The invention concerns a process for the production of butadiene from an ethanol feed comprising at least 80% by weight of ethanol, comprising a step for conversion of ethanol to acetaldehyde, a step for the extraction of butadiene, a step for scrubbing gaseous by-products with water, a step for eliminating impurities and brown oils, a step for treating effluents, a first butadiene purification step, and a subsequent butadiene purification step, said ethanol feed being supplied to said butadiene extraction step, the arrangement of the steps and recycles allowing the recycles to be maximized and allowing the water and energy consumption to be minimized.

The invention concerns a process for the production of butadiene from an ethanol feed comprising at least 80% by weight of ethanol, comprising a step for conversion of ethanol to acetaldehyde, a step for the extraction of butadiene, a step for scrubbing gaseous by-products with water, a step for eliminating impurities and brown oils, a step for treating effluents, a first butadiene purification step, and a subsequent butadiene purification step, said ethanol feed being supplied to said butadiene extraction step, the arrangement of the steps and recycles allowing the recycles to be maximized and allowing the water and energy consumption to be minimized.

The invention concerns a method for purifying a hydroalcoholic feedstock, comprising: a) a step of counter-current liquid-liquid extraction, comprising an extraction section supplied at the top with said hydroalcoholic feedstock and at least one intermediate raffinate fraction from step b) and at the bottom with an extraction solvent, and producing at the top an extraction stream and at the bottom a raffinate, wherein the extraction section is operated at a mean temperature in the extractor of between 10 and 40° C.; b) a counter-current liquid-liquid back-extraction comprising a back-extraction section supplied at the top with an acidic aqueous solution, having a pH between 0.5 and 5.0, and at the bottom with the extraction stream from step a), and producing at the top an extract and at the bottom the intermediate raffinate, wherein the back-extraction section is operated at a mean temperature between 40 and 80° C.

The invention concerns a method for purifying a hydroalcoholic feedstock, comprising: a) a step of counter-current liquid-liquid extraction, comprising an extraction section supplied at the top with said hydroalcoholic feedstock and at least one intermediate raffinate fraction from step b) and at the bottom with an extraction solvent, and producing at the top an extraction stream and at the bottom a raffinate, wherein the extraction section is operated at a mean temperature in the extractor of between 10 and 40° C.; b) a counter-current liquid-liquid back-extraction comprising a back-extraction section supplied at the top with an acidic aqueous solution, having a pH between 0.5 and 5.0, and at the bottom with the extraction stream from step a), and producing at the top an extract and at the bottom the intermediate raffinate, wherein the back-extraction section is operated at a mean temperature between 40 and 80° C.

In the method of the present invention, 1,3-butadiene is produced by vaporizing an ethanol feedstock in a vaporizer (104), feeding the resulting into two or more parallel first reactors (108) to convert the ethanol to acetaldehyde in the presence of a first catalyst, supplying the resulting intermediate gas to a second reactor (110) to convert the ethanol and acetaldehyde to 1,3-butadiene in the presence of a second catalyst, purifying the resulting crude gas containing 1,3-butadiene by a gas-liquid separator (112), a first distillation column (114), a fourth reactor (116), a second distillation column (118), and mixing one of both of a part of the ethanol-containing gas and an acetaldehyde-containing gas obtained in the second distillation column (118) are mixed with the intermediate gas, thereby adjusting an ethanol/acetaldehyde molar ratio in the intermediate gas to 1 to 100.

In the method of the present invention, 1,3-butadiene is produced by vaporizing an ethanol feedstock in a vaporizer (104), feeding the resulting into two or more parallel first reactors (108) to convert the ethanol to acetaldehyde in the presence of a first catalyst, supplying the resulting intermediate gas to a second reactor (110) to convert the ethanol and acetaldehyde to 1,3-butadiene in the presence of a second catalyst, purifying the resulting crude gas containing 1,3-butadiene by a gas-liquid separator (112), a first distillation column (114), a fourth reactor (116), a second distillation column (118), and mixing one of both of a part of the ethanol-containing gas and an acetaldehyde-containing gas obtained in the second distillation column (118) are mixed with the intermediate gas, thereby adjusting an ethanol/acetaldehyde molar ratio in the intermediate gas to 1 to 100.

The present invention relates to a process for producing butadiene from ethanol, in two reaction steps, comprising a step a) of converting ethanol into acetaldehyde and a step b) of conversion into butadiene, said step b) simultaneously implementing a reaction step and a regeneration step in (n+n/2) fixed-bed reactors, n being equal to 4 or a multiple thereof, comprising a catalyst, said regeneration step comprising four successive regeneration phases, said step b) also implementing three regeneration loops.

The present invention relates to a process for producing butadiene from ethanol, in two reaction steps, comprising a step a) of converting ethanol into acetaldehyde and a step b) of conversion into butadiene, said step b) simultaneously implementing a reaction step and a regeneration step in (n+n/2) fixed-bed reactors, n being equal to 4 or a multiple thereof, comprising a catalyst, said regeneration step comprising four successive regeneration phases, said step b) also implementing three regeneration loops.

The method of the present invention for producing 1,3-butadiene includes: vaporizing an ethanol feedstock in a vaporizer (104), supplying the feedstock to two or more parallel first reactors (108) to convert ethanol into acetaldehyde in the presence of a first catalyst; supplying a resulting intermediate gas to a second reactor (110) to convert ethanol and acetaldehyde into 1,3-butadiene in the presence of a second catalyst; purifying a resulting crude gas containing 1,3-butadiene by a gas-liquid separator (112), a first distillation column (114), a fourth reactor (116), and a second distillation column (118); and supplying an oxygen-containing gas to at least one of the two or more parallel first reactors (108) under specific conditions, while discharging a carbon dioxide-containing gas from the first reactor (108), to thereby regenerate the first catalyst, while continuing the conversion reaction.

The method of the present invention for producing 1,3-butadiene includes: vaporizing an ethanol feedstock in a vaporizer (104), supplying the feedstock to two or more parallel first reactors (108) to convert ethanol into acetaldehyde in the presence of a first catalyst; supplying a resulting intermediate gas to a second reactor (110) to convert ethanol and acetaldehyde into 1,3-butadiene in the presence of a second catalyst; purifying a resulting crude gas containing 1,3-butadiene by a gas-liquid separator (112), a first distillation column (114), a fourth reactor (116), and a second distillation column (118); and supplying an oxygen-containing gas to at least one of the two or more parallel first reactors (108) under specific conditions, while discharging a carbon dioxide-containing gas from the first reactor (108), to thereby regenerate the first catalyst, while continuing the conversion reaction.