A natural-gas purification apparatus includes: a compressor; a cooling unit that liquefies and separates a part of natural-gas liquid; a heating unit; first to third carbon-dioxide separation units that separate carbon dioxide through carbon-dioxide separation membranes; a detection carbon-dioxide separation unit that further separates carbon dioxide through a carbon-dioxide separation membrane; a carbon-dioxide-flow-rate sensor that detects the amount of carbon dioxide separated by the detection carbon-dioxide separation unit; an arithmetic control device that adjusts and controls at least one of the pressure to be applied by the compressor, the cooling temperature of the cooling unit, and the heating temperature of the heat unit based on information from the carbon-dioxide-flow-rate sensor such that the amount of carbon dioxide to be separated by the detection carbon-dioxide separation unit will be higher than or equal to a prescribed amount.

A natural-gas purification apparatus includes: a plurality of carbon-dioxide separation units that are arranged in series and separate carbon dioxide, through carbon-dioxide separation membranes, from natural gas pressurized by a compressor, cooled by a cooling unit to liquefy and separate a high-boiling-point hydrocarbon component, and heated by a heating unit; a gas supply pipe that is provided between the plurality of carbon-dioxide separation units through on-off valves and that supplies the natural gas; a compressor that is provided to the gas supply pipe; a cooling unit that liquefies and separates a high-boiling-point hydrocarbon component by cooling the natural gas pressurized by this compressor; and a heating unit that heats the natural gas after the separation of the high-boiling-point hydrocarbon component by this cooling unit.

A system and method for producing acetic acid, including dry reforming methane with carbon dioxide to give syngas, cryogenically separating carbon monoxide from the syngas giving a first stream including primarily carbon monoxide and a second stream including carbon monoxide and hydrogen. The method includes synthesizing methanol from the second stream via hydrogenation of carbon monoxide in the second stream, synthesizing dimethyl ether from the methanol, and generating acetic acid from the dimethyl ether and first-stream carbon monoxide.

A process for recovering at least one fluid (e.g. xenon gas and/or krypton gas, etc.) from a feed gas can include utilization of a compression system, primary heat exchanger unit, a pre-purification unit (PPU), and other units to separate and recover at least one desired fluid. In some embodiments, fluid flows output from a first heat exchanger or separation system of the plant can be split so that a portion of a stream is output for downstream processing to purify xenon (Xe) and/or krypton (Kr) product flow(s) while another portion of the stream is recycled to a compression system or the PPU to undergo further purification and heat exchange so that the product output for downstream processing has a higher concentration of Xe or Kr. Some embodiments can be configured to provide an improved recovery of Xe and/or Kr as well as an improvement in operational efficiency.

A process may be utilized to coat urea-containing granules with organic polymers. The process may involve compressing gaseous carbon dioxide and condensing the carbon dioxide to obtain liquid carbon dioxide, increasing the pressure and/or the temperature above the critical point of carbon dioxide and obtaining supercritical carbon dioxide, dissolving an organic polymer in the supercritical carbon dioxide to obtain a polymer-containing solution, and mixing the polymer-containing solution with urea-containing granules and lowering the temperature and/or the pressure below the critical point of carbon dioxide and obtaining coated urea-containing granules and gaseous carbon dioxide. In some cases the organic polymer may include biodegradable polymers, and the polymer-containing solution may contain between 20 to 70% by weight biodegradable polymers.

A system and method for producing acetic acid, including dry reforming methane with carbon dioxide to give syngas, cryogenically separating carbon monoxide from the syngas giving a first stream including primarily carbon monoxide and a second stream including carbon monoxide and hydrogen. The method includes synthesizing methanol from the second stream via hydrogenation of carbon monoxide in the second stream, synthesizing dimethyl ether from the methanol, and generating acetic acid from the dimethyl ether and first-stream carbon monoxide.

The present disclosure provides an integrated power generating system and method and liquefied natural gas (LNG) vaporization system and method. More particularly, heat from a CO.sub.2 containing stream from the power generating system and method can be used to heat the LNG for re-gasification as gaseous CO.sub.2 from CO.sub.2 containing stream is liquefied. The liquefied CO.sub.2 can be captured and/or recycled back to a combustor in the power generating system and method.

An apparatus for producing dry ice includes a supply means (2) for supplying carbon dioxide in the liquid state and a means (20) for the transition of state of the carbon dioxide in the liquid state flowing along the supply means (2). The state transition means (20) brings about the desired solidification of the carbon dioxide in order to produce dry ice and the undesired formation of carbon dioxide in the gaseous state. A system (3) is provided for the collection and recovery of carbon dioxide in the gaseous state. The collection and recovery system (3) collects carbon dioxide in the gaseous state downstream of the state transition means (20) and has a compressor (4) for compressing the carbon dioxide collected by the collection system (3), a heat exchanger (5) that places the carbon dioxide downstream of the compressor (4) and the carbon dioxide upstream of the compressor (4) in thermal communication, and a storage means (6) for storing the carbon dioxide coming from the compressor (4).

Methods are for storing electricity and producing liquefied natural gas (LNG) or synthetic natural (SNG) and using carbon dioxide and for producing electricity, natural gas (NG) or SNG. The methods involve, starting from a water flow, producing an oxygen gas flow and a hydrogen gas flow by electrolysis in an electrolytic cell. A first hydrogen gas flow portion and a second hydrogen gas flow portion are obtained. The first hydrogen gas flow portion is allocated to a methanation step in the presence of carbon dioxide gas. A condensed recirculation water vapor flow is obtained to be allocated to the methanation step and performing methanation. The second hydrogen gas flow portion is allocated to a cooling and liquefaction step. A liquid hydrogen flow is obtained, which is stored in a liquid hydrogen tank.

An apparatus for separation of a flow containing at least 95 mol % of carbon dioxide and also at least one impurity lighter than carbon dioxide by distillation comprises a heat exchanger (20), a distillation column (30), expansion means (V3), means for sending the flow to be cooled in the heat exchanger, means for sending the cooled flow to be separated in the distillation column, means for withdrawing at the bottom of the column a liquid flow containing at least 99 mol % of carbon dioxide, means for sending at least a portion (12) of the liquid flow to be cooled in the heat exchanger to form a subcooled liquid (3), means for sending at least a portion of the subcooled liquid to the expansion means to produce a two-phase flow, a phase separator (40) for separating the two-phase flow to form a gas and a liquid, means for sending at least a portion (14) of the liquid from the phase separator to be vaporized in the heat exchanger and means for taking a portion (4) of the liquid from the phase separator.