US 4,305,733 AGranted

Method of treating natural gas to obtain a methane rich fuel gas

AssigneesLinde Aktiengesellschaft, Vniigaz

InventorsWalter Scholz, Gerhard Ranke, Hans Becker, Boris G. Bergo, Alexander I. Grizenko, Alexej V. Frolov

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Abstract

A method for the recovery of a methane-rich natural gas from a natural gas containing, apart from methane, also hydrogen sulfide, carbondioxide, higher hydrocarbons and, in most cases, organosulfur compounds. According to the invention a hydrocarbon fraction of C.sub.4 hydrocarbons and higher is naturally removed from the natural gas which is then subjected to a selective scrubbing for the removal of hydrogen sulfide with a regeneratable extraction, of scrubbing liquid. Next a C.sub.3 fraction is removed, the remaining gas being scrubbed with a second regeneratable washing agent, for the removal of carbondioxide to leave the methane-rich gas.

Claims18

Dependent claims

A method of separating components from a raw natural gas containing methane, hydrogen sulfide, higher hydrocarbons and possibly organosulfur compounds and carbonyl sulfide, which comprises the steps of:

(a) removing a higher hydrocarbon fraction from said raw gas which includes hydrocarbons with a carbon number of 4 and greater;
(b) selectively scrubbing hydrogen sulfide with a first regeneratable scrubbing liquid from the raw gas subsequent to its treatment in step (a);
(c) thereafter removing a C.sub.3 -hydrocarbon fraction from the raw gas from which hydrogen sulfide has been scrubbed in step (b);
and
(d) selectively scrubbing the gas from which the C.sub.3 -hydrocarbon fraction has been removed in step (c) with a separate second regeneratable scrubbing liquid to remove CO.sub.2, thereby yielding a gas consisting predominantly of methane.

2 more elements

Dependencies are inferred from the claim text.