This disclosure relates to a process for removing acid gases from a gas stream enriched in acid gases, wherein: (a) the gas stream enriched in acid gases is contacted in an absorption zone with an absorption medium, wherein the absorption medium is an aqueous medium comprising an amine, to form a gas stream depleted in acid gases which comprises an entrained amine and an absorption medium enriched in acid gases; and (b) treating the gas stream depleted in acid gases which comprises an entrained amine in a first scrubbing zone with a first scrubbing medium, wherein the first scrubbing medium is an aqueous medium comprising an amine, the amount of amine comprised by the scrubbing medium being about 0.1 to about 50.0 wt. %, wherein the aqueous medium is saturated with carbon dioxide such that at least 75 wt. % of the amine, based on the total amount of amine comprised by the aqueous medium, is in its carbamate or carbonate form, to form a gas stream depleted in acid gases and in amine and a first scrubbing medium enriched in amine.

The present invention relates to an apparatus and method for recovering carbon dioxide (hereinafter also referred to as “CO.sub.2”) contained in a combustion exhaust gas, and more specifically relates to: an apparatus and method for reactively absorbing CO.sub.2 contained in a combustion exhaust gas into an amine compound-containing absorption liquid; an apparatus and method for desorbing CO.sub.2 contained in an amine compound-containing absorption liquid from the amine compound-containing absorption liquid; an apparatus and method for evaporating and separating impurities from the amine compound-containing absorption liquid containing the impurities; an apparatus and method for performing a pretreatment such as desulfurization, dust removal, and cooling on a combustion exhaust gas; and a carbon dioxide-recovering apparatus and method utilizing the above apparatuses and methods.

A method of removing acid gases from a gaseous stream is provided. The acid gases may include carbon dioxide, hydrogen sulfide and/or sulfur dioxide, by example. Embodiments of the method include mixing an amine-terminated branched polymer solvent with the gaseous stream, resulting in the substantial absorption of at least some of the acid gases. The solvent is an amine-terminated branched PEG, such as by example amine-terminated glycerol ethoxylate, amine-terminated trimethylolpropane ethoxylate, and/or amine-terminated pentaerithritol ethoxylate. Embodiments of the present inventive methods further include regenerating the solvent using electrolysis.

A process for removing hydrogen sulfide and carbon dioxide from a fluid stream comprises a) an absorption step in which the fluid stream is contacted with an absorbent comprising an aqueous solution (i) of an amine of the general formula (I)

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in which R.sub.1, R.sub.2 and R.sub.3 are each independently selected from C.sub.1-4-alkyl and C.sub.1-4-hydroxyalkyl; each R.sub.4 is independently selected from hydrogen, C.sub.1-4-alkyl and C.sub.1-4-hydroxyalkyl; each R.sub.5 is independently selected from hydrogen, C.sub.1-4-alkyl and C.sub.1-4-hydroxyalkyl; X is OH or NH(CR.sub.1R.sub.2R.sub.3); m is 2, 3, 4 or 5; n is 2, 3, 4 or 5; and o is 0 or 1; and optionally (ii) at least one tertiary amine, where the molar ratio of (i) to (ii) is greater than 0.05; wherein at least 90% of the hydrogen sulfide is removed from the fluid stream and selectivity for hydrogen sulfide over carbon dioxide is not greater than 8, wherein a CO.sub.2- and H.sub.2S-laden absorbent is obtained; b) a regeneration step in which at least a substream of the CO.sub.2- and H.sub.2S-laden absorbent is regenerated and a regenerated absorbent is obtained; and c) a recycling step in which at least a substream of the regenerated absorbent is recycled into the absorption step a). The process allows a high level of hydrogen sulfide removal with a simultaneously high coabsorption of carbon dioxide.

The invention relates to methods and systems for determining operating and/or dimensioning parameters of a gas treatment plant including at least one gas treatment unit as well as methods and systems for generating a request to initiate the determination of operating and/or dimensioning parameters of a gas treatment plant. The invention further relates to a computer program and non-volatile or non-transitory storage medium with the computer program, which when executed on one or more processors, performs one or more of the methods.

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 ppmv.

The invention relates to a process for removing a target gas from a gas stream rich in the target gas and to an absorbent solution for absorbing a gas, such as carbon dioxide, from a gas stream. The invention involves the use of a photoactive compound that is convertible from a first state to a second state upon irradiation to facilitate removal or collection of a target gas from a gas stream.

This disclosure relates to a process for removing acid gases from a gas stream enriched in acid gases, wherein: (a) the gas stream enriched in acid gases is contacted in an absorption zone with an absorption medium, wherein the absorption medium is an aqueous medium comprising an amine, to form a gas stream depleted in acid gases which comprises an entrained amine and an absorption medium enriched in acid gases; and (b) treating the gas stream depleted in acid gases which comprises an entrained amine in a scrubbing zone with a scrubbing medium, wherein the scrubbing medium is an aqueous medium comprising an amine, the amount of amine comprised by the scrubbing medium being about 0 to about 10.0 wt. %, to form a gas stream depleted in acid gases and in amine and a scrubbing medium enriched in amine.

An absorbent for the selective removal of hydrogen sulfide from a fluid stream comprising carbon dioxide and hydrogen sulfide, wherein the absorbent contains an aqueous solution, comprising: a) an amine or a mixture of amines of the general formula (I) wherein R.sup.1 is C.sub.1-C.sub.5-alkyl; R.sup.2 is C.sub.1-C.sub.5-alkyl; R.sup.3 is selected from hydrogen and C.sub.1-C.sub.5-alkyl; x is an integer from 2 to 10; and b) an ether or a mixture of ethers of the general formula (II): R.sup.4—[O—CH.sub.2—CH.sub.2].sub.y—OH; wherein R.sup.4 is C.sub.1-C.sub.5-alkyl; and y is an integer from 2 to 10; wherein R.sup.1 and R.sup.4 are identical; wherein the mass ratio of b) to a) is from 0.08 to 0.5. The absorbent is suitable for the selective removal of hydrogen sulfide from a fluid stream comprising carbon dioxide and hydrogen sulfide. The absorbent has a reduced tendency for phase separation at temperatures falling within the usual range of regeneration temperatures for the aqueous amine mixtures and is easily obtainable. ##STR00001##

The present invention relates to an aqueous alkanolamine solution demonstrating low volatility comprising 2-di-methylamino-2-hydroxymethyl-1, 3-propanediol useful for removing acid gases from gaseous mixtures. Said aqueous alkanolamine solution may further comprise one or more of an acid or acid-forming compound, another amino compound, an activator, a physical solvent, or one or more other compounds used in gal-liquid treatment practices. Further, the present invention relates to a process for removing acid gases from a gaseous mixture, preferably hydrogen sulfide, comprising the step of contacting the gaseous mixture with said aqueous alkanolamine solution. Examples of the gaseous mixtures include natural gas, synthesis gas, tail gas, and refinery gas.