Mas Fawzi Mohd Ali

Biodiesel production from multi feedstock as feed with direct ultrasound assisted

The objective of this study was to optimize of ratio oil type, ratio oil to methanol and catalyst concentration. The optimization was used Central Composite Design (CCD). Biodiesel was produced with multi stock oil as feed and conducted in direct ultrasonic radiation. Biosonic equiped with ultrasonic generator with a frequency of 28 kHz. Biodiesel produced at a pressure of 1 atm, reaction time of 60 min and temperature 60 ° C. The optimum conditions of volume ratio for Palm and Coconut oil 4:1, KOH catalyst concentration 0.3% and methanol to oil mole ratio 7:1. Biodiesel yield was determined under this condition and obtained 81.105%.

Effect of Preheated Fuel on Mixture Formation of Biodiesel Spray

The key issue in using vegetable oil-based fuels is oxidation stability, stoichiometric point, bio-fuel composition, antioxidants on the degradation and viscosity thus influences to the different spray atomization and fuel air mixing characteristics. Purpose of this study is to investigate the effect of preheated biodiesel on fuel properties, spray characteristics and mixture formation. The detail behavior of mixture formation was investigated using the direct photography system with a digital color camera. This method can capture spray evaporation, spray length and mixture formation clearly with real images. Increased preheated fuel is found to enhance the spray penetration, resulting in increased the spray area and enhanced fuel-air premixing.

Effect of Gas-Jet Ignition Technique on the Extension of CNG Lean Combustion Limit

Lean combustion of CNG has the advantage of high thermal efficiency and fewer pollutants than other fossil fuels. However, problems such as ignitability, cyclic variation and high THC emission were common at combustion leaner than equivalence ratio φ=0.7. The application of gas-jet ignition method to lean combustion was able to address such problems. This paper introduces the concept of gas-jet ignition method, which ensures ignitability at lean bulk equivalence ratio. Moreover, this method is applied to a real CNG engine. Results of engine performance experiment shows that two-stage injection method combined with gas-jet ignition has successfully widen the operating range of a CNG engine from low to high load at corresponding φ=0.17 to 1.1.

Parametric Study on Geometrical Arrangement of Sister Hole

Modern gas turbines require a sophisticated cooling scheme to remove the heat from its component to ensure it durability. One of the common techniques applied in the cooling scheme is film cooling The present study focuses numerical investigation of an sister cooling hole design. The investigations make use of commercial CFD software, ANSYS CFX. The numerical investigations have been carried out at Reynolds number, Re = 21,000 involving three differens blowing ratios, BR = 0.5, 1.0, and 1.5. Four different cases have been considered; STA, STB STC and SH. The results show promising improvement in terms of film cooling effectiveness with the implementation of sister holes in certain geometrical arrangements.

The Storage Effect on Fuel Properties and Emission for Variety Biodiesel Blends

In this paper, storage effect on biodiesel properties for high blending ratio and the emission are evaluated. The blend level of biodiesel is denoted as B, followed by the percentages of pure biodiesel. The samples used are conventional diesel (STD), B80, B90 and B100 were stored at ambient temperature (24 °C) for nine week. The properties of biodiesel, acid value, flash point, viscosity, density and water content were measured according to ASTM D6751 biodiesel fuel standard. Results show there are no significant effects on it properties while stored in long duration at ambient temperature. Meanwhile, increasing biodiesel ratio is found to enhance the combustion process, resulting in decreased the HC for emissions.

Effect of Two-Stage Injection Timing on a Gas-Jet Ignition CNG Engine

Compressed natural gas (CNG) engines normally operate in lean condition to take the advantage of higher efficiency and better fuel economy. Several studies have shown that gas-jet ignition with two-stage injection technique is effective to extend the lean combustible range of CNG engines. This paper investigates the effectiveness of such technique using a prototype lean burn direct injection CNG engine. The experiment was conducted at speed of 900 rpm, fuel injection pressure of 3 MPa, equivalence ratio φ=0.8, and ignition timing at top dead center. The effect of first injection timing on the test engine performance and exhaust emission was analyzed. The result shows that the first injection timing is crucial in determining the performance of the engine. First injection timings when the piston is near to bottom dead center produced relatively stable combustion. First injection timings when the piston is at midpoint produced misfire. First injection timings near the gas-jet ignition produced unstable combustion except at a certain timings which produced acceptable combustion with low hydrocarbon and carbon monoxide emissions.

Effects of Biodiesel on Performance and Emissions Characteristics in Diesel Engine

Biodiesel is the alternate fuel which is derived from renewable sources either is vegetable oils or animal fats. Biodiesel is non-toxic, have higher biodegradability, free of sulphur, no aromatics and its oxygen content of about 10-11% which is usually not contained in diesel fuel. These characteristics thus predominantly influences to the emissions of carbon monoxide (CO) and hydrocarbons (HC) in the exhaust gas. Purpose of this study is to investigate the effects of oil palm blended fuel, engine speed and test load conditions on the fuel properties, combustion process, combustion characteristics, exhaust emissions and engine performance. The engine speed was varied from 1500 to 3000 rpm, load test condition varied by dynapack chassis dynamometer in 0% ,50% and 100% and blends of 5 (B5), 10 (B10) and 15 vol% (B15) palm oil with the diesel fuel. Increased of blends ratio can improve the combustion process and give less HC and CO emission and almost nearly engine performance. However, this condition tends to produce high NOx production due to higher oxygenated fuel in biodiesel content.