TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The unabsorbed component gas comprises nitrogen or hydrogen. The contaminant comprises carbon dioxide, hydrogen sulfide, mercaptans, oxygen, water or carbon monoxide.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The extractor is a tower with internals to promote mass transfer. (S1) is counter-currently contacted with the lean solvent. The reduced pressure stage comprises at least two flash vessels of which at least one is a surge vessel and wherein a level control instrumentation for the extractor and flash vessels is aligned such as to allow the surge vessel to be close to the middle of the sequence of vessels. The level control instrumentation comprises valves or hydraulic turbines. The level control instrumentation on the vessels upstream of the surge vessel act as downstream controllers, and the level control instrumentation on the vessels downstream of the surge vessel act as upstream controllers. Sufficient volume of rich solvent in the flash vessel is included to allow temporary accumulation of a contaminant in the solvent to the extent that the maximum contaminate concentration in the produced overhead product is reduced. Additional solvent volume is added to increase ability to accommodate contaminants. The operating pressure of the flash vessels is increased to reduce vaporization of a contaminant. (M1) Further involves purification of the overhead unabsorbed component gas and/or the flashed overhead product stream. An absorber/regeneration system employing a circulating solvent is used in the purification step. Adsorption, membrane, incineration or other technologies are used in the purification step. The pressure of the last flash vessel is below atmospheric pressure. At least one reduced pressure stage is conducted at below atmospheric pressure.Preferred Component: (S4) comprises methane. The lean solvent comprises at least one of the components of (S1). The lean solvent is chilled to a temperature as cold as - 40degreesF (-40degreesC) (preferably -185degreesF (-121degreesC). The lean solvent is internal solvent or external solvent. The external solvent comprises a solvent chosen for its ability to selectively hold a contaminant in the solvent. The external solvent comprises sulfinol, selexol, amine compound, glycol compound or morpholine compound. The external solvent is paraffinic solvents, naphthenic solvents and/or aromatic solvents.