A solvent composition for carbon capture according to a preferred embodiment comprises at least two of the following: diethylaminoethanol (DEAE), hexamethylenediamine (HMDA), and polyethylenimine (PEI). Another embodiment includes a method of performing carbon capture using the carbon capture solvent compositions described herein. Another embodiment provides an apparatus for performing carbon capture using the carbon capture compositions described herein and/or the carbon capture methods described herein.

A process for absorbing carbon dioxide from a gas stream containing carbon dioxide, including the steps of contacting the gas stream with an aqueous composition including a substituted heteroaromatic compound having a six-membered heteroaromatic ring with from 1 to 3 nitrogen atoms in the heteroaromatic ring and at least one substituent wherein at least one of the substituents is of formula —R.sup.1NH.sub.2 wherein R.sup.1 is selected from C.sub.1 to C.sub.6 alkylene and ethers of formula —R.sup.2—O—R.sup.3— wherein R.sup.2 and R.sup.3 are C.sub.1 to C.sub.3 alkylene.

Disclosed herein are methods of electrochemically enhanced amine-based CO.sub.2 capture and systems for performing the methods of amine-based CO.sub.2 capture. The present methods and systems advantageously may be carried out at ambient temperatures and allow for reusing the amine through multiple cycles.

An absorbent liquid which absorbs at least one of CO.sub.2 and H.sub.2S from a gas, including a secondary linear monoamine; a tertiary linear monoamine or a sterically hindered primary monoamine; and a secondary cyclic diamine, wherein a concentration of each of the secondary linear monoamine, the tertiary linear monoamine or the sterically hindered primary monoamine; and the secondary cyclic diamine is less than 30% by weight.

The invention relates to an absorber column and to the use thereof for separation of unwanted, especially acidic, gas constituents, for example carbon dioxide and hydrogen sulfide, from a crude synthesis gas by absorption with an absorbent, especially under low load states of the absorber column in relation to the synthesis gas velocity. According to the invention, a defined concentration of carbon dioxide in the clean synthesis gas is established by mixing at least a portion of the absorbent regenerated by flash regeneration with the absorbent regenerated by means of hot regeneration prior to the recycling thereof into the absorber column.

The present invention relates to a biomimetic-hybrid solvent system for simultaneous capture of H.sub.2S and CO.sub.2 from any gaseous composition. The present invention also relates to a process for upgradation of biogas to bio CNG by removing gaseous contaminants, including microbial removal of H.sub.2S, to obtained purified CO.sub.2. The biomimetic-hybrid solvent system contains three components selected from tertiary amine compounds, a functional colloidal fluid, and an enzyme mimic.

The concerns a process for producing formic acid, (a) a carbon capture step in which a source of carbon dioxide is contacted with an amine solution in an amine scrubber, to obtain an ammonium bicarbonate solution, where the carbon capture uses a chilled amine solution having a temperature in the range of 0-20 ° C.; (b) inducing crystallization in the ammonium bicarbonate solution to obtain a concentrated ammonium bicarbonate solution; (c) subjecting the concentrated ammonium bicarbonate solution to a hydrogenation step to obtain an ammonium formate; and (d) heating the ammonium formate to a temperature in the range of 50-150 ° C., to obtain a gaseous product containing the amine and a liquid product stream containing formic acid. The application further concerns a system for performing the process.

A process for producing a deacidified fluid stream from a fluid stream comprising methanol and at least one acid gas and an apparatus for carrying out the process. The process comprising a) an absorption step in which the fluid stream is contacted with an absorbent in an absorber to obtain an absorbent laden with methanol and acid gases and an least partly deacidified fluid stream; b) a regeneration step in which at least a portion of the laden absorbent obtained from step a) is regenerated in a regenerator to obtain an at least partly regenerated absorbent and a gaseous stream comprising methanol, water and at least one acid gas; c) a recycling step in which at least a substream of the regenerated absorbent from step b) is recycled into the absorption step a); d) a condensation step in which a condensate comprising methanol and water is condensed out of the gaseous stream from step b); e) a distillation step in which at least a portion of the condensate from step d) is guided into a distillation column to obtain a top stream comprising methanol and a bottom stream comprising water; which comprises recycling at least a portion of the bottom stream from step e) into the regenerator.

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).

An extraction solvent comprised of one or more ethyleneamines having structure (I), (II), or (III): ##STR00001##
where R.sub.1-R.sub.6 can independently be H, C.sub.1-C.sub.4 linear or branched alkyl, amido (RRNC═O), or hydroxyalkyl, where each R in the amido group independently H or C.sub.1 alkyl, and where x ranges from 1 to 6, may be contacted with a hydrocarbon stream to remove or extract non-acidic contaminants, such as thiophenes, benzothiophenes, alkyl sulfides, alkyl disulfides, mercaptans, aromatics, oxygenates, metals, olefins, and combinations thereof, from the hydrocarbon stream. The extraction solvent may include co-solvents and the hydrocarbon stream may be in gas and/or liquid form.