounters the base, the reaction takes place to form an epoxide, which is exactly the product of the present invention (the desired substance). The product can be obtained by separation. When the epoxide encounters an acid, a reaction and ring opening takes place, and a halohydrin product is formed. The halohydrin is an intermediate product of the present invention, so that it can be directly used. When the epoxide encounters a base, it does not react and does not affect the bipolar membrane electrodialysis.

Example 1

[0100] 1) Halohydrination: In a tubular reactor (wherein a fixed tungstic acid catalyst bed was packed in the tube), 70 wt % hydrogen peroxide H.sub.2O.sub.2, 35 wt % HCl solution (hydrochloric acid) and propylene were added, and chlorohydrination reaction was carried out at a temperature of 45 C., wherein the flow rates of 70 wt % hydrogen peroxide (H.sub.2O.sub.2), 35 wt % HCl solution and propylene respectively were such that the molar ratio of H.sub.2O.sub.2 to HCl to propylene was about 1.2:1.2:1. Halohydrin (a mixture of 2-chloropropan-1-ol and 1-chloropropan-2-ol) was obtained.

Comparative Example 1

[0101] 1) Halohydrination: In a tubular reactor (wherein a fixed tungstic acid catalyst bed was packed in the tube), water, chlorine and propylene are added, and the chlorohydrination was carried out at a temperature of 45 C., wherein the flow rates of water, chlorine gas and propylene respectively should be such that the molar ratio of H.sub.2O to chlorine to propylene was about 88:3.6:1. Halohydrin (a mixture of 2-chloropropan-1-ol and 1-chloropropan-2-ol) was obtained.

Example 2

[0102] 1) Halohydrination: Tungstic acid catalyst, a 35 wt % hydrogen peroxide (H.sub.2O.sub.2), a 20 wt % HCl solution (hydrochloric acid) and propylene were added to a column reactor to carry out a chlorohydrination reaction at a temperature of 35 C., wherein the mass ratio of the tungstic acid catalyst to propylene was 0.05:1, and the added amounts of 35 wt % hydrogen peroxide (H.sub.2O.sub.2), 20 wt % HCl solution and propylene respectively should be such that the molar ratio of H.sub.2O.sub.2 to HCl to propylene was about 1.5:1.1:1. Halohydrin (a mixture of 2-chloropropan-1-ol and 1-chloropropan-2-ol) was obtained.

Comparative Example 2

[0103] 1) Halohydrination: Tungstic acid catalyst, water, chlorine and propylene were added to a column reactor, and the chlorohydrination reaction was carried out at a temperature of 35 C., wherein the mass ratio of the tungstic acid catalyst to propylene was 0.05:1, and the added amounts of water, chlorine gas and propylene respectively should be such that the molar ratio of water to chlorine to propylene is about 80:3.3:1. Halohydrin (a mixture of 2-chloropropan-1-ol and 1-chloropropan-2-ol) was obtained.

Comparative Example 3

[0104] Halohydrination: 65 wt % hydrogen peroxide (H.sub.2O.sub.2), a 35 wt % HCl solution (hydrochloric acid) and propylene were added in a tubular reactor, and a chlorohydrination reaction was carried out at a temperature of 45 C., wherein the flow rates of the 65 wt % hydrogen peroxide (H.sub.2O.sub.2), 35 wt % HCl solution and propylene respectively should be such that the molar ratio of H.sub.2O.sub.2 to HCl to propylene is about 1.2:1.2:1. Halohydrin (a mixture of 2-chloropropan-1-ol and 1-chloropropan-2-ol) was obtained.

Comparative Example 4

[0105] Halohydrination: To a tubular reactor (in which a fixed tungstic acid catalyst bed was packed in a tube) were added a 35 wt % HCl solution (hydrochloric acid) and propylene, and a chlorohydrination reaction was carried out at a temperature of 45 C., wherein the flow rates of the 35 wt % HCl solution and propylene respectively should be such that the molar ratio of HCl to propylene was about 1.2:1.

Example 3

[0106] 1) Halohydrination: In a tubular reactor (wherein a fixed tungstic acid catalyst bed was packed in the tube), 70 wt % hydrogen peroxide (H.sub.2O.sub.2), 35 wt % HCl solution (hydrochloric acid) and propylene were added, and chlorohydrination reaction was carried out at a temperature of 45 C., in which the flow rates of 70 wt % hydrogen peroxide (H.sub.2O.sub.2), 35 wt % HCl solution and propylene respectively should be such that the molar ratio of H.sub.2O.sub.2 to HCl to propylene was about 1.2:1.2:1. Halohydrin (a mixture of 2-chloropropan-1-ol and 1-chloropropan-2-ol) was obtained.

[0107] 2) Saponification: The halohydrin obtained in the step 1) was subjected to a saponification reaction with sodium hydroxide to obtain a propylene oxide organic phase and a sodium chloride solution. The saponification reaction was carried out in a steel column reactor, and the upper part was designed as a sieve tray column. Steam entered the bottom of the column and the resulting crude propylene oxide was blown out from the top of the column. The saponification temperature was controlled at 60 to 70 C.

