Various illustrative embodiments of a system and process for recovering high-quality biomethane and carbon dioxide product streams from biogas sources and utilizing or sequestering the product streams are provided. The system and process synergistically yield a biomethane product which meets gas pipeline quality specifications and a carbon dioxide product of a quality and form that allows for its transport and sequestration or utilization and reduction in greenhouse gas emissions. The system and process result in improved access to gas pipelines for products, an improvement in the carbon intensity rating of the methane fuel, and improvements in generation of credits related to reductions in emissions of greenhouse gases.

A method for producing liquid nitrogen using a residual gas stream derived from a flue gas of a power plant is provided. The residual gas stream is purified in a front-end purification unit to remove freezable components and then the purified stream is compressed. Following compression, the stream can be divided into a first portion and a second portion, wherein the first portion is cooled and sent to a distillation column, wherein oxygen and argon are separated, thereby leaving an essentially pure gaseous nitrogen stream. The gaseous nitrogen stream can then be liquefied using refrigeration provided by expanding the second portion of the purified stream. In a preferred embodiment, the second portion is expanded in two turbines, and the gaseous nitrogen is compressed in a cold nitrogen booster, which is powered by one of the two turbines. In an additional embodiment, after warming, the expanded second portion of the purified stream can be used to regenerate the front-end purification unit.

A method for producing power and argon is provided by providing a residual gas stream, purifying the residual gas stream in a front-end purification unit to remove carbon dioxide, thereby forming a purified residual gas stream, and introducing the purified residual gas stream to a cold box, wherein the purified residual gas stream is cooled and expanded within the cold box to produce power and then fed to a distillation column system for separation therein, thereby forming an argon-enriched stream and optionally a nitrogen-enriched stream and/or an oxygen-enriched stream, wherein the residual gas stream is sourced from a retentate stream of a cold membrane having oxygen, nitrogen, carbon dioxide, and argon.

A process for removing a foulant from a gas stream is disclosed. The gas stream, containing a foulant, is cooled across a first heat exchanger and a second heat exchanger, producing a solid foulant entrained in cryogenic liquid as a foulant slurry, and a foulant-depleted gas stream. The foulant-depleted gas stream is passed through a cryogenic turbine and a first separation vessel, producing a light gas stream and further solid foulant. The solid foulants are recovered by a combination of pressurization, melting, and distillation to produce a liquid foulant product. Heat is recovered from the various streams in the various heat exchangers and the melter.

Various illustrative embodiments of a system and process for recovering high-quality biomethane and carbon dioxide product streams from biogas sources and utilizing or sequestering the product streams are provided. The system and process synergistically yield a biomethane product which meets gas pipeline quality specifications and a carbon dioxide product of a quality and form that allows for its transport and sequestration or utilization and reduction in greenhouse gas emissions. The system and process result in improved access to gas pipelines for products, an improvement in the carbon intensity rating of the methane fuel, and improvements in generation of credits related to reductions in emissions of greenhouse gases.

Light gases such as helium are extacted from a carbon dioxide-containing feed stream by distillation. Costly dehydration steps are avoided by pumping the liquid bottoms stream leaving the distillation column without vaporization so as to ensure that any water present in the feed remains in solution with the bulk stream leaving the process. This prevents any liquid phase water causing corrosion or solid ice or hydrates forming to plug the flow.

Various illustrative embodiments of a system and process for recovering high-quality biomethane and carbon dioxide product streams from biogas sources and utilizing or sequestering the product streams are provided. The system and process synergistically yield a biomethane product which meets gas pipeline quality specifications and a carbon dioxide product of a quality and form that allows for its transport and sequestration or utilization and reduction in greenhouse gas emissions. The system and process result in improved access to gas pipelines for products, an improvement in the carbon intensity rating of the methane fuel, and improvements in generation of credits related to reductions in emissions of greenhouse gases.

A system which integrates a power production system and an energy storage system represented by gas liquefaction systems is provided.

A carbon dioxide capture system includes a first heat exchanger configured to exchange heat between an exhaust stream and a lean carbon dioxide effluent stream. The carbon dioxide capture system also includes a first turboexpander including a first compressor driven by a first turbine. The first compressor is coupled in flow communication with the first heat exchanger. The first turbine is coupled in flow communication with the first heat exchanger and configured to expand the lean carbon dioxide effluent stream. The carbon dioxide capture system further includes a carbon dioxide membrane unit coupled in flow communication with the first compressor. The carbon dioxide membrane unit is configured to separate the exhaust stream into the lean carbon dioxide effluent stream and a rich carbon dioxide effluent stream. The carbon dioxide membrane unit is further configured to channel the lean carbon dioxide effluent stream to the first heat exchanger.

A system that integrates a power production system and an energy storage system represented by gas liquefaction systems is provided.