Effect of biodiesel on particulate numbers and composition emitted from turbocharged diesel engine

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.

Chemical Composition of Diesel/Biodiesel Particulate Exhaust by FTIR Spectroscopy and Mass Spectrometry: Impact of Fuel and Driving Cycle

“…They appear as nitrogenized CN -, C 3 N -, C 5 N -, CNO -, and NO 2 -fragments. Fly ash in exhaust contains mostly transition and alkali earth metals and water-soluble ions produced by inorganic contaminations in lubricating oil and engine wear (Oanh et al, 2010;Popovicheva et al, 2014a;Shah et al, 2014 , which are commonly assigned to pollution of diesel emission (Popovicheva et al, 2014a, b), are observed at relatively small concentrations due to low sulfate abundance in the conventional diesel fuel EN 590 used.…”

“…The growing concern about their environmental impact and health hazard in urban areas has resulted in the development of modern combustion engines that emit less particulate matter (PM). Concurrently, alternative fuels, such as vegetable oil-based biofuels (referred to as biodiesel), tend to be used in modern combustion engines (Agarwal, 2007;Giakoumis et al, 2012) in an attempt to further lessen soot particles emission and the concentration of unburned hydrocarbons (HC) and carbon monoxide (CO) released in engine exhausts (Dwivedi et al, 2006;Jung et al, 2006;Betha and Balasubramanian, 2011;Shah et al, 2014).…”

Role of Biodiesel-Diesel Blends in Alteration of Particulate Matter Emanated by Diesel Engine

“…In order to collect the exhaust for the estimation of sub-50 nm and over-50 nm aerosoles, 2 tandem ejector diluters each with a dilution ratio of almost 8:1 were arranged in series, first at 200 °C and then at ambient temperature. The exhaust was then passed through an ELPI (Dekati, Finland) having a corona charger, an electrometer, and a cascade (Shah et al, 2014). A sampling pump was used to provide flow, while the flow rate was controlled by a controller at about 10 L/min.…”

“…Biodiesel-diesel blends B20 and B50 have been used to gain a deep insight into the biodiesel role in above discussed emissions. Earlier, authors (Shah et al, 2014) have reported that accumulation mode particles, total TME, and individual elements such as iron and calcium are greatly reduced, while nuclei mode particles and sodium are increased with neat biodiesel (B100). In addition to this, it has also been pointed out that sulphates are slightly, only 8%, increased with B100 as compared to petroleum diesel.…”

“…Moreover, smoke opacity and other unregulated emissions comprising aldehyde and ketones, polycyclic aromatic hydrocarbons (PAHs), and volatile organic compounds (VOCs) are also decreased with this alternative fuel (Shah et al, 2009b;Shah et al, 2008;Jha et al, 2008;Lin et al, 2006). However, oxides of nitrogen (NO´) and nuclei mode particles have been reported to be increased with biodiesel (Shah et al, 2014;Shah et al, 2009aShah et al, , 2009bKarabektas et al, 2008;Szybist et al, 2007;Usta, 2005).…”