In an embodiment a method includes loading an absorbent with a carbon dioxide in a first device, wherein a hydrogen carbonate-containing solution is formed, feeding the hydrogen carbonate-containing solution from the first device into an electrolysis unit, electrolyzing the hydrogen carbonate-containing solution in the electrolysis unit to release carbon dioxide, wherein a carbonate-rich solution is formed in the electrolysis unit, forming oxygen, hydrogen and carbon dioxide in the electrolysis unit, and recycling the carbonate-rich solution from the electrolysis unit to the first device.

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.

A composition and a device for purification of nitrogen-oxide-containing gas is provided. It can purify harmful nitrogen-oxide-containing gases, such as nitric oxide or nitrogen dioxide. The composition includes an alkaline substance and at least one organic acid, the organic acids having an enediol group, enediamine group, or amine group of cyclopentane compounds, cyclohexane compounds, cycloheptane compounds, or phenanthrene compounds.

A humidity control device for use in maintaining the desired humidity of a closed environment, e.g., a container, while also decreasing headspace oxygen, the device including a water vapor and oxygen permeable pouch, an aqueous salt solution containing humidity controlling salts in combination with salts of ascorbic acid or isomers thereof.

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.

The present invention relates to a system for desorption of acid gas (1) from an acid gas rich absorption liquid having a steam part (3) and a process part (4). The steam part (3) and the process part (4) are separated to prevent intermixing of fluids in the steam part with fluids in the process part. The system (1) comprises a desorption cylinder (9) which is adapted to rotate about a longitudinal axis of rotation A of the desorption cylinder (9), and a stationary support stand (19) for supporting the desorption cylinder (9), and means for rotating (18) the desorption cylinder. The steam part (3) and the process part (4) are integrated in the desorption cylinder (9) and steam is supplied to the steam part (3) and acid gas rich absorption liquid (2) is supplied to the process part (4). The process part (4) comprises a desorption chamber (12) provided with a stripper unit (33) having an integrated reboiler (52) and the process part (4) is provided with means for discharging an acid gas lean absorption fluid (2) and having means for removing acid gas rich vapor (8), and the steam part (3) is provided with means for discharging condensate (6). The present invention also relates to a method for desorption of acid gas from an acid gas rich absorption liquid.

The present invention relates to a scavenging composition capable of scavenging a wide variety of sulfur-bearing compounds, such as hydrogen sulfide and method of use thereof. Said scavenging composition comprises an aqueous solution of a triazine compound, an anionic surfactant, and optionally an alcohol and/or glycol ether solution. The composition may be used in any kind of sulfide-scavenging operation and is particularly useful for sulfide scavenging in the context of sulfide removal from oil or gas streams and in the treatment of oil or gas transmission lines or equipment.

The implementations described herein generally relate to methods and chemical compositions for scavenging sulfur-containing compounds, and more particularly to methods and compositions for scavenging, for example, H.sub.2S and mercaptans from sulfur-containing streams. In one implementation, a method for scavenging a sulfur-containing compound from a sulfur-containing stream is provided. The method comprises contacting the sulfur-containing stream with a scavenging system for scavenging the sulfur-containing compound, wherein the scavenging system comprises urea formaldehyde reaction products.

A compound of the general formula (I)

##STR00001##

in which R.sub.1 to R.sub.8, x, y and z are as defined in the description. Also described is an absorbent comprising a solution of the compound, and the use thereof and a process for removing acid gases from a fluid stream, wherein the fluid stream is contacted with the absorbent. The compounds of the general formula (I) are notable for thermal stability and low volatility. Absorbents based on the compounds are notable for high loading capacity, high cyclic capacity and good regeneration capacity. The solutions of the compounds in nonaqueous solvents are notable for low viscosities.

An absorbent for selective removal of hydrogen sulfide 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.