| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a catalyst capable of efficiently decomposing ureal water into a gas at low temperature and at normal pressure, and to provide an exhaust gas denitrification method and apparatus using the catalyst by which the possibility of producing precipitates such as cyanuric acid even at low temperature. <P>SOLUTION: This decomposing catalyst for urea is the catalyst (1), which mainly consists of an oxide or oxo acid salt of vanadium (V), which reacts with NH<SB>4</SB>VO<SB>3</SB>or NH<SB>3</SB>to produce NH<SB>4</SB>VO<SB>3</SB>, and decomposes the urea in a urea aqueous solution into ammonia (NH<SB>3</SB>) or isocyanic acid (HCNO), or the catalyst (2), which is obtained by adsorbing/depositing NH<SB>4</SB>VO<SB>3</SB>or V<SB>2</SB>O<SB>5</SB>on a porous carrier containing TiO<SB>2</SB>or Al<SB>2</SB>O<SB>3</SB>. In the urea decomposing method, the urea is decomposed by suspending particles of the catalyst (1) or (2) in ureal water and heating catalyst them to the temperature of >100°C to the boiling point of urea. In the exhaust gas denitrification method, NOx in exhaust gas is reduced and removed by supplying the gas containing steam and the substances obtained by decomposing/gasifying urea by the method for decomposing urea to NOx-containing exhaust gas, and bringing the gas-supplied exhaust gas into contact with a catalytic reduction/denitrification catalyst. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
