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)

##STR00001##

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 system includes: an absorber which brings an introduction gas into contact with an absorbent that absorbs CO.sub.2 and H.sub.2S; an absorbent regenerator which releases CO.sub.2 or the like to regenerate the absorbent; a second supply line which returns a regenerated absorbent to the absorber from the regenerator; a third supply line which extracts a semi-rich solution from the vicinity of a middle stage of the absorber, and introduces the semi-rich solution to the vicinity of the middle stage of the regenerator; and a semi-rich solution heat exchanger which is interposed at an intersection between the third supply line and the second supply line to perform the heat exchange between the semi-rich solution and the lean solution.

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.

Plant and process for separation of sulfur-containing components, H.sub.2S, COS and mercaptans from methanol which is used as absorbent within the Rectisol process by hot regeneration of the methanol laden in the absorption and an additional step for separation of the mercaptans from the methanol by stripping.

Disclosed are systems and methods which provide a process stream comprising a gaseous component, capture the gaseous component from the process stream by an ionic liquid solvent of a separator, and recover a captured gaseous component from the ionic liquid solvent in a regenerator. A second gaseous component from the process stream may be captured by the ionic liquid solvent of the separator, and the second gaseous component may be recovered from the ionic liquid solvent in the regenerator. Alternatively, the second gaseous component from the process stream may be uncaptured by the ionic liquid solvent, and the uncaptured second gaseous component may be recovered from a membrane unit.

A low pressure re-absorber is integrated with a sulfur-rich solvent flash drum or a sulfur-rich solvent stripping column in a solvent acid gas removal process that provides for sufficient sulfur concentration for the downstream sulfur recovery unit. In another aspect of the invention, carbon dioxide containing or carbon dioxide rich gas streams that are at a lower temperature relative to a lean solvent stream are used to cool those lean solvent streams and then optionally to cool other process streams, to save energy consumption.

A process for treating effluent streams in a renewable transportation fuel production process is described. One or more of the sour water stream and an acid gas stream are treated directly in thermal oxidation section. The process allows the elimination or size reduction of a sour water stripper unit, waste water treatment plant, and sulfur recovery unit.

The invention concerns a method for treating a hydrocarbon feed gas stream containing at least CO.sub.2 and H.sub.2S to recover a high quality purified CO.sub.2 gas stream, comprising a. Separating said hydrocarbon feed gas stream into a sweetened hydrocarbon gas stream, and an acid gas stream; b. Introducing said gas stream into a Claus unit, c. Introducing the tail gas into a hydrogenation reactor and then into a quench contactor of the Tail Gas Treatment Unit (TGTU); d. Contacting said tail gas stream with a non-selective amine-based solvent into a non-selective acid gas absorption unit of the TGTU; e. Sending the off gas to an incinerator; f. Contacting said enriched gas stream (vii) with a selective H.sub.2S-absorption solvent into a selective H.sub.2S-absorption unit thereby recovering a highly purified CO.sub.2 gas stream and a H.sub.2S-enriched gas stream, as well as the device for carrying said method.