焦炉烟气高效氧化吸收脱硫脱硝一体化中试实验及模拟优化

发布时间：2019-07-10 11:15

【摘要】：焦炉烟道气中含有大量SO_2和NO_x,排放浓度呈周期性变化。本论文采用氧化吸收法对焦炉烟气中SO_2和NO_x同时脱除进行研究,发现氧化剂、工艺条件和催化剂是高效脱硫脱硝一体化的重要影响因素。选择流量为2000 m~3/h(180 oC)的焦炉烟气作为中试试验对象,根据焦炉烟气的特点,设计氧化吸收脱硫脱硝一体化工艺。选择O3和H2O2作为烟气脱硝的氧化剂,氨水为吸收剂,利用实验室自制催化剂提高氧化剂的氧化效率。NO分两阶段被氧化,第一阶段大部分NO被臭氧氧化,剩余的NO被H2O2在第二阶段氧化,氧化产物随烟气进入吸收塔。在吸收塔中,高价态的NO_x和SO_2一起被吸收液吸收,生成硝酸铵和硫酸铵,可作为化肥原料。中试试验发现,当氨水浓度为1 wt.%,液气比为5 L/m~3时SO_2的脱除率达到98%,而NO基本未脱除。采用臭氧氧化脱硝中试过程中发现,臭氧注入量与烟气中NO摩尔比为0.8时,NO的脱除率达到94%;增加臭氧用量,NO脱除率无明显变化;使用自制臭氧增强催化剂后,臭氧和气态水在催化剂表面反应产生羟基自由基,以提高臭氧的氧化效率,当O3:NO(mol:mol)=0.7时,脱硝效率达到85%以上。双氧水氧化脱硝实验中发现,温度是影响双氧水氧化脱硝的重要因素,气态双氧水与液态双氧水相比脱硝效率更高。在烟气温度120 oC,双氧水气态进料同时使用催化剂的条件下,当H2O2与NO的摩尔比为1.5时,氮氧化物脱除率达到31.4%。利用Aspen Plus大型模拟软件对100000 Nm~3/h的烟气进行工艺流程模拟优化,分别考察了烟气温度、氧化剂用量等对SO_2和NO脱除率的影响,为工程应用提供了有力的数据支持。
文内图片：

图片说明：烟气脱硫脱硝一体化工艺流程图
[Abstract]:The flue gas of the coke oven contains a large amount of SO _ 2 and NO _ x, and the emission concentration is periodically changed. In this paper, the simultaneous removal of SO _ 2 and NO _ x in the flue gas of the coke oven was studied by the oxidation-absorption method, and it was found that the oxidizing agent, the process condition and the catalyst were the important factors of the integration of high-efficiency desulfurization and denitrification. The coke oven flue gas with the flow rate of 2000m ~ 3/ h (180oC) is selected as a pilot test object, and the integrated process of oxidation absorption and desulfurization and denitrification is designed according to the characteristics of the coke oven flue gas. And the oxidation efficiency of the oxidizing agent is improved by using the laboratory self-made catalyst as the oxidizing agent and the ammonia water of the flue gas denitration by using the O3 and the H2O2 as the absorbent. The NO is oxidized in two stages, most of the NO in the first stage is oxidized by ozone, the remaining NO is oxidized by H2O2 in the second stage, and the oxidation product enters the absorption tower with the flue gas. In the absorption tower, the high-valence NO _ x and SO _ 2 are absorbed by the absorption liquid to form the ferric nitrate and the sulfur sulfate, and can be used as a chemical fertilizer raw material. The pilot test found that when the ammonia concentration was 1 wt. The removal rate of SO _ 2 is 98% when the gas-to-gas ratio is 5 L/ m ~ 3, and NO is basically not removed. in that experiment of ozone oxidation and denitration, the removal rate of NO is reach 94 percent when the molar ratio of the ozone injection to the NO in the flue gas is 0.8, the amount of the ozone is increased, the NO removal rate is not obviously change, and after the self-made ozone-enhanced catalyst is used, And the ozone and the gaseous water react on the surface of the catalyst to generate hydroxyl radicals so as to improve the oxidation efficiency of the ozone, and when the O3: NO (mol: mol) is 0.7, the denitration efficiency can reach more than 85 percent. In the experiment of hydrogen peroxide oxidation and denitration, the temperature is an important factor which influences the oxidation and denitration of hydrogen peroxide, and the denitration efficiency of the gaseous hydrogen peroxide is higher than that of the liquid hydrogen peroxide. The removal rate of nitrogen oxide is 31.4% when the molar ratio of H2O2 to NO is 1.5 when the temperature of the flue gas is 120oC and the gaseous feed of the hydrogen peroxide is used as the catalyst. The influence of the flue gas temperature and the dosage of the oxidant on the removal rate of SO _ 2 and NO was studied by using the Aspen Plus large-scale simulation software. The effect of the flue gas temperature and the dosage of the oxidizing agent on the removal rate of SO _ 2 and NO was investigated. The data support was provided for the engineering application.
【学位授予单位】：济南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X784

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