Method for producing butadiene from butanediols

Patent metadata

Field	Value
Publication number	US-10647624-B2
Application number	US-201616063595-A
Country	US
Kind code	B2
Filing date	Dec 13, 2016
Priority date	Dec 18, 2015
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

The invention relates to a method for producing 1,3-butanediene from a butanediol feedstock that includes:
a) A step for esterification of butanediol by a carboxylic acid to form the corresponding diester; b) A step for pyrolysis of the diester effluent obtained from step a); c) A step for distillation fed by at least the carboxylic acid effluent obtained from step a), and producing an aqueous distillate and a carboxylic acid residue; d) A step for drying the carboxylic acid that is fed at least by the carboxylic acid residue obtained from step c) and producing a water effluent and a carboxylic acid product that feeds step a).

First claim

The invention claimed is:

1. A method for producing 1,3-butadiene from butanediol, which method comprises at least:
a) esterifying the butanediol by a carboxylic acid in a mixture comprising the butanediol, the carboxylic acid and a liquid pyrolysis effluent, in a reactive distillation column, in the presence of a homogeneous or heterogeneous acid catalyst, and at a pressure of between 0.01 and 1 MPa to form the corresponding diester, thereby producing at least a carboxylic acid effluent and a diester effluent;
b) pyrolyzing the diester effluent obtained from a) in a reaction section at a temperature of between 500° C. and 650° C. thereby producing a reaction-section effluent, cooling said reaction-section effluent to a temperature that is less than 100° C., and feeding the cooled reaction-section to a separation section and separating at least a liquid pyrolysis effluent comprising at least 50% by weight of carboxylic acid and a vapor pyrolysis effluent comprising more than 90% by weight of butadiene, said liquid pyrolysis effluent feeding the esterification in a);
c) distilling at least the carboxylic acid effluent obtained from a), in a distillation column at a pressure that is less than or equal to 1 MPa, at a temperature at the top of the column between 0 and 110° C. and a temperature at the bottom of the column between 100° C. and 120° C., and producing an aqueous distillate comprising the by-products of a) and b), and a carboxylicacid residue;
d) drying the carboxylic acid residue obtained from c) and producing a water effluent and a carboxylic acid recycle that is fed to esterification in a).

2. The method according to claim 1 , in which said butanediol feedstock comprises at least 90% by weight of a butanediol that is 1,4-butanediol, 1,3-butanediol, or 2,3-butanediol, or a mixture thereof.

3. The method according to claim 1 , in which said carboxylic acid is acetic acid.

4. The method according to claim 1 , in which the reactive distillation of a) comprises a reaction/separation mixed zone located between two separation zones.

5. The method according to claim 4 , in which said mixed zone comprises a heterogeneous acid catalyst that is an ion-exchange acid resin, a mixed oxide, or an acid zeolite.

6. The method according to claim 4 , in which MMH, corresponding to the butane diol molar flow rate divided by the number of moles of catalyst present within said mixed zone, is between 0.05 and 25 h-1.

7. The method according to claim 1 , wherein the reactive distillation column of step a) has a dwell time, defined as the volume of the reactive distillation column divided by the volumetric flow rate of butane-diol and carboxylic acid, between 0.5 h and 10 h.

8. The method according to claim 1 , in which said liquid pyrolysis effluent of b) is purified before being recycled to step a) in a mixture with the carboxylic acid.

9. The method according to claim 1 , in which said aqueous distillate of c) does not comprise more than 10% by weight of carboxylic acid.

10. The method according to claim 1 , in which c) is operated in a distillation column at a temperature of the top of the column between 50° C. and 100° C., and a temperature of the bottom of the column between 100° C. and 115° C.

11. The method according to claim 1 , in which d) is implemented by heterogeneous azeotropic distillation in the presence of a driver.

12. The method according to claim 11 , in which said driver of d) is isopropyl acetate.

Assignees

• Ifp Energies Now
• Michelin & Cie

Inventors

• Pacheco Nuno
• Dorato Margarita
• Jacquin Marc
• Dastillung Rejane
• Couderc Sophie

Classifications

• C07C11/167

  1, 3-Butadiene · CPC title

• C07C51/46

  by azeotropic distillation · CPC title

• C07C1/2078 Primary

  by a transformation in which at least one -C(=O)-O- moiety is eliminated · CPC title

• C07C67/08 Primary

  by reacting carboxylic acids or symmetrical anhydrides with the hydroxy or O-metal group of organic compounds · CPC title

• C07C51/44

  by distillation · CPC title