共查询到19条相似文献,搜索用时 62 毫秒
1.
2.
3.
根据沧州大化稀硝酸装置的具体情况和工艺特点,选择用催化还原法进行尾气处理,以实现排放达标。简要介绍了催化还原法的特点及应用情况,对选择性催化还原法和非选择性催化还原性进行了详细介绍,在此基础上沧州大化采用氨选择性催化还原法处理工艺,大大降低了尾气中NOx的含量,保证最终排放达标。 相似文献
4.
5.
6.
介绍了几种硝酸尾气处理技术的反应原理、工艺描述及其主要优缺点,包括吸附法、吸收法以及催化法等,对各种硝酸尾气处理技术进行了综合比较,并以表格的形式列举了国内硝酸尾气处理技术的应用实例及其治理效果。 相似文献
7.
硝酸尾气治理的改进 总被引:1,自引:0,他引:1
中国石油兰州石化公司化肥厂硝酸生产装置 ,年生产能力为 1 2 0 kt浓硝酸和 2 0 0 kt稀硝酸(折百 )。自投产以来 ,硝酸尾气一直被列为兰州地区大气重点污染源。为此 ,该厂结合实际情况 ,于 1 980年建成了 SCR法 (即氨选择性催化还原法 )处理装置 ,使硝酸尾气得以较好的治理。随着经济发展的需要和环保综合治理的要求 ,1 993年又建成了碱吸收法处理装置副产硝酸钠与亚硝酸钠 (以下简称两钠装置 ) ,不但较好地治理了硝酸尾气 ,而且取得了一定的经济效益。SCR法硝酸尾气治理效果见表 1 ,两钠装置尾气治理效果见表 2。本文提出进一步治理措施… 相似文献
8.
9.
<正> 硝酸是4大强酸之一,也是基本化学工业中重要产品之一,用于制造肥料、炸药及作为有机化工产品的原料。但是自70年代后期开始,西方发达国家已经不再投产新的硝酸装置,其主要原因是因为硝酸生产的腐蚀性强,其排放的废水、废气对环境的污染较大。在我国随着国家和人民对环境保护的重要性认识越来越深刻,现有硝酸装置的改造和污染治理已被提上历史日程,综合法的硝 相似文献
10.
硝酸尾气治理机理探讨与治理方法 总被引:3,自引:0,他引:3
曾祥根 《化学工业与工程技术》2004,25(6):45-47
从硝酸装置中氮氧化物吸收反应机理出发,探讨了降低氮氧化物的途径和措施,提出了降低硝酸尾气的根本途径是变末端控制为清洁生产控制。对4种硝酸尾气治理方法进行了评价。 相似文献
11.
针对硝酸装置存在的问题,选择氨催化还原工艺,进行工艺流程设计与改造,取得开车一次成功,尾气中NO2排放浓度由800mg/m^3降至100mg/m^3以下,达到排放标准。 相似文献
12.
THE SELECTIVE CATALYTIC REDUCTION OF NITRIC OXIDE WITH METHANE OVER NONZEOLITIC CATALYSTS 总被引:2,自引:0,他引:2
This article deals with recent progress in the development of nonzeolitic catalysts for the selective catalytic reduction (SCR) of nitrogen oxides (NOx) with methane. Although metal-exchanged zeolitic catalysts exhibit high activities for this reaction, most of these metastable structures suffer from deactivation problems when exposed to wet exhaust streams at elevated temperatures. Nonzeolitic oxide catalysts have the potential for improved durability because many of these are thermodynamically stable structures.
The NOx reduction activity and poisoning resistance of lanthanide oxides, Group IIA oxides, Group IIIB oxides, as well as gallium-, tin-, and palladium-based catalysts are reviewed. Current opinions on mechanistic aspects of the SCR reaction are discussed in relation to the development of more active catalytic systems.
A detailed experimental study of the SCR of NOx over rare earth oxides has also been performed. The role of absorbed oxygen in the activation of CH4 and consumption of CH3 radicals is discussed and related to the catalytic properties of the rare earth oxides. The presence of highly basic centers is shown to promote catalytic activity, and the presence of weakly absorbed oxygen species is found to be detrimental to catalytic selectivity. Oxides with lower electronic conductivities are found to be more selective than catalysts with higher conductivities. The selectivities of rare earth oxides for the SCR of NOx with methane and the oxidative coupling of methane are also compared and contrasted. 相似文献
The NOx reduction activity and poisoning resistance of lanthanide oxides, Group IIA oxides, Group IIIB oxides, as well as gallium-, tin-, and palladium-based catalysts are reviewed. Current opinions on mechanistic aspects of the SCR reaction are discussed in relation to the development of more active catalytic systems.
A detailed experimental study of the SCR of NOx over rare earth oxides has also been performed. The role of absorbed oxygen in the activation of CH4 and consumption of CH3 radicals is discussed and related to the catalytic properties of the rare earth oxides. The presence of highly basic centers is shown to promote catalytic activity, and the presence of weakly absorbed oxygen species is found to be detrimental to catalytic selectivity. Oxides with lower electronic conductivities are found to be more selective than catalysts with higher conductivities. The selectivities of rare earth oxides for the SCR of NOx with methane and the oxidative coupling of methane are also compared and contrasted. 相似文献
13.
新的烯烃聚合反应技术已经和现代藏金属催化剂的研究与开发紧密相关,并成为世界科学爱研究的热点。本文较为系统地介绍了流化床超冷凝技术,流化床中高沸点的液态单体聚合技术,均相催化剂无载体化聚合技术以及超临界流体聚合技术,这些新技术为茂金属催化剂的开发和应用提供了各种先进的手段。西方还介绍了国内部分研究开发工作的现状。 相似文献
14.
15.
16.
17.
18.
19.
在原有废水处理设施的基础上,对原有水处理工艺进行了改造,强化了预处理过程,采用UASB+CASS工艺处理乳酸生产废水,在进水COD为3 256 mg/L、BOD5为1 320 mg/L、SS和NH3-N的质量浓度分别为635、31 mg/L时,出水水质稳定,COD为98mg/L、BOD5为26mg/L、SS和NH3-N的质量浓度分别为75和22mg/L,达到GB8978-1996表4中规定的二级要求,去除率分别可达到97.0%、98.0%、88.2%和29.05%。该项工程可为类似高含量有机废水的处理提供参考。 相似文献