Nano-magnetic CaO/Fe2O3/Feldspar catalysts for the production of biodiesel from waste oils

Authors: HANIF, MARYAM - University Of Agriculture - Pakistan; BHATTI, IJAZ AHMAD - University Of Agriculture - Pakistan; HANIF, MUHAMMAD ASIF - University Of Agriculture - Pakistan; RASHID, UMER - Universiti Putra Malaysia; Moser, Bryan; HANIF, ASMA - Government College Women University Faisalabad; ALHARTHI, FAHAD - King Saud University

Submitted to: Catalysts
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/4/2023
Publication Date: 6/13/2023
Citation: Hanif, M., Bhatti, I., Hanif, M., Rashid, U., Moser, B.R., Hanif, A., Alharthi, F. 2023. Nano-magnetic CaO/Fe2O3/Feldspar catalysts for the production of biodiesel from waste oils. Catalysts. 13(6). Article 998. https://doi.org/10.3390/catal13060998.
DOI: https://doi.org/10.3390/catal13060998

Interpretive Summary: This research reveals a new solid catalyst for production of biodiesel from low-cost, low-quality, non-food plant oils. The new magnetic catalyst (calcium oxide/iron oxide supported on feldspar) has important advantages over the common catalysts used for production of biodiesel, such as high yield, easy removal, recoverability, re-usability, and avoidance of wastewater generation. Thus, biodiesel was produced from karanja, wild mustard, and wild safflower seed oils using the new catalyst and the resulting fuel properties were measured and compared to the American biodiesel fuel standard. Overall, the properties of biodiesel from these seed oils were comparable to those of soybean-based biodiesel, thus indicating their acceptability as sources of biodiesel fuel. These results will be important to biodiesel producers, distributors, and end-users (customers) because a new catalyst was described that produces biodiesel with favorable fuel properties. This research may ultimately improve market penetration, availability, and public perception of renewable agricultural fuels such as biodiesel, thus affording greater national independence from imported petroleum-based fuels while enhancing rural economies.

Technical Abstract: Production of biodiesel from edible vegetable oils using homogenous catalysts negatively impacts food availability and cost while generating significant amounts of caustic wastewater during purification. Thus, there is an urgent need to utilize low-cost, non-food feedstocks for production of biodiesel using sustainable heterogeneous catalysis. The objective of this study was to synthesize a novel supported nano-magnetic catalyst (CaO/Fe2O3/feldspar) to produce biodiesel (fatty acid methyl esters) from waste and low-cost plant seed oils, including Pongamia pinnata (karanja), Sinapis arvensis (wild mustard) and Carthamus oxyacantha (wild safflower). The structure, morphology and crystallinity of the nano-magnetic catalyst was confirmed using XRD and SEM/EDX. Maximum biodiesel yield (93.6 – 99.9 %) was achieved at 1.0 or 1.5 wt. % catalyst with methanol to oil molar ratios of 5:1 or 10:1 at 40 °C for 2 h. Different physico-chemical parameters, such as pour point, density, cloud point, iodine value, acid value, and cetane number, were also determined of the optimized fuels and found to be within the ranges specified in ASTM D6751 and EN 14214, where applicable.