•Various low-temperature combustion strategies have been discussed briefly.•Effect on emissions has been discussed under low temperature combustion strategies.•Low-temperature combustion reduces NOx ...and PM simultaneously.•Higher CO, HC emissions with lower performance are the demerits of these strategies.•Biodiesels are also potential to attain low temperature combustion conditions.
Simultaneous reduction of particulate matter (PM) and nitrogen oxides (NOx) emissions from diesel exhaust is the key to current research activities. Although various technologies have been introduced to reduce emissions from diesel engines, the in-cylinder reduction techniques of PM and NOx like low temperature combustion (LTC) will continue to be an important field in research and development of modern diesel engines. Furthermore, increasing prices and question over the availability of diesel fuel derived from crude oil have introduced a growing interest. Hence it is most likely that future diesel engines will be operated on pure biodiesel and/or blends of biodiesel and crude oil-based diesel. Being a significant technology to reduce emissions, LTC deserves a critical analysis of emission characteristics for both diesel and biodiesel.
This paper critically investigates both petroleum diesel and biodiesel emissions from the view point of LTC attaining strategies. Due to a number of differences of physical and chemical properties, petroleum diesel and biodiesel emission characteristics differ a bit under LTC strategies. LTC strategies decrease NOx and PM simultaneously but increase HC and CO emissions. Recent attempts to attain LTC by biodiesel have created a hope for reduced HC and CO emissions. Decreased performance issue during LTC is also being taken care of by latest ideas. However, this paper highlights the emissions separately and analyzes the effects of significant factors thoroughly under LTC regime.
•Environmental benefits of JB blends were found but adverse impact on NOx.•Addition of 0.15% (m) DPPD in JB20, average reduction in NO up to 16.54%.•In some cases, engine power is reduced with DPPD ...additive.•Emissions of HC and CO for JB blends with DPPD were lower compared to diesel.•Addition of DPPD in JB blends reduction of EGT was found.
Energy requirements are increasing rapidly due to fast industrialization and the increased number of vehicles on the road. The use of biodiesel in diesel engines instead of diesel results in the proven reduction of harmful exhaust emissions. However, most researchers have reported that they produce higher NOx emissions compared to diesel, which is a deterrent to the expansion of the market for these fuels. Several proposed pathways try to account for NOx formation during the combustion process. Among them, the Fenimore mechanism explains that fuel radicals formed during the combustion process react with nitrogen from the air to form NOx. It could be proposed that if these radical reactions could be terminated, the NOx formation rate for biodiesel combustion would decrease. An experimental study was conducted on a four-cylinder diesel engine to evaluate the performance and emission characteristics of Jatropha biodiesel blends (JB5, JB10, JB15 and JB20) with and without the addition of N,N′-diphenyl-1,4-phenylenediamine (DPPD) antioxidant. For each tested fuel, the engine performance and emissions were measured at engine speeds 1000–4000rpm at an interval of 500rpm under the full throttle condition. The results showed that this antioxidant additive could reduce NOx emissions significantly with a slight penalty in terms of engine power and Brake Specific Fuel Consumption (BSFC) as well as CO and HC emissions. However, when compared to diesel combustion, the emissions of HC and CO with the addition of the DPPD additive were found to be nearly the same or lower. By the addition of 0.15% (m) DPPD additive in JB5, JB10, JB15 and JB20, the reduction in NOx emissions were 8.03%, 3.503%, 13.65% and 16.54% respectively, compared to biodiesel blends without the additive under the full throttle condition. Moreover, the addition of DPPD additive to all biodiesel blend samples reduced the exhaust gas temperature.
•Potential of biodiesel production from crude Moringa oleifera oil.•Characterization of M. oleifera biodiesel and its blend with diesel fuel.•Evaluation of M. oleifera biodiesel blend in a diesel ...engine.
Researchers have recently attempted to discover alternative energy sources that are accessible, technically viable, economically feasible, and environmentally acceptable. This study aims to evaluate the physico-chemical properties of Moringa oleifera biodiesel and its 10% and 20% by-volume blends (B10 and B20) in comparison with diesel fuel (B0). The performance and emission of M. oleifera biodiesel and its blends in a multi-cylinder diesel engine were determined at various speeds and full load conditions. The properties of M. oleifera biodiesel and its blends complied with ASTM D6751 standards. Over the entire range of speeds, B10 and B20 fuels reduced brake power and increased brake specific fuel consumption compared with B0. In engine emissions, B10 and B20 fuels reduced carbon monoxide emission by 10.60% and 22.93% as well as hydrocarbon emission by 9.21% and 23.68%, but slightly increased nitric oxide emission by 8.46% and 18.56%, respectively, compared with B0. Therefore, M. oleifera is a potential feedstock for biodiesel production, and its blends B10 and B20 can be used as diesel fuel substitutes.
