Performance and emissions characteristics of alternative biodiesel fuel on 4-stroke marine diesel engine

Alternative fuels for diesel engines have become increasingly important due to several socioeconomic aspects, imminent depletion of fossil fuel and growing environmental concerns. Global warming concerns due to the production of greenhouse gases (GHGs) such as carbon dioxide (CO2) as results from internal combustion engine have seen as one of major factor the promotion of the use of biofuels. Therefore, the use of biodiesel fuel (BDF) as an alternative for fossil diesel (DSL) is among the effective way to reduce the CO2 emission since it is classified as green and renewable energy. However, it is acknowledged that the use of BDF is restricted due to loss of efficiency and long term problems upon the engine. Hence, a study focussed on investigating the effects of BDF derived from crude palm oil (CPO), jatropha curcas oil (JCO) and waste cooking oil (WCO) blended with DSL at various blending ratio on engine performance and exhaust gas emissions has been performed. This experimental test was done using a small 4-stroke marine diesel engine which operates through engine speeds stimulated at 800, 1200, 1600 and 2000 rpm under 0, 50 and 90% dynamometer loads integrated with emission gas analyser that attached to the exhaust pipeline. As results of experimental investigations, the increment in performance of torque, brake power, brake thermal efficiency (BTE) and brake mean effective pressure (BMEP) while decrease in brake specific fuel consumption (BSFC) has been observed for CPO and JCO fuels comparative to DSL. Meanwhile a contrariwise outcome was obtained for WCO fuels. In conjunction, CPO and JCO promotes lower carbon monoxide (CO) emissions but signified higher nitrogen oxides (NOx), carbon dioxide (CO2) and hydrocarbon (HC) emissions compared to DSL. Apart, WCO promotes lower CO, CO2 and HC emissions but signified higher NOx emissions compared to DSL. It can be concluded that BDF is useable in diesel engines without engine modifications. The outcomes of this study is significantly contributed as a guidence and reference to the local authority in order to evaluate and select the suitable and optimum BDF for development of policies, regulations and standard

Autoignition behavior and emission of biodiesel from palm oil, waste cooking oil, tyre pyrolysis oil, algae and jatropha

Alternative fuels have recently been researched on diesel substitution, with the target of reducing dependence on petroleum-based fuel in addition to reducing environmental pollution. Thanks to its regenerability and ability to absorb emissions, the opted biofuel tends to be advantageous. The present study explored the autoignition behaviour, in particular the ignition delay and process of combustion that strongly influence exhaust emissions. The analysis used biodiesel blends obtained from palm oil, waste cooking oil, algae, jatropha and tyre pyrolysis oil at various blending ratio from 2% to 20%. These blending ratios were achieved independently through a specific blending technique with pure diesel at different volumetric concentrations. The ignition delay was assessed by means of a rapid compression machine (RCM) under variant injection pressure at an elevated ambient temperature of the reaction chamber. This study discovered significant differences in ignition delays and combustion efficiency when different biodiesel blends were operated under higher injection pressures and higher ambient temperatures. The shortest ignition delay of biodiesel blend fuels is achieved at low blending concentrations, implying that lower concentrations of biodiesel encapsulate a lower fuels viscosity, preceded by excellent spray atomization, premixing, and ignitability. In addition to these implications, the shortest ignition delay was undoubtedly influenced by higher injection pressure and higher temperature conditions in which the expansion of the fuel’s molecular bound to the C–H bonding deteriorates and bonding energy dissociates. Emissions are lower than pure diesel with an increased concentration of blends; waste cooking oil-biodiesel blends experienced positive effects on the CO, HC and nitrogen oxides (NOx) via variant injection pressure; while significant improvements in HC were noticed for most fuels, corresponding to the elevated ambient temperature circumstances

Influences of ambient temperature, injection pressure and spray characteristics on ignition delay and combustion process of palm oil and waste cooking oil

Alternative fuels have been explored for the substitution of diesel to lessen dependence on fossil fuel and to mitigate environmental pollution. Opted on biodiesel seem like promising due to its availability and regenerability, as well as ability to lower emissions. The objective of this research is to investigate the effects of ambient temperature, injection characterirics and spray characteristics on ignition delay and combustion process of biodiesel blends derived from palm oil and waste cooking oil. The ignition delay and combustion were observed using a rapid compression machine with ambient temperatures ranging from 850 K to 1050 K and injection pressure ranging from 80 MPa to 130 MPa. Palm and waste cooking oil biodiesel blends fuel were produced by blending these oils with Euro5 pure diesel at concentration of 5vol%, 10vol% and 15vol% correspondingly. Higher injection pressure and higher ambient temperature have been found to significantly reduce the ignition delay and influences to the heat recovery of combustion, while the higher biodiesel blending concentration of biodiesel promotes the reduction of CO emission

Effects of ambient density and high injection pressure on the flow characteristics of biodiesel spray

