密闭电石炉尾气中砷化氢催化氧化净化研究

Hydrogen arsenide (AsH3) of airtight calcium carbide furnace tail gas is a harmful gas which can affect the C1 (one carbon) chemical industry. If airtight calcium carbide furnace tail gas can be used as raw material gas to synthesize chemically product，removal of AsH3 are need. Removal of AsH3 under the condition of strong reducing atmosphere has not reported due to the complexity and particularity of airtight calcium carbide furnace tail gas. According to the characteristics of airtight calcium carbide furnace tail gas and the urgent requirement of depth purification of airtight calcium carbide furnace tail gas, the AsH3 can be removed by catalytic oxidation method. The effect of physicochemical characteristics and structure of carrier on activities of catalysts are studied systematically. The process of dearsenization and the distribution of active component are also discussed according to the new reaction system and reaction conditions. Based on these studies，the new composite catalyst at low temperature are developed. At the same time, AsH3 can be removed at strong reducing atmosphere and CO is not adsorbed as well. Meanwhile the mechanism of catalytic oxidation of AsH3 is investigated at strong reducing atmosphere. The project is in line with the national, industry and local needs of waste gas purification control technology currently. The formation of systems theory is beneficial to expand and deepen the connotation of new dearsenization materials, which provide a theoretical and technical approach for studying application of catalytic oxidation of AsH3 and utilization of airtight calcium carbide furnace tail gas.

砷化氢(AsH3)是影响电石炉气资源化利用的有害物质，密闭电石炉尾气若用于一碳化工原料气必须脱除其中的AsH3。由于密闭电石炉尾气组分的复杂性，对在密闭电石炉尾气强还原气氛下AsH3脱除的研究未见报道。本项目根据密闭电石炉尾气特征，结合密闭电石炉尾气深度净化的重大迫切要求，采用催化氧化脱除其中的AsH3，系统研究载体表面物理化学特性、载体结构等对催化剂性能的影响；针对新的反应体系和条件，深入研究脱砷反应过程及活性物质分布对脱砷性能的影响规律；开发新型中低温复合催化剂，解决在不吸附活化密闭电石炉尾气中CO及强还原气氛下，去除AsH3杂质的关键科学问题；并提出强还原气氛条件下的AsH3催化氧化反应机理。项目符合当前国家、行业、地方废气净化控制技术需求，研究形成的系统理论有利于拓展和深化新型脱砷材料的研究内涵，为AsH3催化氧化的研究应用及密闭电石炉尾气的资源化利用提供理论依据和技术方法。

密闭电石炉尾气广泛产生于各基础工业过程，密闭电石炉尾气通常含有高浓度CO高利用价值组分，是潜在的优质工业原料气，但同时含有大量危害环境、腐蚀材料、导致催化剂中毒的砷等杂质。解决密闭电石炉尾气中含砷杂质深度净化及尾气高附加值资源化利用途径方面的关键共性问题，既是实现节能减排国家目标的需要，也是实现环境保护及行业可持续健康发展的必然要求。项目针对典型密闭电石炉尾气中的主要还原性杂质催化氧化净化进行研究，采用催化氧化的方法能够有效的脱砷，整个工艺简捷、高效，开发出催化剂在低温、微氧条件下可去除废气中砷等杂质，经催化氧化净化后的产品气中杂质含量低于1 mg/m3，满足一碳化工原料气要求，经课题组在工业装置上应用检验表明，催化剂使用寿命长、选择性好、抗毒性强。通过课题研究，提出了还原气氛下杂质催化氧化净化新方法，解决了典型还原性复杂组分协同净化的难题，形成了密闭电石炉尾气低温微氧催化氧化净化理论体系，为密闭电石炉尾气净化提供了全新的净化技术，为密闭电石炉尾气资源化及综合利用提供了必要条件。研究成果已在主要的密闭电石炉尾气产生行业实现产业化应用，产生了显著的经济、环境和社会效益，应用领域涵盖有色冶金、磷化工等典型密闭电石炉行业，对相关行业废气净化与资源化、节能减排具有重要借鉴和推动作用。