[0108] 3) Electrodialysis: The sodium chloride solution obtained in step 2) was subjected to bipolar membrane electrodialysis (TRPB8040-I type, manufactured and sold by Beijing Tingrun Membrane Technology Development Co., Ltd., the applied transmembrane voltage was 1.3V, and the working temperature was 20-30 C.), sodium hydroxide and HCl were obtained.

[0109] 4) Refining of propylene oxide:

[0110] The crude propylene oxide product obtained in the step 2 was subjected to rectification to obtain propylene oxide of high purity (99.9 wt %).

Example 4

[0111] 1) Halohydrination: Tungstic acid catalyst, a 35 wt % hydrogen peroxide (H.sub.2O.sub.2), a 20 wt % HCl solution (hydrochloric acid) and propylene were added to a column reactor, and chlorohydrination reaction was carried out at a temperature of 35 C., wherein the mass ratio of the tungstic acid catalyst to propylene was 0.05:1, and the added amounts of 35 wt % hydrogen peroxide (H.sub.2O.sub.2), 20 wt % HCl solution and propylene respectively should be such that the molar ratio of H.sub.2O.sub.2 to HCl to propylene was about 1.5:1.1:1. Halohydrin (a mixture of 2-chloropropan-1-ol and 1-chloropropan-2-ol) was obtained.

[0112] 2) Saponification: The halohydrin obtained in the step 1) was subjected to a saponification reaction with sodium hydroxide, so as to obtain a propylene oxide organic phase and a sodium chloride solution. The saponification reaction was carried out in a steel column reactor, and the upper part was designed as a sieve tray column. Steam entered the bottom of the column and the resulting crude propylene oxide was blown out from the top of the column. The saponification temperature was controlled at 30 to 40 C.

[0113] 3) Electrodialysis: The sodium chloride solution obtained in the step 2) was subjected to bipolar membrane electrodialysis to obtain sodium hydroxide and HCl.

[0114] 4) Refining of propylene oxide:

[0115] The crude propylene oxide product obtained in the step 2 was subjected to rectification to obtain propylene oxide of high purity (99.9 wt %).

Example 5

[0116] Example 3 was repeated except that the HBr solution was used instead of the HCl solution.

Example 6

[0117] Example 3 was repeated except that the tube of the tubular reactor was packed with a fixed bed of niobic acid catalyst, i.e., niobic acid was used instead of tungstic acid.

Example 7

[0118] Example 3 was repeated except that the molybdenum-bismuth composite metal oxide Mo.sub.12Bi.sub.1.6Fe.sub.2.2Co.sub.5.5Ni.sub.2.5Sb.sub.0.5Zn.sub.0.3K.sub.0.1O.sub.32.8 was used.

Example 8

[0119] Example 3 was repeated except that the tube of the tubular reactor was packed with a fixed catalyst bed of TS-1, i.e., TS-1 was used instead of tungstic acid. For the synthesis method of TS-1, please refer to Example 1 of Chinse Patent Appilcation CN201410812216.8.

Example 9

[0120] Example 3 was repeated except that the catalyst bed of TS-2 was used. For the synthesis method of TS-2, please refer to the Embodiment of CN200910013070. X (only one Example therein).

Example 10

[0121] Example 3 was repeated except that a fixed Ti-MWW catalyst bed was packed in the tube of the tubular reactor. For the synthesis method of Ti-MWW, please refer to Example 1 of CN200710037012.1.

Example 11

[0122] Example 3 was repeated except that a catalyst bed of Ti-Beta was used.

Example 12

[0123] Example 3 was repeated except that a catalyst bed of Ti-SBA-15 was used. For the synthesis method of Ti-SBA-15, please refer to Example 1 of CN201110211854.0.

Example 13

[0124] Example 3 was repeated except that the catalyst bed of HTS-1 was used.

Example 14

[0125] Example 3 was repeated except that the catalyst bed of HTS-2 was used.

Example 15

[0126] Example 3 was repeated except that the catalyst bed of HTS-3 was used.

Example 16

[0127] Example 3 was repeated except that the catalyst bed of ZSM-5 molecular sieve was used. The ZSM-5 molecular sieve was prepared by the method of Examples 1-3 of CN 200510029462.7.

Example 17

[0128] Example 3 was repeated except that the catalyst bed of Silicalite-1 molecular sieve was used. The Silicalite-1 molecular sieve was prepared by the method of Example 1 of CN201010220796.3.

Example 18

[0129] Example 3 was repeated except that ethylene was used instead of propylene.

Example 19

[0130] Example 3 was repeated except that divinylbenzene was used in place of propylene.

Example 20

[0131] Example 3 was repeated except that octene-1 was used instead of propylene.

Example 21

[0132] Example 3 was repeated except that styrene was used instead of propylene.

Example 22

[0133] Example 3 was repeated except that the sodium hydroxide in step (2) was replaced with potassium hydroxide.

