R. Mamat

Effects of Low Proportion Palm Fatty Acids Methyl Ester Blends on the Performance and Combustion of Marine Diesel Engine

Shipping activities are major contributors to air pollution at sea which mostly occur as a result of ships exhaust emissions. Stringent emission limits imposed by the International Maritime Organization (IMO) and concerns about the depletion of fossil fuel reserves have hastened the need to find new alternative fuels for marine engines. This study investigates the effects of a low proportion of palm fatty acid methyl ester (PFAME) biodiesel which is renewable and environmentally friendly fuel on marine diesel engines performance and combustion characteristics. The results revealed the use of PFAME biodiesel blends reduces the harmful gases emission CO2 and NOX emission up to 9.1% and 7.8%, respectively. Oxygen elements in biodiesel has contributed to increase peak in-cylinder pressure and heat release rate up to 2.7% and 4.5% respectively, thereby promoting complete combustion. Besides that, the brake specific fuel consumption raised by 18.8% at higher engine speeds. This finding suggests that a low concentration of PFAME biodiesel is suitable for use in marine diesel engines without engine modification, thereby providing a positive benefit to the environment in terms of lower emission of toxic gases.

Comparison of the Cyclic Variation of a Diesel-Ethanol Blend in a Diesel Engine

Alcohols are renewable and sustainable second generation biofuels which are derived from various biomass feedstock sources. These fuels with similar properties to mineral diesel can be used as a blend or additive to improve the combustion characteristics and pollutant emissions in the automotive engines. However, different fuel properties characterize different combustion phasing parameters for the specific engine operation and test condition. This paper presents the preliminary results of coefficient of variations of IMEP (COVIMEP) and Pmax (COVPmax) for a diesel engine fuelled with mineral diesel (B0) and DE10 blend at full load both engine speeds of 1100 rpm and 2300 rpm. The influence of ethanol content in a blend of diesel on the cyclic combustion variations is explained in the calculation values of the coefficient of cyclic variation (COV). The experimental results showed the DE10 fuelling exhibited larger cyclic variations than mineral diesel (B0) at the same test conditions, owing to the reduction of combustion temperature during combustion phasing and lower reactivity of ethanol.

Effects of the Inlet Velocity Profiles on the Prediction of Velocity Distribution inside an Electrostatic Precipitator (ESP)

In this study, the development of CFD model for nthe description of operation of electrostatic precipitator has been developed. The model is based on the simulation analysis whereby focused on the gas flow by time-averaged conservation equation of mass and momentum. 2D geometry model was extensively applied due to ease the geometry and analysis. The flow simulation was performed by using computational fluid dynamics (CFD) code Fluent. Numerical calculations for the air flow were calculated using the Reynolds-averaged Navier-Stokes equation coupled with the realizable k-e turbulence model equations. Simulations were performed using three velocities at the inlet boundary by considering a uniform (ideal) velocity profile. Simulation with the low velocity profile gives a better flow rate efficiency between the outlet and inlet of the ESP. Overall, all the three velocities give more than 90% of nefficiency of the air flow inside ESP chamber.