A compound of the general formula (I)

##STR00001##

in which R.sub.1, R.sub.2 and R.sub.3 are 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; m is 2, 3, 4 or 5; n is 2, 3, 4 or 5; and o is an integer from 0 to 10. A preferred compound of the formula (I) is 2-(2-tert-butylaminoethoxy)ethylamine. Absorbents comprising a compound of the formula (I) have rapid absorption of carbon dioxide from fluid streams and are also suitable for processes for the simultaneous removal of H.sub.2S and CO.sub.2, where given H.sub.2S limits have to be observed but complete removal of CO.sub.2 is not required.

An improved process for deacidizing a gaseous mixture with reduced overall energy costs is described. The process involves contacting the gaseous mixture with at least one of a vaporizing compound, a vaporized compound, a vaporizing solution of compound and a vaporized solution of compound, and forming a liquid or solid reaction product that can be easily separated from the gaseous mixture.

Method and apparatus for separating a target substance from a fluid or mixture. Capsules having a coating and stripping solvents encapsulated in the capsules are provided. The coating is permeable to the target substance. The capsules having a coating and stripping solvents encapsulated in the capsules are exposed to the fluid or mixture. The target substance migrates through the coating and is taken up by the stripping solvents. The target substance is separated from the fluid or mixture by driving off the target substance from the capsules.

A method for removing carbon dioxide (CO.sub.2) from a gas is described. The method provides a sorbent liquid for the CO.sub.2 in countercurrent flow with a gas stream comprising the CO.sub.2 and absorbs the CO.sub.2 in the sorbent liquid to obtain a gas with a reduced concentration of CO.sub.2, and a sorbent liquid enriched with the absorbed CO.sub.2. The absorbed CO.sub.2 is stripped from the enriched sorbent liquid to obtain a regenerated sorbent liquid and CO.sub.2-containing gas. The absorbing step a) is performed at a first facility provided in a first location and the sorbent liquid enriched with the absorbed CO.sub.2 is then transported from the first facility to a second facility provided in a second location and at a distance of minimum 3 kilometers from the first location. The stripping step b) is performed at the second facility and at least 24 hours later than the absorbing step a). The second facility is a greenhouse.

The present application provides a modular membrane isolation carbon desorption device, a carbon capture system, a method, and an application thereof. The device comprises an electrolyzer in which a plurality of anion exchange membranes are arranged, dividing the electrolyzer into multiple electrolysis units. Each electrolysis unit is equipped with electrodes, and the polarities of the electrodes in adjacent units are opposite. An electrolysis unit containing a positive electrode function as an anode electrolysis unit, while one with a negative electrode serves as a cathode electrolysis unit. This application effectively reduces heat loss during the carbon desorption process and enables dual-sided dissolution of the positive electrode and dual-sided deposition of the negative electrode, thereby enhancing electrolysis efficiency during the carbon desorption process.

Disclosed herein are methods of capturing CO2 from a gas source using electrochemically-enhanced amine capture to form a concentrated CO.sub.2 vapor, followed by sequestering CO.sub.2 from the concentrated vapor in a sequestration step. The sequestration step includes contacting the concentrated vapor with an aqueous sequestration solution comprising ions capable of forming an insoluble carbonate salt, such that the aqueous sequestration solution comprises the CO.sub.2, electrochemically basifying the sequestration solution, thereby precipitating a carbonate solid, separating the carbonate solids from the aqueous sequestration solution or the surface of the mesh.

A water-lean carbon dioxide absorbent according to the present invention comprises a cyclodiamine and a polyalkylene glycol alkyl ether and further comprises an alkanolamine, wherein the absorbent shows an excellent reaction rate with carbon dioxide, is resistant to degradation due to oxygen and heat, and can greatly reduce energy consumption due to latent heat of water when regenerated, and thus leads to a water-lean carbon dioxide absorbent with improved regeneration efficiency.

The present disclosure provides improved systems, assemblies and methods to remove and recover CO.sub.2 from emissions. More particularly, the present disclosure provides improved membrane contactors configured to remove CO.sub.2 from flue gas by temperature swing absorption. In exemplary embodiments, the present disclosure provides a novel hollow fiber membrane contactor that integrates absorption and stripping using a nonvolatile reactive absorbent (e.g., 80% polyamidoamine (PAMAM) dendrimer generation 0, and 20% of an ionic liquid (IL)). Equilibrium CO.sub.2 absorption in the nonvolatile viscous mixed absorbent is as high as 6.37 mmolCO.sub.2/g absorbent in the presence of moisture at 50 C. A novel membrane contactor is provided for CO.sub.2 absorption and stripping via a process identified as temperature swing membrane absorption (TSMAB). The contactor integrates non-dispersive gas absorption and hot water-based CO.sub.2 stripping in one device/assembly containing two sets of commingled hollow fibers.

A method for the treatment of a gas stream, wherein before the combustion of the gas stream, hydrogen sulfide is separated out of the gas stream in a first absorber by an absorption medium, the treated gas stream purified of hydrogen sulfide is burnt in a combustion apparatus, the carbon dioxide contained in the exhaust gas of the burnt gas stream after combustion is separated in a second absorber by an absorption medium, and the separated hydrogen sulfide and carbon dioxide are separated in at least one desorber from the absorption medium for the regeneration of the latter. The same absorption medium separates the hydrogen sulfide out of the gas stream and the carbon dioxide out of the exhaust gas. A corresponding device for the treatment of a gas stream has a first absorber and a second absorber flow-connected to one another for the exchange of absorption medium.

An apparatus and a combined process for carbon dioxide gas separation, combining the hydrate-based process with the chemical absorption process, which reduces secondary pollution and allows the efficient continuous separation of carbon dioxide gas without increasing the pressure and thereby the operating cost is reduced significantly. The apparatus and combined process can be applied in the separation of carbon dioxide in IGCC synthetic gas, natural gas and biogas, and address the issues of the existing processes such as high energy consumption, low throughput, and secondary pollution.