Pre-separation method for ethanediol and 1,2-butanediol-containing raw material and preparation method of epoxybutane

Abstract

The invention discloses a preparation method of epoxybutane. The preparation method comprises the following steps: performing reactive distillation on an ethanediol and 1,2-butanediol-containing raw material and an esterifying agent under the action of an esterifying catalyst to respectively obtain a light component containing a reaction product corresponding to the esterifying agent and a heavy component containing ethylene carbonate and butylene carbonate, rectifying the heavy component containing the ethylene carbonate and the butylene carbonate to respectively obtain the ethylene carbonateand the butylene carbonate, and decarboxylating the butylene carbonate under the action of a decarboxylating catalyst to obtain the epoxybutane. According to the preparation method of the epoxybutane, the ethanediol and 1,2-butanediol-containing raw material and the esterifying agent are subjected to ester exchange reaction, so that 1,2-butanediol is converted into the butylene carbonate which isnot azeotropic with ethanediol to purify the ethanediol, and the butylene carbonate obtained by the conversion of the 1,2-butanediol is decarboxylated to obtain the epoxybutane with a relatively highadditional value.

Description

technical field

[0001] The invention relates to the technical field of chemical synthesis, in particular to a method for pre-separating raw materials containing ethylene glycol and 1,2-butanediol and a method for preparing butylene oxide. Background technique

[0002] By the end of 2016, the global ethylene glycol (EG) production capacity reached 37.47 million tons, and the average annual growth rate of production capacity reached more than 5%. At present, there are two main synthesis methods of ethylene glycol, namely: ethylene-ethylene oxide-ethylene glycol route and synthesis gas (hydrogen and carbon monoxide)-ethylene glycol route (commonly known as coal-to-ethylene glycol route).

[0003] Because domestic coal resources are abundant, and when the crude oil price is higher than US$55 / barrel, the coal-to-ethylene glycol line shows obvious cost advantages, so this technology has been sought after by domestic enterprises in recent years. The coal-to-ethylene glycol line ma...

Examples

preparation example Construction

[0071] see figure 1 , is a schematic flow chart of a method for preparing butylene oxide in one embodiment, and the corresponding method for preparing butylene oxide includes the following steps S210 to S260:

[0072] S210, reacting and rectifying the raw material containing ethylene glycol and 1,2-butanediol and the esterification esterification agent under the action of a catalyst to obtain the light component of the corresponding reaction product containing the esterification agent and the light component containing ethylene carbonate and carbonic acid Heavy component of butenyl esters.

[0073] Wherein, the structural general formula of esterifying agent is as follows:

[0074]

[0075] In this structural formula, X is Cl, NH 2 Or OR, R is a C1-C4 linear or branched alkyl group.

[0076] That is, the esterification agent is phosgene, urea, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, etc., which are not listed here, as long as the abo...

Embodiment 1

[0113] Reactive distillation of raw materials containing 95% ethylene glycol and 5% 1,2-butanediol and dimethyl carbonate under the action of sodium methoxide to obtain light components containing methanol and dimethyl carbonate and ethylene carbonate And the heavy component of butylene carbonate, wherein the top temperature of reactive distillation is 64°C, the kettle temperature is 100°C, the number of plates is 50, the absolute pressure is 1Bar, and the mol ratio of dimethyl carbonate and mixed alcohol in the raw material is 1.3:1, The molar ratio of sodium methoxide to mixed alcohol in the raw material is 0.01:1.

[0114] After the heavy components containing ethylene carbonate and butylene carbonate are subjected to primary rectification, high-purity ethylene glycol is extracted from the top of the tower, and a mixture of ethylene carbonate, butylene carbonate and sodium methylate is extracted from the bottom of the tower. The above-mentioned mixture of ethylene carbonate...

Embodiment 2

[0120] The raw material containing 40% ethylene glycol and 60% 1,2-butanediol and diethyl carbonate are subjected to reactive distillation under the action of tetrabutyl titanate to obtain light components containing ethanol and diethyl carbonate and The heavy components of ethylene carbonate and butylene carbonate, wherein the top temperature of reactive distillation is 90°C, the kettle temperature is 130°C, the number of trays is 69, the absolute pressure is 1Bar, and the molar ratio of diethyl carbonate to mixed alcohol in the raw material is 4 :1, the molar ratio of tetrabutyl titanate to the mixed alcohol in the raw material is 0.05:1.

