摘要
柴油机械是羰基化合物的重要排放源,其排放羰基化合物可通过复杂的非均相反应促进二次有机气溶胶的生成,危害人体健康和大气环境。采用生物柴油替代化石柴油可能会有效控制非道路柴油机械污染。但是,目前有关生物柴油机械排放羰基化合物特征的研究十分缺乏。该实验利用便携式采样系统,对比实测了燃烧生物柴油对于农业机械尾气中羰基化合物排放因子、组成、环境效应及其健康效应的影响。结果表明:(1)使用不同比例生物柴油为燃料的农业机械会不同程度地增加羰基化合物的排放量;(2)使用B0、B5和B20为燃料的农业机械排放的羰基化合物组成基本相似。主要为丙醛、乙醛、丙烯醛和丁醛。(3)燃烧B0、B5和B20农业机械排放羰基化合物的臭氧生成潜势分别为6.5±5.0、8.9±6.2和8.1±5.3 g O^(3)/kg。该研究表明,生物柴油替换普通柴油的过程中需重点关注羰基化合物等氧含量高的有机组分。该项研究直观地对于当前热点大气环境问题进行研究和分析,具有较为重要的现实意义。
[Objective]Carbonyl compounds are important precursors of ozone and significantly affect air quality and human health.Diesel vehicles have been identified as a dominant contributor to carbonyl compound emissions.In China,agricultural machines have become an important emission source of off-road mobile pollution because of its increasing number and the backward control of its emission.With worsening atmospheric pollution and depleting petroleum resources,finding alternatives to petroleum is urgent.Biodiesel,mainly referred to as fatty acid methyl ester formed by esterification reactions of vegetable,animal,and waste oils with methanol or ethanol,is regarded as an important clean energy source.In this context,the impact of biodiesel on reducing carbonyl emissions compared with fossil diesel remains unclear,leading to a very large uncertainty in achieving China’s goal of“reducing pollution and carbon”for diesel machinery.[Methods]Therefore,five representative agricultural machines(three tractors and two combine harvesters)fueled with different biodiesel and diesel blends—pure fossil diesel(B0),B5 biodiesel,and B20 biodiesel—were selected in this study to characterize carbonyl compound emissions.Real-world measurements were conducted using a dilution system in a rice field in Gongdao Town,Yangzhou City,Jiangsu Province.A total of 17 carbonyl compounds(formaldehyde,methanol,acetaldehyde,formic acid,acrolein,propionaldehyde,acetic acid,butenone,butyraldehyde,valeraldehyde,ethyl acetate,cyclohexanone,hexaldehyde,benzaldehyde,heptaldehyde,methylbenzaldehyde,and caprylaldehyde)were detected using a proton-transfer reaction time-of-flight mass spectrometer(Ionicon Analytik,Innsbruck,Austria).[Results]Overall,biodiesel-fueled engines exhibited significantly higher carbonyl emission factors than diesel-fueled engines,demonstrating the trend of B5>B20>B0.Average emission factors for B5,B20,and B0 fueled engines were(1.64±1.04),(1.41±0.84),and(1.18±0.76)g/kg fuel,respectively.These results were consistent with emissions from light-duty diesel trucks(LDDTs)but were higher than those from three-and four-wheel rural vehicles and LDDTs.Propionaldehyde,acetic acid,acrolein,and butyraldehyde were the dominant carbonyl species for the tested agricultural machines,accounting for 71.4%,73.2%,and 80.1%of the total carbonyls for B0,B5,and B20,respectively.The ozone formation potential(OFP)of carbonyl was higher for B5-and B20-fueled agricultural machines than those fueled by B0,owing to the biodiesel’s higher oxygen content than diesel.Furthermore,the OFPs for agricultural machines were higher than those for diesel trucks.In addition,cancer risks from carbonyls were the highest for B5,followed by B20 and B0.[Conclusions]In conclusion,different biodiesel blend ratios,engine types,and operation modes affect carbonyl emissions.Although biodiesel is promoted as an alternative fuel in some cities,its impact on carbonyl emission,air quality,and human health should be carefully addressed owing to its higher oxygen content than diesel.
作者
崔敏
刘劲毅
侯筱筱
韩缘欣
张帆
李嘉
CUI Min;LIU Jinyi;HOU Xiaoxiao;HAN Yuanxin;ZHANG Fan;LI Jia(College of Environmental Science and Engineering,Yangzhou University,Yangzhou 225000,China;School of Geographics Sciences,East China Normal University,Shanghai 200062,China)
出处
《实验技术与管理》
CAS
北大核心
2024年第11期52-57,共6页
Experimental Technology and Management
基金
扬州大学教育改革项目(YZUJX2023-C9,YZUJX2023-C10)
扬州大学“青蓝工程”项目(扬大人资[2024]22号)
扬州大学大学生创新创业训练计划项目(XCX20240643)
国家自然科学基金项目(42107105)。
关键词
生物柴油
农业机械
羰基化合物
排放因子
环境效应
biodiesel
agricultural machine
carbonyl compounds
emission factors
environmental impacts
作者简介
崔敏(1989-),女,安徽合肥,博士,副教授,主要研究方向为典型大气污染源排放特征研究,mcui@yzu.edu.cn。;通信作者:李嘉(1990-),男,山东烟台,博士,副教授,主要研究方向为土壤微塑料迁移转化机制研究,lijia3611@yzu.edu.cn。
