氢气还原硝酸盐的理论研究.pdf

石油学报(石油加工)
2013年6月
ACTA PETROLEI SINICA (PETROLEUM PROCESSING SECTION)
第29卷第3期
文章编号:1001-8719(2013)03-042706
氢气还原硝酸盐的理论研究
李倩,郭大为,周涵
(中国石化石油化工科学研究院,北京100083)
摘要:从烟气中NO在吸附剂表面形成硝酸盐的事实出发,结合理论计算研究了硝酸盐被还原的微观反应过程
以H2为还原剂、AI(NO3)3为模型化合物,采用密度泛函方法得到的计算结果显示,H2还原AI(NO)。的反应是
分步进行的,H2吸收热量,解离成H·,H·将AI(NO3)3还原为Al(OH)3和NO,然后NO进入气相与H2反应
生成N2。H2解离成H?的反应需要445.43kJ/mol的能量,翻越反应能垒需要586.80kJ/mol,是整个反应的控速
步骤。除H2离解形成H·反应之外的其余步骤均为放热反应。
关键词:氢气;硝酸盐;还原;反应机理
中图分类号:O642.12文献标识码:Adoi:10.3969/j.issn.1001-8719.2013.03.010
Theoretical Study on Hydrogen Reduction of Nitrate
LI Qian, GUO Dawei, ZHOU Han
( Research Institute of Petroleum Processing, SINOPEC, Beijing 100083, China
Abstract: From the fact that the NO, in flue gas was adsorbed on the surface of adsorbents in the
form of nitrate, the micro mechanism of H reduction of nitrate was studied with theoretical
calculations by using density functional method, in which H2 was used as reducing agent, AI(NO)3
as model compound. The results of thermodynamics and dynamics indicated that the procedures o
H2 reduction of nitrate were performed by separated steps. Firstly, the H absorbed heat and
decomposed into hydrogen radical (H ) Then Al (NO% )3 reacted with H. and converted into
Al(OH); and NO. Finally NO was reducted by Ha to N2 in gas strcam. The reaction energy of H2
to H. was 445.43 KJ/mol with the energy barrier of 586.80 KJ/mol, so the conversion of H2 to H
was the key step in the reduction, apart from which the remaining steps were exothermic reactions
Key words: hydrogen; nitrate; reduction; reaction mechanism
近年来,氮氧化物NO2(N2O、NO、NO2等)生的烟气排放占炼油厂总污染气体排放的50%2
的排放量呈整体增长趋势,如果得不到有效控制,随着原料中硫、氮等元素含量的增加,经由FCCU
2030年全球NO排放量将超过1.6亿t。如此大外排的硫化物和氮化物的量也在增加,尤其是经过
的NO2排放量将给公众健康和生态环境带来灾难性FCCU再生烟气外排的硫氧化物SO)(SO。和SO2)
的后果
和氮氧化物NO-(N2O、NO、NO2等)的量逐年增
流化催化裂化装置(FCCU)是炼油厂最重要的加。控制FCCU中NO,排放问题逐渐受到关注,
重质油轻质化的过程之一。FCCU作为核心装置产成为研究热点,其工艺方法的发展已经从最初的单独
收稿日期:2012-05-14
甚金项目;催化裂化烟气同时脱硫脱氮的研究项目(RO8063)资助
第一作者:李情,女,博土研究生,从事分子模拟在石油化工领域中的应用方面的研究;E-mail: Xiaogan0606@126.cor
通讯联系人:周涵,男,教授级高级工程师,博士,从事分子模拟在石油化工领域中的应用方面的研究;Tel:010-82368717;
E-mail:zhouhanripp@sinopec.com