US 4,348,487 AGranted

Production of methanol via catalytic coal gasification

AssigneeExxon Research & Engineering Co.

InventorsStuart S. Goldstein, William J. Calvin, Harry A. Marshall

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Abstract

Methanol is produced by gasifying a carbonaceous feed material with steam in the presence of a carbon-alkali metal catalyst and added hydrogen and carbon monoxide at a temperature between about 1000.degree. F. and about 1500.degree. F. and at a pressure in excess of about 100 psia to produce a raw product gas comprising methane, steam, carbon dioxide, carbon monoxide, hydrogen and hydrogen sulfide; withdrawing the raw product gas from the gasifier and treating it for the removal of steam, particulates, hydrogen sulfide and carbon dioxide to produce a treated gas containing primarily carbon monoxide, hydrogen and methane; separating the treated gas into a methane-rich gas stream and a gas stream containing primarily carbon monoxide and hydrogen; passing the gas stream containing primarily carbon monoxide and hydrogen to a methanol synthesis reactor where the carbon monoxide is reacted with the hydrogen in the presence of a methanol synthesis catalyst to form methanol; recovering methanol product from the effluent exiting the methanol synthesis reactor thereby leaving a gas comprised of carbon monoxide, hydrogen, methane and carbon dioxide; and passing a portion of this gas to a steam reforming furnace wherein at least a portion of the methane is reacted with steam to produce hydrogen and carbon monoxide which is then passed from the steam reforming furnace into the gasifier. Preferably, at least a portion of the methane-rich gas produced in the separation step is used as fuel for the steam reforming furnace.

Claims10

Dependent claims

A process for the production of methanol from a carbonaceous feed material which comprises:

(a) gasifying said carbonaceous feed material with steam in a gasification zone at a gasification temperature between about 1000.degree. F. and about 1500.degree. F. and at a gasification pressure in excess of about 100 psia in the presence of a carbon-alkali metal catalyst and added hydrogen and carbon monoxide;
(b) withdrawing from said gasification zone an effluent gas containing methane, carbon monoxide, steam, hydrogen, carbon dioxide and hydrogen sulfide;
(c) treating said effluent gas for the removal of steam, particulates, hydrogen sulfide and carbon dioxide to produce a treated gas containing primarily carbon monoxide, hydrogen and methane;
(d) passing said treated gas to a separation zone wherein said treated gas is separated into a methane-rich gas stream and a gas stream containing primarily carbon monoxide and hydrogen;
(e) passing said gas stream containing primarily carbon monoxide and hydrogen produced in step (d) to a methanol synthesis zone wherein at least a portion of said carbon monoxide is reacted with at least a portion of said hydrogen in the presence of a methanol synthesis catalyst to form methanol;
(f) recovering methanol product from the effluent stream exiting said methanol synthesis zone, thereby leaving a gas comprised of carbon monoxide, hydrogen, methane and carbon dioxide;
(g) passing at least a portion of said gas stream comprised of carbon monoxide, hydrogen, methane and carbon dioxide produced in step (f) to a steam reforming zone wherein at least a portion of said methane in said gas stream is reacted with steam to produce hydrogen and carbon monoxide;
and
(h) passing the effluent from said steam reforming zone into said gasification zone, thereby supplying said added hydrogen and carbon monoxide required in said gasification zone.

6 more elements

Dependencies are inferred from the claim text.