The invention discloses methods and apparatus(es) for the removal and control of pollutants such as gases and suspended particulates in the air of an enclosed space or an outdoor environment by passing the air through absorbent media. The absorbent media includes any liquid, solid or combination of liquid and solid media that is capable of absorbing a material in which it comes in contact. In one aspect of the invention, formaldehyde is removed by air sparging through a liquid such as water, optionally containing additional scavenging agents.

The invention relates to a process for dehumidifying a moist gas mixture and to the absorption medium used in the process. The invention further relates to an apparatus for dehumidifying a moist gas mixture and to the use of said apparatus in the process according to the invention.

The present disclosure provides a method for the separation of a gas constituent from a gaseous mixture. The disclosure also provides polyethylene glycol disubstituted siloxane based solvents for use in the method. These solvents are of use for pre-combustion CO.sub.2 capture and are capable of replacing glycol-based solvents while offering operation at a higher temperature region. These solvents are also of use for generation of hydrogen from reformed natural gas or syngas, adjusting CO/H.sub.2 ratio for Coal & Biomass to Liquids, removal of CO.sub.2 from syngas for coal & biomass to NH.sub.3/Fertilizer, natural gas sweetening, and upgrading of landfill and biogas.

The use of a chemical composition in degassing of vessels is taught, said chemical composition comprising 1-10% by weight of an oxyalkylated dodecyl thiol; and 1-20% by weight of an alkyl di-substituted 9-decenamide. A method is further provided for degassing a vessel. The method comprises charging said vessel with chemical composition and a carrier medium, wherein said chemical composition comprises 1-10% by weight of an oxyalkylated dodecyl thiol and 1-20% by weight of an alkyl di-substituted 9-decenamide.

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.

The invention discloses methods and apparatus(es) for the removal and control of pollutants such as gases and suspended particulates in the air of an enclosed space or an outdoor environment by passing the air through absorbent media. The absorbent media includes any liquid, solid or combination of liquid and solid media that is capable of absorbing a material in which it comes in contact. In one aspect of the invention, formaldehyde is removed by air sparging through a liquid such as water, optionally containing additional scavenging agents.

A chemical composition for use in degassing of vessels is taught, said chemical composition including 1-10% by weight of an oxyalkylated dodecyl thiol; and 1-20% by weight of an alkyl di-substituted 9-decenamide. A method is further provided for degassing a vessel. The method includes charging said vessel with chemical composition and a carrier medium, wherein said chemical composition comprises 1-10% by weight of an oxyalkylated dodecyl thiol and 1-20% by weight of an alkyl di-substituted 9-decenamide.

Processes and apparatuses for treating a sour synthesis gas are provided. The process comprises passing the sour synthesis gas stream to an acid gas removal unit to provide a treated synthesis gas stream and a CO.sub.2 rich stream. At least a portion of the CO.sub.2 rich stream is passed to a thermal oxidizer unit to provide a treated CO.sub.2 gas stream. At least a portion of the treated synthesis gas stream is passed to a pressure swing adsorption unit to obtain a purified hydrogen stream and a tail gas stream. At least a portion of the tail gas stream is passed to the thermal oxidizer unit.

An apparatus for purifying gas where gas is treated in a multistage treatment having at least two ejector stages, a motive medium including liquid, steam or gaseous agent at high pressure injected by an ejector of the ejector stage, and the gas is sucked into the same ejector and mixed with the motive medium for forming a mixture, at least a part of gas and/or liquid phase of the mixture is supplied to a second ejector stage having so that a second motive medium which includes liquid, steam or gaseous agent is injected to the ejector and the gas and/or the liquid phase is sucked into the same ejector in which the gas and/or liquid phase is mixed with the second motive medium for forming a second mixture, at least one of the mixtures includes an additive for removing impurities of the gas, and a purified gas is formed.

A method for cleaning a contaminated solvent used to treat a gas stream, for example a contaminated glycol or a contaminated amine stream, by vacuum evaporation using a mechanically-maintained horizontally-orientated thin film evaporator, where the contaminant material is recovered from the thin film in solvent-free form, as either a heavy organic material or as free flowing salts.