Saifuddin Nomanbhay

UV-Vis Spectroscopy: A New Approach for Assessing the Color Index of Transformer Insulating Oil

Monitoring the condition of transformer oil is considered to be one of the preventive maintenance measures and it is very critical in ensuring the safety as well as optimal performance of the equipment. Various oil properties and contents in oil can be monitored such as acidity, furanic compounds and color. The current method is used to determine the color index (CI) of transformer oil produces an error of 0.5 in measurement, has high risk of human handling error, additional expense such as sampling and transportations, and limited samples can be measured per day due to safety and health reasons. Therefore, this work proposes the determination of CI of transformer oil using ultraviolet-to-visible (UV-Vis) spectroscopy. Results show a good correlation between the CI of transformer oil and the absorbance spectral responses of oils from 300 nm to 700 nm. Modeled equations were developed to relate the CI of the oil with the cutoff wavelength and absorbance, and with the area under the curve from 360 nm to 600 nm. These equations were verified with another set of oil samples. The equation that describes the relationship between cutoff wavelength, absorbance and CI of the oil shows higher accuracy with root mean square error (RMSE) of 0.1961.

Sustainability of biodiesel production in Malaysia by production of bio-oil from crude glycerol using microwave pyrolysis: a review

ABSTRACT Biodiesel being one of the most promising renewable biofuels has seen rapid increase in production capacity due to high demand for diesel replacement; along with oversupply of its by-product, crude glycerol. Developing new industrial usage for glycerol is essential to defray the cost and sustainability of biodiesel industry and to promote the biodiesel industrialization. One of the approaches is by the transformation of glycerol into a liquid, referred as bio-oil through pyrolysis technology. Bio-oils produced by pyrolysis processes can be upgraded to produce transportation fuels or for power generation. However, current state of pyrolysis technologies are still major hurdles their development with respect to its commercial applications. Recently, microwave technology has attracted considerable attention as effective method for significantly reducing reaction time, improving the yields and selectivity of target products. Hence, this review strives extensively towards addressing the application of microwave-assisted technology applied to the pyrolysis process as a way of cost-effective and operationally feasible processes to directly utilize crude glycerol. The present review will focus on the pyrolyzed liquid product (bio-oil) derived by employing the microwave-assisted pyrolysis method. This review concludes that microwave-assisted glycerol conversion technology is a promising option as an alternative method to conventional glycerol conversion technology. GRAPHICAL ABSTRACT

Preparation and characterization of kenaf derived heterogeneous catalyst for esterification reaction

A Kenaf fibers supported transition metal oxide solid acid catalyst (SAC) was prepared by wet impregnation method followed by calcination at 700°C. The characterizations of catalyst were studied by various methods. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Energy dispersive spectrometer (EDX) showed that tungsten oxide particle was synthesized and well dispersed on the surface of fibers. A catalytic activity with 68% free fatty acid (FFA) conversion was achieved in esterification reaction. The catalyst can be easily separated from the mixture and reused for few cycles. This finding proved that Kenaf fibers derived SAC has the ability to esterify free fatty acid prior to transesterification reaction to produce biodiesel.