ABSTRACT

It is crucial to control NO_x emission into the atmosphere because it can make several harmful health and environmental effects. Many techniques are available for NO_x reduction, and among them, selective catalytic reduction (SCR) is one of the most efficient techniques for NO_x removal in flue gas cleaning process. The reduction of NO_x by CO offers a simple and low-cost technology for reducing NO_x emissions from mobile or stationary sources. In this review, NO_x emission, different NO_x control technologies, and the challenges for the SCR process are studied. This paper reviews various types of catalysts, including supported and unsupported metal oxide catalysts as efficient catalysts for NO_x reduction by CO. The reported experimental researches are analyzed to make an overview of the NO_x reduction through CO-SCR process. Moreover, catalytic performances in the presence of oxygen, water steam, and sulfur dioxide, which usually exist in exhaust gases produced in the combustion process, are discussed. Moreover, this paper reviews the possible reaction mechanisms for the CO–SCR.

摘要

这是无法控制的关键_X排放到大气中，因为它可以使一些有害健康和环境的影响。许多技术可用于NO _X还原，并且其中，选择性催化还原（SCR）是一种最有效的技术为NO一个_X在烟道气净化过程的去除。NO的还原_X由CO提供了一种简单和低成本的技术用于减少NO _X从移动或固定排放源。在这篇评论中，NO _x排放，不同的NO _x控制技术，以及SCR过程的挑战。包括支持此各种催化剂，的类型的纸的评价和不支持的金属氧化物催化剂作为NO有效的催化剂_X由CO，还原报道的实验研究进行了分析，使NO的概述_X通过CO-SCR过程减少。此外，还讨论了在燃烧过程中产生的废气中通常存在的氧气，水蒸气和二氧化硫存在下的催化性能。此外，本文回顾了CO–SCR可能的反应机理。