Teisan Kabushiki Kaisha

L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des

American Air Liquide, Inc.

Takashi Nagamura

Shinji Tomita

Takao Yamamoto

Naohiko Yamashita

An ultra-high purity nitrogen trifluoride production method comprises: pressurizing a nitrogen trifluoride feed gas, eliminating moisture and carbon dioxide from the feed gas, and cooling down the same feed gas; causing the cooled feed gas to pass through adsorption columns, and introducing it into a medium-pressure rectification column by way of a reboiler in the medium-pressure rectification column, where it is rectified in the medium-pressure rectification column; introducing the resulting gas obtained by this rectification into a middle stage of a low-pressure rectification column, where it is rectified; and taking out ultra-high purity nitrogen trifluoride obtained by virtue of this rectification from the lower part of the low-pressure rectification column.

Ultra-high purity nitrogen trifluoride production method, and unit

An argon recovery and purification process in which the consumption of energy is small because of simple steps, is provided. This process comprises: a first step of reacting impure argon gas with hydrogen gas (H2) so that oxygen (O2) contained in the impure argon gas is converted to water (H2O), thereby substantially removing oxygen (O2) from the impure argon gas; a second step of introducing the impure argon gas into an adsorption unit for adsorbing water (H2O) and carbon dioxide (CO2) contained in the impure argon gas, thereby substantially removing the water (H2O) and carbon dioxide (CO2) from the impure argon gas; and a third step of subjecting the impure argon gas to a low temperature liquefaction and introducing the liquefied argon into a rectification unit for removing low boiling point impurity components and high boiling point impurity components contained in the impure argon gas by purification and separation, thereby obtaining substantially pure argon gas.

Argon purification process

Method and apparatus for preparing high purity hydrogen bromide

Ultra-high purity nitrogen is generated by removing, from feed air, carbon dioxide, moisture and catalyst poisons of an oxidation catalyst contained therein by a decarbonating drier (4). The feed air is then introduced into a low-pressure rectification column (6), where it is roughly rectified to further remove the carbon dioxide, moisture and catalyst poison. Then raw nitrogen gas obtained in the low-pressure rectification column (6) is introduced into an oxidation column (8) so that carbon monoxide in the raw nitrogen gas is converted to carbon dioxide and hydrogen also contained therein to water. Thereafter the raw nitrogen gas is introduced into an adsorption column (10) so that carbon dioxide and water are removed by adsorption to provide feed raw nitrogen gas, which is fed into an intermediate-pressure rectification column (11), where it is rectified. Nitrogen gas from the top portion of the intermediate-pressure rectification column is condensed by a reboiler-condenser (6RC) to provide high purity liquid nitrogen; and the liquid nitrogen is returned to the intermediate-pressure rectification column (11), whereby a part of this high purity liquid nitrogen is used as a reflux liquid and the remaining part thereof is taken out of a rectifying stage that is several stages below the rectifying stage in the top portion of the intermediate-pressure rectification column as an ultra-high purity nitrogen gas product or ultra-high purity liquid nitrogen product.

Ultra-high purity nitrogen generating method and unit

Method of producing ultra high purity monosilane and apparatus therefor

An air separating unit which can jointly produce high purity nitrogen gas and compressed dry air of high quality freed of hydrocarbons such as methane and ethane. The air separating unit is constructed such that compressed dry air freed of hydrogen, carbon monoxide, carbon dioxide and moisture is cooled down near to its liquefying point and introduced into a rectification column (30) and nitrogen gas separated by rectification from the compressed dry air in this rectification column (30) is taken out as a product. The rectifying portion in the rectification column (30) is divided into a lower rectifying portion (34) and an upper rectifying portion (36), and in this lower rectifying portion (34), hydrocarbons such as methane are mainly removed from the compressed dry air, and the compressed dry air which has passed through the lower rectifying portion (34) is taken out as a product.

Air separating unit

Ultra-high purity monosilane producing process and unit

An ultra-high purity nitrogen generating method comprises: feeding feed air to a carbon dioxide eliminator-drier and a primary rectification column, thereby removing catalyst poisons for an oxidation catalyst used for oxidation of carbon monoxide and hydrogen in the feed air by means of the carbon dioxide eliminator-drier and the primary rectification column, condensing and liquefying a part of low purity nitrogen gas separated in the primary rectification column by means of a condenser, warming the raw nitrogen gas which has not been condensed and liquefied in the condenser to normal temperature by means of a heat exchanger and compressing it by a recyclic compressor so that the pressure thereof is increased and the temperature thereof is raised, oxidizing carbon monoxide and hydrogen in an oxidation column and removing the resulting carbon dioxide and water by an adsorption column.

