Kinetics study of biodiesel production at room temperature based on eggshell-derived CaO as basic heterogeneous catalyst

摘要

Eggshell-derived calcium oxide (CaO) materials were used as a heterogeneous base catalyst for biodiesel production from palm oil with methanol at room temperature (30±2 °C). The physicochemical properties of the catalyst were characterized by TG-DTA, XRD, FT-IR, SEM-EDX, Hammett indicator method, BET surface area, and CO2-TPD. The comparison of catalytic performance transesterification reaction at the temperature of 65 °C against room temperature was investigated. Kinetics of the reaction were studied following pseudo-first order with under the optimal condition with catalyst loading amount of 15 wt.%, methanol to oil molar ratio of 15:1 and 10% v/v of the co-solvent in methanol. Under the optimal reaction conditions, the result showed that the yield of fatty acid methyl ester (FAME) was achieved 96.6% in 9 h and the obtained k value was 3.28×10-1 h-1 which higher than that of without co-solvent system (3.07×10-1 h-1). After purification with a cation-exchange resin to remove calcium ion (Ca2+), high-quality biodiesel product with the fuel properties of the biodiesel especially the major physicochemical properties meet both the ASTM and EN standard specifications. Utilization of waste eggshell-derived CaO as catalysts and performing the reaction at room temperature were not only environmentally-friendly technique but also decreasing biodiesel production cost.