| 燃煤电厂产生和排放的PM2.5中水溶性离子特征 |
| 摘要点击 2825 全文点击 1392 投稿时间：2014-12-26 修订日期：2015-01-28 |
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| 中文关键词 燃煤电厂 PM2.5 水溶性离子 煤粉炉 循环流化床 |
| 英文关键词 coal-fired power plant PM2.5 water-soluble ions pulverized coal boiler circulating fluidized bed |
| 作者 | 单位 | E-mail | | 马子轸 | 成都信息工程学院资源环境学院, 大气环境模拟与污染控制四川省高校重点实验室, 成都 610225 | sweety12315@126.com | | 李振 | 清华大学环境学院, 国家环境保护大气复合污染来源与控制重点实验室, 北京 100084 | | | 蒋靖坤 | 清华大学环境学院, 国家环境保护大气复合污染来源与控制重点实验室, 北京 100084 | | | 叶芝祥 | 成都信息工程学院资源环境学院, 大气环境模拟与污染控制四川省高校重点实验室, 成都 610225 | | | 邓建国 | 清华大学环境学院, 国家环境保护大气复合污染来源与控制重点实验室, 北京 100084 | | | 段雷 | 清华大学环境学院, 国家环境保护大气复合污染来源与控制重点实验室, 北京 100084 | lduan@tsinghua.edu.cn |
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| 中文摘要 |
| 为了认识我国燃煤电厂一次PM2.5排放特征,并定量评估大规模开展烟气脱硫与脱硝对其影响,本研究选取了国内一个煤粉炉电厂和一个循环流化床电厂,对其产生和排放的PM2.5进行现场测试,并进行水溶性离子组分的分析. 结果表明,在所测的这两个电厂中,循环流化床电厂产生的PM2.5的质量浓度高于煤粉炉电厂产生的PM2.5的质量浓度,但是这两个电厂排放的PM2.5的质量浓度相当. 产生此结果的主要原因是该循环流化床电厂配备的电袋复合除尘器比煤粉炉电厂的普通电除尘器对PM2.5去除效率更高. 煤粉炉电厂产生PM2.5中水溶性离子浓度低于循环流化床电厂,但是煤粉炉电厂排放PM2.5中水溶性离子浓度却远远高于循环流化床电厂,表明煤粉炉电厂排放的PM2.5受脱硫和脱硝设施的影响较大. 煤粉炉烟气脱硝过程中可能形成硫酸雾,烟气中的部分硫酸雾和过剩的NH3反应生成NH4HSO4进入颗粒相,同时降低了PM2.5的pH值; 而脱硫过程中脱硫液的夹带也会导致NH4+和SO42-进入PM2.5. 所以,虽然两个电厂产生的PM2.5中水溶性离子均以Ca2+和SO42-为主,但煤粉炉排放PM2.5中的水溶性离子则以NH4+和SO42-为主. |
| 英文摘要 |
| To characterize the primary PM2.5 emission from coal-fired power plants in China, and to quantitatively evaluate the effects of flue gas denitrification and desulfurization on PM2.5 emission, a pulverized coal fired (PC) power plant and a circulating fluidized bed (CFB) plant were selected for measuring the mass concentration and water-soluble ion composition of PM2.5 in flue gas. The results showed that the mass concentration of PM2.5 generated from the CFB was much higher than that from the PC, while the mass concentrations of PM2.5 emitted from these two plants were very similar, because the CFB was equipped with an electrostatic-bag precipitator (EBP) with higher PM2.5 removal efficiency than the common electrostatic precipitator (ESP). Although the total concentration of water-soluble ions in PM2.5 generated from the PC was lower than that from the CFB, the total concentration of water-soluble ions in PM2.5 emitted from the PC was much higher than that from the CFB, which implied that PM2.5 emission from the PC was greatly affected by the flue gas treatment installations. For example, the flue gas denitrification system produced H2SO4 mist, part of which reacted with the excessive NH3 in the flue gas to form NH4HSO4 in PM2.5 and to increase the acidity of PM2.5. In addition, the escaping of desulfurization solution during the flue gas desulfurization process could also introduce NH4+ and SO42- into PM2.5. Therefore, although the main water-soluble ions in PM2.5 generated from both of the plants were Ca2+ and SO42-, the major cation was changed to NH4+ when emitted from PC. |
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