Abstract: The processing of gaseous streams of feed gas containing hydrocarbons, and other gases of similar volatility, to recover components such as ethane, propane and heavier hydrocarbons from a residue gas containing methane, by cooling the incoming raw gas and to separate the desired products by distillation. The cooling action is obtained by expanding the raw feed gas from a high feed pressure to a lower pressure at which distillation occurs. In the present invention, the raw feed gas is divided into two gas streams before expansion, the first stream, which consists primarily of vapor, is again cooled through a heat exchange device, and is then expanded through an expansion valve to lower the pressure and then fed into the top of the conventional demethanizer column.

Abstract: A process for recovery of components of volatile gas containing methane and heavier components, by a cryogenic process, cooling the incoming raw gas and separating the desired products by distillation, wherein the feed gas is divided into two streams, one being primarily liquid, which is expanded to lower the pressure and then fed into the demethanizer tower at a selected point, and the other stream, being primarily gas, is divided and expanded and discharged into the demethanizer at selected positions to place the streams in the demethanizer to accomplish maximum separation and recovery of the desired components in either an ethane recovery mode or an ethane rejection mode, the pressures and temperatures of the demethanizer being adjustable for either.

Abstract: A process for low temperature fractionation of natural gas to recover as product propane and the heavier hydrocarbons with an efficiency of 90% or greater and an ethane content rejection of 90% or more. The process includes passage of the natural gas through several refrigeration zones followed by a first separation stage to separate liquid condensate from C.sub.1, C.sub.2 and C.sub.3 hydrocarbon gas. The gas stream is cooled further by expansion followed by a second separation stage to separate liquid containing C.sub.1, C.sub.2 and C.sub.3 hydrocarbons from the gas which contains only C.sub.1 and C.sub.2 hydrocarbons. Both streams are fed to a de-ethanizer fractionating column, with the liquid entering at a point intermediate the ends and the gas being utilized in a reflux condenser internal to the column above the point of entry of the liquid stream. Employment of the low temperature C.sub.1, C.sub.