A process to produce helium gas from a feed to a nitrogen rejection unit comprising employing refrigeration from the nitrogen rejection unit to increase the recovery of helium by cooling crude helium prior to further processing.

Process to produce helium gas

A gas centrifuge operating to separate gases of differing chemical composition and molecular weight by a centrifugal force field. Such a centrifuge is operable to separate methane and carbon dioxide, and to produce torque, and a cascade of such centrifuges is operable to concentrate produced streams of carbon dioxide and methane, and to produce torque. A compact centrifugal gas processing system incorporating the gas centrifuge with other centrifugal components, is also provided.

Centrifuge and cascade for the separation of gases

Process for the recovery of chlorine from chlorine-containing gas mixtures in a multi-stream heat exchanger wherein the chlorine-containing mixtures are separated from other gases which would solidify or liquify in the process, either before or after compression of the mixture, and is then cooled below the dew-point of chlorine in one stream of the heat exchanger; the liquid and gaseous phases thus produced are then separated and re-passed separately through the heat exchanger, the chlorine passing to recovery and the gas phase to re-cooling before being re-passed once more through the heat exchanger prior to discharge and wherein a predetermined mixture of gaseous and liquid phases is also recycled separately through the heat exchanger before re-compression and return via the heat exchanger to the phase-separation apparatus

Chlorine recovery process

The present invention is directed to a process for the purification and liquefaction of helium from a feed stream consisting essentially of nitrogen and helium with some minor impurities, wherein the helium is purified in a two step process: the first purification step comprising refrigerating the feed stream to condense nitrogen and any impurities from the feed stream, feeding the cooled feed stream to a separator, and removing from the bottom of the separator the condensed nitrogen and impurities in the feed stream and from the top of the separator a gaseous, high-helium-content stream; the second purification step comprising warming the gaseous, high-helium-content stream from the first purification step, feeding said stream to a pressure swing adsorber, and removing from the pressure swing adsorber an essentially pure helium stream, which is liquefied by feeding said essentially pure helium stream to a liquefier; wherein refrigeration is provided for the warm end of the liquefier and the two step purification; the improvement comprising providing said refrigeration by compressing a side stream of the essentially pure helium in a compressor and expanding said compressed stream in an expansion engine thereby producing a cold helium gas stream; splitting said cold helium stream into two substreams and circulating said cold helium gas stream to the warm end of the liquefier and to the two step purification to provide refrigeration duty.

Combined process to produce liquid helium, liquid nitrogen, and gaseous nitrogen from a crude helium feed

A process to produce cold helium gas suitable for use as a feed to a helium liquifier comprising employing refrigeration from a nitrogen rejection unit to reduce the temperature of the helium gas just prior to its passage to the liquifier thus enabling a reduction in the liquifier energy requirement.

Process to produce cold helium gas for liquefaction

A light gas, namely hydrogen or helium, of increased purity is obtained from a gaseous mixture consisting predominantly of the light gas by passing the mixture through a rotating gas centrifuge under conditions such that gaseous impurities are condensed and a light gas stream of increased purity is recovered. The process may be applied to a light gas concentrate obtained from a gaseous mixture by separation of the constituents other than the light gas by low-temperature condensation, in which case a gas expansion turbine used to produce refrigeration for the process may be used to drive the gas centrifuge.

Stanley Mercer

Papers

Recovery of gases