甲烷对非分散红外吸收法测定固定污染源废气中二氧化硫的干扰  

Study on the Interference of Methane to the Determination of Sulfur Dioxide in Stationary Pollutant Exhaust Gas by Non-dispersive Infrared Absorption Method

作　　者：刘通浩 张守斌[1] 敬红[1] 王军霞[1] 李恒庆 谷树茂 付斌 LIU Tonghao;ZHANG Shoubin;JING Hong;WANG Junxia;LI Hengqing;GU Shumao;FU Bin(State Environmental Protection Key Laboratory of Quality Control in Environmental Monitoring,China Environmental Monitoring Centre,Beijing 100012,China;Shandong Provincial Eco-environment Monitoring Centre,Jinan 250101,China;Beijing SDL Technology Co,Ltd,Beijing 102206,China)

机构地区：[1]中国环境监测总站,国家环境保护环境监测质量控制重点实验室,北京100012 [2]山东省生态环境监测中心,山东济南250101 [3]北京雪迪龙科技股份有限公司,北京102206

出　　处：《中国环境监测》2020年第6期143-149,共7页Environmental Monitoring in China

摘　　要：二氧化硫是中国重点管控的废气污染物。固定污染源废气二氧化硫测定有定电位电解法、非分散红外吸收法、碘量法等,其中非分散红外吸收法具有选择性好、寿命长、灵敏度高等优势,是固定污染源废气二氧化硫测定的常见方法。在波长为7.3μm附近的红外吸收波段,甲烷和二氧化硫的特征吸收峰有明显重叠,造成交叉干扰。实验研究表明:甲烷将对二氧化硫的测定引入5%左右的正干扰。现场验证表明:对于含有高浓度甲烷的焦化废气,非分散红外吸收法测定二氧化硫结果显著偏高,经过数学修正后与其他方法可比。在应用非分散红外吸收法测定二氧化硫时,应确认烟气中不含甲烷或其浓度很低,否则应当采取有效手段消除或减小甲烷的干扰。Sulfur dioxide is a key controlled waste gas pollutant in China.The determination of sulfur dioxide in fixed pollution source exhaust gas includes fixed potential electrolysis method,non-dispersive infrared absorption method and iodine quantity method.The non-dispersive infrared absorption method has the advantages of good selectivity,long life and high sensitivity,which is a common method for the determination of sulfur dioxide in stationary pollution sources.In the infrared absorption band near 7.3 μm,the characteristic absorption peaks of methane and sulfur dioxide overlapped significantly,causing cross interference.Experimental studies show that methane will introduce about 5% positive interference to the determination of sulfur dioxide.Field verification shows that the results of sulfur dioxide determination by non-dispersing infrared absorption method are significantly higher than those of other methods for coking gases containing high concentrations of methane,which will be comparable after mathematical correction.In the application of non-dispersive infrared absorption method in the determination of sulfur dioxide,it is necessary to confirm that there is no methane in the flue gas or the concentration is very low,otherwise effective measures should be taken to eliminate or reduce the interference of methane.

关 键 词：二氧化硫 非分散红外吸收法 甲烷 干扰 

分 类 号：X830.7[环境科学与工程—环境工程]