Abstract: A process for separating components of gas mixtures which have different hydrate forming characteristics which uses an aqueous liquid to absorb one of the gases preferentially by attaining conditions slightly above the catastrophic point at which gas hydrates form. Specifically, the separation of gas mixtures containing light hydrocarbons and carbon dioxide is accomplished without significantly reducing the pressure of the carbon dioxide or without requiring significant amounts of heat energy for regeneration.

Abstract: Nitrogen and methane are separated in a nitrogen-methane cryogenic fractionator operating at a temperature between the boiling points of nitrogen and methane. A distillative aid or absorbent is injected into the nitrogen-methane cryogenic fractionator for enhancing separation, for enabling an increase in operating pressure, and for enabling a high separation rate at relatively high temperature.

Abstract: Disclosed is a method and apparatus for refrigeration utilizing a combined mechanical and absorption cycle. Two immiscible or only partly miscible refrigerants are mixed and evaporated in an evaporator to cool a process stream. The refrigerants are separated in an absorber which absorbs one of the refrigerants from the vapor mixture. The non-absorbed refrigerant vapor is compressed and condensed, while the absorbed refrigerant is desorbed and condensed to produce respective liquid refrigerant streams to the evaporator. Optionally the vapor mixture from the evaporator is compressed in a first stage of compression prior to passing to the absorber.

Abstract: Disclosed is a method and apparatus for separating and purifying carbon dioxide and natural gas contained in the associated gas of an oil well. Feed containing hydrocarbons, carbon dioxide, water and hydrogen sulfide, is fed to a stabilizer column where heavy hydrocarbons and water are removed. Hydrogen sulfide is then stripped from the gas in a carbon dioxide fractionator using a solvent which absorbs H.sub.2 S and increases the relative volatility of carbon dioxide to hydrogen sulfide. Overhead from the CO.sub.2 fractionator contains carbon dioxide and light hydrocarbons, which are then separated in a demethanizer column which produces liquid carbon dioxide as a bottoms product. The invention is particularly useful in recovering carbon dioxide from the associated gas of oil produced from enhanced oil recovery processes using carbon dioxide injection.