Abstract: An aqueous solvent composition useful for CO2 capture is described, that includes one or more CO2-sorbing amines, e.g., an amino acid salt and a tertiary or a sterically hindered amine. The solvent composition may include one or more promoters that are effective to enhance solvent characteristics such as (i) CO2 sorption capacity, (ii) CO2 sorption rate, (iii) CO2 desorption capacity, (iv) CO2 desorption rate, and (v) regeneration temperature, in relation to a corresponding solvent lacking the promoters. In relation to existing CO2 capture solvent compositions, the disclosed aqueous solvent composition provides high solvent CO2 capacity, high rate of CO2 absorption and desorption, high thermal and oxidative stability, low solvent regeneration energy, low solvent emissions, and low solvent toxicity.

Abstract: A continuous desulfurization process and process system are described for removal of reduced sulfur species at gas stream concentrations in a range of from about 5 to about 5000 ppmv, using fixed beds containing regenerable sorbents, and for regeneration of such regenerable sorbents. The desulfurization removes the reduced sulfur species of hydrogen sulfide, carbonyl sulfide, carbon disulfide, and/or thiols and disulfides with four or less carbon atoms, to ppbv concentrations. In specific disclosed implementations, regenerable metal oxide-based sorbents are integrated along with a functional and effective process to control the regeneration reaction and process while maintaining a stable dynamic sulfur capacity. A membrane-based process and system is described for producing regeneration and purge gas for the desulfurization.