Umer Rashid

Exhaust emission profiling of fatty acid methyl esters and NO x control studies using selective synthetic and natural additives

The present study was focused on the optimized biodiesel production using Moringa oleifera (M. oleifera) and rice bran oils, characterization, and comparative evaluation of the exhaust emission profile using artificial and natural additives resulting from synthesized biodiesel. Furthermore, various biodiesel blends (B10, B20, B50, and B100) of Moringa oleifera (M. oleifera) and rice bran oils were studied in a four-cylinder, direct injection engine at different engine speeds (1800–3000xa0rpm). The optimal yields (%) for both the M. oleifera and rice bran oil-based biodiesel were found to be 87xa0±xa02.0 and 93xa0±xa02.6%, respectively, using sodium methoxide as the catalyst. The optimized reaction parameters involved in the transesterification of the M. oleifera and rice bran oils were revealed to be catalyst concentration (1.25%), methanol-to-oil molar ratio (9:1), reaction temperature (60xa0°C), and reaction time (90xa0min). The fuel properties of the M. oleifera and rice bran oil-based biodiesel were found to be in compliance with ASTM D6751 and EN 14214. The exhaust emission levels of the synthesized biodiesel and its blends with conventional diesel showed a significant reduction in the particulate matter and carbon monoxide levels comparative to the fossil fuel-based diesel combustion, whereas an increasing trend was observed in case of the oxides of nitrogen (NOx) emission. The results of the engine performance test indicated that the brake power in all of the samples had approximately similar values for each load and the enriched blends showed a distinct improvement in brake-specific fuel consumption. The effect of antioxidants on the NOx emission levels resulting from the combustion of the biodiesel and its blends showed that the synthetic additives (butylated hydroxyl anisole (BHA), butylated hydroxyl toluene (BHT), t-butyl hydroquinone (TBHQ), and propyl gallate (PG)) were more effective than the natural methanolic antioxidant extracts (extract of P. pinnata (EPPL), extract of A. lebbeck (EPPL), extract of P. guajava (EPG), and extract of M. azedarcah (EMA) for reduction in the NOx emission level.

Mesoporous Catalysts for Biodiesel Production: A New Approach

Abstract Recently, mesostructured solid catalysts have been attracting attention for biodiesel synthesis owning to their remarkable characteristics, such as harmonized surface characteristic, large surface area, large and flexible pore size, specific crystallization, and high thermal stability. Principally, higher surface area can be obtained as a result of either porous creation or transforming bulk material to nanoparticles. The bigger pore diameters simplify the diffusion of the reactants into pore channels, which consequently enhances the accessibility of the reactants to the majority of the active sites. The considerable physicochemical, morphological, structural, and textural properties of mesoporous materials have found applicable as heterogeneous catalysts, support catalysts, and adsorbents in many fields of studies. The absorbent surface property of the mesoporous catalysts makes them to absorb long-chain organic molecules such as free fatty acids (FFAs). It highly improves the catalytic activity through reaction for transforming of high FFAs feedstocks to biodiesel.