In the case of cold-starting of diesel engine under low-temperature condition, exhaust odor increases due to the worsening of engine starting performance. The main components of the odor are thought to be aldehydes and organic acids. As for the organic acids, its emission characteristics during cold-starting is not fully understood, thus we focused on measurement of organic acids. Organic acids contained in diesel exhaust were collected using a sorbent tube from a gas sampling line. Suitable sorbent tube for the organic acids measurement was selected through evaluation of recovery rate. In addition, improvement of the recovery rate by phosphoric acid treatment of sorbent tube was investigated, and around 80 ~ 85% recovery rate for formic and acetic acids were confirmed. Temporal variations in formic acid and acetic acid concentrations during engine warm-up under low-temperature condition were clarified.
SHIMAZAKI et al. (2025) studied this question.