Babcock-hitachi Kabushiki Kaisha

Babcock-hitachi K.k.

Yoshinori Nagai

Yasuyoshi Kato

Takashi Michimoto

Isato Morita

Hiroshi Kuroda

Tomihisa Ishikawa

Masato Mukai

Akihiro Yamada

Masaharu Morii

Hirofumi Kikkawa

Hidehiro Iizuka

Naomi Imada

Toshio Katsube

Eiji Miyamoto

Masatoshi Fujisawa

Kouichi Yokoyama

Naomi Yoshida

Noriko Yoshida

This invention provides a method involving the use of a non-ammonia-based deNOx catalyst for reducing the amount of NOx in exhaust combustion gas discharged from a boiler and an internal-combustion engine, wherein NOx and CO contained in exhaust gas are allowed to selectively react to reduce and remove NOx. This method involves the use of a catalyst comprising a cerium-zirconium composite oxide with Au supported thereon or a catalyst comprising a cerium-oxide-containing porous carrier with zirconium and Au supported thereon. Use of such catalyst enables purification of NOx and CO in exhaust gas and also enables generation of hydrogen.

Method for purifying gas, gas purifying apparatus, and gas purifying catalyst

An apparatus for removing of traces of toxic substances from exhaust gas, comprising, disposed in sequence from the upstream side in a flow channel of exhaust gas emitted from combustion equipment, a denitration unit including a denitration catalyst layer capable of removing nitrogen oxides from the exhaust gas and capable of oxidizing metallic mercury; an air preheater adapted for heat exchange between air for combustion in the combustion equipment and the exhaust gas; a dust removal unit having a bag filter containing a catalyst for metallic mercury oxidation; and a desulfurization unit for removing sulfur oxide from the exhaust gas. The bag filter may be disposed in advance of the desulfurization unit. Thus, there can be provided an apparatus for removing of traces of toxic substances from exhaust gas that is stable over a prolonged period of time and is highly reliable; and provided a method of operating the same.

Apparatus for removing of trace of toxic substance from exhaust gas and method of operating the same

A method is disclosed for producing a NOcatalyst which includes dispersing a hydrated titanium dioxide or dried material, tungstic acid or a salt, and a sol-like material. The sol-like material is formed by dispersing cerium dioxide in a dispersion medium to form a catalyst slurry or paste. Supporting the catalyst slurry or paste is a catalyst carrier.

Production of catalyst for removal of introgen oxides

The catalyst structure of the present invention for purifying an exhaust gas is preferable for increasing the contact of an exhaust gas, to be treated, with a catalyst by disturbing the flow of the exhaust gas in a gas flow passage thereby obtain a highly efficient and compact apparatus for treating the exhaust gas. Such catalyst structure is produced by forming two or more catalyst elements each supporting a catalyst component on its surface and having flat plate portions and level-changing portions formed alternately therein with the angle formed between the flat plate portion and the level-changing portion being in a specific range, and then stacking the catalyst elements in a frame. A catalyst structure is also obtained by stacking a large number of the catalyst elements described above through metallic, ceramic, or glass netlike members interposed therebetween and each having a large number of perforated holes. The catalyst structure has such advantages that dust is hardly deposited between the catalyst elements, that a sufficiently high strength can be obtained even when the thickness of catalyst elements is reduced, and that the catalyst structure can be placed in an exhaust gas flue to use as an exhaust gas treating apparatus. When the exhaust gas treating apparatus is employed, an efficient exhaust gas treatment can be effected without damaging the catalyst elements while repressing the pressure loss.

Exhaust emission control catalyst element, catalyst structure, production method thereof, exhaust emission control apparatus and exhaust emission control method using the apparatus

A catalyst unit is constructed by alternately stacking rectangular catalyst elements (1) formed by cutting catalyst support plates coated with a catalytic material and having ribs (2) inclined at 45.degree. to one specified side edge (1a) of each thereof, and those turned upside down in a case, and the catalyst unit is disposed in a gas passage with the ribs (2) of the catalyst elements (1) inclined at an angle greater than 0.degree. and smaller than 90.degree. to the direction of the gas flow (6). When the catalyst unit comprising the catalyst elements (1) coated with a denitrating catalyst is placed in the gas passage, the ribs (2) of the catalyst elements (1) blocks the gas flow (6) and generate turbulent currents on the downstream side thereof to promote the contact of ammonia and NOx contained in the exhaust gas with the catalyst. When the gas flow (6) is disturbed, the thickness of laminar films covering the surface of the catalyst elements (1) is reduced, so that ammonia and NOx can be easily diffused and the catalytic activity can be enhanced. The catalyst elements exhibits their catalytic abilities effectively without entailing significant pressure loss in the gas flow.

Catalyst unit and gas purifying apparatus

Growing community of inventors

Hiroshima, Japan

Yoshinori Nagai