Emission Analysis of Alternative Diesel Fuels Using a Compression Ignition Benchtop Engine Generator

Abstract

A compact diesel-powered generator (5 kW) experimental setup was used to systematically evaluate the emissions generated by the combustion of several commercially produced alternative diesel fuels. The measured diesel engine exhaust components include oxides of nitrogen (NO x ), carbon monoxide (CO), particulate matter (PM), volatile hydrocarbons (HCs), and carbon dioxide (CO2). Alternative diesel fuels, including biodiesel made from various feedstocks (soy, canola, palm, and tallow) and gas-to-liquid (GTL) diesel fuel, were compared to Texas low-emission diesel (TxLED), a petroleum-based ultra-low sulfur diesel (ULSD), in terms of emissions and fuel consumption. The biodiesel feedstock oil identity is an important variable affecting the level of NO x emissions, because increases were found for soy biodiesel and canola biodiesel, which are the most common feedstocks in the United States and Europe, respectively. At low engine load, NO x emissions increased for all biodiesels when compared to the ULSD, with the soy-based fuel giving the largest increase, followed by canola-based fuel and then tallow-based fuel, with palm-based biodiesel producing the smallest increase in NO x . At high engine load, NO x emissions for biodiesels followed the same relative ranking, but the increases were smaller for biodiesel made from the soy and canola feedstocks and decreases were observed for palm- and tallow-based biodiesel. NO x emissions for the GTL decreased at both low and high load. Emissions of CO and HCs decreased for all alternative diesel fuels at both load points. Quantification of several exhaust HC species was accomplished, with the highest concentrations belonging to ethene, pentane, formaldehyde, and acetaldehyde. Biodiesels produced slightly more CO2 compared to ULSD, while GTL produced slightly less. The small differences in CO2 emissions were attributed to the carbon/hydrogen (C/H) ratio of the fuels and to the conversion of CO, HCs, and PM to CO2. This study provides further evidence that alternative diesel fuels can be used in compression ignition engines designed for conventional diesel without modification and that emission reductions can be achieved in some cases.

Biodiesel from Microalgae, Yeast, and Bacteria: Engine Performance and Exhaust Emissions

“…The comparison of the performance of an engine operated with an alternative fuel is an important tool in evaluating the potential of the fuel to replace the traditional fossil fuel. Using engines equipped with measurement instrumentation such as dynamometers, soybean biodiesel has been established as a suitable replacement for diesel #2. − Here, microbial biodiesels, prepared from oleaginous yeast, bacteria, and microalgae, were tested in a diesel engine coupled to a dynamometer and the performance output for each microbial fuel was compared to that achieved with both soybean biodiesel and diesel #2. The specifications for the engine setup are summarized in Table .…”

“…Biodiesel (FAME) can be a renewable, low CO 2 -footprint replacement for petroleum-derived diesel. The majority of biodiesel used today is derived from oil seed crops, primarily soybeans in the U.S. A number of studies have established the functional properties of biodiesel derived from various sources to determine the potential to displace petroleum diesel. ,,, Based on the volumetric energy density of biodiesel and diesel fuels, power output for biodiesel is expected to be ∼8% lower than for diesel #2, largely due to the oxygen content of biodiesel. In practice the difference in power output can be higher or lower, because of other factors.…”

Investigation of the impact of injection timing and pressure on emissions characteristics and smoke/soot emissions in diesel engine fuelling with soybean fuel

“…Different parameters can affect exhaust gas emissions from the combustion of renewable fuel like the quality and origin of biodiesel, ambient conditions, engine type, and engine operation conditions (speed and load). The present oxygen content in biodiesel was also reviewed by improving engine combustion resulting in lower particulate emissions, CO, THC, and smoke opacity (Bugosh, 2011, Robbins, 2011. In addition, the previous work reported that NO X emissions reduced around 50% with injecting 20% of biodiesel postinjection (Ye, 2013).…”

Emissions from a Diesel Power Generator Fuelled with Biodiesel and Fossil Diesel Fuels

“…Therefore, studies on the environmental impact of diesel generators are rare because they are classified as non-road sources and would be subjected to emission and fuel regulations in the future [17], such as reducing the level of sulphur [18]. For this purpose, the exhaust emissions from diesel generators fueled by different alternative fuels have been investigated by Bugosh et al [19], Pereira et al [20] and Valente et al [21], and different trends have been reported.…”