Development of new exhaust gas purification catalyst for a co-generation system

开发用于热电联产系统的新型废气净化催化剂

• 批准号: 16510055
• 负责人: OKAZAKI Noriyasu
• 金额: $ 1.41万
• 依托单位: Kitami Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16510055/
• 关键词: SCR-NO; Methane; Metal oxides; Alumina; Method of using catalyst; Dual beds catalysts; Multi beds catalysts; Carbon speceis of alumia surface; 硫黄不純物; ナトリウム不純物; 酸化チタン

The activity of aluminas for the selective reduction of NO with methane in excess oxygen (CH_4-SCR-NO) was greatly dependent upon their chemical compositions. The selective catalytic reduction of NO proceeds by the successive reactions of(1)NO+1/2O_2→NO_2 and (2)NO_2+HC (hydrocarbon)→ N_2+CO_2+H2_O. In addition to the reactions (1)and (2),undesirable reaction (3)HC+O_2→CO_2+H_2O occurs. In particular, the presence of TiO_2 in some aluminas seems to affect their activity, and so the role of TiO_2 was examined in CH4-SCR-NO and related reactions using pure alumina (ALOA) and TiO_2-doped ALOA. As a result, it was found that the addition of TiO_2 to ALOA promoted the reaction (1)and inhibited effectively the reaction (3). These results will give a good explanation for higher activity of TiO_2-doped ALOA.Carbonaceous deposit produced from C_2H_4 effectively reduced NO to N_2 in the presence of O_2. The presence of NO greatly promoted the conversion of ethene to carbonaceous deposit, which was revealed to contain nitrogen atoms with the N/C atomic ratio of unity. This N-containing carbonaceous deposit reacted with O_2 or suitably a mixture of NO and O_2 to produce N_2. On the other hand, the presence of O_2 greatly suppressed the conversion of C_2H_4 to carbonaceous deposit.The arrangement of an Al_2O_3 catalyst bed and a Co/Al_2O_3 catalyst bed in a row has been shown to be very effective to expand the active temperature region for the reduction of NO. The reverse arrangement or the physical mixture of two catalysts did not widen it. Effectiveness of the dual beds system has been discussed from the viewpoint of oxidation activity of the catalysts.

铝的活性在多余的氧气（CH_4-SCR-NO）中取决于（1）NO+1/ 2O_2→NO_2和（2）NO_2+HC（碳氢化合物）→N_2+CO_2+H2_O。 Tio_2在CH4-SCR Lumina（ALOA）和TIO_2掺杂的ALOA中进行了检查。在O_2的存在下，由C_2H_4产生的Aloa.C_2H_4有效地降低了N_2。另一方面，使用O_2或合适的混合物来产生N_2。有两个催化剂的反向排列或物理混合物从催化剂的氧化性角度讨论了两个催化剂的活性区域。