Abstract: A process for recovering a light hydrocarbon, such as ethane, from a sour hydrocarbon gas. The process involves mixing the sour hydrocarbon gas with an azeotrope inhibitor and then passing the mixture into a first distillation column. The first distillation column is operated under a set of temperature and pressure conditions in which the light hydrocarbon is substantially separated from the mixture as an overhead vapor product. The sour species in the mixture can be recovered by passing the bottoms liquid product into a second distillation column under a second set of temperature and pressure conditions in which the sour species is separated as a second overhead vapor product.

Abstract: The invention provides a process for recovering a light hydrocarbon, such as ethane, from a sour hydrocarbon gas. The process involves mixing the sour hydrocarbon gas with an azeotrope inhibitor and then passing the mixture into a first distillation column. The first distillation column is operated under a set of temperature and pressure conditions in which the light hydrocarbon is substantially separated from the mixture as an overhead vapour product. The sour species in the mixture can be recovered by passing the bottoms liquid product into a second distillation column under a second set of temperature and pressure conditions in which the sour species is separated as a second overhead vapour product.

Abstract: A process for removing water from a natural gas in an underwater environment is described. The process comprises dehydrating a natural gas feed stream in an apparatus arranged to exchange heat with the underwater environment, preferably including the step of forming hydrates in a hydrate forming zone of a hydrate vessel. The step of forming hydrates in the hydrate zone may comprise the step of introducing the natural gas feed stream into the hydrate vessel through an expansion device with the expansion device is located at and defines a gas inlet to the hydrate vessel. Heat exchange with the hydrate vessel itself need not occur as in one embodiment, heat exchange with the underwater environment takes place through an arrangement of pipes upstream of the hydrate vessel.

Abstract: A process for removal of sour species from a dehydrated natural gas feed stream is provided. The dehydrated natural gas feed stream is cooled to conditions where a slurry of solid sour species and hydrocarbon liquids is formed together with a gaseous stream containing gaseous sour species. The gaseous stream containing gaseous sour species is then separated from the slurry and treated with a liquid solvent, thereby forming a liquid solution of the sour species and a dehydrated sweetened natural gas product stream. An apparatus for removing sour species from a dehydrated natural gas feed stream is also provided. The apparatus has a vessel with a solids formation zone in fluid communication with a gas solvation zone. The solids formation zone is configured to facilitate formation of a slurry of solid sour species and hydrocarbon liquids and a gaseous stream containing gaseous sour species. The gas solvation zone is configured to facilitate formation of a liquid solution of sour species.

Abstract: A process is described for removing contaminants from a natural gas feed stream including water. The process includes the steps of cooling the natural gas feed stream in a first vessel to a first operating temperature at which hydrates are formed, heating the hydrates to a temperature that is above the first operating temperature by introducing a warm liquid to the first vessel so as to melt the hydrates and liberate a dehydrated gas and a water-containing liquid, and removing from the first vessel a stream of dehydrated gas.

Abstract: The invention provides a method of removing solid carbon dioxide from cryogenic equipment, including the steps of: (a) introducing a stream including ethane to the cryogenic equipment to convert solid carbon dioxide to liquid form whereby a mixture of liquid ethane and liquid carbon dioxide is formed; and (b) removing the mixture of liquid ethane and liquid carbon dioxide from the cryogenic equipment. In particular, the method can be used in a liquefied natural gas (LNG) plant wherein cryogenic equipment contains LNG, and the method includes the steps of: (a?) removing the LNG from the cryogenic equipment; (a) introducing a stream including ethane to convert solid carbon dioxide to liquid form whereby a mixture of liquid ethane and liquid carbon dioxide is formed; and (b) removing the mixture of liquid ethane and liquid carbon dioxide from the cryogenic equipment. The result is an effective cleaning method for fouled LNG equipment.

Abstract: The invention provides a method of removing solid carbon dioxide from cryogenic equipment, including the steps of: (a) introducing a stream including ethane to the cryogenic equipment to convert solid carbon dioxide to liquid form whereby a mixture of liquid ethane and liquid carbon dioxide is formed; and (b) removing the mixture of liquid ethane and liquid carbon dioxide from the cryogenic equipment. In particular, the method can be used in a liquefied natural gas (LNG) plant wherein cryogenic equipment contains LNG, and the method includes the steps of: (a?) removing the LNG from the cryogenic equipment; (a) introducing a stream including ethane to convert solid carbon dioxide to liquid form whereby a mixture of liquid ethane and liquid carbon dioxide is formed; and (b) removing the mixture of liquid ethane and liquid carbon dioxide from the cryogenic equipment. The result is an effective cleaning method for fouled LNG equipment.

Abstract: Novel processes and devices for the removal of freezable species such as carbon dioxide, water and heavy hydrocarbons from a natural gas feed stream during liquefaction to produce LNG are disclosed. The freezable species are able to be removed as a solid, avoiding the costly step of pretreatment to remove the freezable species from the natural gas feed stream prior to the liquefaction stage. The freezable species may be removed on a continuous basis being separated as solids following liquefaction of the natural gas feed stream with subsequent separation of the solids. The solid freezable species may then be liquefied on a continuous basis if required with natural gas recycled to the process. Continuous removal of the freezable species from the natural gas feed stream is achievable by maintaining cooling and separation apparatus at the same working pressure.

