Energy Conversion and Management, Vol.196, 979-987, 2019
Production of biodiesel utilizing laccase pretreated lignocellulosic waste liquor: An attempt towards cleaner production process
Substituting conventional fossil-based energy with eco-friendly and renewable option is inevitable owing to the harmful environmental emissions and steep increase in energy demand. In this context, biodiesel is a clean fuel considering fewer particulate and carbon emissions in comparison to fossil fuels. However, it still faces concerns towards commercialization due to the high cost of raw materials. Thus, in this study, laccase treated waste liquor of Ricinus communis was utilized for lipid production employing Aspergillus awamori. Detailed characterization of laccase treated waste liquor of Ricinus communis revealed that it is favourable for fungal lipid production owing to C/N molar ratio of 132.45 and phenolic content of 0.609 g Gallic Acid Equivalent per L. Major components of phenolics include cinnamic acid, 3-Bromo-5-ethoxy-4-hydroxybenzaldehyde and benzoic acid. Central composite design based response surface methodology was further adopted to maximize lipid content where optimal solution was predicted as 31 degrees C, carbon to nitrogen molar ratio 156 and inoculum volume 11.5% v/v resulting in 134 mg lipid/g sugar consumed. Further, validation of the process was carried out at pilot scale to justify the feasibility of the process and its applicability for industrial application. Biodiesel, thus produced was characterized for iodine value, acid value and gross calorific value which has been measured to be 73.68 g /100 g, 0.25 mg KOH/g and 37 MJ/kg respectively and conforms to EN 14214 and ASTM D6751. Thus, the present study led to the development of an efficient and clean process for valorization of laccase treated Ricinus communis waste liquor towards biodiesel production.