多针—板脉冲放电反应器结构优化及降解甲醛的研究

发布时间：2017-12-30 20:35

本文关键词：多针—板脉冲放电反应器结构优化及降解甲醛的研究　出处：《江西理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：近年来,以甲醛为代表的挥发性有机物(Volatile Organic Compounds,VOCs)严重危害着人们的身心健康和居住环境。逐步发展起来的脉冲放电协同催化技术在降解甲醛的应用中显示出了效率高、副产物少、运行稳定等优势,且相关研究日趋深入,但如何对脉冲放电反应器进行结构优化,从而提高放电能量的利用率,需要进一步深入研究。本文对多针-板高压脉冲放电反应器结构优化及降解甲醛作了深入的实验研究。实验采用自制的多针-板高压脉冲电晕放电反应器,通过研究反应器在不同电极结构下的放电特性优化了其电极配置(针板间距、针针间距),在优化的电极配置下,进一步考察了电极配置、电参数(脉冲峰值电压、重复频率)、气体参数(气体流量、进气方向)对脉冲放电能量注入及甲醛降解变化规律的影响。并采用优化后的反应器,深入研究了脉冲电晕放电协同过渡金属(Mn、Fe、Cu)、贵金属(Ag)催化剂对甲醛降解率、O3产量、CO2选择性和能量效率的影响,探讨了甲醛的降解机理。研究结果表明:(1)脉冲放电经历了不稳定放电、稳定电晕放电、放电受阻三个基本过程;多针电极结构与单针电极相比,起晕电压低,火花击穿电压高,放电稳定性较好;(2)针板间距为20mm,针针间距为20mm时脉冲放电的单脉冲注入能量达到最大,且最大脉冲注入功率密度达到极值;当脉冲峰值电压为17k V,重复频率为40Hz,气体流量为0.3L/min且反向进气时,单独电晕放电降解甲醛的效果达到本实验条件下最佳,甲醛降解率和能量效率分别为86.1%,3.19g/(k W·h)。(3)脉冲电晕放电协同Mn-Ti、Fe-Ti、Cu-Ti催化剂时,其降解顺序为Mn-TiCu-TiFe-Ti无催化剂,其中Mn-Ti催化剂协同效果较好,相比无催化剂时,甲醛降解率和能量效率分别为92.6%和3.51 g/(k W·h),O3产量由175 mg/m3下降至50mg/m3,CO2选择性由22%上升至38%;相比Mn-Ti催化剂而言,Ag-Mn-Ti催化剂进一步改善和提高了甲醛降解效果,且光催化协同效果达到本实验条件下最佳,甲醛降解率和能量效率依次为98.6%、3.65g/(k W·h),O3产量为35mg/m3,CO2选择性达48%。通过实验优化了多针-板高压脉冲电晕放电反应器的各项配置参数,并采用优化后的反应器协同不同催化剂对甲醛进行降解研究,为脉冲放电协同催化剂降解工业废气的实际应用提供一定的理论参考。
[Abstract]:In recent years, volatile organic compounds (VOCs), such as formaldehyde, are volatile Organic Compounds. VOCs) seriously endanger people's physical and mental health and living environment. The application of pulse discharge synergistic catalysis technology in the degradation of formaldehyde has shown the advantages of high efficiency, less by-products, stable operation and so on. But how to optimize the structure of pulsed discharge reactor to improve the utilization of discharge energy. In this paper, the structure optimization and degradation of formaldehyde in a multi-needle plate high-pressure pulse discharge reactor were studied. The self-made high-voltage pulse corona discharge reactor was used in the experiment. The electrode configuration (needle plate spacing, needle needle spacing) was optimized by studying the discharge characteristics of the reactor under different electrode structures. Under the optimized electrode configuration, the electrode configuration was further investigated. The effects of electrical parameters (pulse peak voltage, repetition rate, gas flow rate, inlet direction) on the energy injection of pulse discharge and the degradation of formaldehyde were studied. The optimized reactor was used. The effects of pulse corona discharge (PCD) and transition metal (Mn-Mn-Fe-Cu), noble metal (Ag) catalyst on the CO _ 2 selectivity and energy efficiency of O _ 3 / O _ 3 yield in formaldehyde degradation rate were studied. The degradation mechanism of formaldehyde is discussed. The results show that the pulse discharge has three basic processes: unstable discharge, stable corona discharge and blocked discharge. Compared with single needle electrode, the structure of multi-needle electrode has lower halo voltage, higher spark breakdown voltage and better discharge stability. (2) the maximum single pulse injection energy and maximum pulse injection power density are obtained when the spacing of needle and needle is 20mm and 20mm respectively. When the pulse peak voltage is 17 kV, the repetition rate is 40 Hz, the gas flow rate is 0.3 L / min and the reverse inlet, the effect of single corona discharge on formaldehyde degradation is the best in this experiment. The degradation rate and energy efficiency of formaldehyde were 86.1% and 3.19 g / kg 路kW 路h ~ (-1) ~ (3) pulse corona discharge combined with Mn-Ti-Fe-Ti-Cu-Ti catalyst. The degradation order was Mn-TiCu-TiFe-Ti without catalyst, and the synergistic effect of Mn-Ti catalyst was better than that without catalyst. The degradation rate and energy efficiency of formaldehyde were 92.6% and 3.51 g / h respectively, and the yield of O _ 3 decreased from 175 mg/m3 to 50 mg / m ~ 3. The selectivity of CO2 increased from 22% to 38. Compared with Mn-Ti catalyst, Ag-Mn-Ti catalyst further improved the degradation efficiency of formaldehyde, and the photocatalytic synergistic effect reached the best in this experiment. The degradation rate and energy efficiency of formaldehyde were 98.6% and 3.65g / kg 路hmm3, respectively. The yield of O _ 3 was 35mg / m ~ 3. The selectivity of CO2 is up to 48. The configuration parameters of multi-needle plate high pressure pulse corona discharge reactor are optimized, and the degradation of formaldehyde is studied by the optimized reactor and different catalysts. It provides a theoretical reference for the practical application of pulsed discharge co-catalyst in the degradation of industrial waste gas.
【学位授予单位】：江西理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X51;O646.7

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