Exxon Research and Engineering Company

Exxonmobil Research and Engineering Company

Dennis G Alexion

Geoffrey R Say

James H Taylor, Jr

Robert Basil Fedich

James P Glass, Jr

Richard P O'Connor

John C Wilbur

Russell J Koveal

Constantine A Coulaloglou

Russel J Koveal

Sour natural gas is processed to remove the sulfur compounds and recover C /C hydrocarbons by scrubbing the gas with an amine solution to remove most of the sulfur, followed cooling the gas to remove C /C hydrocarbons and more sulfur compounds as liquid condensate to produce a gas having less than 20 vppm of total sulfur. The condensate is sent to a fractionator to recover the C /C hydrocarbons. The sulfur and hydrocarbon reduced gas is contacted first with zinc oxide and then nickel, to produce a gas having less than 10 vppb of total sulfur which is passed into a synthesis gas generating unit to form a very low sulfur synthesis gas comprising a mixture of H and CO. This synthesis gas is useful for hydrocarbon synthesis with increased life of the hydrocarbon synthesis catalyst and greater hydrocarbon production from the hydrocarbon synthesis reactor. Contacting the synthesis gas with zinc oxide further reduces the sulfur content to below 3 vppb.

Production of low sulfur syngas from natural gas with C4&plus;/C5&plus; hydrocarbon recovery

Sour natural gas is processed to remove the sulfur compounds and recover C,/C,hydrocarbons by scrubbing the gas with an amine solution to remove most of the sulfur, followed cooling the gas to remove C,/C,hydrocarbons and more sulfur compounds as liquid condensate to produce a gas having less than 20 vppm of total sulfur. The condensate is sent to a fractionator to recover the C,C,hydrocarbons. The sulfur and hydrocarbon reduced gas is contacted first with zinc oxide and then nickel, to produce a gas having less than 10 vppb of total sulfur which is passed into a synthesis gas generating unit to form a very low sulfur synthesis gas comprising a mixture of H,and CO. This synthesis gas is useful for hydrocarbon synthesis with increased life of the hydrocarbon synthesis catalyst and greater hydrocarbon production from the hydrocarbon synthesis reactor. Contacting the synthesis gas with zinc oxide further reduces the sulfur content to below 3 vppb.

Production of low sulfer syngas from natural gas with C4&plus;/C5&plus; hydrocarbon recovery

A process for producing and cleaning a synthesis gas which contains ammonia and hydrogen cyanide catalytically converts most of the cyanide to ammonia which, along with some of the cyanide, is removed from the gas with water to form aqueous solutions of ammonia and cyanide. The hydrocarbon gas feed to the synthesis gas generator is used to strip ammonia and cyanide out of one or more of the aqueous solutions of these two species formed during the process and pass them into the generator in which they are consumed to form clean water. A portion of the resulting clean water is recycled back into the process where it used to scrub the synthesis gas, with the remainder used for other purposes or sent to disposal.

Removal of ammonia and cyanide from synthesis gas with water production

A gas conversion process includes producing a synthesis gas which contains ammonia and hydrogen cyanide and forms hydrocarbons by reacting the hydrogen and carbon monoxide in the gas in the presence of a hydrocarbon synthesis catalyst also reversibly deactivates the catalyst due to the presence of the ammonia and hydrogen cyanide in the gas. The catalyst is rejuvenated with a gas comprising hydrogen and produces an ammonia containing rejuvenation offgas. The ammonia is dissolved out of the offgas with water and then stripped out of the water with the hydrocarbon feed to the synthesis gas generator and into the generator where it is consumed.

Gas conversion with rejuvenation ammonia removal

In a hydrocarbon synthesis process, nitrogen is cryogenically removed from natural gas to produce a synthesis gas feed comprising methane which is substantially free of nitrogen. This feed is converted to a synthesis gas comprising a mixture of H.sub.2 and CO which is substantially free of the HCN and NH.sub.3 hydrocarbon synthesis catalyst deactivating nitrogen species. This reduces the need for rejuvenating the hydrocarbon synthesis catalyst. During the cryogenic separation, C.sub.2+ hydrocarbons are separated from the natural gas and all or a portion of the separated C.sub.2 -C.sub.4 hydrocarbons are added to the methane feed before it is converted into syngas, to increase syngas production. All or a portion of the separated C.sub.2 -C.sub.3 hydrocarbons may be removed as LPG.

Growing community of inventors

Succasunna, NJ, United States of America

Dennis G Alexion