Systems and methods for removing hydrogen sulfide from an ammonia stream in the NH3 purification and liquefaction stage of a conventional two-column sour water stripping system using an adsorbent bed.

An absorbing liquid which absorbs the CO.sub.2 or H.sub.2S or both contained in a gas, and which comprises 1) at least one tertiary-monoamine main agent selected from a tertiary-monoamine group and 2) at least one secondary-diamine first additive selected from a secondary-diamine group, the secondary-diamine concentration being within the range of 0.05 to 0.5 in terms of the additive concentration index represented by the following expression (I).

(Additive concentration index)=[(secondary-diamine acid dissociation index) (pKa)/(tertiary-monoamine acid dissociation index) (pKa)](index ratio)×[(secondary-diamine molar concentration) (mol/L)/(tertiary-monoamine molar concentration) (mol/L)](molar ratio)  (I).

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.

Disclosed is a process for regenerating a hybrid solvent used to remove contaminants from a fluid stream and to provide an improved yield of purified fluid. Said process comprises at least one purification unit (12) and at least one regeneration unit (40) wherein condensed water 62 from the regeneration unit is recycled back into the purification unit and none of the condensed water is reintroduced into the regeneration unit.

The invention relates to a method of selectively removing hydrogen sulfide H.sub.2S from a gaseous effluent comprising at least H.sub.2S and CO.sub.2, wherein a stage of selective absorption of hydrogen sulfide over CO.sub.2 is carried out by contacting said effluent with a solution comprising (a) water and (b) at least the following diamine: 1,2-bis(2-dimethylaminoethoxy)ethane ##STR00001##
and wherein the absorption selectivity is controlled by adding (c) a viscosifying compound to the absorbent solution.

A process and system for treating a hydroprocessing unit effluent gas stream for recycling includes introducing the effluent gas stream into a hydrogen purification zone and recovering a hydrogen-rich gas stream and a liquid stream containing a mixture that includes C1 to C4 hydrocarbons and H.sub.2S which is then mixed with an oxidant and fed to an oxidation unit containing catalyst for conversion of the H.sub.2S to elemental sulfur vapors that is separated for recovery of the elemental sulfur, and recovering a sweetened mixture that includes C1 to C4 hydrocarbons. Alternatively, the hydroprocessing unit effluent gas stream containing H.sub.2S is cooled, contacted with a solvent to absorb the C1 to C4 hydrocarbons and H.sub.2S, with the hydrogen-rich stream being recovered for recycling to the hydroprocessing unit, and the rich liquid solvent being flashed to produce a lean solvent stream for recycling to the adsorption zone and a mixed gas stream that includes the C1 to C4 hydrocarbons and H.sub.2S that is passed to an oxidation zone and is reacted with an oxidant in the presence of a catalyst to complete the process as described above for the recovery of elemental sulfur and a mixture that includes the sweetened C1 to C4 hydrocarbons.

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.

An H.sub.2S stripper that utilizes random packing material in the center column to greatly increase the conversion of H.sub.2S gas to a solid form of sulfur. A thin film of scrubbing solution coating the packing material allows for a more efficient process of H.sub.2S scrubbing that can reduce the chemical consumption rates of traditional, commercially available sulfide scavengers by 25 to 60%. This unit also allows for an easy clean out and is built to handle the pressure extremes that could be encountered in oil wells and/or gas wells, gas plants, offshore rigs, gas gathering systems, or pipe lines while not having any mechanical parts. This invention improves the H.sub.2S removal process and reduces the amount of H.sub.2S in natural gas streams as well as reducing the amount of treating chemicals.

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##