Process for the preparation of methanol

Patent metadata

Field	Value
Publication number	US-2021363079-A1
Application number	US-201917269607-A
Country	US
Kind code	A1
Filing date	Aug 28, 2019
Priority date	Sep 13, 2018
Publication date	Nov 25, 2021
Grant date	—

Abstract

Process for the preparation of a methanol product comprising the steps of a) providing a first process stream consisting essentially of carbon dioxide; b) providing a second process stream consisting of hydrogen by electrolyzing water in an electrolysis unit; c) mixing the first and second process in amount to obtain a methanol synthesis gas with a mole ratio of H2 and CO2 of between 2.5 and 3.5; d) catalytic converting the methanol synthesis gas into raw methanol in at least one methanol reactor; e) purifying the raw methanol in a distillation unit; and recovering waste heat generated in the electrolysis unit in step (b) by transferring the waste heat to a circulating heat transfer medium by indirect heat exchange with the waste heat and by indirect heat exchange of the heated heat transfer medium with steam used for the distillation of the raw methanol, wherein the heated transfer medium is compressed upstream the indirect heat exchange with steam.

First claim

1 . Process for the preparation of a methanol product comprising the steps of:
a) providing a first process stream consisting essentially of carbon dioxide; b) providing a second process stream consisting of hydrogen by electrolyzing water in an electrolysis unit; c) mixing the first and second process stream in amount to obtain a methanol synthesis gas with a mole ratio of H 2 and CO 2 of between 2.5 and 3.5; d) catalytic converting the methanol synthesis gas into raw methanol in at least one methanol reactor; e) purifying the raw methanol in a distillation unit; and recovering waste heat generated in the electrolysis unit in step (b) by transferring the waste heat to a circulating heat transfer medium by indirect heat exchange with the waste heat and by indirect heat exchange of the heated heat transfer medium with steam used for the distillation of the raw methanol, wherein the heated transfer medium is compressed upstream the indirect heat exchange with steam.

2 . Process of claim 1 , wherein the heat transfer medium has a boiling point lower than the waste heat from the electrolysis at a pressure prevailing in the indirect heat exchange with the waste heat and a boiling point higher than the temperature in the indirect heat exchange with the steam at a pressure prevailing in the indirect heat exchange with the steam.

3 . Process of claim 1 , wherein the distillation unit comprises two or more distillation towers operated in series.

4 . Process of claim 1 , wherein at least a part of the water electrolyzed in the electrolysis unit is distillation water withdrawn from the methanol distillation unit.

Assignees

• Haldor Topsoe As

Inventors

• Tjärnehov Emil Andreas
• Pedersen Lars Storm
• Hultqvist Michael
• Eskesen Søren Grønborg
• Jensen Louise Wissing

Classifications

• Y02P20/50

  Improvements relating to the production of bulk chemicals · CPC title

• Y02P20/129

  Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines · CPC title

• C07C29/152

  characterised by the reactor used · CPC title

• Y02E60/36

  Hydrogen production from non-carbon containing sources, e.g. by water electrolysis · CPC title

• C25B15/081

  Supplying products to non-electrochemical reactors that are combined with the electrochemical cell, e.g. Sabatier reactor · CPC title