Metallgesellschaft Aktiengesellschaft

Karl Bratzler

Alexander Doerges

Paul Rudolph

Manfred Kriebel

Johann Schlauer

Georg Kempf

Friedrich-Wilhelm Moller

Karl-Heinz Eisenlohr

Wolf-Dieter Muller

Gerhard Hochgesand

Alexander Dorges

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 in a third scrubbing stage in which the water content of the solvent is kept at 5-30 mol percent H.sub.2 O in which H.sub.2 S and COS are entirely and selectively removed from the gas. Lastly, the scrubbing agents from the second and third scrubbing stages are separately regenerated and recycled to the second and the third scrubbing stages for re-use.

Process for purifying gases from the gasification of fossil fuels

A high methane gas which can be substituted for natural gas is produced from a primary gas made by the gasification of coal, tar, or heavy residual oil under superatmospheric pressures. The primary gas is purified to remove catalyst poisons and is scrubbed to remove carbon dioxide to a residual content below 2% by volume. The water vapor to carbon monoxide volume ratio of the scrubbed gas is adjusted to 0.55 : 1 to 1 : 1 and is then passed through a reaction zone containing a shift conversion catalyst and a methanation catalyst in a volume ratio of approximately 1 : 4 to 1 : 10. The scrubbed gas entering the reaction zone enters the reaction zone at a temperature of 300.degree.-500.degree. C.

Process for producing a gas which can be substituted for natural gas

A process for recovering elemental sulfur from gases containing inorganic and/or organic sulfur compounds together with large quantities of carbon dioxide and other possible impurities such as unsaturated hydrocarbon and hydrogen cyanide. The waste gas is combined with a combustion-promoting gas and the resulting mixture is burned with a slight excess of air and caused to contact coke at a temperature of 300.degree. to 450.degree. C. The resulting gas, from which oxygen, sulfur trioxide and nitrogen oxide have been removed, by contact with the coke, is cooled to 20.degree. to 80.degree. C and then is scrubbed with aqueous alkali salts of weak inorganic and/or organic acids or amines to remove SO.sub.2. The absorbent is stripped and the recovered SO.sub.2 is reacted with hydrogen at 200.degree. to 400.degree. C to form sulfur and/or hydrogen sulfide and, when hydrogen sulfide is produced, the latter is reacted on alumina or activated carbon at 200.degree. to 300.degree. C to produce the elemental sulfur. All or part of the gas after recovery of the elemental sulfur is recycled.

Process for recovering elemental sulfur from gases having a high carbon

A process of purifying gases produced by a gasification of fossil fuels wherein the gas is cooled and scrubbed under superatmospheric pressures at normal temperatures while the raw gas, at a temperature of 150.degree.-170.degree. C, is indirectly cooled to ambient temperatures, the condensible hydrocarbons are separated and removed, the gas is scrubbed with water to remove ammonia in a first scrubbing stage in which 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 is added, the gas is subsequently scrubbed with the same solvent in a third scrubbing stage in which the water content of the solvent is kept at 5-30 mole percent H.sub.2 O and in which H.sub.2 S and COS are entirely removed from the gas, and the scrubbing agents from the second and third scrubbing stages are separately regenerated and recycled to the second and third scrubbing stages. The scrubbing agent used in the second scrubbing stage is flashed approximately to atmospheric pressures, adding water, heating the scrubbing agent to the boiling temperature but not in excess of 170.degree. C, treating the scrubbing agent in a stripping column with water vapor or stripping gas to remove liquid impurities, condensing the mixed vapors, isolating the condensates by phase separation, and feeding part of the aqueous phase as a reflux to the upper portion of the stripping column while the stripped scrubbing agent is cooled and is fed back to the top of the second scrubbing stage.

Process of purifying gases produced by the gasification of solid or

A process for desulfurization of fuel or synthesis gases containing carbon oxysulfide wherein the carbon oxysulfide is hydrolyzed by treating the gas at a temperature of 50.degree. to 105.degree.C with a low-volatility organic solvent inert to the carbon oxysulfide and containing 15 to 50 mole-percent water, the hydrolysis products and other sulfur-containing compounds being removed by subsequent scrubbing of the gas.

Process for the desulfurization of gases

Gases produced by reacting fuels with oxygen containing gases and water vapor under pressure are desulfurized by scrubbing with a concentrated solution of one or more alkali salts of weak inorganic acids at a temperature near the atmospheric-pressure boiling point of the solution in a column while maintaining an exchange ratio of from 0.2 to 2.0 cubic meters of the concentrated solution per standard cubic meter hydrogen sulfide in the gas to be purified.

Growing community of inventors

Bad Homburg, Germany

Karl Bratzler