•The attempt was to improve palm and jatropha biodiesel–diesel blends with additives.•Ethanol, n-butanol and diethyl ether were used as additives.•Diethyl ether gave almost 4.5% increment of brake ...power with 3.5% increment of BTE.•Ethanol gave up to 40% decrement of CO and 8% decrement of NO.•Diethyl ether, n-butanol improved performance and emission, ethanol only improved emission.
In recent years, palm and jatropha biodiesels have been considered as potential renewable energy sources in Malaysia. Therefore, this experimental investigation was conducted to improve the blend of these two biodiesels (20% biodiesel blend, named P20 and J20, respectively) with the help of oxygenated additives. The comparative improvement of P20 and J20 blends with ethanol, n-butanol, or diethyl ether as additives was evaluated in terms of performance and emissions characteristics of a four-stroke single cylinder diesel engine. The final blend consisted of 80% diesel, 15% biodiesel, and 5% additive. Tests were conducted at different speeds (1200–2400rpm) at constant full load conditions. Use of additives significantly improved brake power and brake thermal efficiency (BTE). Compared with P20 blend, the use of diethyl ether as additive increased brake power and BTE by about 4.10% and 4.4%, respectively, at 2200rpm. A similar improvement was observed for J20. The other two additives also improved performance. Although HC emission increased slightly, all blends with additives reduced more NOx and CO emissions than P20 and J20 almost throughout the entire engine test. The use of ethanol as additive reduced CO emission by up to 40%, while the use of diethyl ether as additive reduced NOx emissions by up to 13%. The additives’ oxygen content, volatility, and latent evaporation heat controlled the emissions characteristics of the blends. An analysis of the combustion chamber pressure, temperature and heat release rate of the modified blends revealed interesting features of combustion mechanism, which are indicative of the performance and emissions characteristics. This experiment reveals the potential improvement of palm and jatropha biodiesel blends with the addition of three promising additives.
•Viability of oxygenated additives to improve jatropha biodiesel–diesel blend.•Performance, emission and combustion analysis at different conditions.•Physicochemical properties of the blends improved ...with the additives.•10% additive blends performed better than 5% additive blends.•Diethyl ether performed better than n-butanol regarding engine performance.
Jatropha biodiesel is considered as one of the most prospective renewable energy sources of Malaysia in recent years. Hence, an investigation was conducted for the improvement of jatropha biodiesel–diesel blend with the addition of 5–10% n-butanol and diethyl ether by vol. which are commonly known as oxygenated cold starting additive. Engine tests were conducted at variable speed, ranging from 1000rpm to 3000rpm at constant 80Nm torque on a 4-cylinder turbocharged indirect injection diesel engine. Engine performance parameters like brake specific fuel consumption, brake specific energy consumption, brake thermal efficiency and engine emissions like carbon monoxide, unburned hydrocarbons, nitrogen oxide and smoke opacity were measured. Performance and exhaust emissions variation of the modified blends from the baseline fuel (jatropha biodiesel–diesel blend) were compared for the assessment of the improvement quantitatively. In-cylinder pressure diagram of all the test fuels were acquired and the heat release rate analysis was conducted at different operating conditions to explore the features of combustion mechanism and correlate them with the performance and emission characteristics to acquire better understanding of the scenario. However, in a nut-shell, the investigation reveals the potential of n-butanol and diethyl ether to be used as the additive of jatropha biodiesel–diesel blend in the context of combustion, performance and emission characteristics.
The energy security concern has been established as an alarming issue in context of petro diplomacy now-a-days. Global warming with rapid changes in climate, increase in price and depletion in ...reserve of fossil fuel are leading scientists to work toward alternative fuel. Biodiesel could be an answer for the alternative fuel, which is renewable, biodegradable, non-toxic and less polluting. This paper is comprised of fuel properties, engine performance and emission characteristics of commonly used different vegetable (jatropha, palm, coconut, cottonseed, sunflower, soybean and canola/rapeseed) based biodiesel derived from experimental results at different conditions performed worldwide. It can introduce a potential guideline to improve engine performance and emission characteristics using different biodiesels and their blends as well. This paper provides a comparative baseline to make an easy comparison among the biodiesels in respect of fuel properties, engine performance and emission characteristics.
•Properties limitation of biodiesel has been overcome using multiple biodiesel blends.•New biodiesel was developed using biodiesel–biodiesel optimum blend.•Engine performance and emission was tested ...with the newly developed biodiesels.•New biodiesels showed better engine performance than other tested fuels.
Fossil fuel depletion, global warming with rapid changes in climate, and increases in oil prices have motivated scientists to search for alternative fuel. Biodiesel can be an effective solution despite some limitations, such as poor fuel properties and engine performance. From this perspective, experiments were carried out to improve fuel properties and engine performance by using a binary blend of palm and coconut biodiesel at an optimized ratio. MATLAB optimization tool was used to determine this blend ratio. A new biodiesel was developed and represented by PC (optimum blend of palm and coconut biodiesel). Engine performance and emission were tested under a full load at variable speed condition by using a 20% blend of each biodiesel with petroleum diesel, and the results were compared with petroleum diesel under both turbocharged and non-turbocharged conditions. PC20 (blend of 20% PC biodiesel and 80% petroleum diesel) showed the highest engine power with lower brake-specific fuel consumption than the other tested fuels in the presence of a turbocharger. The emissions of PC20 were lower than those of all other tested fuels. The experimental analysis reveals that PC showed superior performance and emission over palm biodiesel blend.
