Influence of cetane number improver on performance and emissions of a common-rail diesel engine fueled with biodiesel-methanol blend

Abstract

In this paper, the effect of cetane number (CN) improver on performance and emissions, including particulate number concentration and size distribution, of a turbocharged, common-rail diesel engine fueled with biodiesel-methanol were studied. Two volume fractions (0.3% and 0.6%) of CN improver were added to BM30 (30% of methanol in the biodiesel-methanol blend) in the experiment. The results show that, compared with those of biodiesel-methanol blend, the peak value of cylinder pressure increases, the second peak of heat release rate decreases, the start of second heat release are advanced, and the fuel economy and thermal efficiency are improved when CN improver is added to biodiesel-methanol blend. Besides, CO and HC emissions decrease, NO x emission varies little and smoke emissions increase slightly. Moreover, exhaust particles of BM30 mainly distribute in nanosize range. Furthermore, particle number concentration decreases and peak of size distribution profile shifts toward large size direction.

An overview of methanol as an internal combustion engine fuel

“…The addition of oxygen containing compounds to diesel fuel has been proposed as a method to complete the oxidation of carbonaceous particulate matter and associated hydrocarbons. In addition, many oxygenates have high cetane number and their association with diesel results in high cetane number and hence lower CO and HC emissions with little variation in NO x emission [131]. Methanol fuel can be blended with diesel/ isopropyl alcohol in engine.…”

Performance and Emission Improvement of Biodiesel Fueled Diesel Engine with Exhaust Gas Recirculation and Ethyl Hexyl Nitrate Additive

“…Higher cetane fuels will have shorter ignition delay periods than lower cetane fuels in a particular diesel engine [8]. Higher cetane numbers reduced the regulated and unregulated emissions including NO x in addition to the improvement in the engine performance [9][10][11]. Several authors [12][13][14] reported that cetane improver in combination with oxygenates improved engine performance in addition to the reduction in emissions.…”