Abstract: A process is provided for treating a hydrocarbon gas stream by condensing a portion of the gas stream to produce a liquid stream, then through several steps subcooling a portion of the liquid stream to be introduced into a midpoint into a fractionation column. Unexpectedly, it has been found that the recompression and refrigeration power requirements are substantially reduced and the minimum approach to carbon dioxide freezing are increased when the liquid stream is introduced to a midpoint in the column when compared to introducing the liquid stream to a top position or a lower position in the fractionation column.

Abstract: A process and an apparatus are disclosed for the recovery of components from a hydrocarbon gas stream containing significant quantities of components more volatile than methane (hydrogen, nitrogen, etc.). The gas stream is partially condensed, then the remaining vapor is expanded to lower pressure and supplied to a fractionation tower at a mid-column feed position. The condensed liquid is cooled and divided into two portions. The first portion is expanded to tower pressure, heated by cooling the liquid, and supplied to the tower at a lower column feed position. The second portion is further cooled, expanded to tower pressure, and supplied to the tower at a top feed position. The tower overhead vapor is heated by cooling the second portion. The quantities and temperatures of the feeds to the tower maintain the overhead temperature of the tower whereby the major portion of the desired components is recovered.

Abstract: A process and an apparatus are disclosed for separation of a hydrocarbon gas stream containing methane and heavier hydrocarbons and significant quantities of nitrogen and carbon dioxide. The gas stream is cooled and expanded, then fractionated in a first distillation column into a first overhead vapor and a hydrocarbon liquid stream containing the majority of the carbon dioxide. The hydrocarbon liquid stream is fractionated into a hydrocarbon vapor stream and a less volatile fraction comprised of heavier hydrocarbons. The first overhead vapor is cooled, expanded, and separated into vapor and liquid streams. Both streams are cooled and expanded before feeding a second distillation column that produces a second overhead vapor that is predominantly nitrogen and a bottom liquid that is predominantly methane. The bottom liquid is vaporized and combined with the hydrocarbon vapor stream to form a volatile residue gas fraction containing the majority of the methane.

Abstract: A process and an apparatus are disclosed for separation of a hydrocarbon gas stream containing methane and heavier hydrocarbons and significant quantities of nitrogen and carbon dioxide. The gas stream is cooled and expanded, then fractionated in a first distillation column into a first overhead vapor and a hydrocarbon liquid stream containing the majority of the carbon dioxide. The hydrocarbon liquid stream is fractionated into a hydrocarbon vapor stream and a less volatile fraction comprised of heavier hydrocarbons. The first overhead vapor is cooled, expanded, and separated into vapor and liquid streams. Both streams are cooled and expanded before feeding a second distillation column that produces a second overhead vapor that is predominantly nitrogen and a bottom liquid that is predominantly methane. The bottom liquid is vaporized and combined with the hydrocarbon vapor stream to form a volatile residue gas fraction containing the majority of the methane.

Abstract: A process is provided for treating a hydrocarbon gas stream by condensing a portion of the gas stream to produce a liquid stream, then through several steps subcooling a portion of the liquid stream to be introduced into a midpoint into a fractionation column. Unexpectedly, it has been found that the recompression and refrigeration power requirements are substantially reduced and the minimum approach to carbon dioxide freezing are increased when the liquid stream is introduced to a midpoint in the column when compared to introducing the liquid stream to a top position or a lower position in the fractionation column.

Abstract: A process and an apparatus are disclosed for separation of a hydrocarbon gas stream containing methane and heavier hydrocarbons and significant quantities of nitrogen and carbon dioxide. The gas stream is cooled and expanded, then fractionated in a first distillation column into a first overhead vapor and a hydrocarbon liquid stream containing the majority of the carbon dioxide. The hydrocarbon liquid stream is fractionated into a hydrocarbon vapor stream and a less volatile fraction comprised of heavier hydrocarbons. The first overhead vapor is cooled, expanded, and separated into vapor and liquid streams. Both streams are cooled and expanded before feeding a second distillation column that produces a second overhead vapor that is predominantly nitrogen and a bottom liquid that is predominantly methane. The bottom liquid is vaporized and combined with the hydrocarbon vapor stream to form a volatile residue gas fraction containing the majority of the methane.

Abstract: A process and an apparatus are disclosed for the recovery of components from a hydrocarbon gas stream containing significant quantities of components more volatile than methane (hydrogen, nitrogen, etc.). The gas stream is partially condensed, then the remaining vapor is expanded to lower pressure and supplied to a fractionation tower at a mid-column feed position. The condensed liquid is cooled and divided into two portions. The first portion is expanded to tower pressure, heated by cooling the liquid, and supplied to the tower at a lower column feed position. The second portion is further cooled, expanded to tower pressure, and supplied to the tower at a top feed position. The tower overhead vapor is heated by cooling the second portion. The quantities and temperatures of the feeds to the tower maintain the overhead temperature of the tower whereby the major portion of the desired components is recovered.

Abstract: A process and an apparatus are disclosed for the recovery of components from a hydrocarbon gas stream containing significant quantities of components more volatile than methane (hydrogen, nitrogen, etc.). The gas stream is partially condensed, then the remaining vapor is expanded to lower pressure and supplied to a fractionation tower at a mid-column feed position. The condensed liquid is cooled and divided into two portions. The first portion is expanded to tower pressure, heated by cooling the liquid, and supplied to the tower at a lower column feed position. The second portion is expanded to tower pressure and supplied to the tower at an upper mid-column feed position. A distillation vapor stream is withdrawn from the fractionation tower below the mid-column feed position and is heated, compressed to higher pressure, and cooled to substantial condensation before it is expanded and supplied to the tower as its top feed.

Abstract: A process and an apparatus are disclosed for the recovery of ethane, ethylene, propane, propylene, and heavier hydrocarbon components from a hydrocarbon gas stream. The stream is divided into first and second streams. The first stream is cooled to condense substantially all of it, expanded to lower pressure, and supplied to a fractionation tower at an upper mid-column feed position. The second stream is cooled sufficiently to partially condense it and separated into vapor and liquid streams. The vapor stream is divided into first and second portions. The first portion is cooled to condense substantially all of it, expanded to the tower pressure, and supplied to the tower at the top feed position. The second portion is expanded to the tower pressure and supplied to the fractionation tower at an intermediate mid-column feed position. The liquid stream is expanded to the tower pressure and supplied to the column at a lower mid-column feed position.

Abstract: A process and an apparatus are disclosed for the recovery of ethane, ethylene, propane, propylene, and heavier hydrocarbon components from a hydrocarbon gas stream. The stream is divided into first and second streams. The first stream is cooled to condense substantially all of it, expanded to lower pressure, and supplied to a fractionation tower at an upper mid-column feed position. The second stream is cooled sufficiently to partially condense it and separated into vapor and liquid streams. The vapor stream is divided into first and second portions. The first portion is cooled to condense substantially all of it, expanded to the tower pressure, and supplied to the tower at the top feed position. The second portion is expanded to the tower pressure and supplied to the fractionation tower at an intermediate mid-column feed position. The liquid stream is expanded to the tower pressure and supplied to the column at a lower mid-column feed position.