CN1485313A - Method for preparing methyl carbonate by directly esterfying ethylene oxide - Google Patents
Method for preparing methyl carbonate by directly esterfying ethylene oxide Download PDFInfo
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- CN1485313A CN1485313A CNA02137113XA CN02137113A CN1485313A CN 1485313 A CN1485313 A CN 1485313A CN A02137113X A CNA02137113X A CN A02137113XA CN 02137113 A CN02137113 A CN 02137113A CN 1485313 A CN1485313 A CN 1485313A
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- oxyethane
- methylcarbonate
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Abstract
A process of preparing methylcarbonate comprises: taking epichlorohydrin, methanol and carbon dioxide as the raw material, esterifying directly at the presense of a catalyst, which is one of potassium iodide,potassium chloride,potassium bromide, potassium carbonate, or two or more thereof in combination. The amount of the catalyst is: epichlorohydrin: catalyst is 100:5-10 by weight, the temperature is 80-190degree C , the pressure of carbon dioxide is 5-30Mpa, the reaction time is 0.5-4hours. The invention synthesizes methylcarbonate by direct esterification taking epichlorohydrin as the raw material. 1, 2-propylene glycol propylene carbonate are produced at the same time. The selectivity and recovery rate of product are high, which save the production cost of methylcarbonate.
Description
Technical field
The present invention relates to the preparation method of methylcarbonate, is raw material with oxyethane, monobasic lower aliphatic alcohols and carbonic acid gas particularly, carries out the method that building-up reactions obtains methylcarbonate in the presence of catalyzer.
Background technology
Methylcarbonate is a kind of important chemical material, is good organic solvent, and can be used as methylating reagent, carbonylation agent and gasoline dope.Methylcarbonate can synthesize by methods such as phosgenation, ester-interchange method and oxidative carbonylation methods.Wherein phosgenation is a raw material with the phosgene of severe toxicity, so eliminated gradually.Though the oxidative carbonylation method is still the main production method of methylcarbonate at present, its shortcoming is that to adopt the higher carbon monoxide of price be raw material, and has problems such as equipment corrosion is more serious.Comparatively speaking, ester-interchange method is concerned by people in recent years day by day owing to be raw material with carbonic acid gas cheap and easy to get and the industrial methyl alcohol that is easy to get and epoxide (as oxyethane, propylene oxide).
In the prior art, the ester-interchange method Synthesis of dimethyl carbonate adopts two-step approach usually, at first under catalyst action, react and generate NSC 11801 or propylene carbonate by oxyethane or propylene oxide and carbonic acid gas, carry out transesterification reaction by NSC 11801 or propylene carbonate and methyl alcohol again and generate methylcarbonate, while coproduction ethylene glycol or 1, the 2-propylene glycol.As application number is that the Chinese patent application of 00120873.X has been introduced a kind of catalyzer that the epoxide addition prepares carbonic acid third (second) alkene ester that is used for, and the each component weight percent of catalyst material is: KI 10～65wt%, LiNO
31～35wt%, gac or SiO
234～88wt%.The catalyst reaction mild condition that this invention is introduced is easily separated with reaction product, and can be used repeatedly.U.S. Pat 4,181,676 to have introduced a kind of be catalyzer with basic metal or alkali metal compound, under higher temperature, by containing two alkyl to four carbon atom-1, the cyclic carbonate ester of 2-glycol and methyl alcohol carry out the method for transesterification reaction Synthesis of dimethyl carbonate.U.S. Pat 4,062,884 to have introduced a kind of be catalyzer with the organic bases, by the method for cyclisation alkyl carbonate and methyl alcohol prepared in reaction methylcarbonate.Its advantage of two-step process by ester-interchange method reaction Synthesis of dimethyl carbonate is that reaction conditions is relatively gentleer, and technology is controlled easily.But because technical process is long and equipment is more, so production cost is higher relatively.Oxyethane or propylene oxide can generate methylcarbonate by direct esterification with methyl alcohol and carbonic acid gas in theory; but because the activity of methyl alcohol is in the ordinary course of things far above carbonic acid gas; therefore oxyethane or propylene oxide react preferential and methyl alcohol usually; the main ethylene glycol or 1 that generates; the ether of 2-propylene glycol can only obtain very a spot of methylcarbonate.Though the report of more existing step esterification process Synthesis of dimethyl carbonate, the selectivity of purpose product and yield are all very low.
