Abstract: Process for regeneration of a solvent for preferentially absorbing acid gases. The solvent, which comprises between 5 and 55 percent by weight water, is steam stripped in a regenerator, and vapor leaving the regenerator with the acid gases is condensed. The resulting condensate is returned to the solvent downstream of the regeneration zone. The condensate may be partially or wholly recirculated to the upper part of the regenerator provided that the majority of it is withdrawn above the regeneration zone. Some of the condensate may be added back to the solvent at the bottom of the regenerator or in a reboiler associated with the regenerator.

Abstract: Middle distillate compositions are disclosed which contain a filterability improver which may be considered to be a mono- or polyester of a specified C.sub.10-40 hydrocarbyl alcohol and a hydroxy-carboxylic acid and, in some cases, a pour point depressant.

Abstract: An oil recovery process in which an aqueous solution is injected into a subterranean reservoir to displace oil through the reservoir is improved by thickening the solution with a substantially linear block copolymer containing both water-soluble and water-insoluble polymer chains. The composition and concentration of the copolymer are correlated with the temperature and injectivity of the reservoir to provide a thickened solution of selected mobility and stability within the reservoir.

Abstract: The flow properties of waxy crude oils are improved by the incorporation therein of a copolymer of (1) an olefinically unsaturated compound containing a long hydrocarbon side chain and (2) an olefinically unsaturated heterocyclic nitrogen-containing compound, e.g., 4-vinyl pyridine.