分级氧化尿素还原吸收去除高浓度氮氧化物实验研究

发布时间：2018-03-15 19:44

本文选题：高浓度NOx　切入点：分级氧化　出处：《湘潭大学》2015年硕士论文　论文类型：学位论文

【摘要】：目前NOx渐渐取代SO2成为大气污染最主要的污染物,对其进行治理迫在眉睫,现有的高浓度NOx废气治理技术都有不足,难以达标排放,需要技术创新。本文针对高浓度NOx废气的净化,设计了分级氧化尿素还原吸收的净化方案,并进行了小试、放大实验和中试研究。首先以鼓泡吸收器为吸收装置,模拟某石化企业生产催化剂产生的高浓度NOx废气进行了小试研究,NOx浓度100000 mg/m3,NO/NO2的体积比为2,实验结果表明,分级氧化尿素还原吸收工艺基本能够满足NOx达标排放,经过第一级氧化NOx出口浓度为2100 mg/m3左右,经过第二级氧化NOx出口浓度为300 mg/m3,第三级氧化最终出口浓度为100 mg/m3左右。随后在内径φ100 mm的有机玻璃筛板塔中进行了放大实验,筛板开口率为7.65%,分三个吸收段。并进一步深入讨论分级氧化阶段,氧化罐中停留时间与氧化度的关系,停留时间对吸收塔内吸收段脱硝效率的影响,尿素浓度、液气比对NOx去除率的影响。实验结果表明,氧化度越大所需停留时间越长,在一级氧化罐中停留时间为150s,第二、三级氧化罐中停留时间为4min,尿素吸收液浓度为10%,塔内液气比为3.5 L/m3时,吸收塔内脱硝效率可达99.87%,最终出口浓度可达到100 mg/m3左右。最后,在小试和放大实验的基础上在某催化剂企业现场开展中试实验研究,以该催化剂企业生产废气为烟气,自制吸收装置,以尿素为吸收液,调节空塔气速、氧化剂浓度、循环水、吸收液浓度等实验条件,得出本中试装置最佳实验条件为,空塔气速0.016m/s、O3/NOx为0.17、尿素浓度20%时,本吸收装置可达最佳吸收效果,出口NOx为100 mg/m3左右。本文通过小试、放大、中试实验研究了分级氧化处理浓度高达100000 mg/m3的NOx(NO/NO2=2)的性能,NOx出口浓度为100 mg/m3,满足我国最新NOx排放标准,是可行的新工艺。
[Abstract]:At present, NOx is gradually replacing SO2 as the most important pollutant in air pollution. It is urgent to treat it. The existing treatment technology of high concentration NOx exhaust gas is insufficient, and it is difficult to meet the emission standard. Technology innovation is needed. In this paper, the purification scheme of redox absorption of NOx waste gas with high concentration is designed, and small scale experiment, scale up experiment and pilot-scale study are carried out. Firstly, bubbling absorber is used as absorber. The volume ratio of 100000 mg / m ~ (3) no ~ (2) O _ (2) to 100000 mg / m ~ (3) O _ (3) no _ (2) in high concentration NOx waste gas produced by a petrochemical plant was simulated. The experimental results showed that the stepwise redox urea reduction absorption process could basically meet the standard of NOx emission. After the first oxidation of NOx was about 2100 mg/m3, after the second stage of oxidation the outlet concentration of NOx was 300 mg / m 3, the final outlet concentration of the third stage of oxidation was about 100 mg/m3. Then the amplification experiments were carried out in the inner diameter 蠁 100mm column of organic glass sieve plate. The opening rate of sieve plate is 7.65, which is divided into three absorption sections. The relationship between residence time and oxidation degree in oxidation tank, the effect of residence time on denitrification efficiency of absorption section in absorption tower, urea concentration, urea concentration are discussed. The experimental results show that the longer the residence time is, the longer the residence time in the primary oxidation tank is 150 s. When the residence time is 4 minutes, the concentration of urea absorbent is 10 and the ratio of liquid to gas is 3.5 L / m ~ 3, the denitrification efficiency can reach 99.87 and the final outlet concentration is about 100 mg/m3. On the basis of small scale test and scale up experiment, a pilot experiment was carried out in a catalyst enterprise. The waste gas produced by the catalyst enterprise was used as flue gas, the absorption device was made by oneself and urea was used as the absorbent liquid to adjust the air velocity, the concentration of oxidant and the circulating water. The optimum experimental conditions are as follows: the gas velocity of the empty tower is 0.016 m / s / s O _ 3 / no _ x = 0.17, and the concentration of urea is 20%, the best absorption effect can be achieved, and the NOx at the outlet is about 100 mg/m3. In this paper, the gas velocity of the empty tower is 0.016 m / s / s O _ 3 / no _ x = 0.17, and the outlet NOx is about 100 mg/m3. The performance of no _ x / no _ 2 / no _ 2 / no _ 2 / no _ 2 / no _ 2 / no _ x / no _ 2O _ (2) treated by staged oxidation with concentration up to 100000 mg/m3 was studied in a pilot scale.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X701

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