A batch process for producing a purified, pressurized liquid carbon dioxide stream, includes withdrawing a liquid carbon dioxide stream (A) from a liquid carbon dioxide supply (10); introducing the liquid carbon dioxide stream (A) into a distillation column (B) having packing (C) therein, and stripping volatile impurities from the liquid carbon dioxide stream with the packing; vaporizing the liquid carbon dioxide stream (A) in a sump (D) of the distillation column (B) for providing a carbon dioxide vapor; withdrawing from a vaporized portion (F) of carbon dioxide vapor in the sump (D) a first vapor stream (G) vented from the distillation column (B); withdrawing from the vaporized portion (F) of the carbon dioxide vapor in the sump (D) a second vapor portion (H) vented from the sump into a conduit (I); and introducing the second vapor portion (H) in the conduit (I) into a carbon dioxide vapor feed stream.

Methods and systems for separating components are disclosed. A process liquid stream is provided that contains a first component and a second component. The process liquid stream is cooled to near a temperature at which the second component forms a solid. The process liquid stream is expanded into a vessel such that the first component and a first portion of the second component vaporize to form a process vapor stream and a second portion of the second component forms a solid to form a solid product stream. The process vapor stream and the solid product stream are passed out of the vessel.

A method and a system for separating components is disclosed. A process liquid stream, containing a first component and a second component, is passed into an expansion device. The process liquid stream is expanded such that the first component and a first portion of the second component vaporize to form a process vapor stream and a second portion of the second component freezes to form a first solid product stream. The first solid product stream passes out of the expansion device. The process vapor stream passes into a direct-contact heat exchanger against a contact liquid stream. The first portion of the second component desublimates into the contact liquid stream as a second solid product stream. The contact liquid stream and the second solid product stream leave the direct-contact heat exchanger as a slurry stream. The process vapor stream leaves the direct-contact heat exchanger as a stripped process vapor stream.

A CO2 separation and liquefaction system such as might be used in a carbon capture and sequestration system for a fossil fuel burning power plant is disclosed. The CO2 separation and liquefaction system includes a first cooling stage to cool flue gas with liquid CO2, a compression stage coupled to the first cooling stage to compress the cooled flue gas, a second cooling stage coupled to the compression stage and the first cooling stage to cool the compressed flue gas with a CO2 melt and provide the liquid CO2 to the first cooling stage, and an expansion stage coupled to the second cooling stage to extract solid CO2 from the flue gas that melts in the second cooling stage to provide the liquid CO2.

A system and method for capturing and separating carbon dioxide from mixed gas streams. The gas stream is processed in a structure including a compression module comprising a plurality of compressors, intercoolers and inter-stage condensate separators. The flow path from the compression module includes a plurality of flow separators, gas stream splitters, heat exchangers and at least a first mixer and a first expander. The gas stream is sequentially compressed and cooled to form process condensate and separate it from the compressed gas stream. The gas stream is further dried and cooled to liquefy carbon dioxide and separate it from the non-condensable portion. Selective expansion of liquid carbon dioxide streams provides cooling for the system, and further energy efficiency is achieved by selective recycling of portions of gas streams, allowing for compact equipment and economical operation, while providing for high purity product streams of carbon dioxide.

A compressing system includes a compression section that compresses a target gas to an intermediate pressure, which is equal to or higher than a critical pressure and lower than a target pressure to generate an intermediate supercritical fluid, a cooling section that cools the intermediate supercritical fluid generated in the compression section to near a critical temperature to generate an intermediate supercritical pressure liquid, and a pumping section that compresses the intermediate supercritical pressure liquid generated in the cooling section to a pressure that is equal to or higher than the target pressure. At least one of the intermediate supercritical pressure liquid compressed in the pumping section, a low-temperature liquid generated by extracting the intermediate supercritical pressure liquid on the upstream side of the pumping section to reduce pressure to near the critical pressure, and an external cooling medium is used as a cooling medium in the cooling section.

Methods and systems of the current invention separate condensable vapors such as carbon dioxide from light gases or liquids in a mixed process stream. The separation is carried out in a cryogenic process using one or more external cooling loops (ECLs) that first cool down a mixed process stream containing condensable vapors and light gases or liquids, causing the condensable vapors to desublimate and form solids. Next, the solids are separated from the light gases or liquids, forming a solid stream and a light gas or liquid stream. Then the refrigerants of the ECL are cooled by warming the separated solid stream and light gas or liquid stream, efficiently recovering energy used in cooling and desublimating the condensable vapors.

Impurities that are less volatile than carbon dioxide, e.g. hydrogen sulfide, are removed from crude carbon dioxide by processes involving distillation of said crude carbon dioxide in a distillation column system operating at super-atmospheric pressure(s) to produce carbon dioxide-enriched overhead vapor and bottoms liquid enriched with said impurities. Where such processes involve a single heat pump cycle, significant savings in power consumption are realized when the distillation column system is re-boiled by at least partially vaporizing liquid in or taken from an intermediate location in the column system.

The invention relates to a method for the treatment of natural gas containing carbon dioxide, methane and paraffins. The method comprising: a step of extracting the paraffins from the natural gas in a paraffin-removal column, and a step of separating the carbon dioxide and the methane in a distillation column. The operation of the two columns being provided by means of the thermal coupling of said two columns using a thermal coupling heat exchanger.

A boosting system which boosts a target gas to a pressure which is equal to or greater than a target pressure higher than a critical pressure includes a compression portion which compresses the target gas to an intermediate pressure which is equal to or greater than the critical pressure and is less than the target pressure to generate an intermediate supercritical fluid, a cooling portion which cools the intermediate supercritical fluid generated by the compression portion to a temperature near to a critical temperature to generate an intermediate supercritical pressure liquid, a pump portion which boosts the intermediate supercritical pressure liquid generated by the cooling portion to a pressure which is equal to or greater than the target pressure, and a cooling temperature adjusting portion which adjusts a temperature of the intermediate supercritical pressure liquid generated by the cooling portion in an upstream side of a pump.