Novel Solar Parabolic Trough Collector cum Reactor for the Production of Biodiesel from Waste Cooking Oil using Calcium Oxide catalyst derived from seashells waste

[Display omitted] •Parabolic trough collector used as intensification tool for enhanced biodiesel production.•CaO catalyst packed column reactor is also used in combination.•Temperature reached around 95 °C in 20 min in day time.•Yield up to 95.84% obtained by recirculating batch reactions.•Net energy ratio and energy efficiency indices were analyzed for various conditions. Waste cooking oil was converted to biodiesel using a parabolic trough collector using solar radiations as a heating source and a parabolic trough collector as an intensifier. Calcium oxide (CaO) derived from seashells was used as a catalyst in order to boost the rate of the reaction. Temperatures of almost 95 °C were reached using this collector although the temperature was limited to below 78.4 °C in order to prevent the vaporization of ethanol. The influence of different parameters on the reaction was analyzed. The maximum yield was found to be 95.84%, obtained under conditions of 180 LPH reactant flow rate, 300 rpm stirring speed, 60 minutes reaction time, 9:1 ethanol to oil ratio and 90 cm catalyst bed height. The composition and properties of the biodiesel were found to be in accordance with literature and ASTM and BIS norms. The energy efficiency of the process was analyzed by net energy ratio (NER). The net energy efficiency index (NEEI) was obtained from the ratio of NER of the solar method to the conventional method. NEEI of the process was found to be 4.16, thereby making the process a highly promising method of biodiesel production.