百万吨级CO_(2)捕集项目亚硝胺污染物扩散健康风险评估

Health risk assessment of nitrosamine pollutant diffusion in a million ton CO_(2) capture project

有机胺排放至大气中的光化学产物包括氨气、醛类、酰胺、亚硝胺等。亚硝胺类具有致癌性,被认为是危害健康的物质,也是有机胺吸收法尾气排放大气的健康风险影响因素。针对胜利电厂200万吨/年CO_(2)捕集工程,采用高斯模型来模拟排放吸收塔尾气扩散,研究亚硝胺随距离的排放浓度。依据美国环境保护署(EPA)健康风险评价方法,核算儿童和成人允许吸收亚硝胺的大气浓度,进行风险水平评估,确定了居民安全防护距离。针对风险控制,提出了削减塔顶亚硝胺的排放强度以及增加尾气的排放高度两种方法,研究结论表明,当亚硝胺的排放强度在吸收塔顶部削减83%时,或尾气的排放高度高于128m时,可接受的致癌风险值达到10^(-6)的水平。

The photochemical products discharged by organic amines to the atmosphere include ammonia,aldehydes,amides,nitrosamines and so on.Nitrosamines have carcinogenicity and are considered as hazardous substances to health,as well as the health risk factors of air exhaust emissions from organic amine absorption process.Aiming at the CO_(2) capture project of 2 million t/a in Shengli Power Plant,gaussian model was used to simulate the exhaust diffusion of emission absorber,and the emission concentration of nitrosamine with distance was studied.According to the American EPA health risk assessment method,the allowable atmospheric concentration of nitrosamines for children and adults was calculated,the risk level was assessed,and the safe protection distance of residents was determined.In view of the risk control,two methods were proposed to reduce the emission intensity of nitrosamine at the top of the tower and increase the emission height of tail gas.The research conclusion showed that when the emission intensity of nitrosamine at the top of the tower was reduced by 83%,or the emission height of tail gas was higher than 128m,the acceptable carcinogenic risk value reached 10^(-6) level.