Process for desulfurization of fuel gas

Patent · Tue Feb 04 04:00:00 EST 1986

OSTI ID:6083967

Galstaun, L S; Geosits, R F

This patent describes a system for removal of acid gases from a first gas rich in carbon dioxide, available at superatmospheric pressure and containing hydrogen sulfide, and a second gas containing carbon dioxide at a partial pressure lower than in the first gas and containing hydrogen sulfide. The acid gases removed will comprise mainly carbon dioxide and hydrogen sulfide and may have a hydrogen sulfide content below mole 30%. The process consists of: contacting the first gas in a first absorber having a first stage and a second stage with a first solvent having a high selectivity for hydrogen sulfide in counter-current flow of the solvent and the first gas; recovering a hydrogen rich gas from the second stage of the first absorber; contacting the second gas in a second absorber with another portion of the solvent from the second stage of the first absorber under conditions sufficient to cause the solvent to extract hydrogen sulfide and to release carbon dioxide from the second gas; flashing the solvent from the first stage of the first absorber consecutively at an intermediate pressure and a lower pressure; flashing the solvent separated from the first stage of the second absorber at the lower pressure; compressing the flashed gases from the intermediate and lower pressure flashes to produce compressed gases rich in both carbon dioxide and hydrogen sulfide; returning the compressed gases to the second absorber; stripping the carbon dioxide and hydrogen sulfide from the combined flashed first and second solvents to regenerate a lean solvent; and recovering an acid gas stream comprising carbon dioxide containing less than 30 mole percent of hydrogen sulfide from the stripped solvents.

• Assignee: Bechtel International Corp., San Francisco, CA
• Patent Number(s): US 4568364
• OSTI ID: 6083967
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
030300* -- Natural Gas-- Drilling
Production
& Processing
ATMOSPHERIC PRESSURE
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
COMPRESSED GASES
COMPRESSION
COUNTER CURRENT
DESULFURIZATION
ELEMENTS
EVAPORATION
FLASHING
FLUIDS
FUEL GAS
FUELS
GAS FUELS
GASES
HYDROGEN
HYDROGEN COMPOUNDS
HYDROGEN SULFIDES
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PARTIAL PRESSURE
PHASE TRANSFORMATIONS
PURIFICATION
QUANTITY RATIO
REGENERATION
REMOVAL
SOLVENTS
SULFIDES
SULFUR COMPOUNDS