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.

The method combines different electrolyte solutions having the same solvent. The solution is successively compressed and vaporized at different temperatures and the vapor is successively absorbed by the second solution that exhibits higher negative deviation, at higher temperature. The absorption heat of each absorber is recovered by the next evaporator. The more evaporator-absorber pairs that are used the higher the temperature lift or the created pressure ratio. Finally the vapor returns to the first solution at high temperature. Electrolyte is dissolved and rejected from each solution to achieve total heat recovering and the very high efficiency of the cycle. Gas absorption is suggested instead of solvent vapor.

The present invention relates to methods for improving carbon capture by providing particles within an amine solvent. The particles provide for increased turbulence at the interface between the counter-flowing gas and solvent, which allows for increased amine and carbamate salt diffusion between the liquid film and bulk.

A process for selectively removing hydrogen sulphide relative to carbon dioxide from a gaseous mixture containing at least hydrogen sulphide H.sub.2S and carbon dioxide CO.sub.2, includes a step of contacting the gaseous mixture with an absorbent solution including at least one amine, water, and at least one C.sub.2 to C.sub.4 thioalkanol. A use of the absorbent solution for selectively removing hydrogen sulphide relative to carbon dioxide from a gaseous mixture containing at least hydrogen sulphide and carbon dioxide, is disclosed. Disclosed is a use of at least one C.sub.2 to C.sub.4 thioalkanol as an additive in an absorbent solution including at least one amine, and water, for increasing the selectivity of the absorbent solution for the removal of hydrogen sulphide relative to carbon dioxide from a gaseous mixture containing at least hydrogen sulphide and carbon dioxide.

An apparatus and process are provided for electricity production and high-efficiency trapping of carbon dioxide, using carbon dioxide within combustion exhaust gas and converging technologies associated with a carbon dioxide absorption tower and a generating device using ions which uses a difference in concentration of salinity between seawater and freshwater. It is expected that enhanced electrical energy production efficiency, an effect of reducing costs for the operation of a carbon dioxide trapping process, and electricity production from carbon dioxide, which is a greenhouse gas, can be simultaneously achieved by increasing the difference in concentration using an absorbent for absorbing carbon dioxide.

A process and an apparatus for dehumidifying a moist gas mixture are provided. The apparatus for dehumidifying a moist gas mixture can be used and in the process. The absorption medium used in the process and the apparatus is also provided.

A method and apparatus are provided for recovering an amine solvent from an acid gas stream. The apparatus includes a water wash recovery column, a nozzle for spraying water wash and an amine nucleation agent into the water wash recovery column and an inlet port for introducing acid gas into the water wash recovery column adjacent the lower end thereof. The method includes the steps of treating the acid gas stream in the water wash recovery column with a counter-current flow of water wash in an amine nucleation agent, discharging treated acid gas from an upper end of the water wash recovery column and collecting water wash, amine nucleation agent and entrained amine solvent from the acid gas stream and a sump at a lower end of the water wash recovery column.

Embodiments relate to a gas dehydration drying agent solution composition, comprising a solvent that includes at least one glycol having a number average molecular weight from 40 g/mol to 500 g/mol and from 0.01 wt % to 8.00 wt % of a cyclohexylamino sulfonic salt.

An absorbent for selective removal of hydrogen sulfide over carbon dioxide from a fluid stream comprises an aqueous solution of a) a tertiary amine, b) a sterically hindered secondary amine of the general formula (I) ##STR00001##
in which R.sub.1 and R.sub.2 are each independently selected from C.sub.1-4-alkyl and C.sub.1-4-hydroxyalkyl; R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are each independently selected from hydrogen, C.sub.1-4-alkyl and C.sub.1-4-hydroxyalkyl, with the proviso that at least one R.sub.4 and/or R.sub.5 radical on the carbon atom bonded directly to the nitrogen atom is C.sub.1-4-alkyl or C.sub.1-4-hydroxyalkyl when R.sub.3 is hydrogen; x and y are integers from 2 to 4 and z is an integer from 1 to 4; where the molar ratio of b) to a) is in the range from 0.05 to 1.0, and c) an acid in an amount, calculated as neutralization equivalent relative to the protonatable nitrogen atoms in a) and b), of 0.05 to 15.0%. One preferred amine of the formula I is 2-(2-tert-butylaminoethoxy)ethanol. The absorbent allows a defined H.sub.2S selectivity to be set at pressures of the kind typical in natural gas processing.

A process is described, as well as a plant, for treating a raw vent gas (4,4′) containing bitumen vapours and released by a piece of equipment (1) of a polymer-bitumen membranes production line, in which operations are carried out involving a filler powder (3), such as an operation of mixing the filler powder (3) with the bitumen (2), during which the raw vent gas (4,4′) is changed from a substantially powder-free raw vent gas (4), into a raw vent gas (4′) containing the filler powder (3). The process includes steps of first conveying the raw vent gas (4,4) into a gas-washing device (20) along with a solution (9) of a surfactant; contacting the raw vent gas (4,4) with the solution (9) and removing the powder from the powder-containing gas (4′), releasing a purified vent gas (5) that is substantially free from the filler powder; conveying the purified vent gas (5) into a boiler (40) and burning the bitumen vapours. In a preferred exemplary embodiment, it is conveyed in the gas-washing device only the powder-containing gas (4′) produced during the operations of the piece of equipment (1) that involve the filler powder (3), while in the remainder steps the substantially powder-free raw vent gas (4) is directly conveyed into the boiler (40) by a direct vent line (50) that can be automatically selected. In a preferred exemplary embodiment, the gas-washing device comprises a tank (25) configured to form inside a predetermined head of the washing solution (9) and having an inlet port for the raw vent gas arranged below the liquid head. The process prevents the powder from quickly reaching the boiler (40) making the burner and the heat-exchange surfaces ineffective.