Abstract: The processing of gas streams containing hydrocarbons and other gases of similar volatility to recover components such as ethane, propane and heavier hydrocarbons from a residue gas containing methane is disclosed. In prior art processes, it has been customary to cool incoming raw feed gas and to separate the desired products by distillation. A part of the needed cooling 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 gaseous streams before expansion. The first stream is expanded in the usual fashion and supplied to the demethanizer as a mid-column feed. The remaining part is cooled to substantial condensation. The condensed stream is expanded and supplied to the demethanizer column above the feed point of the first stream.

Abstract: The processing of gas streams containing hydrocarbons and other gases of similar volatility to recover high yields of components such as ethane, propane, and heavier hydrocarbons therefrom by cooling said gas stream under pressure to form a liquid portion, and expanding the liquid portion to a pressure lower than feed pressure whereby a part of the liquid portion vaporizes to cool the remaining part of the liquid portion is improved by pre-cooling the liquid portion prior to flash expansion. In one embodiment this is accomplished by dividing the remaining part of the liquid portion into a first and second stream, directing the first liquid stream into heat exchange relation with the liquid portion of the feed stream prior to expansion to warm the first liquid stream and pre-cool the liquid portion prior to expansion. Both first and second liquid streams are then supplied to a fractionating column, the second stream being supplied to the fractionating column at a point thereon higher than the first stream.

Abstract: A process for separating hydrocarbon gases is described for the recovery of gases such as ethane and heavier hydrocarbons from natural gas streams or similar refinery or process streams. In the process described, the gas to be separated is cooled at a high pressure to produce partial condensation. The liquid from the partial condensation is further cooled and then expanded to a lower pressure. At the lower pressure, the liquid is then separated into fractions in a distillation column. The basic separation process is improved by combining the condensed high-pressure liquid with a stream having a lower bubble point, with cooling of one or both streams prior to expansion.

Abstract: A process for separating hydrocarbon gases is described for the recovery of gases such as ethane and heavier hydrocarbons from natural gas streams or similar refinery or process streams. In the process described, the gas to be separated is cooled at a high pressure to produce partial condensation, and the vapor and liquid portions are separated. Liquid from the partial condensation is further cooled and then expanded to a lower pressure. At the lower pressure, the liquid is supplied to a distillation column, wherein it is separated into fractions. The vapor portion is work-expanded to the operating pressure of the distillation column and supplied to the distillation column below the feed point of the expanded liquid portion. The operating efficiency of the process is improved by turning back at least part of thevapor portion and warming it by heat exchange against incoming feed before it is work-expanded. By thus warming the vapor, more work and refrigeration can be recovered in the work expansion machine.

Abstract: The processing of gas streams containing hydrocarbons and other gases of similar volatility to recover high yields of components such as ethane, propane, and heavier hydrocarbons therefrom by expanding said gas stream in at least two stages through turboexpanders, each stage cooling the gas stream and producing energy in the form of horsepower used to drive a recompressor unit or other mechanical apparatus. Condensed liquids are collected intermediate the expansion stages. Preferably, a supplemental gas cooling stage and condensed liquid recovery occurs following each expansion stage.