Crude oil price hikes, energy security concerns and environmental drivers have turned the focus to alternative fuels. Gas to liquid (GTL) diesel is regarded as a promising alternative diesel fuel, ...considering the adeptness to use directly as a diesel fuel or in blends with petroleum-derived diesel or bio-diesel. GTL fuel derived from Fischer–Tropsch synthesis is of distinctly different characteristics than fossil diesel fuel due to its paraffinic nature, virtually zero sulfur, low aromatic contents and very high cetane number. GTL fuel is referred to as a “clean fuel” for its inherent ability to reduce engine exhaust emission even with blends of diesel and bio-diesel.
This paper illustrates feasibility of GTL fuel in context of comparative fuel properties with conventional diesel and bio-diesels. This review also describes the technical attributes of GTL and its blends with diesel and bio-diesel focusing their impact on engine performance and emission characteristics on the basis of the previous research works. It can introduce an efficacious guideline to devise several blends of alternative fuels, further the development of engine performance and constrain exhaust emission to cope with the relentless efforts to manufacture efficient and environment friendly powertrains.
Depletion and environmental impacts of the fossil fuel are the major concerns to think about the alternative energy sources to reduce the load on petroleum fuel. Researchers worldwide are working ...years to improve the biodiesel fuel economy and emission characteristic. At the same time, they are working on fuel development so that can be used in the IC engine without significant modification in vehicle design. Among different alternative fuels biodiesel as well as hydroxyl gas (HHO, also known as Oxyhydrogen gas) are renewable, recyclable and non-polluting fuel. In this study, HHO gas has been introduced with ordinary diesel (OD) and 20% (v/v) palm biodiesel blended with OD (PB20) for evaluating the engine performance and emission characteristics. Optimum yield of HHO was found using single anode and two cathodes from a solution containing 1% KOH and 100 ml of water producing 2150 cc of HHO gas when electrolysis was carried out for 15 min. Using the HHO generator, about 2% more power and 5% less consumption was observed for biodiesel blended fuel in a single cylinder CI engine at full load variable speed operating conditions. Besides, on an average 20% and 10% reduction of CO and HC emission were observed respectively.
•HHO gas production investigated varying different parameter of the designed electrolyzer.•Optimum yield was investigated at 1% KOH, 3E (50 mm) arrangement.•Performance, emission on IC engine was investigated with PB20, OD + HHO and PB20 + HHO.•20% and 10% reduction of CO and HC emission were obtained in this investigation.
•Production of biodiesel and comparative fuel properties analysis of all fuels.•Combined blend of biodiesel, GTL and diesel was introduced with comparative analysis.•Combustion analysis of blends ...CI20, G20 and DCIG20 were discussed.•Analysis of engine performance–emission characteristics for all fuel blends.•DCIG20 showed improvement than CI20, but G20 was the best of all.
This study investigates of the production of calophyllum biodiesel (CIBD) from its crude oil and provides a comparative analysis of the blends of CIBD (CI20) and GTL fuel (G20) with diesel, including a combined blend (DCIG20) of CIBD, GTL and diesel, in the context of fuel properties, combustion, engine performance and emission characteristics. This combined blend was selected to aggregate the promising properties of the two alternative fuels, which is a pioneer investigation that involves GTL fuel. All of the blends were investigated in a four cylinder compression ignition engine. CIBD and CI20 showed improved fuel properties than their crude oil, and DCIG20 and G20 showed promising properties compared with the biodiesel blend. Combustion analysis showed that the peaks of both in-cylinder pressure and heat release rate (HRR) of G20 were slightly lower and occurred at later crank angles than those of diesel. Unlike G20, the other two blends demonstrated higher peak values of in-cylinder pressure and HRR than diesel, and DCIG20 showed lower peak values than CI20 in both cases. The peak locations of CI20 and DCIG20 were slightly advanced compared to those of diesel. The engine performance test results revealed an increase in brake thermal efficiency (BTE), and low Brake Specific Fuel Consumption (BSFC) and Brake Specific Energy Consumption (BSEC) in G20. The two other blends showed a decrease in BTE, but an increase in both BSFC and BSEC, when compared with diesel. Emission analysis results showed that all fuel blends exhibited a reduction in CO, HC and smoke emissions compared with diesel. In the case of NOx emission, both CI20 and DCIG20 showed high values, but G20 showed a significant decrease, when compared with diesel. DCIG20 exhibited an improvement in all of the performance–emission test parameters compared with CI20.
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