Abstract: In the process for the recovery of e.g. LPG or NGL and sales gas from a gaseous hydrocarbon feed 11 by partially condensing the feed in heat exchanger 1 at superatmospheric pressure, separating the condensate from the uncondensed gas in gas/liquid separator 2, rectifying the uncondensed gas to produce the sales gas and stripping the condensate to produce the LPG or NGL, substantially power savings are obtained if the rectification is effected in a reflux exchanger 103 and the stripping is effected in a separate distillation column 203.

Abstract: In the single column process for the recovery of nitrogen from air wherein reflux for the distillation is provided by condensing a first portion of the overhead stream by indirect heat exchange in a reflux condenser with oxygen-rich liquid from the bottom of the column which has been subjected to a first expansion to an intermediate pressure, refrigeration for the process is provided by work expanding evaporated oxygen-rich liquid from the reflux condenser, and prior to said first expansion, the oxygen-rich liquid recovered from the bottom of the column is sub-cooled by indirect heat exchange in a sub-cooler with the work-expanded evaporated oxygen-rich liquid, nitrogen recovery is increased by work expanding the evaporated oxygen-rich liquid at a temperature not substantially greater than that at which it is recovered from the reflux condenser or by first passing it through said sub-cooler at a temperature not substantially greater than that at which it is recovered from the reflux condenser and thereafter w

Abstract: In a process for the separation of a gas mixture at superatmospheric pressure by partial condensation at cryogenic temperatures and wherein the separated condensate and uncondensed vapor are passed back as returning streams in indirect countercurrent heat exchange relationship with the incoming feed mixture, the power required for providing the refrigeration and energy requirements for the separation are reduced by supplying said requirements by means of a heat pump alone or together with at least one separate refrigeration cycle and/or some Joule-Thomson expansion of the condensate, and in the heat pump a compressed multi-component gaseous medium is condensed by heat exchange with said returning streams over a first temperature range and then expanded by Joule-Thomson expansion, and the expanded condensate is evaporated by heat exchange with the feed gas mixture over a lower temperature range than said first temperature range, and recycled for recompression.

Abstract: Power is produced from a methane-containing cryogenic liquid such as LNG by compressing the liquid and employing the compressed liquid as a refrigerant in the condensers of two closed and independent power cycles. The heat exchange medium in the first of the cycles evaporates in a lower temperature range than that at which the heat exchange medium in the second cycle condenses. The first heat exchange medium is condensed by heat exchange in a first heat exchange step with the compressed cryogenic liquid and the second heat exchange medium is condensed by heat exchange in a second heat exchange step with compressed cryogenic liquid recovered from the first heat exchange step and evaporating first heat exchange medium. Power is recovered from the expansion engines associated with the two power cycles.

Abstract: A process is disclosed for recovering hydrogen from an ammonia synthesis plant comprising(a) cooling a high pressure stream of said purge gas to a sub-ambient temperature at which substantially all of the methane and argon contained in said purge gas stream and a portion of the nitrogen condense,(b) expanding liquid and vapor components of the cooled high pressure stream to an intermediate pressure,(c) phase separating liquid and vapor components of the cooled and expanded purge gas stream,(d) expanding separated liquid component from step (c), and(e) heating expanded separated liquid component from step (d) and separated vapor component from step (c) in heat exchange with said high pressure stream of purge gas to cool the latter.

Abstract: In the synthesis of ammonia with recycle of unreacted nitrogen and hydrogen to the reactor, a purge gas stream is removed from the recycle stream and partially condensed using refrigeration provided by the expansion and subsequent vaporization of the condensate. After partial condensation the condensate is rich in methane and argon while the gaseous phase is hydrogen enriched. The gaseous stream from the partial condensation is returned to the reactor and a bleed stream is removed from this gaseous stream at a temperature not exceeding 30.degree. C above the subambient temperature of the condensation. At least a part of the bleed stream is then expanded and injected into the expanded condensate prior to vaporization in the refrigeration step. Accumulation of helium, argon and methane impurities in the reactor can thus be prevented and expanded vaporized combined condensate and bleed can be recovered at a suitable pressure for use as a fuel gas stream.

Abstract: Process for upgrading an air-contaminated methane composition such as is found near coal measures comprises condensing this gas, and thereafter fractionating it to yield a first product having a methane content higher than that of the initial composition and a calorific value commensurate with that of natural gas, and a second product having a methane content below that of the initial composition but above the highest limit of the flammability range for methane-air mixtures under the conditions of temperature and pressure prevailing in the process.

Abstract: Substantially pure methane and ethylene are supplied economically from a transportable liquefied methane-ethylene-ethane mixture by a two-stage distillation at superatmospheric pressure wherein the refrigeration for the first stage reflux may be supplied entirely from sensible cold of the compressed mixture and the second stage reflux is obtained by heat exchange with first stage reboil so that the only power requirement is for compressing the mixture. The mixture is conveniently obtained by combining a cracker gas fraction with a natural gas fraction.

Abstract: A method and apparatus for the separation of gases by preferential adsorption of at least one of the gases in which at least three adsorption zones are used, at least two of which are arranged in series to form the separation zone while at least one other is being regenerated for re-use in the separation zone, and in which periodically a fresh zone is added to the end of the separation section from which the product gas is recovered and the zone forming the first zone of the separation section is removed for regeneration whereby each zone is successively incorporated into the separation section and subsequently removed from it and regenerated ready for reincorporation into the separation section. Improved utilisation of adsorbent and reduced loss of product gas for regeneration purposes is thereby achieved without loss of product purity.