Process for purifying gases from the gasification of fossil fuels

US4088735A · kind A · utility

Assignee

• Metallgesellschaft AG · DE

Inventors

• Karl Bratzler
• Alexander Doerges · Frankfurt am Main, DE
• Gerhard Hochgesand
• Manfred Kriebel · Frankfurt am Main, DE

Key dates

• Filing date: Jan 31, 1977
• Grant date: May 9, 1978
• Expiry date: Jan 31, 1997

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C10K1/16
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A process for purifying gases produced by the gasification of fossil fuels by a treatment with water vapor and oxygen under superatmospheric pressure. The raw gas produced is treated to remove catalyst-deteriorating impurities such as mono- and polyunsaturated hydrocarbons, mercaptans, HCN, HCl, H.sub.2 S, CS.sub.2, COS, and NH.sub.3, and to desulfurize the gas to produce an exhaust gas which is rich in H.sub.2 S. The gas is cooled and scrubbed under superatmospheric pressures and at normal temperatures. The raw gas, at a temperature of 150.degree.-170.degree. C., is indirectly cooled to ambient temperature. The condensible hydrocarbons are then separated and removed, and the gas is then scrubbed with water to remove ammonia in a first scrubbing stage wherein the rate of water addition is controlled to be just sufficient to remove the ammonia. The gas is then scrubbed with a high-boiling organic solvent which is miscible with water and to which sulfur has been added in a second scrubbing stage in which the rate of solvent addition is controlled in dependence on the solubility of the methyl mercaptan, which is to be removed, in the solvent. The gas is scrubbed with the same solvent …