Takeda Chemical Industries, Inc.

Rengo Co., Ltd.

Mitsubishi Petrochemical Engineering Co., Ltd.

Kiyoshi Itoga

Toshio Aibe

Fumiichi Ogino

Masanori Tsuji

Hiroshi Nishino

Nobutaka Ninomiya

Yoshio Tsutsumi

Kinichi Shirakawa

Yoshihiro Saitou

Yasuhiro Tomizuka

Yasuyuki Soga

Ayako Tatebayashi

A nitrogen-containing molecular sieving carbon which contains at least 0.1 weight % nitrogen bonded to constituent carbon of the activated carbon. It exhibits improved ability to remove nitrogen oxides compared with the conventional adsorption methods using commercially available activated carbons or other absorbents. Also an economically advantageous system for removing nitrogen oxides is provided which needs no reducing agent such as ammonia, no oxidizing agent such as ozone, or no electrical and physical energy such as electron rays or ultraviolet light in its operation, needs no expensive catalysts, and can be semipermanently operated with regular changes of the relatively low-priced activated carbon.

Nitrogen-containing molecular sieving carbon, a process for preparing

The present invention provides a method for economical recovery of ethylene from ethylene-containing vent gas from a plant for production of ethylene oxide, wherein ethylene is separated from saturated hydrocarbons such as methane, ethane and oxygen and then recovered efficiently. In this method, the vent gas is made to contact with molecular sieve carbon to selectively adsorb ethylene without substantial adsorption of the oxygen contained in the vent gas, the ethylene then being desorbed and recovered.

Method for recovering ethylene from vent gas from ethylene oxide plant

A carbonaceous molecular sieve having micropores with diameters in the range of 4 to 6 Angstrom units and bromine as adsorbed on said carbonaceous molecular sieve is able to remove selectively low molecular weight organic gases such as ethylene, acetylene, methyl sulfide, acetaldehyde etc. from air and other gases containing the same with a reduced tendency toward deactivation with time, and is useful as a removing agent of low molecular weight organic gases.

Agent for the removal of low molecular weight organic gases

A closable container in which is enclosed brominated carbonaceous molecular sieve having micropores within the range of 4 to 6 Angstrom units in diameter and a method for prolonging the shelf-lives of green perishable foods and flowers by the use of said container.

Brominated carbonaceous molecular sieve and method of use therefor

Malodorous gas containing (1) ammonia and/or amines and (2) hydrogen sulfide is deodorized by reacting the gas with oxygen in the presence of activated carbon having supported thereon at least a metal compound selected from the group consisting of vanadium compounds, molybdenum compounds and tungsten compounds.

Method of deodorizing gas containing hydrogen sulfide and ammonia and/or

Nitrogen oxides contained in waste gases can be effectively removed from waste gases by a novel process which comprises contacting the waste gases with activated carbon in the presence of gaseous ammonia at a temperature between about 110.degree. C. and about 350.degree. C. to convert the nitrogen oxides to nitrogen. When waste gases containing sulfur oxides together with nitrogen oxides are subjected to this process, both the nitrogen oxides and the sulfur oxides can be simultaneously removed from the waste gases with a high efficiency. The effects of this process can be enhanced by employing a specific element-supporting activated carbon or an oxidized activated carbon.

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Kawanishi, Japan

Kiyoshi Itoga