Fuel spray and mixture formation are playing as an important criteria in displaying a fuel's combustion and emission characteristics since it has an instantaneous impact on the creation of an air fuel combination. The purpose of this study is to compare the effects of three different Crude Palm Oil (CPO) biodiesel blends, B5, B10, and B15, with different ambient density on nozzle flow and spray characteristics, computational fluid dynamics (CFD) were used to determine the nozzle flow and spray characteristics for different injection pressure of biodiesel spray to ambient variant conditions on mixture formation. Injection of biodiesel into the RCM constant volume chamber was considered in the simulation. While maintaining constant values for the other parameters, the boundary condition is adjusted at a different ambient parameter. Under the presence of in-cylinder flow, the impact of fuel type, injection pressure, and ambient variables on spray behaviour, such as spray penetration, has been explored. It was projected that high injection pressures would be more essential for the biodiesel fuels to develop their breakup. The effects of these various parameters are examined in terms of spray characteristics and opposed with the results of the experimen

Effects of ambient density and high injection pressure on the flow characteristics of biodiesel spray

Fuel spray and mixture formation are playing as an important criteria in displaying a fuel's combustion and emission characteristics since it has an instantaneous impact on the creation of an air fuel combination. The purpose of this study is to compare the effects of three different Crude Palm Oil (CPO) biodiesel blends, B5, B10, and B15, with different ambient density on nozzle flow and spray characteristics, computational fluid dynamics (CFD) were used to determine the nozzle flow and spray characteristics for different injection pressure of biodiesel spray to ambient variant conditions on mixture formation. Injection of biodiesel into the RCM constant volume chamber was considered in the simulation. While maintaining constant values for the other parameters, the boundary condition is adjusted at a different ambient parameter. Under the presence of in-cylinder flow, the impact of fuel type, injection pressure, and ambient variables on spray behaviour, such as spray penetration, has been explored. It was projected that high injection pressures would be more essential for the biodiesel fuels to develop their breakup. The effects of these various parameters are examined in terms of spray characteristics and opposed with the results of the experimen

Effect of ambient temperature on ignition delay, combustion process and emission of biodiesel derived from algae

Global warming and energy crises have increased the awareness about eco-friendly fuels and also accelerated the search of alternative fuels. Biodiesel is defined as methyl esters of long chain fatty acids derived from vegetable oils or animal fats or similar which conform to ASTM D6751 specifications for use in diesel engines. However, low temperature combustion mode has attracted widespread attention in particulate matter and NOx emissions reduction simultaneously. Thus, this paper evaluates the potential of using algae as the alternative fuel for diesel engines and focuses on experimental investigation for the influence of ambient temperature on ignition delay and emission with different types of biodiesel. A Rapid Compression Machine (RCM) is used for simulated the diesel combustion as similar in the real diesel engine. Besides, two types of biodiesel blends, B2 (2vol%) such as Algae and Jatropha biodiesel were tested on RCM at injection pressure of 130 MPa under different ambient temperatures from 750 K to 1100 K. The experimental results were compared with Palm-Oil biodiesel with blending ratio of 5vol%, 10vol% and 15vol%. Nevertheless, the result indicated that the ignition delay is slowed when ambient temperature is increased. These phenomena can be explained by the thermal properties of fuels. Ignition delay is found to be slower if premixed combustion process is reduced and also higher ambient temperature due to the increased in fuel ignitibility. The emission of NOx increased as the ambient temperature increased to cause highly combustion temperature

Performance and emissions of diesel engine fuelled with preheated biodiesel fuel derived from crude palm, jatropha, and waste cooking oils

Biodiesel is typically made by chemically reacting lipids of palm, vegetable, and waste cooking oils and animal fat with an alcohol producing fatty acid esters. Biodiesel is not efficient in cold weather and this is biodiesel’s major problem. Viscosity has influences on the fuel flow rate and leads to poor fuel atomisation during the combustion process. The aim of this study is to determine the effects of biodiesel temperature in the range fom 40 °C and 60 °C on engine performance such as torque, brake power, brake mean effective pressure, and fuel consumption. Three types of biodiesel oil were used (crude palm oil (CPO), waste cooking oil (WCO), and jatropha oil) under biodiesel blending ratio of 5vol%. A single cylinder four-stroke engine was used and operated under different load conditions of 0% and 50% and observed emission of CO, CO2, NOx, and HC. The engine operated at 0% and 50% dynamometer load conditions and running speeds of the engine of 800 rpm, 1200 rpm, 1600 rpm, and 2000 rpm. The results of this study showed that the heating temperatures in the range from 40 °C and 60 oC in CPO10 produced the highest brake power as well as torque and BMEP. For the experimental results of exhaust emission, the preheated temperature affected the degradation of the exhaust emission. In addition, preheated biodiesel increased the pressure on the cylinder combustion chamber. It can be concluded that the biodiesel preheated blend influences the performance and emission. For CPO biodiesel, the preheated biodiesel decreased CO and NOx while the standard diesel produced the lower emission of CO2 and HC. WCO biodiesel blend produced a lower emission with increasing fuel temperature