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.

There is provided a method for producing an optionally substituted olefin, comprising the steps of: dehydrogenating an optionally substituted alcohol in a first reaction zone comprising a first catalyst supported on a porous silica-based particle to form an optionally substituted carbonyl at a first set of reaction conditions; converting the optionally substituted alcohol and the optionally substituted carbonyl from the first reaction zone in a second reaction zone at a second set of reaction conditions that is different to the first set of reaction conditions and is selected to form the optionally substituted olefin, wherein the second reaction zone comprises a second catalyst supported on a porous silica-based particle. There is also provided a system for producing the optionally substituted olefin.

There is provided a method for producing an optionally substituted olefin, comprising the steps of: dehydrogenating an optionally substituted alcohol in a first reaction zone comprising a first catalyst supported on a porous silica-based particle to form an optionally substituted carbonyl at a first set of reaction conditions; converting the optionally substituted alcohol and the optionally substituted carbonyl from the first reaction zone in a second reaction zone at a second set of reaction conditions that is different to the first set of reaction conditions and is selected to form the optionally substituted olefin, wherein the second reaction zone comprises a second catalyst supported on a porous silica-based particle. There is also provided a system for producing the optionally substituted olefin.

A method for producing butadiene, the method including: a first synthesis step of bringing a mixed gas containing hydrogen and carbon monoxide into contact with a first catalyst to obtain a primary product containing ethanol as an intermediate; and a second synthesis step of bringing the primary product into contact with a second catalyst to obtain butadiene.

A method for producing butadiene, the method including: a first synthesis step of bringing a mixed gas containing hydrogen and carbon monoxide into contact with a first catalyst to obtain a primary product containing ethanol as an intermediate; and a second synthesis step of bringing the primary product into contact with a second catalyst to obtain butadiene.

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.