Summary of the invention
The purpose of this invention is to provide a kind of method for preparing methylcarbonate, its technical problem to be solved is to be raw material with oxyethane, methyl alcohol and carbonic acid gas, obtain methylcarbonate by direct esterification method one-step synthesis, and coproduction ethylene glycol and NSC 11801, and the selectivity of purpose product and yield are all very high, thereby reduce the production cost of methylcarbonate.
Below be the technical scheme that the present invention solves the problems of the technologies described above:
A kind of method for preparing methylcarbonate, this method is with oxyethane, methyl alcohol and carbonic acid gas are raw material, in the presence of catalyzer, carry out the direct esterification reaction, the molar feed ratio of oxyethane and methyl alcohol is an oxyethane: methyl alcohol=1: 3～10, catalyzer is taken from potassiumiodide, Repone K, a kind of compound in Potassium Bromide or the salt of wormwood or the mixture of two or more compounds, catalyst consumption is an oxyethane: catalyzer=100: 5～10 weight ratios, temperature of reaction is 80～180 ℃, the pressure of carbonic acid gas is 5～30MPa, reaction times is 0.5～4 hour, and reaction product obtains methylcarbonate and ethylene glycol and NSC 11801 simultaneously after separating.
The molar feed ratio of above-mentioned oxyethane and methyl alcohol is preferably oxyethane: methyl alcohol=1: 3～5; Temperature of reaction is preferably 120～160 ℃; The pressure of carbonic acid gas is preferably 8～20MPa; Reaction times is preferably 0.5～2 hour; Catalyst consumption is preferably oxyethane: catalyzer=100: 6～8 weight ratios.
For this reaction, catalyzer is to take from a kind of compound in potassiumiodide, Repone K, Potassium Bromide or the salt of wormwood or the mixture of two or more compounds all is feasible, but the mixture that contriver's suggestion preferably adopts potassiumiodide and salt of wormwood to form, the weight ratio of potassiumiodide and salt of wormwood can be a potassiumiodide: salt of wormwood=1: 1～1: 5, be preferably 1: 3～and 4.
Reaction product can adopt the method for multitower rectifying to separate usually, at first distill through distillation tower, obtain methyl alcohol and dimethyl carbonate mixture material from cat head, the tower still obtains containing the mixture of materials such as NSC 11801, ethylene glycol, ethylene glycol monomethyl ether and catalyzer.Methylcarbonate that cat head obtains and methyl alcohol can form azeotrope, and the separation of this azeotrope can be adopted extraction fractional distillation usually.Make extraction agent as available furfural, the extracting rectifying top of tower obtains the methyl alcohol that purity is 99.5wt%.The available subsequently common rectificating method of the mixture of methylcarbonate and furfural is separated obtains smart methylcarbonate, and purity can reach 99.5wt% usually.The boiling point of each component differs bigger in the mixture that is obtained by the tower still, and can not produce azeotrope, generally adopts common rectification method can be separated with the rectification under vacuum method.The purity that obtains ethylene glycol, ethylene glycol monomethyl ether, NSC 11801 after the separation all can reach more than the 99wt%.Generally speaking, the methyl alcohol that separation can be obtained, NSC 11801 and catalyzer Returning reactor recycle.
The transformation efficiency of preparation method's oxyethane provided by the invention can reach 100%, and the once through yield of main purpose product methylcarbonate can reach more than 73%, and main by product is an ethylene glycol monomethyl ether, and its reaction preference is less than 3%.While a certain amount of ethylene glycol of coproduction and NSC 11801 in the preparation process, they all are the industrial chemicals that economic worth is arranged very much, NSC 11801 not only can prepare the raw material of dialkyl carbonate as ester-interchange method, also can be as the electrolytic solution of lithium cell.
