Mitsubishi Jukogyo Kabushiki Kaisha

Mitsubishi Jukogyo Kaisha

Toshiyuki Onishi

Atsushi Morii

Osamu Naito

Satoru Serizawa

Kouzo Iida

Shigeyuki Nishijima

Hitoshi Nakamura

Norihisa Kobayashi

Shozo Kaneko

Masanori Demoto

Teruko Shimada

Toshihiko Imamoto

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

The object of the present invention is to provide a device to make flow uniform in a denitrification system, which can achieve a predetermined flow regulation effect with low pressure loss independently of the gas flow rate. According to the present invention, the device installed on the upstream side of a chemical injection means for the denitrification system is composed of at least one perforated plate 11, and the perforated plate 11 can be turned by a rotating shaft 10 or 10a from the closed position where the gas flow path is closed to the open position where the gas flow path is opened or vice versa.

Denitrification system

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

A method for treating ammonia in an exhaust gas on the downstream side of a dry denitration device using ammonia as a reducing agent comprises the step of alternately carrying out ammonia adsorption and ammonia desorption/decomposition to continuously treat ammonia in the exhaust gas in a plurality of constitutional units parallelly connected on an exhaust gas line, the aforesaid constitutional units being constituted so as to carry out the steps of adsorbing/removing ammonia in an ammonia adsorbent-filling tower disposed at a position, where an exhaust gas temperature is 200.degree. C. or less, on the downstream side of the dry denitration device; heating, up to a temperature of 300.degree. C. or more, the ammonia adsorbent-filling tower on which ammonia is adsorbed in a saturated state, to desorb ammonia; and decomposing ammonia in an ammonia decomposition catalyst-filling tower disposed on a desorption ammonia gas line.

Method for treating ammonia

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.

Growing community of inventors

Nagasaki, Japan

Toshiyuki Onishi