Example 23

[0134] Example 3 was repeated except that the flow rates of 65 wt % hydrogen peroxide (H.sub.2O.sub.2), 35 wt % HCl solution and propylene respectively in step (1) was such that the molar ratio of H.sub.2O.sub.2 to HCl to propylene was about 0.8:0.3:1.

Example 24

[0135] Example 3 was repeated except that the flow rates of 20 wt % hydrogen peroxide (H.sub.2O.sub.2), 35 wt % HCl solution and propylene respectively in step (1) was such that the molar ratio of H.sub.2O.sub.2 to HCl to propylene was about 0.9:1.1:1.

Example 25

[0136] Example 3 was repeated except that the reaction temperature in the step (1) was 20 C.

Example 26

[0137] Example 3 was repeated except that the temperature in step (2) was controlled at 50 C.

[0138] Table 1 Reaction conditions and reaction results of Examples 1-26 and Comparative Examples 1-4

TABLE-US-00002 H.sub.2O.sub.2 Catalyst (or amount Water): (based hydrogen on halide the (or mass halogen): of halohydrination Reaction Olefin Halohydrin Halohydrin Epoxide olefin olefin), temperature, time, conversion, selectivity, yield, yield, Items Catalyst (mole) % C. min % % % % Ex.1 tungstic acid 1.2:1.2:1 bed 45 40 100.00 96.34 96.34 / Comp. tungstic acid 88:3.6:1 bed 45 40 78.84 78.17 61.63 / Ex.1 Ex.2 tungstic acid 1.5:1.1:1 5 35 10 100.00 96.01 96.01 / Comp. tungstic acid 80:3.3: 5 35 10 75.13 74.86 56.24 / Ex.2 Comp. None 1.2:1.2:1 0 45 40 1.02 31.24 0.32 / Ex.3 Comp. tungstic acid 0:1.2:1 bed 45 40 0 0 0 / Ex.4 Ex.3 tungstic acid 1.2:1.2:1 bed 45 40 100.00 96.34 96.34 93.73 Ex.4 tungstic acid 1.5:1.1:1 5 35 10 100.00 96.01 96.01 93.11 Ex.5 tungstic acid 1.2:1.2:1 bed 45 40 100.00 96.33 96.33 93.72 Ex.6 niobic acid 1.2:1.2:1 bed 45 40 100.00 96.41 96.41 93.89 Ex.7 Mo.sub.12Bi.sub.16Fe.sub.2.2 1.2:1.2:1 bed 45 40 100.00 96.44 96.44 93.90 Co.sub.5.5Ni.sub.2.5Sb.sub.0.5 Zn.sub.0.3K.sub.0.1O.sub.32.8 Ex .8 TS-1 1.2:1.2:1 bed 45 40 100.00 98.16 98.16 92.34 Ex.9 TS-2 1.2:1.2:1 bed 45 40 100.00 98.19 98.19 96.31 Ex.10 Ti-MWW 1.2:1.2:1 bed 45 40 100.00 98.21 98.21 96.58 Ex.11 Ti-Beta 1.2:1.2:1 bed 45 40 100.00 98.22 98.22 97.00 Ex.12 Ti-SBA-15 1.2:1.2:1 bed 45 40 100.00 98.25 98.25 97.22 Ex.13 HTS-1 1.2:1.2:1 bed 45 40 100.00 98.52 98.52 95.89 Ex.14 HTS-2 1.2:1.2:1 bed 45 40 100.00 98.89 98.89 96.99 Ex.15 HTS-3 1.2:1.2:1 bed 45 40 100.00 99.01 99.01 97.15 Ex.16 ZSM-5 1.2:1.2:1 bed 45 40 100.00 98.83 98.83 94.41 Ex.17 Silicalite-1 1.2:1.2:1 bed 45 40 100.00 98.83 98.83 96.01 Ex.18 tungstic acid 1.2:1.2:1 bed 45 40 100.00 95.18 95.18 92.77 (ethylene) Ex.19 tungstic acid 1.2:1.2:1 bed 45 40 100.00 96.30 96.30 92.28 (diyinyl benzene) Ex.20 tungstic acid 1.2:1.2:1 bed 45 40 100.00 96.46 96.46 92.37 (octene-1) Ex.21 tungstic acid 1.2:1.2:1 bed 45 40 100.00 96.39 96.39 92.42 (styrene) Ex.22 tungstic acid 1.2:1.2:1 bed 45 40 100.00 96.34 96.34 92.28 Ex.23 tungstic acid 0.8:0.3:1 bed 45 40 30.00 96.11 28.83 91.22 Ex.24 tungstic acid 0.9:1.1:1 bed 45 40 90.00 96.19 86.57 91.89 Ex.25 tungstic acid 1.2:1.2:1 bed 20 2 100.00 96.30 96.30 92.19 Ex.26 tungstic acid 1.2:1.2:1 bed 45 40 100.00 96.34 96.34 92.18

[0139] By catalyst amount being a bed, it is meant that the catalyst is disposed in the reactor in the form of a fixed catalyst bed, such as a plurality of reactors in series, tubular reactors or microchannel reactors. The weight ratio of ethylenically unsaturated compound to catalyst in the catalyst bed was 1:0.3.