A process for recovery of helium from one or more than one helium-containing off-gas streams comprises preconditioning off-gas through a multi-stage preconditioning device, cryogenically separating a helium-enriched gas fraction from the preconditioned off-gas received from the preconditioning device a cryogenic separation device, and purifying the helium-enriched gas fraction received from the cryogenic separation device using a purification device so as to obtain purified helium gas with a higher helium content than the helium-enriched gas.

Disclosed is a process system and a process for converting the sulfur-containing flue gas into the sulfuric acid. The process system comprises: a flue gas preheater, which for preheating the sulfur-containing flue gas to 15˜30° C. above its dew point, and the flue gas preheater has a glass tube as a heat exchange tube; a flue gas fan for boosting the pressure of the preheated acid process gas and transporting one part of which to a combustion furnace, and the other part of which to a process gas steam heater; a sulfuric acid steam condenser for condensing SO.sub.3 generated by the combined reactor into sulfuric acid. The device of the present invention can resist the fluctuation of SO.sub.2 concentration in the feed gas, and can realize considerable economic benefits and rational utilization of energy.

Disclosed is a process system and a process for converting the sulfur-containing flue gas into the sulfuric acid. The process system comprises: a flue gas preheater, which for preheating the sulfur-containing flue gas to 15˜30° C. above its dew point, and the flue gas preheater has a glass tube as a heat exchange tube; a flue gas fan for boosting the pressure of the preheated acid process gas and transporting one part of which to a combustion furnace, and the other part of which to a process gas steam heater; a sulfuric acid steam condenser for condensing SO.sub.3 generated by the combined reactor into sulfuric acid. The device of the present invention can resist the fluctuation of SO.sub.2 concentration in the feed gas, and can realize considerable economic benefits and rational utilization of energy.

In a helium purification process, a stream containing at least 10% of helium, at least 10% of nitrogen in addition to hydrogen and methane is separated to form a helium-enriched stream containing hydrogen, a first stream enriched in nitrogen and in methane and a second stream enriched in nitrogen and in methane, the helium-enriched stream is treated to produce a helium-rich product and a residual gas containing water, the residual gas is treated by adsorption (TSA) to remove the water and the regeneration gas from the adsorption is sent to a combustion unit (O).

A gas inerting system employs a carbon dioxide separation unit to remove carbon dioxide and water from an oxygen depleted gas stream generated from a catalytic oxidation unit and subsequently provides a nitrogen rich inerting gas to a fuel tank and/or to a cargo hold. A method of producing an inert gas passes an oxygen depleted gas stream from a catalytic oxidation unit through a carbon dioxide separation unit and provides a nitrogen rich inerting gas for fuel tank inerting and/or cargo hold fire suppression.

In a helium purification process, a stream containing at least 10% of helium, at least 10% of nitrogen in addition to hydrogen and methane is separated to form a helium-enriched stream containing hydrogen, a first stream enriched in nitrogen and in methane and a second stream enriched in nitrogen and in methane, the helium-enriched stream is treated to produce a helium-rich product and a residual gas containing water, the residual gas is treated by adsorption (TSA) to remove the water and the regeneration gas from the adsorption is sent to a combustion unit (O).

A process is disclosed for removing nitrous components from a raw liquid nitric acid stream to produce a bleached nitric acid product (55). The raw liquid nitric acid stream (37) is from an absorber (19) of a nitric acid process. The process comprises contacting the raw nitric acid liquid stream with an oxidising gas (12) in a bleaching stage (52). At least some of the gas effluent (12c) from the bleaching stage enters (12d) a combustion stage (15) of the nitric acid process. The oxidising gas (12) entering the bleaching stage (52) may comprise at least about one-third of an oxidising gas feed (12) to the nitric acid process. At least about one-tenth of the bleaching stage gas effluent (12c) may enter (12d) the combustion stage (15).

Systems and methods for purifying a carbon dioxide gas mixture are disclosed. A carbon dioxide purification and in liquefaction unit integrated with an external hydrocarbon dosing system is used to purify a mixture that includes (1) primarily carbon dioxide and (2) other material including an organic chloride and other organic hydrocarbons. The organic chloride in the mixture may be substantially removed via controlling the amount of the organic chloride reacted in the reactor of the carbon dioxide purification and liquefaction unit. The controlling of the organic chloride content is executed by the external hydrocarbon dosing system. The external hydrocarbon dosing system is configured to maintain a temperature of the effluent from the reactor within a predetermined range via controlling the flow rate of the external hydrocarbon into the mixture.

The invention relates to a process for the recovery and recycling of the iodine from aqueous solutions comprising iodine-comprising aromatic compounds in which the iodine contained in said aromatic compounds is directly converted into molecular iodine at a pH lower than 1, in the absence of a catalyst.

A process for removing hydrogen and methanol from a CO2 stream which contains hydrogen and methanol as contaminants, wherein hydrogen and methanol are removed by contacting the CO2 stream with a catalyst which oxidizes hydrogen to water and methanol to carbon dioxide, obtaining a purified CO2 stream.