Recovering helium from a gaseous stream includes contacting an acid gas removal membrane with a gaseous stream to yield a permeate stream and a residual stream, removing a majority of the acid gas from the residual stream to yield a first acid gas stream and a helium depleted clean gas stream, removing a majority of the acid gas from the permeate stream to yield a second acid gas stream and a helium rich stream, and removing helium from the helium rich stream to yield a helium product stream and a helium depleted stream. A helium removal system for removing helium from a gaseous stream including hydrocarbon gas, acid gas, and helium includes a first processing zone including a first acid gas removal unit, a second processing zone including a second acid gas removal unit, a third processing zone, and a helium purification unit.

Combining multiple subsystems involving biomass processing, biomass gasification of the processed biomass where a synthesis gas is produced then converted to hydrogen fuels or other transportation fuels for use in coupled transportation systems sized to consume all the transportation fuel produced. Carbon in the biomass is converted to CO.sub.2 in the conversion process and a portion of that CO.sub.2 is captured and sequestrated for long term storage as CO.sub.2 or as carbon black.

A helium-containing stream is recovered from a natural gas feed using a membrane followed by multiple distillation steps. Refrigeration is provided by expanding a bottoms liquid with a higher nitrogen content than the feed, achieving a lower temperature in the process. The helium-enriched vapor is then purified and the helium-containing waste stream is recycled to maximize recovery and reduce the number of compressors needed. The helium-depleted natural gas stream can be returned at pressure for utilization or transportation.

The invention provides a process for producing a fermentable gas stream from a gas source that contains one or more constituent which may be harmful to the fermentation process. To produce the fermentable gas stream, the gas stream is passed through a specifically ordered series of removal modules. The removal modules remove and/or convert various constituents found in the gas stream which may have harmful effects on downstream removal modules and/or inhibitory effects on downstream gas fermenting microorganisms. At least a portion of the fermentable gas stream is preferably capable of being passed to a bioreactor, which contains gas fermenting microorganisms, without inhibiting the fermentation process.

A method of obtaining helium from a helium-containing feed gas. Helium-containing feed gas is fed to a prepurifying unit that uses a pressure swing adsorption process to remove undesirable components from the helium-containing feed gas and obtain a prepurified feed gas. The prepurified feed gas is fed to a membrane unit connected downstream of the prepurifying unit and that has at least one membrane more readily permeable to helium than to at least one further component present in the prepurified feed gas. A pressurized low-helium retentate stream that has not passed through the membrane is fed to the prepurifying unit. The pressurized low-helium retentate is used to displace helium-rich gas from an adsorber that is to be regenerated into an already regenerated adsorber.

Techniques for treating a natural gas feed stream include receiving a natural gas feed stream that includes one or more acid gases, one or more hydrocarbon fluids, and one or more non-hydrocarbon fluids; circulating the natural gas feed stream to a membrane module; separating, with the membrane module, at least a portion of the one or more acid gases into a permeate stream and at least a portion of the one or more hydrocarbon fluids into a reject stream; circulating the permeate stream to a distillation unit; and separating, in the distillation unit, the one or more acid gases from the one or more non-hydrocarbon fluids.

Recovering helium from a gaseous stream includes contacting an acid gas removal membrane with a gaseous stream to yield a permeate stream and a residual stream, removing a majority of the acid gas from the residual stream to yield a first acid gas stream and a helium depleted clean gas stream, removing a majority of the acid gas from the permeate stream to yield a second acid gas stream and a helium rich stream, and removing helium from the helium rich stream to yield a helium product stream and a helium depleted stream. A helium removal system for removing helium from a gaseous stream including hydrocarbon gas, acid gas, and helium includes a first processing zone including a first acid gas removal unit, a second processing zone including a second acid gas removal unit, a third processing zone, and a helium purification unit.

It is provided a process for optimizing syngas carbon utilisation and syngas purity from a varying scrubbed syngas source before feeding into a syngas conversion unit comprising the steps of feeding a scrubbed syngas into a purification unit comprising at least one absorption unit to remove CO.sub.2 from the scrubbed syngas. producing a clean CO+H.sub.2+CO.sub.2 syngas stream and a CO.sub.2 rich stream: and mixing the clean CO+H.sub.2+CO.sub.2 syngas stream with hydrogen producing a balanced syngas stream. wherein the balanced syngas stream meet the stoichiometric ratio and purity requirement of the syngas conversion unit.

Disclosed are methods and systems for desulfurization of CO-rich streams. A method can include contacting a CO-rich gas stream with activated carbon and/or contacting the CO-rich gas stream with a zinc-oxide sorbent material at a temperature of ( ) to 50 C. to remove at least a portion of the sulfur-containing compounds present in the stream.

A feed stream including hydrogen sulfide is heated to a preheat temperature. At least a portion of the hydrogen sulfide in the feed stream is converted into hydrogen and sulfur to form a mixed product stream including the hydrogen, the sulfur, and a remaining, unconverted portion of the hydrogen sulfide. The preheat temperature is a temperature that is sufficiently hot to maintain a desired reaction temperature while converting at least the portion of the hydrogen sulfide in the feed stream into hydrogen and sulfur. At least a portion of the mixed product stream is cooled to a specified temperature at which recombination of the hydrogen and the sulfur into hydrogen sulfide is prevented. Cooling at least the portion of the mixed product stream includes condensing at least a portion of the sulfur to form a sulfur stream.