In the present invention, its key is to be in super (Asia) criticality as the carbonic acid gas of one of raw material.Be in super (Asia) criticality Substance Properties, its specific inductivity, polarizability and molecular behavior and be in normal state following time tangible difference is arranged, the reaction of under super (Asia) criticality, carrying out usually, its speed of response can be faster.Therefore the present invention is actually and has improved the activity of carbonic acid gas in reaction, and this makes carbonic acid gas to react prior to methyl alcohol and oxyethane.In addition, in the method for existing two-step approach Synthesis of dimethyl carbonate, the reaction of the first step synthesizing ethylene carbonate or propylene carbonate generally need be carried out in solvent, and polarity of solvent is very big to the influence of speed of response, and the solvent of high polarity helps the carrying out that react.Prior art reacts for fear of oxyethane and solvent, has to adopt the less and little organic solvent of chemical activity of some polarity, as benzene etc.Methyl alcohol is not only the raw material of reaction among the present invention, and also as the solvent of reaction, because methyl alcohol is the very strong organic solvent of polarity, this has just accelerated speed of response greatly, has also save the operation that removes of reaction back solvent simultaneously.
Positive effect of the present invention has been to provide a kind of method of new single stage method Synthesis of dimethyl carbonate, and the selectivity of its purpose product and yield are all very desirable, thereby has obviously reduced the production cost of methylcarbonate.
Embodiment
In an embodiment, the definition of the selectivity of oxyethane transformation efficiency, product is:
[embodiment 1～11]
At capacity is the catalyzer that adds aequum in the autoclave that stirs of 0.15 liter band, seal reactor, and fall air in the still with carbon dioxide replacement, in reactor, add the methyl alcohol that accounts for reactor volume about 1/2～2/3 again, and feed oxyethane by required feed ratio.Feed and open the temperature of reaction that stirs and heat to setting behind an amount of carbonic acid gas, then with high-pressure pump or compressor again supplementary carbon dioxide to the reaction pressure of setting.Keep temperature of reaction to react, reaction is cooled to room temperature with reaction product after finishing.The decompression venting, the carbonic acid gas of emitting can be re-used as the raw material of reaction after compression.The product that obtains is weighed, and with the gc analysis content of each material wherein.
In each embodiment, the feed ratio of oxyethane and methyl alcohol, the catalyzer of employing and with seeing Table 1; Temperature of reaction, reaction times, pressure carbon dioxide see Table 2; Oxyethane transformation efficiency and each purpose product selectivity see Table 3 among each embodiment.
Reaction product is carried out rectifying earlier, the tower still material that obtains containing the cat head material of methylcarbonate and methanol azeotrope respectively and contain NSC 11801, ethylene glycol, ethylene glycol monomethyl ether and catalyzer.The cat head material adopts extraction fractional distillation to separate, and extraction agent is a furfural, and extractive distillation column is the packing tower of filling the gauze filler in the high 1000mm of internal diameter 20mm, furfural is 6: 1 with the methanol quality ratio, reflux ratio is 7, and tower still temperature is controlled at about 110 ℃, and tower top temperature is controlled at about 64 ℃.The cut of collecting about 64 ℃ gets methyl alcohol, stops to add extraction agent after the fraction collection about 64 ℃ is intact, collects 89～90 ℃ cut, must contain the thick product of methylcarbonate of extraction agent.Stop heating after the thick product collection of methylcarbonate finishes, remaining extraction agent recycles after cooling in the still.The purity that cat head obtains methyl alcohol is 99.5wt%, and the thick product of methylcarbonate gets the methylcarbonate purified product by conventional distillation subsequently, and its purity can reach 99.5wt%.General rectificating method is adopted in the sepn process of tower still material, and this is known by those skilled in the art, and the present invention is no longer enumerated in an embodiment or describes.
Table 1.