[0121] After the heavy components containing ethylene carbonate and butylene carbonate are subjected to primary rectification, high-purity ethylene glycol is extracted from the top of the tower, and ethylene carbonate, butylene carbonate and tetrabutyl titanate are extracted from the bottom of the tower The mixture of ethylene carbonate, ...

technical field

[0001] The invention relates to the technical field of chemical synthesis, in particular to a method for pre-separating raw materials containing ethylene glycol and 1,2-butanediol and a method for preparing butylene oxide. Background technique

[0002] By the end of 2016, the global ethylene glycol (EG) production capacity reached 37.47 million tons, and the average annual growth rate of production capacity reached more than 5%. At present, there are two main synthesis methods of ethylene glycol, namely: ethylene-ethylene oxide-ethylene glycol route and synthesis gas (hydrogen and carbon monoxide)-ethylene glycol route (commonly known as coal-to-ethylene glycol route).

[0003] Because domestic coal resources are abundant, and when the crude oil price is higher than US$55 / barrel, the coal-to-ethylene glycol line shows obvious cost advantages, so this technology has been sought after by domestic enterprises in recent years. The coal-to-ethylene glycol line ma...

Examples

preparation example Construction

[0071] see figure 1 , is a schematic flow chart of a method for preparing butylene oxide in one embodiment, and the corresponding method for preparing butylene oxide includes the following steps S210 to S260:

[0072] S210, reacting and rectifying the raw material containing ethylene glycol and 1,2-butanediol and the esterification esterification agent under the action of a catalyst to obtain the light component of the corresponding reaction product containing the esterification agent and the light component containing ethylene carbonate and carbonic acid Heavy component of butenyl esters.

[0073] Wherein, the structural general formula of esterifying agent is as follows:

[0074]

[0075] In this structural formula, X is Cl, NH 2 Or OR, R is a C1-C4 linear or branched alkyl group.

[0076] That is, the esterification agent is phosgene, urea, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, etc., which are not listed here, as long as the abo...

Embodiment 1

[0113] Reactive distillation of raw materials containing 95% ethylene glycol and 5% 1,2-butanediol and dimethyl carbonate under the action of sodium methoxide to obtain light components containing methanol and dimethyl carbonate and ethylene carbonate And the heavy component of butylene carbonate, wherein the top temperature of reactive distillation is 64°C, the kettle temperature is 100°C, the number of plates is 50, the absolute pressure is 1Bar, and the mol ratio of dimethyl carbonate and mixed alcohol in the raw material is 1.3:1, The molar ratio of sodium methoxide to mixed alcohol in the raw material is 0.01:1.

[0114] After the heavy components containing ethylene carbonate and butylene carbonate are subjected to primary rectification, high-purity ethylene glycol is extracted from the top of the tower, and a mixture of ethylene carbonate, butylene carbonate and sodium methylate is extracted from the bottom of the tower. The above-mentioned mixture of ethylene carbonate...

Embodiment 2

[0120] The raw material containing 40% ethylene glycol and 60% 1,2-butanediol and diethyl carbonate are subjected to reactive distillation under the action of tetrabutyl titanate to obtain light components containing ethanol and diethyl carbonate and The heavy components of ethylene carbonate and butylene carbonate, wherein the top temperature of reactive distillation is 90°C, the kettle temperature is 130°C, the number of trays is 69, the absolute pressure is 1Bar, and the molar ratio of diethyl carbonate to mixed alcohol in the raw material is 4 :1, the molar ratio of tetrabutyl titanate to the mixed alcohol in the raw material is 0.05:1.

[0121] After the heavy components containing ethylene carbonate and butylene carbonate are subjected to primary rectification, high-purity ethylene glycol is extracted from the top of the tower, and ethylene carbonate, butylene carbonate and tetrabutyl titanate are extracted from the bottom of the tower The mixture of ethylene carbonate, ...

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