【作者】 黄鹏；

【导师】 蒋翔； 彭元芳；

【作者基本信息】 华南理工大学 ， 化学工程（专业学位）， 2018， 硕士

【摘要】 我国工业的迅猛发展伴随着工业挥发性有机废气（VOCs）的排放量不断增加。空气中过量的有机气体对环境和人体有诸多危害,开发一种节能高效的有机废气处理技术对环境保护和国民健康有着重要意义。目前众多的有机废气净化技术中,催化燃烧法具有工艺流程简单、净化彻底等特点,受到广泛应用和关注。催化剂的催化活性以及经济性是催化燃烧技术能否应用于实际的关键因素,同时传统加热方式存在升温慢、床层受热不均匀的问题,这也制约了催化燃烧技术的进一步应用。MnO₂因其特殊的孔道结构以及廉价易得的特性受到广泛研究,但是纯商业MnO₂存在起燃温度高、活性较低的问题。针对这些问题,本文采用传统水热氧化还原法制备催化活性较高的α-MnO₂,通过向其中掺杂碱金属Mg,研究Mg掺杂对二氧化锰结构以及活性的影响,进一步采用微波加热的方式考察微波对MnO₂催化性能的影响。以广州市某汽车零配件企业废气处理项目为依托验证微波辅助MnO₂催化对废气的处理效果,主要内容如下:（1）Mg掺杂对MnO₂催化性能的影响。通过水热法合成Mg掺杂α-MnO₂,发现适量Mg掺杂能够促进反应过程中MnO₂的结晶成型,显著提高α-MnO₂的比表面积以及催化活性。掺杂量从0%提升至30%过程中,比表面积先增加后下降,样品10Mg/α-MnO₂比表面积最高,达到110.2m²/g,是0Mg/α-Mn O₂的2.28倍。在催化甲苯实验中,Mg掺杂α-MnO₂表现出更加优异的催化活性,其中催化活性最高的10Mg/α-MnO₂相比0Mg/α-Mn O₂的T₁₀₀降低50℃,同时10Mg/α-MnO₂的热稳定性能更好。（2）微波对MnO₂催化活性的影响。相比于传统电阻管式炉加热,微波具有加热快、能耗低的特点,微波具有其非热效应,能够有效降低二氧化锰甲苯的起燃温度和完全转化温度。相比电阻炉加热,微波加热下0Mg/α-Mn O₂T₁₀和T₁₀₀分别降低21℃、20℃,10Mg/α-Mn O₂的T₁₀和T₁₀₀分别降低32℃、18℃。同时微波加热时催化剂的热稳定性要明显优于电阻炉加热。（3）以广州市某汽车零配件生产企业废气处理项目为依托,验证微波辅助二氧化锰催化技术是否能有效处理工业排放有机废气。确定并分析了该公司的废气处理方案,对废气处理设备进行设计选型。经实际工程运行表明,微波辅助二氧化锰催化法能够实现对有机废气的有效降解,稳定运行后能保持对甲苯和二甲苯90%以上的去除率,非甲烷总烃的去除率也能达到90%以上,排放浓度远低于广东省地方标准。设备日均运行维护费用约为338元,用户满意度较高。表明微波辅助二氧化锰催化技术是一种经济有效的催化处理技术,具备较高的推广应用价值。更多还原

【Abstract】 The rapid development of our country’s industry is accompanied by the rising emissions of industrial volatile organic compounds（VOCs）.Excessive organic gases in the air have many hazards to the environment and the human body.Developing an energy-saving and efficient VOCs treatment technology is of great significance to environmental protection and national health.At present,catalytic combustion technology is being widely used and concerned due to its characteristic of simple process and Purification thoroughly.The catalytic activity and economy of the catalyst are the key factors which influence the catalytic combustion technique applied to engineering.At the same time,the traditional heating methods have the problems of slow heating and uneven heating of the bed,which limits the further application of the catalytic combustion technique.MnO₂ has been extensively studied for its special pore structure and cheap and easy-to-obtain properties,but pure commercial MnO₂ has the problems of high light-off temperature and low activity.In response to these problems,this paper prepared higher catalytic activityα-MnO₂ by traditional hydrothermal oxidation reduction and studed the effect of Mg doping on the structure and activity of manganese dioxide,further studied the effect of microwave heating on the catalytic performance of MnO₂.Taking Guangzhou Auto Parts Enterprise as an Example to Verify the Effect of Microwave Assisted MnO₂ Catalysis on VOCs Treatment.The main research contents are as follows:（1）Effect of Mg Doping on the Catalytic Performance of MnO₂.Mg-dopedα-MnO₂were synthesised by hydrothermal method,The results show that Mg doping can promote the crystallization of MnO₂ during the reaction and increase the specific surface area and catalytic activity ofα-MnO2 significantly.Specific surface area of Mg-dopedα-Mn O₂ increase at first and then descend with the doping amount increasing from 0 to 30%.The specific surface area of the sample 10Mg/α-MnO₂ was the highest,reaching 110.2m²/g,which was 2.28 times of0Mg/α-Mn O2.In the catalytic toluene experiment,Mg-doped/α-MnO₂ showed more excellent catalytic activity than pureα-MnO₂,The complete conversion temperature(T₁₀₀)of 10Mg/α-MnO₂ is reduced by 50℃compared to 0Mg/α-MnO₂ and the Thermal stability of 10Mg/α-MnO₂ is better than pureα-MnO₂.（2）Effect of Microwave on MnO₂ Catalytic Activity.Compared with the traditional resistance tube furnace heating,microwave heating with fast,low energy consumption characteristics,and Microwave has its non-thermal effect,can effectively reduce the catalyst on the toluene light-off temperature and complete conversion temperature.Compared with the heating in the resistance furnace,Light-off temperature(T₁₀)and complete conversion temperature(T₁₀₀)of 0Mg/α-MnO₂ decreased by 21℃and 20℃,respectively.10Mg/α-MnO₂ decreased by 32℃and 18℃respectively under microwave heating.At the same time,the thermal stability of the catalyst when microwave heating is obviously better than the resistance furnace heating.（3）Taking an auto parts manufacturers VOCs treatment project as an example to verify whether microwave assisted manganese dioxide catalyst technology can effectively purify industrial emissions of organic waste gas.Determined and analyzed the company’s VOCs treatment program,And the VOCs purification equipment was further designed and selected.The actual engineering operation shows that the microwave assisted manganese dioxide catalyst can effectively degrade the organic waste gas,and can keep 90%of the removal rate of toluene and xylene after stable operation,and the removal rate of non-methane total hydrocarbons can reach 90%,Emission concentration is far lower than the local standards in Guangdong Province.The average daily operation and maintenance costs of equipment is about 338 yuan and has high user satisfaction.It was shown that microwave assisted manganese dioxide catalyst technology is a cost-effective catalytic treatment technology,with a high value of popularization and application.更多还原