Abstract: A process for removing contaminants from a natural gas feed stream including water and sour species is provided, which process comprises the steps of cooling the natural gas feed stream in a first vessel (12) to a first operating temperature at which hydrates are formed and removing from the first vessel (12) a stream of dehydrated gas (34); and cooling the dehydrated gas in a second vessel (14) to a second operating temperature at which solids of the sour species are formed or at which the sour species dissolve in a liquid and removing from the second vessel (14) a stream of dehydrated sweetened gas (62).

Abstract: A process for removing contaminants from a natural gas feed stream including water and sour species is provided, which process comprises the steps of cooling the natural gas feed stream in a first vessel (12) to a first operating temperature at which hydrates are formed and removing from the first vessel (12) a stream of dehydrated gas (34); and cooling the dehydrated gas in a second vessel (14) to a second operating temperature at which solids of the sour species are formed or at which the sour species dissolve in a liquid and removing from the second vessel (14) a stream of dehydrated sweetened gas (62).

Abstract: A process for removing water from a natural gas in an underwater environment is described. The process comprises dehydrating a natural gas feed stream in an apparatus arranged to exchange heat with the underwater environment, preferably including the step of forming hydrates in a hydrate forming zone of a hydrate vessel. The step of forming hydrates in the hydrate zone may comprise the step of introducing the natural gas feed stream into the hydrate vessel through an expansion device with the expansion device is located at and defines a gas inlet to the hydrate vessel. Heat exchange with the hydrate vessel itself need not occur as in one embodiment, heat exchange with the underwater environment takes place through an arrangement of pipes upstream of the hydrate vessel.

Abstract: The invention provides a method of removing solid carbon dioxide from cryogenic equipment, including the steps of: (a) introducing a stream including ethane to the cryogenic equipment to convert solid carbon dioxide to liquid form whereby a mixture of liquid ethane and liquid carbon dioxide is formed; and (b) removing the mixture of liquid ethane and liquid carbon dioxide from the cryogenic equipment. In particular, the method can be used in a liquefied natural gas (LNG) plant wherein cryogenic equipment contains LNG, and the method includes the steps of: (a?) removing the LNG from the cryogenic equipment; (a) introducing a stream including ethane to convert solid carbon dioxide to liquid form whereby a mixture of liquid ethane and liquid carbon dioxide is formed; and (b) removing the mixture of liquid ethane and liquid carbon dioxide from the cryogenic equipment. The result is an effective cleaning method for fouled LNG equipment.

Abstract: A method for the separation of non-hydrocarbon gases from hydrocarbon gases, the method comprising the steps of: adding water and an agent adapted to reduce the interfacial tension between water and hydrocarbons to a first stream of desired hydrocarbon and undesired non-hydrocarbon gases to form a gas-agent-water mixture; pressurising the gas-agent-water mixture; and cooling the gas-water-agent mixture to initiate the formation of a hydrate richer in desired hydrocarbons and leaner in undesired non-hydrocarbons relative to the first stream of desired hydrocarbon and undesired non-hydrocarbon gases.

Abstract: Novel processes and devices for the removal of freezable species such as carbon dioxide, water and heavy hydrocarbons from a natural gas feed stream during liquefaction to produce LNG are disclosed. The freezable species are able to be removed as a solid, avoiding the costly step of pretreatment to remove the freezable species from the natural gas feed stream prior to the liquefaction stage. The freezable species may be removed on a continuous basis being separated as solids following liquefaction of the natural gas feed stream with subsequent separation of the solids. The solid freezable species may then be liquefied on a continuous basis if required with natural gas recycled to the process. Continuous removal of the freezable species from the natural gas feed stream is achievable by maintaining cooling and separation apparatus at the same working pressure.

Abstract: A method for the production of the natural gas hydrate characterized by the steps of: combining natural gas and water to form a natural-gas water system and an agent adapted to reduce the natural gas-water interfacial tension to form a natural-gas water-agent system, allowing the natural gas-water-agent system to reach equilibrium at elevated pressure and ambient temperature and reducing the temperature of the natural gas-water-agent system to initiate the formation of the natural gas hydrate.

Abstract: A process for removing contaminants from a natural gas feed stream including water and sour species is provided, which process comprises the steps of cooling the natural gas feed stream in a first vessel (12) to a first operating temperature at which hydrates are formed and removing from the first vessel (12) a stream of dehydrated gas (34); and cooling the dehydrated gas in a second vessel (14) to a second operating temperature at which solids of the sour species are formed or at which the sour species dissolve in a liquid and removing from the second vessel (14) a stream of dehydrated sweetened gas (62).

Abstract: A method for the separation of non-hydrocarbon gases from hydrocarbon gases, the method comprising the steps of: adding water and an agent adapted to reduce the interfacial tension between water and hydrocarbons to a first stream of desired hydrocarbon and undesired non-hydrocarbon gases to form a gas-agent-water mixture; pressurising the gas-agent-water mixture; and cooling the gas-water-agent mixture to initiate the formation of a hydrate richer in desired hydrocarbons and leaner in undesired non-hydrocarbons relative to the first stream of desired hydrocarbon and undesired non-hydrocarbon gases.