Configurations and methods of high pressure acid gas removal in the production of ultra-low sulfur gas
AssigneeFluor Technologies Corporation
InventorJohn Mak
Life of this patent
Estimating the term…
Abstract
Acid gas is removed from a high pressure feed gas that contains significant quantities of CO2 and H2S. In especially preferred configurations and methods, feed gas is contacted in an absorber with a lean and an ultra-lean solvent that are formed by flashing rich solvent and stripping a portion of the lean solvent, respectively. Most preferably, the flash vapors and the stripping overhead vapors are recycled to the feed gas/absorber, and the treated feed gas has a CO2 concentration of less than 2 mol % and a H2S concentration of less than 10 ppmv, and more typically less than 4 ppm
Claims20
A plant for acid gas removal from a feed gas, comprising:
- an absorber configured to receive a feed gas and to produce a treated gas, wherein the absorber is further configured to separately receive a lean physical solvent and an ultra-lean physical solvent and to produce a rich physical solvent;
- a flash regeneration section fluidly coupled to the absorber and configured to receive the rich physical solvent and to produce the lean physical solvent from the rich physical solvent;
- a stripping column fluidly coupled to the flash regeneration section and configured to receive a first portion of the lean physical solvent, and to produce the ultra-lean physical solvent from the lean physical solvent;
- a first conduit coupled to the flash regeneration section and configured to provide a second portion of the lean physical solvent to the absorber;
- and
- a second conduit coupled to the stripping column and configured to provide the ultra-lean physical solvent to the absorber.
A plant for acid gas removal from a feed gas, comprising:
- a multistage flash regeneration section fluidly coupled to an absorber, wherein the multistage flash regeneration section is configured to receive a rich solvent and flash the rich solvent from a first pressure to a second pressure to generate a hydrocarbon-containing flash gas and a flashed solvent, wherein the multistage flash regeneration section comprises a plurality of flash vessels;
- a flash section fluidly coupled to the multistage flash regeneration section, wherein the flash section is configured to heat and flash the flashed solvent from the second pressure to a third pressure to produce a CO2-containing flash gas and a lean solvent;
- a stripping column fluidly coupled to the flash section and configured to receive a first portion of the lean solvent and a portion of a treated gas, and to produce a stripping column overhead product and ultra-lean solvent from the lean solvent;
- an absorber configured to receive the feed gas and to produce the treated gas, wherein the absorber is configured to separately receive the lean solvent and the ultra-lean solvent at different positions and to produce the rich solvent;
- and
- an expander fluidly coupled between the absorber and the stripping column, wherein the expander is configured to expand the portion of the treated gas prior to the portion of the treated gas being received by the stripping column.
Dependencies are inferred from the claim text.