Physicochemical properties of lard oil and rubber seed oil blends and their comprehensive characterization

Abstract

This research investigates the potential of blending complementary lard oil with rubber seed oil as feedstock for biodiesel production. Rubber seed oil, obtained through hexane extraction using the Soxhlet method, contains the major fatty acids of oleic acid (C18:1), palmitic acid (C16:0), linoleic acid (C18:2), and stearic acid (C18:0), while rubber seed oil primarily consists of linoleic acid (C18:2), oleic acid (C18:1), linolenic acid (C18:3), palmitic acid (C16:0), and stearic acid (C18:0). Th least acid value of lard oil (0.55 mg KOH/g) can benefit of reducing soap formation of rubber seed oil during transesterification process in biodiesel production due to its substantial-high acid value (16.28 mg KOH·g–1). Blending at ratios below 80:20 v/v produced biodiesel exceeding 85%, utilizing CaO as a catalyst. Lard oil demonstrated a higher reaction rate constant (11.88×10–3 min–1) than rubber seed oil (2.11×10–3 min–1), indicating a significant difference in performance. High acid value and free fatty acids in rubber seed oil correlated with lower reaction rates. Maintaining a mixture ratio below 80:20 v/v optimized reaction rates during biodiesel production. Biodiesel obtained from blends below 80:20 v/v met ASTM D6751 and EN 14214 standards, demonstrating suitability for bio-auto fuel. The drawbacks of using rubber seed oil as a raw material for biodiesel production are overcome by blending with lard oil, giving rise to expanding renewable energy options for rural communities, community enterprises, and large-scale biodiesel production.