Production of methanol via catalytic coal gasification

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.