| Feed ratio (mol ratio) | Catalyzer (compound/weight ratio) | Catalyst levels (weight ratio) | |
| Embodiment 1 | ????1∶3 | ????KI∶K 2CO 3/1∶1 | ????100∶6 |
| Embodiment 2 | ????1∶5 | ????KI∶K 2CO 3/1∶3 | ????100∶8 |
| Embodiment 3 | ????1∶5 | ????KI∶K 2CO 3/1∶4 | ????100∶6 |
| Embodiment 4 | ????1∶8 | ????KI | ????100∶5 |
| Embodiment 5 | ????1∶10 | ????K 2CO 3 | ????100∶10 |
| Embodiment 6 | ????1∶10 | ????KI∶K 2CO 3/1∶1 | ????100∶8 |
| Embodiment 7 | ????1∶10 | ????KI∶K 2CO 3/1∶1 | ????100∶10 |
| Embodiment 8 | ????1∶10 | ????KI∶K 2CO 3/1∶2 | ????100∶8 |
| Embodiment 9 | ????1∶8 | ????KI∶K 2CO 3/1∶5 | ????100∶8 |
| Embodiment 10 | ????1∶8 | ????KBr | ????100∶5 |
| Embodiment 11 | ????1∶8 | ????KCl | ????100∶5 |
Annotate: feed ratio is an oxyethane: methyl alcohol; Catalyst consumption is an oxyethane: catalyzer.
Table 2.
| Temperature of reaction (℃) | Reaction times (hr) | ????CO 2Pressure (MPa) | |
| Embodiment 1 | ????140 | ????2 | ????15 |
| Embodiment 2 | ????140 | ????2 | ????15 |
| Embodiment 3 | ????180 | ????1 | ????5 |
| Embodiment 4 | ????80 | ????3 | ????15 |
| Embodiment 5 | ????100 | ????3 | ????8 |
| Embodiment 6 | ????140 | ????0.5 | ????15 |
| Embodiment 7 | ????140 | ????3 | ????25 |
| Embodiment 8 | ????140 | ????4 | ????15 |
| Embodiment 9 | ????140 | ????3 | ????15 |
| Embodiment 10 | ????140 | ????3 | ????15 |
| Embodiment 11 | ????140 | ????3 | ????15 |
Table 3
| Oxyethane transformation efficiency (%) | Methylcarbonate selectivity (%) | Ethylene glycol monomethyl ether selectivity (%) | Glycol selectivity (%) | NSC 11801 selectivity (%) | |
| Embodiment 1 | ????100 | ??67.2 | ??3.1 | ????67.0 | ??29.7 |
| Embodiment 2 | ????100 | ??73.5 | ??2.9 | ????71.7 | ??24.3 |
| Embodiment 3 | ????100 | ??42.2 | ??4.4 | ????54.2 | ??53.4 |
| Embodiment 4 | ????100 | ??30.8 | ??3.6 | ????33.4 | ??63.1 |
| Embodiment 5 | ????63.2 | ??36.9 | ??15.4 | ????37.3 | ??45.7 |
| Embodiment 6 | ????100 | ??46.7 | ??5.6 | ????53.1 | ??47.7 |
| Embodiment 7 | ????100 | ??58.9 | ??6.8 | ????42.4 | ??34.3 |
| Embodiment 8 | ????100 | ??71.9 | ??5.1 | ????49.4 | ??23.1 |
| Embodiment 9 | ????100 | ??67.21 | ??5.02 | ????57.22 | ??27.76 |
| Embodiment 10 | ????94.3 | ??24.3 | ??10.1 | ????21.5 | ??64.3 |
| Embodiment 11 | ????96.8 | ??27.8 | ??9.9 | ????25.7 | ??60.8 |
Claims (8)
1, a kind of method for preparing methylcarbonate, this method is with oxyethane, methyl alcohol and carbonic acid gas are raw material, in the presence of catalyzer, carry out the direct esterification reaction, the molar feed ratio of oxyethane and methyl alcohol is an oxyethane: methyl alcohol=1: 3～10, catalyzer is taken from potassiumiodide, Repone K, a kind of compound in Potassium Bromide or the salt of wormwood or the mixture of two or more compounds, catalyst consumption is an oxyethane: catalyzer=100: 5～10 weight ratios, temperature of reaction is 80～180 ℃, the pressure of carbonic acid gas is 5～30MPa, reaction times is 0.5～4 hour, and reaction product obtains methylcarbonate and ethylene glycol and NSC 11801 simultaneously after separating.
2, the method for preparing methylcarbonate according to claim 1, the molar feed ratio that it is characterized in that described oxyethane and methyl alcohol is an oxyethane: methyl alcohol=1: 3～5.
3, the method for preparing methylcarbonate according to claim 1 is characterized in that described temperature of reaction is 120～160 ℃.
