Process and apparatus for the production of higher alcohols

Patent metadata

Field	Value
Publication number	US-9988330-B2
Application number	US-201314651083-A
Country	US
Kind code	B2
Filing date	Dec 18, 2013
Priority date	Dec 20, 2012
Publication date	Jun 5, 2018
Grant date	Jun 5, 2018

Abstract

In a process for the production of higher alcohols, i.e. C 4+ alcohols, from syngas, the syngas is first reacted in a heterogeneous alcohol pre-converter (A) using an alcohol synthesis catalyst, whereby methanol as the main product in a concentration corresponding to or close to the equilibrium concentration is produced. Then the effluent from the pre-converter is mixed with unconverted wet recycle gas and reacted in a heterogeneous reactor for higher alcohols synthesis (B) containing a higher alcohols synthesis catalyst, and finally the effluent from the reactor for higher alcohols synthesis is separated into (i) unconverted syngas, which is recycled to the higher alcohols synthesis reactor, (ii) methanol and light alcohols, which are recycled to the higher alcohols synthesis reactor, and (iii) the final product consisting of higher alcohols.

First claim

The invention claimed is:

1. A process for the production of higher alcohols from a gas mixture of hydrogen and carbon monoxide, so-called syngas, comprising:
a) reacting syngas in a heterogeneous alcohol pre-converter containing a methanol synthesis catalyst and producing an effluent comprising methanol in a concentration corresponding to or about the equilibrium concentration at a given temperature and concentration, and removing heat of the methanol synthesis reaction,
b) mixing the effluent from the pre-converter reactor with unconverted recycle syngas to form a mixture and reacting the mixture in a heterogeneous higher alcohols synthesis reactor in the presence of a higher alcohols synthesis catalyst, to form a product gas containing carbon dioxide, and
c) feeding the product gas to a separation unit and separating the product stream into recycle streams of (i) unconverted syngas, which is recycled to the higher alcohols synthesis reactor and (ii) methanol and light alcohols, which are recycled to the higher alcohols synthesis reactor, and into a final product stream consisting of higher alcohols, wherein the separation unit removes carbon dioxide from the recycle streams.

2. The process according to claim 1 , wherein the alcohol pre-converter is either a gas-liquid cooled reactor or a boiling water reactor (BWR).

3. The process according to claim 1 , wherein the higher alcohols synthesis reactor is a single bed adiabatic reactor, a single stage adiabatic reactor, a multi-bed adiabatic reactor with inter-bed cooling, or a multi-stage adiabatic reactor with inter-stage cooling.

4. The process according to claim 1 , wherein the recycle syngas is a wet recycle gas saturated with methanol and light alcohols.

5. The process according to claim 3 , wherein the higher alcohols synthesis reactor includes multiple beds or multiple stages, and cooling is achieved by either injection of a recycled light alcohol solution, or an unconverted syngas.

6. The process according to claim 5 , wherein the reactor is cooled by unconverted recycle gas.

7. The process according to claim 1 , wherein the heterogeneous alcohol pre-converter is either an adiabatic reactor, an isothermal reactor, or a semi-isothermal reactor.

8. The process according to claim 1 , wherein the condition of the methanol pre-converter is set in such a way that the inlet feed to the higher alcohols synthesis reactor, after being mixed with recycle gas and other alcohols, is equal to or at least about the equilibrium composition of methanol at the inlet to the higher alcohols synthesis reactor.

9. The process according to claim 1 , wherein steam is generated from the removal of the heat of the reaction and is used to drive a compressor for unconverted recycled syngas.

10. An apparatus for carrying out the method according to claim 1 , said apparatus comprising a pre-converter for pre-converting syngas to alcohols, a higher alcohols reactor for further reaction of the effluent with wet recycle gas and light alcohols and a separation unit to separate unconverted reactants in the effluent into recycle gas streams, purge streams and a product stream, the apparatus further comprising a compressor in fluid communication with the separation unit which comprises: a gas/liquid separator, a distillation unit, a carbon dioxide removal unit, and a saturator unit, where pressurize recycle syngas is contacted pressurized gas is contacted with recycle alcohol mixtures.

11. The apparatus according to claim 10 , wherein the pre-converter is a boiling water reactor and the higher alcohols reactor is a multi-bed quench reactor.

12. The process according to claim 3 , wherein the higher alcohols synthesis reactor includes multiple beds and multiple stages, and cooling is achieved by indirect cooling.

Assignees

• Haldor Topsoe As
• Haldor Topsoe As

Inventors

• Modarresi Hassan
• Wix Christian

Classifications

• C07C29/152 Primary

  characterised by the reactor used · CPC title

• C07C29/32

  increasing the number of carbon atoms by reactions without formation of -OH groups · CPC title

• C07C31/04

  Methanol · CPC title

• C07C31/08

  Ethanol · CPC title

• C07C31/12

  containing four carbon atoms · CPC title