METHODS AND CONFIGURATIONS FOR ACID GAS ENRICHMENT

摘要

A plant for treating a feed gas (1) having an H2S concentration of less than 10% and comprising carbon dioxide, comprising:
a first absorber (51) fluidly coupled to a regenerator (53), wherein the first absorber (51) is configured to promote absorption of hydrogen sulfide from a feed gas (1) by a portion of a lean hydrogen-sulfide-selective solvent (10, 19, 20, 21, 2), and wherein the regenerator (53) is configured to produce the lean hydrogen sulfide-selective solvent (10, 19, 20, 21, 2) and to promote formation of a hydrogen-sulfide rich gas (9) from the hydrogen-sulfide selective solvent (4, 7, 34, 35, 36, 8);
a second absorber (72) fluidly coupled to the regenerator (53) and further configured to receive another portion of the lean solvent (10, 19, 20, 21, 32), wherein a portion (17) of the hydrogen sulfide-rich gas (9) of the regenerator (53) is fed to the first absorber (51) to thereby allow for an increase in a hydrogen sulfide concentration in the hydrogen-sulfide-rich gas (9) whose formation is promoted by the regenerator (53);
a Claus plant (70) that receives another portion (18) of the hydrogen-sulfide-rich gas (9) of the regenerator (53) and produces a tail gas (30) that is fed to a hydrogenation unit (71) to produce a hydrogenated gas that is fed to the second absorber (72); and
wherein the first and second absorbers (51, 52/72) are configured to allow production of an overhead product (3, 23, 24, 33) that is enriched in carbon dioxide and substantially depleted in hydrogen sulfide.