Biodiesel Emissions from a Baseline Engine Operated with Different Injection Systems and Exhaust Gas Recirculation (EGR) Strategies during Transient Sequences

Abstract

This work is focused on the measurement and analysis of biodiesel emissions resulting from two commercial diesel engines derived from the same baseline engine. One of the engines was equipped with a rotary fuel injection pump electronically controlled. Another engine was equipped with a common-rail injection system. Both engines were tuned by the manufacturer with diesel fuel, and each of them was optimized with different exhaust gas recirculation (EGR) strategies. Both engines were tested under several transient conditions. A methyl ester obtained from unused sunflower oil was tested as diesel fuel, pure and blended with 30 and 70% of a commercial diesel fuel, which was also used pure. The engines were mounted in a test bench prepared for operating under transient conditions. An AVL 439 smoke meter and an Environnement gas analyzer allowed for the study of the effect of these fuels on the variations of the engine emissions with time. The consideration of the thermochemical properties of the tested fuels and the engine parameters, such as fuel/air ratio or EGR ratio, were used for the analysis of the results. The studied engine transient processes were (a) a load increase at constant engine speed and (b) an engine speed decrease at constant torque. The obtained results proved that the biodiesel effect on pollutant emissions during transient conditions depends upon the fuel injection system and EGR strategy used during the engine tuning.

Effect of Biodiesel on the Performance and Emission Characteristics of Diesel Engines

“…Ghosh et al [31] observed that viscosity of biodiesel varies from 3.5 to 5.5(cSt). Similar results were obtained by Ocatvio and Gomej [17] for sunflower oil. They got results by testing various blends of sunflower oil.…”

“…It produces NOX but is completely free of SOX. It produces less amount of hydrocarbons (HC), CO, PM and CO2 [5,16,17,[19][20][21][22][23][24][25][31][32][33][34][35][36][37][38][39][40][41][42].Wang et al [32] concluded that with increase in blending, NOX emissions also increases. Same Conclusion was given by Leila et al [13].On the other hand, a study tells that other emissions like total Hydrocarbon, Smoke Opacity and PM decreases with blending [43].…”

“…These results could be due to the properties of biodiesel such as higher viscosity [4,17], low cetane number [33], lower heating value [21] etc.…”

“…In transesterification, the oil is converted chemically into its corresponding fatty ester [7]. E Duffy and J. Patrick conducted this test in 1853 and since then, lots of studies have been done on biodiesel till now using different oils like soybean oil [9,10], cotton seed [11][12][13][14], waste cooking oil [40], rapseed oil [14,16], Sunflower oil [14,17], Tyre pyrolysis oil [TPO] [18], Jatropha [7,10,[19][20][21][22][23][24][25][26][27] and many others. A study tells that there are around 300 different kinds of oil seeds, amongst which "Oleander", "Bitter Groundnut" and Kusune are the only vegetable oils which are considered to be a potential alternatives fuel for CI Engines [27].…”

Control Applied to a Reciprocating Internal Combustion Engine Test Bench under Transient Operation: Impact on Engine Performance and Pollutant Emissions

“…In other cases, different EGR and injection strategies have been compared in order to study the effect of biodiesel fuels on performance and emissions of Diesel light-duty engines [12].…”