Universiti Teknologi Petronas

About: Universiti Teknologi Petronas is a education organization based out in Ipoh, Malaysia. It is known for research contribution in the topics: Adsorption & Ionic liquid. The organization has 6127 authors who have published 11284 publications receiving 119400 citations.

Treatment technologies of palm oil mill effluent (POME) and olive mill wastewater (OMW): A brief review

Abstract: Attributable to the enormous population growth, tonnes of effluents are unavoidably generated throughout the agricultural activities. The inadequate effluents disposal induces perpetual contamination to the sea and river water sources, which has subsequently raised the public environmental concern. For that reason, the handling protocol of agricultural effluents was flagged up as an interest area for research. Despite the environmental hazards, agricultural effluents have the potential to be transformed from wastes into wealth via biological, physicochemical, thermochemical or a combination of processes thereof. The identical characteristics of palm oil mill effluent (POME) and olive mill wastewater (OMW) render the possibility of treating these wastes using the similar treatment method. Generally, biological treatment requires a longer process time compared to physicochemical and thermochemical technologies despite its easy and low-cost operation. Comparatively, physicochemical and thermochemical methods extend their potentiality in converting the agricultural effluents into higher value products more efficiently. This paper reviews the source and characteristics of both POME and OMW. Subsequently, a comparison of the current and alternative treatments for both effluents was done before the future perspectives of both effluents’ treatment are paved based on the well-being of the human, environment, and economic.

Performance and emission of diesel engine fuelled by waste cooking oil methyl ester derived from palm olein using hydrodynamic cavitation

Abstract: The depleting of fossil fuel reserves and increasing environmental concerns have continued to stimulate research into biodiesel as a greener fuel alternative produced from renewable resources. In this study, the performance and emission characteristics of biodiesel blends of 10, 30 and 50 % from waste cooking oil based on hydrodynamic cavitation were compared to diesel fuel, and found to be acceptable according to the EN 14214 and ASTM D 6751 standards. The tests have been performed using an in-line vertical six-cylinder diesel engine at different engine speeds, ranging from 1000 to 2000 rpm under full throttle load. During engine performance tests, biodiesel blends showed higher brake specific fuel consumption (2.1–9.0 %) and exhaust gas temperature (1.0–6.8 %), while lower brake power (1.6–6.7 %), torque (0.6–5.2 %) and brake thermal efficiency (1.9–8.4 %) than diesel fuel. Engine emissions showed higher carbon dioxide (8.7–38.5 %) and nitrogen oxide (4.7–19.0 %) releases, but surprisingly decreased amount of carbon monoxide (3.3–26.3 %) for biodiesel blends compared to diesel fuel. Although higher carbon dioxide amounts were emitted, the use of biodiesel greatly reduced the life cycle circulation of carbon dioxide. Waste cooking methyl ester produced by using hydrodynamic cavitation seems to be relatively easy to scale up to higher production values, is energy efficient, time saving and eco-friendly, which results in biodiesel being a viable fuel for industrial production. The waste cooking oil-based biodiesel can also be used without any engine modifications.

Thermal analysis during turning of AZ31 magnesium alloy under dry and cryogenic conditions

Abstract: In this study, the effect of both cryogenic and dry machining of AZ31 magnesium alloy on temperature and surface roughness was examined. Cryogenic machining experiments were conducted by applying liquid nitrogen at the cutting zone. The cutting parameters (cutting speed, depth of cut, and feed rate) were varied, and their effect on the results was identified. It was found that the cryogenic machining was able to reduce the maximum temperature at the machined surface to about 60% as compared with dry machining. A finite element model was developed to predict the temperature distribution at the machined surface. The simulated results showed good agreement with the experimental data. After analyzing the temperature distribution, the model also suggested that the cryogenic-assisted machining removes heat at a faster rate as to that of the dry machining. An arithmetic model using the response surface method was also developed to predict the maximum temperature at the surface during cryogenic and dry machining. The analysis pointed out that the maximum temperature was greatly affected by the cutting speed followed by feed rate and depth of cut. Cryogenic machining leads to better surface finish with up to 56% reduction in surface roughness compared with dry machining.

Vacuum pyrolysis incorporating microwave heating and base mixture modification: An integrated approach to transform biowaste into eco-friendly bioenergy products

Abstract: The escalating consumption of fossil fuels and dumping of palm kernel shells (PKS) drives biofuel production to improve supply and waste disposal. To convert PKS into modified biochar (MBC) value-added solid fuel, we use microwave vacuum pyrolysis accompanied by sodium-potassium hydroxide mixture modification. First, PKS underwent microwave vacuum pyrolysis to produce biochar, and then it was chemically activated using sodium-potassium hydroxide mixture. The MBC surface morphology, porous characteristics, proximate content, and energy properties depended on microwave irradiation period and power. High yields (79 ± 1.5 wt%) were recorded at microwave power 700 W and irradiation period of 10 min, giving a high BET surface area (1320 m2/g) and pore volume (0.70 cm3/g). The MBC had acceptable low content of ash, nitrogen, and no sulphur, demonstrating its potential as an environmental friendly fuel to replace conventional coal in combustion. The MBC shows high energy yield (≤90.5%), fuel ratio (≤26.47), and heating value (≤28.69 MJ/kg) comparable to conventional fuels, thus showing desirable solid fuel properties. Energy balance analysis shows positive energy ratio of up to 10 and net energy output of up to 24.47 MJ/kg, recovering a product with a higher energy content compared to electrical power input for the pyrolysis operation. These findings demonstrate the exceptional potential of the MBC produced by this innovative approach for bioenergy generation that per se will reduce the emissions of greenhouse gases and thereby reducing global warming and climate change.