Journal of the Graduate School of Biosphere Science, Hiroshima University Volume 50
2011-12-24 発行

自動車および焼却炉排ガス中の有機酸濃度の測定と発生量の見積り

Concentrations of organic acids in automobile and incinerator exhaust gases and their emission rates into the atmosphere
Miyake, Takayuki
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abstract
The concentrations of organic acids (formic, acetic, propionic and oxalic acids) were measured in automobile and incinerator exhaust gases, which are one of major sources of atmospheric organic acids. The mean concentrations of formic, acetic, propionic and oxalic acids in the exhaust gases of gasoline-powered vehicles (seven automobile models) were 59.7, 327, 12.1 and 0.77ppbv (parts per billion by volume), respectively. The organic acid concentrations in exhaust gases from one diesel-powered automobile model and two motorcycle models were higher than those from the gasoline-powered vehicles. The acetic acid concentrations in the exhaust gases from the motorcycles were particularly high at >10ppmv (parts per million by volume). The type of fuel, engine, and purification system of the exhaust gas probably determine the concentrations of organic acids in the exhaust gas. The concentrations of organic acids in exhaust gas from an incinerator at the Higashi-Hiroshima campus of Hiroshima University (Japan) were similar to those in the exhaust gas from gasoline-powered vehicles. The concentration ratios of formic, acetic and oxalic acids in automobile exhaust gas were compared with those of atmospheric organic acids, precipitation, and dew. The organic acid concentration ratios in automobile exhaust gas were more similar to those in dew and the atmosphere than those in precipitation. Based on the organic acid concentrations in the automobile exhaust gases, the annual emission rates from all automobiles in Japan were estimated to 3.0×109, 5.3×109, 4.6×108 and 7.9×107g yr-1 for formic, acetic, propionic and oxalic acids, respectively, The percentage contributions of formic and acetic acids from automobile exhaust gas to the acid concentrations in the atmosphere were estimated to 41% and 18%, respectively, using carbon monoxide as an indicator of automobile exhaust gas.
description
本研究は,科学技術振興事業団(JST,現科学技術振興機構),戦略的基礎研究推進事業(CREST),環境低負荷型の社会システムより支援を受けて行われた。また文部科学省科学研究費補助金(研究課題番号14380244)および日産科学振興財団からも助成を受けたものである。
subject
自動車排ガス
焼却炉排ガス
年間発生量
有機酸
有機酸濃度比
annual emission rate
automobile exhaust gas
incinerator exhaust gas
organic acids
organic acids concentration ratio