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South East Asian cities such as Kuala Lumpur, Jakarta and Bangkok rely heavily on motorcycles. A huge number of urban residents depend on motorcycles for all types of activities such as working, ridehailing and delivery services, going to school or leisure. According to Malaysia Automotive Association (MMA) statistics, there are about 13 million registered motorcycles in Malaysia as of August 2017. The pollutants that a four-stroke-engine 50 cc motorcycle emits per kilometre are usually much higher than a 2-litre passenger car; 2.7 times higher for CO and 6.7 times higher for HC and NOX. Controlling excessive air pollution and emissions levels generated by the use of a motorcycle is one of the keys to improving air quality. Electric two-wheelers have been well adopted in Asia Pacific countries like China and Taiwan. This paper provides extensive review and analysis on development history, environmental and mobility impacts, challenge and limitation of electric two-wheelers from around the world and the potential of its emergence in Malaysia.

This study focuses on a feasibility study of alternative nonedible crude oil such as jatropha and used cooking oil in biodiesel production. Crude jatropha oil (CJO) and used cooking oil (UCO) were converted to biodiesel using a two-step transesterification process with presents of acid-based and alkaline-based catalysts. Each three biodiesel blends (B5, B15 and B25) have been produced by blended with conventional diesel fuel (CDF). Determination of the fuel properties for each blend including CDF, Jatropha Methyl Ester (JME) and Used Cooking Oil Methyl Ester (UCOME) have been carried out. The average yield for jatropha and used cooking oil biodiesels production was 94.3% and 92% respectively. The increment of the percentage of JME or UCOME in its blends is proportional to fuels physical properties such as density, specific gravity, kinematic viscosity and surface tension, however inversely proportional to fuels calorific value. Based on the results of this study, it is acceptable to conclude that non-edible CJO and UCO are viable alternatives to edible oil as feedstock to renewable fuel in order to reduce the greenhouse gases produced.

In recent years, electric two-wheelers are emerging as one of the alternatives to improve the sustainability of transportation energy and air quality, especially in urban areas. Although electric two-wheeler motorcycles are environmentally friendly, they underperform compared with gasoline two-wheelers in many respects, particularly in speed and cruise distance between refuelling and recharging. Therefore, the engine development program can be done with a dynamometer. Variables such as the shape of torque and power curves can be analyzed. Hence, this project is aimed to develop a chassis dynamometer that can be used to measure mechanical power, speed and torque, and provide a controllable load to the electric motorcycle being tested. The prototype of chassis dynamometer for electric motorcycle had been developed and performance of the chassis dynamometer was tested by using an electric bicycle to emulate the basic performance requirements of an electric motorcycle which consist of maximum speed, driving range and acceleration.

With its unique qualities, such as infinite supply, high octane number, and capacity to cut greenhouse gas emissions, alcohol is a viable alternative fuel for SI engines. This review article aims to reveal to readers the effects of alcohol on the performance, combustion behavior, and emission characteristics of SI engines by collecting the outcomes from previous research. This article looks at methanol, ethanol, and butanol fuel qualities. The performance of SI engines with butanol, ethanol, and methanol combined with gasoline is investigated in terms of brake torque, brake power, fuel consumption, thermal efficiency, volumetric efficiency, mean effective pressure, and coefficient of variation under various conditions. Second, in-cylinder pressure, mass fraction burnt, ignition delay, pressure increases, and heat release rates are also used to evaluate the combustion characteristic. Finally, the article discusses pollutant emissions such as CO, CO2, NOx, UHC, and exhaust gas temperature. Methanol, ethanol, and butanol mixed with gasoline increased fuel consumption and lowered spark-ignition engines' thermal efficiency. When alcohol was combined with gasoline, most research found that CO, NOx, and UHC emissions were reduced due to improved combustion. [ABSTRACT FROM AUTHOR]

Biofuel includes biodiesel is introduced to overcome the air pollution problems. Biodiesel is the sustainable and alternative fuel that derived from edible and non-edible oil produced from bio-originated species, plants, and animals. This paper presents the simulation analysis on the effect of fuel temperature variations on diesel engine performance and emission using palm-biodiesel. A one-dimensional numerical analysis, Diesel RK software is used to simulate a single cylinder, four-stroke diesel engine on the performance and emission when operated at a full load condition using fuel temperature variations ranging 300 K to 333 K. Results showed that simulated results for brake power and brake torque were 0.7% each when compared to the highest and lowest fuel temperature ranging from 333 K to 300 K. Moreover, higher fuel temperature for palm biodiesel tends to produce lower exhaust gas temperature and brake specific fuel consumption at a constant engine speed of 2400 rpm. It can be concluded that from the study, fuel temperature variations of biodiesel could produce a significant effect regarding engine performance and emission that influence the driving economy of the engine.

