HASHIMOTO Mitsuo NIPPON OIL COMPANY LIMITED,CENTRAL RESEARCH LABORATORY,SPECIAL RESEARCHER, 中央研究所, 特別研究員
SATO Masayuki GUNMA UNIVERSITY DEPT.OF BIOLOGICAL AND CHEMICAL EMGINEERIMG,PROFESSOR, 工学部, 教授 (70008473)
|Budget Amount *help
¥12,000,000 (Direct Cost : ¥12,000,000)
Fiscal Year 1997 : ¥3,800,000 (Direct Cost : ¥3,800,000)
Fiscal Year 1996 : ¥8,200,000 (Direct Cost : ¥8,200,000)
In this study, we proposed the novel De-NOx technologies by using the fine water droplets which produced by electrospray method. First one is the enhancement of thermal De-NOx reaction at low temperature by atomization of phenol and/or ammonia solution. We obtained the following results.
(1) By coexisting ammonia with phenol aqueous solution, reduction of NO was proceeded at the range of lower temperature, 650-750ﾟC,but was restrained at the range of higher temperature, 750-850ﾟC.
(2) By injecting phenol/ammonia aqueous solution as droplet by electrospray method, the markedly improvement of NO reduction was confirmed. About 30% of nitrogen monoxide was reduced at 650ﾟC (twice as much as the case of pre-vaporized solution), and about 50% at 700ﾟC in the following condition, NO 388ppm, O2 4%, NH_3400ppm, phenol 102ppm, H_2O6.4%, N_2 balance, residence time 1.5-1.8sec.
(3) As a result of the measurement of CO,CO_2 in outlet gas, we could see more CO concentration at low temperature, 600-650ﾟC.So phenol seems to be decomposed by adding sprayd solutions.
Second, the effects of the atomization of droplets into corona discharge reactor on the NOx reduction were examined and have obtained the following results.
(1) The efficiency of NOx removal was improved via atomization of fine water droplets into the discharge plasma.
(2) Decreasing the mean diameter of droplets, which were injected in the corona discharge, the De-NOx efficiency improved. Especially, we obtained the maximum De-NOx efficiency by using nebulizer.
(3) The effect of pH on the De-NOx efficiency was investigated. The efficiency of De-NOx was improved both side of pH5.0.
(4) NOx reduction was improved by the addition of H_2O_2. The amount of NO reduction was in the case of H_2O_2 was 1.5 times that of water droplets.
(5) The necessary amount of water of this technology are less than that of conventional wet De-NOx process by a factor of about 1/100.