Production Of Biodiesel From Waste Frying Oil Using Calcium Oxidebio-Derived Catalyst From Waste Eggshells

Abstract

Waste Frying Oil (WFO) has significant potential as a raw material for biodiesel production. About 80% of the total production cost of biodiesel goes to feedstock when high-grade oil is used. The objective of this research is to reduce the cost of biodiesel production by utilization of waste materials in the production process. The methodology used in this study is the catalytic transesterification reaction method which was conducted to produce biodiesel using WFO specifically collected from chips frying as a raw material and calcium oxide bio- derived from waste eggshells (Rich in calcium carbonate) as a catalyst. The catalyst was successfully prepared by calcination of waste eggshells at 900°C, and analyzed by IR before and after calcination. The comparison between the spectrums of raw eggshells, calcined eggshells and standard calcium oxide showed that, the obtained peaks in both spectrums of calcined eggshells and standard calcium oxide are identical. Furthermore, preliminary investigations were performed on the WFO and the results showed that the WFO from chips frying has a density of (0.91 g/cm3), acid value (0.92 mg KOH /g Oil), free fatty acid (0.46%), fatty acid profile, by GC-MS, contains (Saturated fatty acid 25.77 %, Monounsaturated fatty acid 27.58%, Polyunsaturated fatty acid 46.55%) and average molecular weight (877.78 g/mole). Additionally, the corresponding biodiesel fuel properties of the WFO were predicted using the fatty acid profile and biodiesel analyzer software. Almost all the obtained data met the standard specification of biodiesel (ASTM and EN). The most interesting finding in this study was that the free fatty acid (FFA %) of the WFO is (0.46%), this finding meets the reference standard of the FFA% of high- grade oils (< 1% FFA), accordingly, the WFO from chips frying could be considered as high-grade oil. A significance of this finding helped in production of biodiesel through only one step transesterification reaction at mild reaction conditions. Finally, the produced biodiesel was separated, purified and then analyzed. The obtained results showed that the biodiesel has a yield of (85%), density (0.85 g/cm3), acid value (0.30 mg KOH /g Oil) and, by GS-MC, found that the most abundant esters in the methyl ester profile of biodiesel are (9, 12-Octadecadienoic acid (Z, Z)-, methyl ester 54.66% and 9-Octadecenoic acid (Z)-, methyl ester 31.74%). This study provides an important opportunity to design an inexpensive simple approach for scaling up the production of biodiesel from waste materials.