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 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.

Methods and compositions useful, for example, for physical solvent carbon capture. The solvents may include an aqueous mixture of 2-amino-2-methylproponol, 2-piperazine-1-ethylamine, diethylenetriamine, 2-methylamino-2-methyl-1-propanol, and potassium carbonate or potassium carbonate buffer salt. The solvent may also contain less than about 75% by weight of dissolving medium (i.e., water) and may have a single liquid phase. The solvents and methods have favourable regeneration energies, chemical stability, vapour pressure, total heat consumption, net cyclic capacity, and reaction kinetics.

The present invention relates to methods for improving carbon capture using entrained catalytic-particles within an amine solvent. The particles are functionalized and appended with a CO.sub.2 hydration catalyst to enhance the kinetics of CO.sub.2 hydration and improve overall mass transfer of CO.sub.2 from an acid gas.

An acid gas absorbent includes at least one kind of secondary amine compound represented by formula (1): ##STR00001##
where R.sup.1 is a cyclopentyl group or a cyclohexyl group which may be substituted by a substituted or non-substituted alkyl group having 1 to 3 carbon atoms, R.sup.2 and R.sup.3 each indicate an alkylene group having 2 to 4 carbon atoms, and R.sup.2 and R.sup.3 may each be the same or different, and be a straight chain or have a side chain.

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.

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.

The gas separation device separates or captures a target gas component from a gas to be processed by: causing an absorbing liquid to flow down on a surface of a packing disposed inside a processing tank while supplying the gas to be processed containing the target gas component into the processing tank; bringing the absorbing liquid flowing down on the surface of the packing and the gas to be processed into gas-liquid contact; and thereby causing the absorbing liquid to absorb the target gas component contained in the gas to be processed. The packing includes at least one packing unit formed from multiple expanded metal plates, which are disposed vertically and arranged in parallel. Each expanded metal plate includes strands forming the openings which are arranged like stairs. Each strand is inclined to the vertical direction at an angle in a range from 48° to 73°.

A method and apparatus for enhanced oil recovery comprising separating CO.sub.2 gas from coal or flue emissions of a power plant, and flash freezing the CO.sub.2 gas with super chilled air, to form frozen CO.sub.2 ice blocks or cylinders, wherein the CO.sub.2 blocks or cylinders can then be inserted into an abandoned oil well, and the CO.sub.2 can be allowed to warm up and change phase to a gas, which enables the CO.sub.2 gas to mix with the oil, and helps reduce the viscosity of the oil and allows it to flow more freely, so that it can be pumped out using conventional equipment. A first application comprises having top and bottom valves and the CO.sub.2 blocks or cylinders being allowed to change phase to a gas while inside the injection pipe, to increase the pressure therein, such that, by opening the bottom valve, pressurized jets of CO.sub.2 gas can be released into the oil, causing the oil to mix vigorously with the carbon dioxide gas, and reduce the viscosity thereof. A second application comprises allowing the CO.sub.2 cylinders or blocks to drop into the oil itself, wherein the relatively warm oil causes the frozen CO.sub.2 to change phase to a gas, which causes violent gas bubbles to form that vigorously mix with the oil, which helps reduce the viscosity of the oil so it flows more freely through the reservoir.

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.