A study on the application of oxygenated turpentine oil as a bio-additive in diesel fuel was conducted. The purpose of this research was to investigate the effect of oxygenated turpentine oil additive in diesel fuel on the performance and emission characteristics in diesel engines. Oxygenated turpentine oil is obtained from the oxidation process of turpentine oil. In this experimental study, the influences of oxygenated turpentine oil-diesel blended fuel OT0.2 (0.2% vol oxygenated turpentine oil and 99.8% vol diesel) were compared with pure diesel on engine performance, and emission characteristics were examined in a one-cylinder four-stroke CI engine. The test was performed at two engine loads (25% and 50%) and seven engine speeds (from 1200-2400 rpm with intervals of 200 rpm). The physiochemical characteristics of test fuels were acquired. The engine indicated power, indicated torque, fuel flow rate, and emissions (carbon dioxide, CO2; carbon monoxide, CO; and nitrogen oxide, NOX) were examined. The results revealed that the engine power shows slight increments of 0.7-1.1%, whereas the engine torque slightly decreased with oxygenated turpentine usage compared to pure diesel in most conditions. Furthermore, a reduction in NOX emission decreased by about 0.3-66% with the addition of oxygenated turpentine in diesel compared to diesel. However, usage of OT0.2 decreased fuel flow rate in most speeds at low load but gave a similar value to diesel at 50% load. CO emissions slightly increased with an average of 1.2% compared to diesel while CO2 emissions increased up to 37.5% than diesel. The high-water content, low cetane number, and low heating value of oxygenated turpentine oil were the reasons for the inverse effect found in the engine performances. [ABSTRACT FROM AUTHOR]

Increasing global population in present years means more vehicle ownership which leads to the increasing of oxides of nitrogen (NOx) and greenhouse gas emission. Oxides of nitrogen (NOx) are produced from the fuels which burned at high temperatures; contributes to the formation of ozone smog, harmful unseen particles, acid rain, and oxygen depletion that reduced the water quality. The use of higher oxygenated nature biodiesel as an alternative fuel also contributes to the increasing formation levels of NOx emission. In respond to the matters arise, exhaust gas recirculation (EGR) has been introduced to control NOx emissions from diesel engines effectively which lowers the oxygen concentration in the combustion chamber. In this paper, an experimental study was conducted on a Mitsubishi 4D68 four stroke, water cooled DI diesel engine fuelled with neat palm-biodiesel operating with diaphragm exhaust gas recirculation (EGR). Both biodiesel fuel and EGR are employed together to evaluate the engine performance and exhaust emission particularly NOx content. Tests were performed under a steady state condition where conventional diesel fuel was used as a baseline fuel. According to the experimental results, diesel engine operating with palmbiodiesel and EGR reduced the brake power output, decreased the engine torque, increased fuel consumption, decreased NOx and absolute slight increment in other emissions include CO2, CO, and particulate matters. [ABSTRACT FROM AUTHOR]

This study has focused on the PM emissions of diesel engines. Diesel engines are attractive power units that are used widely in many fields and have become one of the larger contributors of total petroleum consumption. However, diesel engines are among the main contributors of emissions into the air, especially particulate matter (PM) and nitrogen oxides (NOx). PM is one of the major pollutants emitted by diesel engines and has adverse effects on human health. Accordingly, many studies have been conducted to find alternative fuels that are clean and efficient. Biodiesel, which produces less PM than diesel fuel, is preferred as an alternative source for diesel engines. Therefore, using palm oil methyl ester (POME) for diesel engines would be a more economical and sustainable solution. This study has focused on the PM emissions of diesel engines fuelled by a diesel and POME blend (B5, B10, B20, and B100). A comparison between diesel and the POME blend has been made which involves PM mass concentration and its components (soluble organic fraction (SOF) and dry soot (DS)). Combustion characteristics, such as in-cylinder pressure and rate of heat release of the engine, as well as gaseous emissions, have also been observed at different operating engine loads (0.05 MPa 20%, 0.4 MPa 40%, and 0.7 MPa 60%). The results show that PM emissions of B100 are lower than those of diesel fuel owing to the oxygen content of POME. With regard to the SOF concentration, B100 has a higher SOF value than diesel fuel at all engine loads. Meanwhile, the DS for B100 is lower than that of diesel fuel. Moreover, as the engine load increased, PM and SOF concentrations increased, while DS concentration decreased. The observation of in-cylinder pressure showed that the increment of pressure with the increasing POME blend, as well as the increasing engine load due to the high cetane number for B100, led to a short ignition delay. The engine brake thermal efficiency between the POME blend and mineral diesel was comparable. Furthermore, B100 fuels showed lower engine power at higher brake-specific fuel consumption compared to other tested fuels. In terms of gaseous emissions, increasing POME blends led to an increase in NOx emissions. Meanwhile, as the engine load increased, NOx also continued to increase. The effect of the POME blend on the PM-NOx trade-off observation showed that B100 simultaneously increased the NOx and decreased the PM emissions. It can be concluded that POME creates a lower PM concentration while giving some negative feedback to NOx. [ABSTRACT FROM AUTHOR]