Ultra-high purity nitrogen generating method

Ultra-high purity nitrogen is generated by feeding feed air to a carbon dioxide eliminator-drier and a primary rectification column, thereby removing catalyst poisons for an oxidation catalyst used for oxidation of carbon monoxide and hydrogen in the feed air by the carbon dioxide eliminator-drier and the primary rectification column. A part of low purity nitrogen gas separated in the primary rectification column is condensed and liquefied by a condenser. The raw nitrogen gas which has not been condensed and liquefied in the condenser is warmed to normal temperature by a heat exchanger and compressed by a recyclic compressor so that the pressure thereof is increased and the temperature thereof is raised. Carbon monoxide and hydrogen are oxidized in an oxidation column and the resulting carbon dioxide and water are removed by an adsorption column.

Ultra-high purity nitrogen generator

An ultra-high purity nitrogen generating method is disclosed which comprises: oxidizing feed nitrogen gas containing oxygen added therein so that carbon monoxide in the feed nitrogen gas is converted for removal to carbon dioxide and hydrogen to water; then introducing the feed nitrogen gas to a nitrogen rectification column, and taking out liquid nitrogen containing unreacted oxygen from the lower portion thereof; adding nitrogen gas obtained by gas liquid separation in a gas-liquid separator and containing the unreacted oxygen gas to the feed nitrogen gas, and using a resulting mixture in circulation; taking out high purity nitrogen gas from the top portion of the nitrogen rectification column, condensing in a condenser the taken out high purity nitrogen gas by liquid nitrogen from the gas-liquid separator, refluxing the condensed nitrogen gas to the upper portion of the nitrogen rectification column as a reflux liquid, and taking out ultra-high purity nitrogen gas or ultra-high purity liquid nitrogen. An ultra-high purity nitrogen generator therefor is also provided.

A generator produces ultra-high purity nitrogen and ultra-high purity oxygen simultaneously by the liquefaction and rectification of feed air. Feed air is rectified in a first rectification column, and nitrogen gas separated to the top of that column is liquefied, in a nitrogen condenser, by oxygen-enriched liquid air separated to the bottom portion of the first rectification column. The oxygen-enriched liquid is fed to the upper portion of a second rectification column having a reboiler at its bottom, so that through rectification oxygen gas is fed from above a liquid reservoir to the lower portion of a third rectification column. Through rectification of the oxygen gas in the third rectification column, high purity oxygen gas, from which impurities having boiling points higher than that of oxygen have been removed by liquefaction, is fed to the center portion of a fourth rectification column which has a condenser in its top portion and a reboiler in its bottom portion. Through rectification of the high purity oxygen gas in the fourth rectification column, impurities having boiling points lower than that of oxygen are exhausted from the top portion thereof as non-condensed gas and ultra-high purity liquid oxygen is separated to the bottom thereof.

Ultra-high purity nitrogen and oxygen generator

Air separation by low temperature liquefaction and fractionation wherein feed air is compressed and cooled and supplied to a single stage air separation column from which gaseous nitrogen is removed frown the top and wherein an oxygen-rich liquid is removed from the bottom. The column contains solid material providing solid surfaces on which mass and energy transfer takes place to effect fractionation over a substantial vertical height in the single stage of the column. Liquid is removed from the column intermediate that height, and the removed liquid is subcooled and expanded to produce a gas and a liquid. The liquid is an ultra-high purity nitrogen product, and can be withdrawn from the cycle in liquid or vapor phase. Vapor is removed from the top of the column, cooled and partially condensed and phase separated. Vapor from the last-mentioned phase separation is discharged, thereby to eliminate from the cycle most of the impurities boiling lower than nitrogen. Liquid from the last-mentioned phase separation is returned to the top of the column as reflux.

Method and apparatus for the production of ultra-high purity nitrogen

A method and apparatus for separating air by low temperature liquefaction and fractionation wherein feed air is compressed and cooled and supplied to the high pressure stage of a two-stage fractionation column from the bottom of the high pressure stage of which liquid is expanded and introduced at an intermediate level of the low pressure stage and a gaseous nitrogen product is removed from the top of the high pressure stage of the column, and wherein an oxygen product is removed from the bottom of the low pressure stage and a gaseous nitrogen product is removed from the top of the low pressure stage. Both stages contain solid material providing solid surfaces on which mass transfer takes place to effect fractionation over a substantial vertical distance. The improvement comprises removing a liquid from the high pressure stage intermediate the height of the solid material therein. The removed liquid is subcooled and expanded to produce a gas and a liquid, and the last-named liquid is withdrawn as ultra-high purity nitrogen.

The invention concerns the separation of air with an external cold source. An internal cold source is provided to supply cold heat to a compressed inert gas by expansion of a part of a liquefied inert gas when the cold from the external cold source proves to be insufficient. This part of the liquefied inert gas is combined with recycling and compressed gases. The desired production of liquid oxygen and nitrogen is thus assured in spite of variations in the external cold source.

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Hyogo, Japan

Takashi Nagamura