典型燃煤电厂废SCR催化剂解析及环境管理思考

目的提出废烟气脱硝催化剂成分解析、产生量预测及处理处置的对策。方法用ICP方法对烟气选择性催化还原脱硝过程中产生的大量废SCR催化剂化学成分等进行分析。采用数学模型对废SCR产生量进行估算,并在此基础上给出将废SCR催化剂列入危废名单的原因。结果在燃煤电厂装机容量的基础上进行理论推算,我国将从2017年开始大量产生SCR催化剂固体废弃物,并会逐年增加,在2020年以后逐步稳定在25×104~30×104 m3/a。废SCR催化剂中Ti的含量最高,约占23.3%~46.2%。W,V,Mo,Ba是SCR催化剂中的活性组分,并且不同SCR催化剂中活性组分的含量并不相同。钒的含量对废SCR催化剂的潜在判定影响较大。SCR催化剂可能会吸附砷、汞、镉等重金属以及各种飞灰成分等物质,从而增加了废SCR催化剂的化学成分。依据《国家危险废物名录》第二条的相关规定,鉴于废烟气脱硝催化剂不排除具有危险特性,且不处理或处理不当可能对环境或者人体健康造成有害影响。基于此,本研究团队将烟气脱硝过程中产生的废钒钛系催化剂建议纳入危险废物统一管理。结论废SCR催化剂是我国近期出现并将长期存在的一种脱硝危废,尚缺乏符合国情的处理处置经验。为了建设"天蓝、地绿、水清"的美丽中国,需要继续探索可行的废SCR催化剂的监督和管理措施,完善各项标准和法规,最终实现对废SCR催化剂进行有效的监管。

Spent SCR Catalysts and Environmental Management in Typical Coal-fired Power Plant

Objective To propose counter measures for composition analysis, output estimation and disposal methods of spent SCR catalysts. Methods Inductive coupled plasma emission spectrometer (ICP) was used to analyze chemical component of large amount of SCR catalyst generated in spent SCR catalysts. A mathematical model was used to estimate the amount of waste SCR produced, and the reasons for the inclusion of spent SCR catalyst in the hazardous waste lists was given on this basis. Results On the basis of coal-fired power plant installed capacity, from the year of 2017, large amount of spent SCR catalyst solid waste will come in China, and the amount will increase year by year. It will reach 25×104~30×104 m3per year after 2020. Ti was the highest content in the spent SCR catalyst, accounting for 23.3%~46.2%. Wolfram (W), vanadium (V), molybdenum (Mo) and barium (Ba) were active components in catalyst. And the ratio of different element was different in different catalysts. The content of vanadium had great influence on the potential determination of spent SCR catalyst. At the same time, the SCR catalyst might adsorb arsenic (As), mercury (Hg), cadmium (Cd) and other heavy metals, which would increase the chemical composition of the spent SCR catalyst. According to relecant provisions in National Hazardous Waste List, the spent SCR catalysts could not be ruled out from hazardous characteristics, no treatment or improper treatment might have adverse effect on human body and environment. On this basis, it is suggested to put the spent SCR catalysts into the hazardous waste list. Conclusion The spent SCR catalyst is a new kind of hazardous waste which has been present in China and will be long existed. There is no sufficient experience on its treatment. It is needed to explore the feasible monitoring and management measures of spent SCR catalysts, and finally implement effective supervision over the spent SCR catalysts for the aim of beautiful China of "Blue sky, green land and clear water".