A solvent and method for removing carbon dioxide from a gaseous mixture flow with high carbon dioxide partial pressures are disclosed. The solvent includes a secondary or tertiary amine, an amine activator, a physical solvent (e.g., thioalkanol), and a carbonate buffer. The solvent contains less than about 60% by weight of water and is in a single liquid phase.

A non-aqueous solvent system configured to remove acidic gas from a gas stream comprises a solution formed of a chemical absorption component and a physical absorption component. The chemical absorption component includes a nitrogenous base, wherein the nitrogenous base has a structure such that it reacts with a portion of the acidic gas. The physical absorption component includes an organic diluent that is non-reactive with the acidic gas and that has a structure such that it absorbs a portion of the acidic gas at a pressure above atmospheric pressure. The solvent system has a solubility with water of less than about 10 g of solvent per 100 mL of water.

A process for adsorbing impurities from hydrocarbon gas streams is disclosed. The process involves passing a hydrocarbon gas stream and a solid dry adsorbent under inert environment to a scrubbing chamber for adsorbing impurities from the hydrocarbon gas streams within the scrubbing chamber. The process adsorption of impurities in scrubbing chamber is carried under non-oxidative conditions to generate a clean product gas.

A system for melting contaminant-laden solids that have been separated from a hydrocarbon-containing vapor stream in a hydrocarbon distillation tower, comprising at least one plate positioned where the solids form within the hydrocarbon distillation tower, hollow tubing forming an integral part of each of the at least one plate, and a heating medium disposed to flow through the hollow tubing at a higher temperature than a temperature of the solids to at least partially melt the solids.

A system and method for removing hydrogen sulfide from natural gas using a triazine scavenger is described. The system includes a pre-treatment system that can be connected to an existing hydrogen sulfide removal system to more fully utilize the triazine scavenger. The pre-treatment system includes a contactor vessel in which sour natural gas is contacted with fresh and/or partially consumed scavenger to partially sweeten the sour gas by removing H.sub.2S. The partially sweetened gas then flows to the existing hydrogen sulfide removal system where it is fully sweetened.

An aminal compound is injected into a fluid gas stream including at least one acid gas to reduce the amount of acid gas in the fluid gas stream. Having two reactive sites present in the aminal compound enables a much higher efficiency of acid gas capture than a simple alkanolamine, which isn't effective, for example, under dilute circumstances.

A process for producing a deacidified fluid stream from a fluid stream comprising methanol and at least one acid gas and an apparatus for carrying out the process. The process comprising a) an absorption step in which the fluid stream is contacted with an absorbent in an absorber to obtain an absorbent laden with methanol and acid gases and an least partly deacidified fluid stream; b) a regeneration step in which at least a portion of the laden absorbent obtained from step a) is regenerated in a regenerator to obtain an at least partly regenerated absorbent and a gaseous stream comprising methanol, water and at least one acid gas; c) a recycling step in which at least a substream of the regenerated absorbent from step b) is recycled into the absorption step a); d) a condensation step in which a condensate comprising methanol and water is condensed out of the gaseous stream from step b); e) a distillation step in which at least a portion of the condensate from step d) is guided into a distillation column to obtain a top stream comprising methanol and a bottom stream comprising water; which comprises recycling at least a portion of the bottom stream from step e) into the regenerator.

Systems and processes for detecting leaks into a refrigeration system having a heat exchanger where the process side is configured to operate at a higher pressure than the refrigerant side. The system includes a refrigerant circulation system including a refrigerant feed pipe fluidly connected to and configured to provide a refrigerant to an inlet of the refrigerant side of the heat exchanger, as well as a refrigerant effluent pipe fluidly connected to and configured to receive a refrigerant from an outlet of the refrigerant side of the heat exchanger. One or more sensors are provided, the sensors being configured to measure a property of the refrigerant, such as temperature, pressure, or flow rate, for example. Additionally, the system for detecting leaks includes a digital control system configured to provide an alert when a signal from at least one of the one or more sensors is indicative of a leak from the process side of the heat exchanger to the refrigerant side of the heat exchanger.

A process for producing liquefied natural gas and liquid carbon dioxide from a natural gas feed gas comprising at least the following steps: Separation of a natural gas feed gas into a CO.sub.2-enriched gas stream and a natural gas stream; Cooling of said natural gas in a heat exchanger; Purification of the in step 1 from compounds containing at least six carbon atoms; At least partial condensation of said gas stream resulting from step 3 to form a two-phase stream; Separation of said two-phase stream resulting from step 4 to form a gas stream and a liquid stream; Condensation of the gas stream resulting from step 5 to form a liquefied gas containing less than 5 ppm by volume of compounds containing at least six carbon atoms; Liquefaction of the CO.sub.2-enriched gas stream resulting from step 1 with a portion of the liquid stream resulting from step 5.

A system for removing acid gases from a raw gas stream is provided. The system includes a cryogenic distillation column. The cryogenic distillation column receives a dehydrated and chilled sour gas stream, and separates the sour gas stream into an overhead gas stream comprised primarily of methane, and a bottom acid gas stream comprised primarily of carbon dioxide. The system also includes a series of co-current contactors. The co-current contactors may be placed in series to receive the bottom acid gas stream and recapture any entrained methane gas. Alternatively or in addition, the co-current contactors may be placed in series to receive the overhead gas stream, and sweeten it using a reflux liquid such as methane. In this instance, the sweetened gas is optionally liquefied and delivered for commercial sale, or is used as fuel gas on-site.