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Effect of biodiesel on particulate numbers and composition emitted from turbocharged diesel engine
Shah, A. N.; Yun-shan, G.; Shah, F. H.; Mughal, H. U.; Rahman, Z. u. & Naveed, A.
Abstract
In present study a turbocharged, medium duty
compression ignition engine was alternatively fuelled with
biodiesel to investigate the changes in particulate matter
composition, relative to that taken with diesel fuel. The
engine was operated on an AC electrical dynamometer in
accordance with an 8-mode, steady-state cycle. The numbers
of particles were estimated through electrical low
pressure impactor, while sulfates and trace metals were
analyzed by ion chromatography and inductively coupled
plasma-atomic emission spectroscopy, respectively. Nitric
oxides and nitrogen dioxides were measured separately
using SEMTECH-DS. Experimental results revealed that,
on account of elevated ratios of nitrogen dioxide to nitrogen
oxides, mean accumulation mode particles were 42 %
lower with biodiesel. On the other hand, nuclei mode particles
were higher with biodiesel, owing to heterogeneous
nucleation and accounting for an increase in sulfate emissions
up to 8 % with biodiesel as compared to diesel. On the
average, trace metal emissions were significantly reduced
showing 65–85.4 % reduction rates with biodiesel, relative
to its counterpart. Further to this, individual congeners
such as iron, calcium, and sodium were the predominant
elements of the trace metals emitted from engine. The mean
relative decrease in iron and calcium was 89–97.8 and
77.6–87 %, respectively, while the relative rise in sodium
was in the range of 29–46 % with biodiesel. Further, elements
such as zinc, chromium, and aluminum showed
substantial abatement, whereas potassium, magnesium, and
manganese exhibited irregular trends on account of variable
engine loads and speeds during the various modes of cycle.
Keywords
Nanoparticles; Particulate matter; Sulfates; Trace metals; Unregulated emissions
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