Oxidation within the system CCl4/CH4/O2/N2 is studied at atmospheric pressure in a tubular flow reactor to investigate the influence of reaction temperature and chlorine content on chlorinated waste combustion and fin...Oxidation within the system CCl4/CH4/O2/N2 is studied at atmospheric pressure in a tubular flow reactor to investigate the influence of reaction temperature and chlorine content on chlorinated waste combustion and find incineration process optimization methods for pollution control.The reaction temperature varies from 700℃ to 1000℃ and the CCl4/CH4(or Cl/H) mole ratio of the inlet mixture varies from 0.21 to 0.84.Products profiles are measured with FT-IR.It is shown that at the same initial CCl4 concentration and reaction temperature adding CH4 favors CCl4 destruction and CO2 formation.But the destruction and removal efficiency(DRE) of CH4 decreases with lower Cl/H and higher concentrations of toxic products of incomplete combustion such as COCl2 and CH3Cl are formed at the same time.The chlorine in the system favors CH4 decomposition,but it also inhibits further oxidation of CO.Higher temperature assists in both CCl4 destruction and CH4 conversion,and the concentration of toxic combustion intermediates is reduced.Increasing the temperature is the most effective way to enhance CCl4 oxidation.The CO2 concentration increases with temperature.A CO concentration peak is observed around 800℃:with a certain Cl/H,the CO concentration first increases with temperature and then declines.The effect of increasing CH4 concentration on CCl4 destruction becomes mild above 900℃.Rather,it enhances the interaction between chlorine and carbonaceous radicals,which leads to higher concentration of toxic products.展开更多
全氟化物气体(PFCs)中典型的温室气体SF_(6)和CF_(4)在环境中的排放从长远来看对大气温室效应的影响非常大。大气压微波等离子体炬的稳定放电状态提供了适合于气相化学反应的等离子体环境。为此利用大气压微波等离子体炬对SF_(6)和CF_(4...全氟化物气体(PFCs)中典型的温室气体SF_(6)和CF_(4)在环境中的排放从长远来看对大气温室效应的影响非常大。大气压微波等离子体炬的稳定放电状态提供了适合于气相化学反应的等离子体环境。为此利用大气压微波等离子体炬对SF_(6)和CF_(4)的分解和转化进行了研究,考察了通过傅立叶红外吸收光谱(FTIR)定量测量的去除率(destruction and remove efficiency,DRE)随着微波功率、气体体积流量、混合体积分数、反应室的结构等外部控制参数的变化规律。实验表明:通过增加优化化学反应缓冲室的结构参数和设置合适的工作条件可以使两者的去除率接近100%。因此,利用大气压微波等离子体炬针对一些实际工况下SF_(6)和CF_(4)的排放是能够有效控制的,例如,基于大气压微波等离子体技术的车载移动式处理设备,对降解和处理电力工业排放的SF_(6)给出了一种解决方案;采用管线末端处理方式,大气压微波等离子体炬应用于降解半导体工业排放的CF_(4)等尾气是一种具有应用前景的技术。展开更多
文摘Oxidation within the system CCl4/CH4/O2/N2 is studied at atmospheric pressure in a tubular flow reactor to investigate the influence of reaction temperature and chlorine content on chlorinated waste combustion and find incineration process optimization methods for pollution control.The reaction temperature varies from 700℃ to 1000℃ and the CCl4/CH4(or Cl/H) mole ratio of the inlet mixture varies from 0.21 to 0.84.Products profiles are measured with FT-IR.It is shown that at the same initial CCl4 concentration and reaction temperature adding CH4 favors CCl4 destruction and CO2 formation.But the destruction and removal efficiency(DRE) of CH4 decreases with lower Cl/H and higher concentrations of toxic products of incomplete combustion such as COCl2 and CH3Cl are formed at the same time.The chlorine in the system favors CH4 decomposition,but it also inhibits further oxidation of CO.Higher temperature assists in both CCl4 destruction and CH4 conversion,and the concentration of toxic combustion intermediates is reduced.Increasing the temperature is the most effective way to enhance CCl4 oxidation.The CO2 concentration increases with temperature.A CO concentration peak is observed around 800℃:with a certain Cl/H,the CO concentration first increases with temperature and then declines.The effect of increasing CH4 concentration on CCl4 destruction becomes mild above 900℃.Rather,it enhances the interaction between chlorine and carbonaceous radicals,which leads to higher concentration of toxic products.
文摘全氟化物气体(PFCs)中典型的温室气体SF_(6)和CF_(4)在环境中的排放从长远来看对大气温室效应的影响非常大。大气压微波等离子体炬的稳定放电状态提供了适合于气相化学反应的等离子体环境。为此利用大气压微波等离子体炬对SF_(6)和CF_(4)的分解和转化进行了研究,考察了通过傅立叶红外吸收光谱(FTIR)定量测量的去除率(destruction and remove efficiency,DRE)随着微波功率、气体体积流量、混合体积分数、反应室的结构等外部控制参数的变化规律。实验表明:通过增加优化化学反应缓冲室的结构参数和设置合适的工作条件可以使两者的去除率接近100%。因此,利用大气压微波等离子体炬针对一些实际工况下SF_(6)和CF_(4)的排放是能够有效控制的,例如,基于大气压微波等离子体技术的车载移动式处理设备,对降解和处理电力工业排放的SF_(6)给出了一种解决方案;采用管线末端处理方式,大气压微波等离子体炬应用于降解半导体工业排放的CF_(4)等尾气是一种具有应用前景的技术。
