A method of treating oil and gas streams to remove total organic sulfur or total acid gas including the step of treating the gas stream with a solution of an amine, physical solvent, and water wherein the amine solution may optionally also contain an activator.

A carbon dioxide removal system includes: an absorption system including a first absorption stage and a second absorption stage. The first absorption stage includes: a first compressor configured to receive and compress a first carbon dioxide-containing exhaust stream from an anode of a fuel cell, and a first direct contact absorption cooling tower configured to absorb carbon dioxide from the compressed first exhaust stream and lower a temperature of the compressed first exhaust stream using a first solvent stream containing a physical solvent, to generate a second exhaust stream. The second absorption stage includes: a second compressor configured to receive and compress the second exhaust stream from the first absorption stage, and a second direct contact absorption cooling tower configured to absorb carbon dioxide from the compressed second exhaust stream and lower a temperature of the compressed second exhaust stream using a second solvent stream containing a physical solvent.

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.

An absorbent for removing carbon dioxide from a fluid stream, comprising an aqueous solution a) 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.1-4alkyl 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 b) at least one activator selected from b1) a sterically unhindered primary amine and/or a sterically unhindered secondary amine; and a carboanhydrase. The absorbent allows rapid absorption of carbon dioxide from fluid streams.

The present invention relates to a dehydration composition and method of use thereof for drying gas streams, in particular natural gas streams, wherein the dehydration composition comprises (i) a glycol, (ii) an imidazole compound, and optionally (iii) one or more of an alkali metal carboxylate, an additional glycol different than (i), an alkanolamine, a phosphate acid, a salt of a phosphate acid, a borate acid, a salt of a borate acid, a sweetening agent, a low temperature viscosity improver, a corrosion inhibitor, an antifoaming agent, or mixtures thereof.

Disclosed is a solvent composition and use thereof for removal of one or more acid gas from a fluid stream comprising: i) a physical solvent, ii) an alkali metal organoborate, where R.sub.3 and R.sub.4 may be the same or different and are independently an alkylene group comprising 2 to 6 carbons, R.sub.5 and R.sub.6 may be the same or different and are independently H or a linear or branched alkyl group comprising from 1 to 18 carbons, and Z is an alkali metal ion; and iii) optionally an amine compound.

##STR00001##

A method for treatment of a flue gas involves feeding the flue gas and a lean solvent to an absorber. The method further involves reacting the flue gas with the lean solvent within the absorber to generate a clean flue gas and a rich solvent. The method also involves feeding the clean flue gas from the absorber and water from a source, to a wash tower to separate a stripped portion of the lean solvent from the clean flue gas to generate a washed clean flue gas and a mixture of the water and the stripped portion of the lean solvent. The method further involves treating at least a portion of the mixture of the water and the stripped portion of the lean solvent via a separation system to separate the water from the stripped portion of the lean solvent.

A process and an apparatus for gas denitration, involving first the use of an oxidizing agent to oxidize NO in a gas to NO.sub.2, then using a denitration agent to absorb the NO.sub.2 in the gas, thus achieving the purpose of denitration.

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.

Method for extracting a gas from a gas mixture by: during a purification step, bringing a first sorption medium into contact with the gas mixture in order to extract the gas from the gas mixture, whereby an enriched first sorption medium is formed in which the gas is at least partially sorbed; during a regeneration step, bringing a second sorption medium into contact with the enriched first sorption medium in order to extract the gas from the enriched liquid first sorption medium; whereby for the contact in the purification step and/or in the regeneration step use is made of a separate venturi ejector.