Abstract: An apparatus and method are provided which are capable of independent adjustment of the heat and power in a combined system. Intermediate heat and pressure exhaust is extracted from an intermediate point in the main turbine system. This exhaust goes to a regenerator and then an auxiliary turbine. The exhaust that is not extracted continues to power the main turbine system and flows from the low pressure end to the turbine system to a waste heat boiler.

Abstract: An improved method of recovering liquid nitrogen as a by-product in a natural gas liquid (NGL) recovery plant is provided. In accordance with the method a plant-separated, nitrogen-rich gas stream is compressed to a super-atmospheric pressure, and the stream is chilled whereby a portion of the nitrogen and other components therein are condensed by passing the stream in an indirect heat exchange relationship with a methane refrigerant stream. The methane refrigerant stream is a portion of the plant methane-rich product gas stream which is expanded, utilized as the refrigerant stream and then recycled to and combined with the plant feed stream.

Abstract: An improved apparatus and process are disclosed for nitrogen rejection from a gaseous hydrocarbon stream recovered from an enhanced oil recovery project employing nitrogen for miscible flood of oil reservoirs. The process utilizes a modified dual distillation column arrangement including two fractionators which do not utilize overhead reflux condensers or reboilers for separating a nitrogen-methane mixture. Further, process conditions can be adjusted so as to provide efficient nitrogen rejection from a feedstream in which nitrogen content varies widely over a comparatively long period of time during enhanced recovery of oil.

Abstract: A super-pressured, sub-cooled feed gas, predominating in methane and containing significant amounts of ethane and higher hydrocarbons and nitrogen, is separated by passing the feed gas through at least one separation step to separate a vapor phase and a liquid phase, fractionating the liquid phase to recover ethane and higher hydrocarbons as a liquid and a pipeline gas as a vapor phase product, the vapor phase from the separation step is then sequentially fractionated in second, third and fourth fractionation steps to produce liquid phase from the second fractionation step, which is recycled to the first fractionation step as a reflux, a liquid phase from the third fractionation step which is recovered as a product pipeline gas, a liquid phase from the fourth fractionation step which is recovered as an in-plant fuel and a vapor phase from the fourth fractionation step which is vented to the atmosphere as substantially pure nitrogen.

Abstract: By incorporating a gas permeable membrane into a hydrogen purification process at the front end of the cryogenic unit, the low purity hydrogen can be made into a high purity stream and a low purity stream. The critical pressure of the low purity stream is such that the low purity stream can be purified cryogenically without depressurization.

Abstract: Normally gaseous feed materials, having a pressure significantly above ambient pressure, are cooled by passing the gaseous feed through an indirect heat exchange means, such as a plate-fin heat exchanger, passing a normally gaseous refrigerant, having a pressure substantially above ambient pressure, through the heat exchange means as a first stream in a concurrent direction with the feed stream, reducing the pressure of at least one second stream of refrigerant, preferably a plurality of second streams, as it exits the heat exchange means and passing the second stream of refrigerant, which has thus been reduced in pressure, through the heat exchange means in a countercurrent direction to the feed stream. This method can be employed for each cooling cycle of a method for cooling a natural gas stream to remove components therefrom and/or liquify the same.

Abstract: A cryogenic hydrogen purification system is disclosed which produces low and high BTU substitute natural gas byproduct from a feed stream containing substantial carbon monoxide concentration. The required process cooling is provided by a pair of gas expanders. The purified hydrogen stream can be recycled to a hydroretort. The low BTU substitute natural gas stream contains most of the carbon monoxide. The high BTU natural gas stream forms suitable feed for a hydrogen plant.