【作者】 曾浩；

【导师】 靳世平； 李光兴；

【作者基本信息】 华中科技大学 ， 动力工程， 2016， 硕士

【摘要】 挥发性有机物对人体健康、大气环境具有巨大的危害,本文从环保和节能两方面对挥发性有机物的处理进行了研究和探索。首先研究了高效、低温、无二次污染的催化燃烧技术对VOCs气体的处理,然后在此基础上分析了催化燃烧过程中的热力性能,提出了蓄热式催化燃烧放-吸热耦合技术,进一步的提高了能源利用率。本文利用浸渍法制备了单活性组分催化剂MnO/γ-Al₂O₃、双活性组分催化剂CuMnOx/γ-Al₂O₃和复合组分催化剂CuMnOx-CeO₂/γ-Al₂O₃,并考察了三种催化剂对苯、甲苯、二甲苯的催化活性。结果表明:催化剂CuMnOx-CeO₂/γ-Al₂O₃具最好的催化效果,在体积空速为10000h-1,反应物质量浓度为105mg/m³,温度为300℃时,对三种反应物的转化率分别为97.27%、98.30%、98.07%,该工况与实际生产大致相当,本文研制的催化剂可用于工业化推广。本文对催化剂的制备工艺、催化燃烧过程中等温区的寻找、催化剂装填对气路输送的影响进行了分析和探索,对反应物结构、催化剂活性组分对催化燃烧的影响进行了研究,并对催化燃烧的机理进行了初步分析,本文研制的催化剂中助剂CeO₂具有极其优异的储氧能力及较高的氧流动性,MnOx具有较强的再生氧能力,CuO具有较强的催化氧化能力,三者形成的催化剂CuMnOx-CeO₂/γ-Al₂O₃在催化燃烧中各组分优异性能可形成互补,催化效果较为理想。同时本文对催化燃烧过程中“飞温”现象进行了分析,并利用理论计算证实了该现象的科学性,为合理开发、利用该部分的热能提供了理论依据。本文对催化剂的导热系数、比热容等热工参数进行了测定,测试结果表明:研制的三种催化剂的导热系数较小,分别为0.09497 w/（m·k）、0.09130 w/（m·k）、0.10500 w/（m·k）。为避免局部高温造成的催化剂失活等问题,本文采用填充2倍催化剂体积的稀释剂石英砂以增强整体导热性能,同时避免了气路短路。最后本文对催化剂进行了热稳定分析,提出了更加节能的蓄热式催化燃烧放-吸热耦合技术,并以污染物处理浓度为105mg/m³、气体流量为104m³/h、体积空速为10000h-1的实际参数对该计算的节能潜景进行了评估,评估结果表明该技术节能潜景较大,按照年均300天计算,可年均节能6.044′109 kcal,折算经济价值为43.17万元,有较大推广潜景。更多还原

【Abstract】 Volatile organic compounds（VOCs） are not only extremely toxic to human health but also greatly harmful to the atmospheric environment. This article studies the treatment of volatile organic compounds from the aspects of environmental protection and energy efficiency. Firstly, the catalytic combustion technology was studied to deal with the VOCs gas because of its efficiency, low temperature and no secondary pollution. And then the thermal performance of the catalytic combustion process was analyzed, coupling technology of the regenerative combustion and catalytic combustion technology was proposed to increase the energy utilization rate.The single-component catalyst MnO/γ-Al₂O₃, two-component catalyst Cu MnO/γ-Al₂O₃ and multi-component catalyst CuMnOx-CeO₂/γ-Al₂O₃ were prepared with impregnation method. Also, their activity in catalyzing the benzene, toluene and xylene were observed. The results indicated that CuMnOx-CeO₂/ γ-Al₂O₃ was most effective, the conversion rate of benzene, toluene and xylene were 97.27%, 98.30% and 98.07% at the temperature of 300℃, space velocity is 10000h-1 and the reactant’s mass concentration is 105 mg/m³. Such conditions are equivalent to the actual production condition, so the CuMnOx-CeO₂/γ-Al₂O₃ can be applied in industrial production.The research and exploration on the preparing process of catalyst, isothermal region and the influence on the catalytic activity by catalyst loading were carried out. This article also studied the mechanisms for catalytic combustion. CeO₂ has high oxygen storage capacity and oxygen mobility. Moreover, MnOx has high regeneration oxygen capacity, and catalytic oxidation ability of CuO is stronger. A catalyst consisting of these three components has high catalytic activity.In this paper, the phenomenon of runaway in the process of catalytic combustion is analyzed, and the scientificalness of this phenomenon is proved by theoretical calculation, it provided theoretical evidence for recycling energy of the this part. This article mensurated thermal parameters such as thermal conductivity and specific heat of the catalyst. Test results showed that the thermal conductivity of the three catalysts was small, the thermal conductivity of Mno/γ-Al₂O₃ is 0.09497 w/（m·k）, CuMnOx-CeO₂/γ-Al₂O₃ is 0.09130 w/（m·k）, and the thermal conductivity of CuMnOx-CeO₂/γ-Al₂O₃ is 0.10500 w/（m·k）. In order to avoid the catalyst deactivation caused by high temperature, we diluted the catalyst with the double SiO₂, it can also avoid the gas circuit short circuited.Finally, thermo stability of the catalyst was analyzed in this paper. We proposed the new technology coupling of the regenerative combustion and catalytic combustion. Calculation results showed that we can save 0.4317 million a year in energy consumption costs when the pollutant concentration was 105 mg/m³, the gas flow was 104 m³/ h, and the space velocity was 10000h-1. This new technology bears a huge energy conservation potential and relatively great prospect of popularization.更多还原