Optimization of Trans-esterification Process and Characterization of Biodiesel from Soapstock Using Silica Sulfuric Acid as a Heterogeneous Solid Acid Catalyst

The main objective of this study was production, optimization, and fuel quality characterization biodiesel from equal weight ratio blended acid oil cottonseed sunflower soapstock using silica sulfuric as a solid catalyst in laboratory scale. physicochemical properties soap stock samples extracted each were determined. experiment designed by design expert (version 11) software. 5-level 4-factors (methanol to molar ratio, weight, stirring rate, reaction time) the central composite method. From experimental results, maximum yield 90.68% obtained methanol 7:1 5.5(%wt/wt) with rate 300rpm at 3hr time. average value triplicate experimentation optimized condition 92.62%. analysis variance results indicated that satisfactory achieved. carried out physiochemical produced within range some closest American European standards.