Mitsubishi Jukogyo Kabushiki Kaisha

Mitsubishi Jidosha Kogyo Kabushiki Kaisha

Satoru Serizawa

Norihisa Kobayashi

Atsushi Morii

Osamu Naito

Kouzo Iida

Toshiyuki Onishi

Yoshiaki Obayashi

Shigeru Nojima

Kozo Iida

Yoshiaki Danno

Shozo Kaneko

Kazuo Koga

Takashi Dogahara

Daisuke Sanbayashi

Shigeyuki Nishijima

Masanori Demoto

Teruko Shimada

Kouza Iida

Toshihiko Imamoto

A method of denitrating an exhaust gas by means of removing nitrogen oxides catalytically using ammonia as a reducing agent while introducing an exhaust gas containing the nitrogen oxides into a reaction vessel packed with a catalyst, comprising:

Methods of denitrating exhaust gases

Disclosed is an ammonia adsorption apparatus for removing ammonia contained in a treated gas discharged from a denitrator for decomposing nitrogen oxides present in exhaust gas using ammonia as a reducing agent, comprising at least two adsorption towers into which ammonia-containing exhaust gas is introduced in a vertical direction for removing the ammonia by adsorption, wherein, during regeneration of each adsorption tower, hot gas used for desorption purposes flows from a top toward a bottom of the adsorption tower and cooling gas flows from the bottom toward the top of the adsorption tower.

Ammonia adsorption apparatus

An exhaust gas purifying apparatus, which is intended to improve hydrocarbon purifying performance and simplify the after-treatment of adsorbed hydrocarbon, an in which a three way valve 51 is operated under the control of a controller 80 to cause a bypass exhaust gas passage 30 to be communicated with a main exhaust gas passage, so that hydrocarbon in exhaust gas is adsorbed onto an adsorption catalyst 40 when the temperature of a three way catalyst 20 in the main exhaust gas passage 13 is low. When the three way catalyst temperature increases, the bypass exhaust gas passage is shut off from the main exhaust gas passage by the three way valve and the adsorption catalyst is heated by a heater 60, so that the adsorbed hydrocarbon is oxidized at the adsorption catalyst to form a harmless substance.

Exhaust gas purifying apparatus

A method for recovering an ammonia adsorbent which comprises streaming an NO.sub.x -containing gas at 300.degree.-600.degree. C. through an ammonia adsorbent layer which adsorbs ammonia and which is saturated with ammonia.

Method for recovering ammonia adsorbent

This invention relates to a catalyst for purifying an exhaust gas, which has a denitrification property in the lean atmosphere and good durability and is hardly deteriorated even in a high temperature rich atmosphere. The feature thereof consists in a catalyst for purifying an exhaust gas, comprising a crystalline silicate having the specified X-ray diffraction pattern and a chemical composition represented by the following chemical formula in the term of mole ratios of oxides under dehydrated state,

Catalyst for purifying an exhaust gas

A method for the denitration of exhaust gas from a gas turbine or an internal combustion engine which comprises (a) reducing a part of the NO.sub.2 constituting NO.sub.x contained in the exhaust gas to NO by means of a reduction catalyst bed for reducing NO.sub.2 to NO, the reduction catalyst bed being installed in flow communication with the exhaust gas outlet of the gas turbine or internal combustion engine, and (b) injecting NH.sub.3 into the exhaust gas within an exhaust heat recovery unit and then decomposing and removing NO.sub.x contained in the exhaust gas and now composed chiefly of NO, by means a denitration catalyst bed installed within the exhaust heat recovery unit to effect the catalytic reduction of NO.sub.x with NH.sub.3.

Method for the denitration of exhaust gas

A method for denitrating an exhaust gas is disclosed which comprises the steps of injecting ammonia from an ammonia injection device into a high-temperature exhaust gas containing nitrogen oxides in a temperature range of 480.degree. C. or more, and then bringing a mixture of ammonia and the high-temperature exhaust gas into contact with a denitration catalyst to reduce the mixture, said method being characterized in that ammonia is injected through the ammonia injection device in which at least an inner surface is subjected to an aluminizing treatment, whereby ammonia is prevented from decomposing; and an apparatus for denitrating an exhaust gas is also disclosed.

Prevention of ammonia decomposition

A denitration catalyst for a high-temperature exhaust gas which is used to catalytically reduce and remove nitrogen oxides in the reaction temperature range of from 500.degree. to 700.degree. C. in the process of adding an ammonia gas to the exhaust gas containing the nitrogen oxides, the aforesaid catalyst being characterized by carrying 0.5 to 10% by weight of cerium in terms of Ce.sub.2 O.sub.3 or 0.5 to 5% by weight of iron in terms of Fe.sub.2 O.sub.3 on a high silica type zeolite in which the molar ratio of SiO.sub.2 /Al.sub.2 O.sub.3 is 20 or more.

Growing community of inventors

Nagasaki, Japan

Satoru Serizawa