Researchers from Tianjin University and Xiangfan Da An Automobile Test Center report in a paper in the journal Fuel that while the profiles of total carbonyl compounds (CBCs) emitted by conventional diesel (DF) and Fischer-Tropsch synthetic diesel produced from coal (CFT) show no significant differences, the use of CFT resulted in significant reductions of total and individual CBCs.
Other research has shown that carbonyls directly influence physiological response to diesel exhaust particles and can also contribute to secondary organic aerosol formation. (Jakober, 2008)
In the Tianjin study, they team fueled a four-cylinder light-duty diesel engine fueled with CFT and DF, identifying 13 individual carbonyl compounds in the exhaust. Tests were performed under constant speed/varying load and under constant load/varying speed.
Under the engine operating conditions used, formaldehyde and acetaldehyde were the dominant carbonyl compounds for both test fuels.
There was no significant difference in the profiles of total carbonyl emissions between CFT and DF. However, the use of CFT resulted in a remarkable reduction in carbonyl emissions in comparison with using DF. A 27.2–44.6% reduction in total carbonyls and a 6.0–100% reduction in individual carbonyls in the constant speed/varying load test mode, were observed. In addition, there was an 18.0–35.8% reduction in total carbonyls and a 3.4–100% drop in individual carbonyls in the constant load/varying speed test mode. CFT had 16.5–44.1% lower ozone formation potential of the carbonyl compounds present than DF under the identical operating conditions.—Hao et al.
Bin Hao, Chonglin Song, Gang Lv, Bo Li, Xiaofang Liu, Kan Wang, Yaowu Liu (2014) “Evaluation of the reduction in carbonyl emissions from a diesel engine using Fischer–Tropsch fuel synthesized from coal,” Fuel Vol. 133:115–122, doi: 10.1016/j.fuel.2014.05.025
Chris A. Jakober, Michael A. Robert, Sarah G. Riddle, Hugo Destaillats, M. Judith Charles, Peter G. Green, and Michael J. Kleeman (2008) “Carbonyl Emissions from Gasoline and Diesel Motor Vehicles,” Environmental Science & Technology 42 (13), 4697-4703 doi: 10.1021/es7029174