4, the method for preparing methylcarbonate according to claim 1, the pressure that it is characterized in that described carbonic acid gas is 8～20MPa.
5, the method for preparing methylcarbonate according to claim 1 is characterized in that the described reaction times is 0.5～2 hour.
6, the method for preparing methylcarbonate according to claim 1 is characterized in that described catalyst consumption is an oxyethane: catalyzer=100: 6～8 weight ratios.
7, the method for preparing methylcarbonate according to claim 1 is characterized in that described catalyzer is potassiumiodide and salt of wormwood, and the weight ratio of potassiumiodide and salt of wormwood is a potassiumiodide: salt of wormwood=1: 1～5.
8, the method for preparing methylcarbonate according to claim 7, the weight ratio that it is characterized in that described potassiumiodide and salt of wormwood is a potassiumiodide: salt of wormwood=1: 3～4.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB02137113XA CN1235864C (en) | 2002-09-24 | 2002-09-24 | Method for preparing methyl carbonate by directly esterfying ethylene oxide |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB02137113XA CN1235864C (en) | 2002-09-24 | 2002-09-24 | Method for preparing methyl carbonate by directly esterfying ethylene oxide |
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| CN1485313A true CN1485313A (en) | 2004-03-31 |
| CN1235864C CN1235864C (en) | 2006-01-11 |
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| CNB02137113XA Expired - Fee Related CN1235864C (en) | 2002-09-24 | 2002-09-24 | Method for preparing methyl carbonate by directly esterfying ethylene oxide |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102126956A (en) * | 2010-11-30 | 2011-07-20 | 中国科学院过程工程研究所 | Catalytic method for preparing dimethyl cabonate along with ethylene glycol |
| CN102671705A (en) * | 2012-05-14 | 2012-09-19 | 浙江大学 | Preparation method and application of catalyst for synthesizing dimethyl carbonate |
| CN103508894A (en) * | 2012-06-19 | 2014-01-15 | 嘉兴学院 | Method for synthetizing dimethyl carbonate |
| CN104610064A (en) * | 2015-01-29 | 2015-05-13 | 大连理工大学 | Process for preparing dimethyl carbonate through taking carbonate as catalyst by one-pot method |
| CN105712883A (en) * | 2014-12-04 | 2016-06-29 | 中国科学院大连化学物理研究所 | Preparation method of dimethyl carbonate and glycol |
| CN116078417A (en) * | 2023-03-01 | 2023-05-09 | 山东海科新源材料科技股份有限公司 | Transesterification catalyst and recovery method |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10131620B2 (en) | 2015-10-20 | 2018-11-20 | Chang Chun Plastics Co., Ltd. | Process for producing dimethyl carbonate |
-
2002
- 2002-09-24 CN CNB02137113XA patent/CN1235864C/en not_active Expired - Fee Related
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102126956A (en) * | 2010-11-30 | 2011-07-20 | 中国科学院过程工程研究所 | Catalytic method for preparing dimethyl cabonate along with ethylene glycol |
| CN102126956B (en) * | 2010-11-30 | 2013-10-16 | 中国科学院过程工程研究所 | Catalytic method for preparing dimethyl cabonate along with ethylene glycol |
| CN102671705A (en) * | 2012-05-14 | 2012-09-19 | 浙江大学 | Preparation method and application of catalyst for synthesizing dimethyl carbonate |
| CN103508894A (en) * | 2012-06-19 | 2014-01-15 | 嘉兴学院 | Method for synthetizing dimethyl carbonate |
| CN103508894B (en) * | 2012-06-19 | 2015-08-05 | 嘉兴学院 | A kind of method of Synthesis of dimethyl carbonate |
| CN105712883A (en) * | 2014-12-04 | 2016-06-29 | 中国科学院大连化学物理研究所 | Preparation method of dimethyl carbonate and glycol |
| CN104610064A (en) * | 2015-01-29 | 2015-05-13 | 大连理工大学 | Process for preparing dimethyl carbonate through taking carbonate as catalyst by one-pot method |
| CN116078417A (en) * | 2023-03-01 | 2023-05-09 | 山东海科新源材料科技股份有限公司 | Transesterification catalyst and recovery method |
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| CN1235864C (en) | 2006-01-11 |
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