Ex-situ biodiesel production from Simmondsia chinensis (Jojoba) biomass: Process evaluation and optimization

Abstract

Biodiesel production is explored in the current study through the ex-situ extraction and trans-esterification approach from commercially available Jojoba seed. This biomass is regarded as a beneficial feedstock for biodiesel production as it contains non-edible oil. Also, this feedstock can be cultivated and grown in wastewater and in variable climate conditions. According to the characteristic analysis Jojoba oil is composed of 6.9% saturated fatty acids (4.6% C16:0, 1.3% C18:0 and 0.2% C20:0), 68.7% monounsaturated fatty acids (48% C20:1, 20.2% C18:1 and 0.5% C16:1) and 24.4% polyunsaturated fatty acids (14.8% C18:2, 9.2% C20:2 and 0.4% C18:3). The acid value of crude Jojoba oil is 0.05 mg KOH/ g sample, which feasible the alkaline catalyzed trans-esterification. The effect of variables on oil extraction was explored preliminary through the time-efficient and low-cost central composite design response surface methodology (CCD-RSM). According to the results, 67.51 wt.% saponifiable oil can be extracted from Jojoba seed at 64.5 °C, reaction duration of 187.7 min, rotation rate of 393.2 rpm, and solvent to biomass ratio of 14.6 cc:1 g. The maximum yield of biodiesel production is also obtained at 50 °C, methanol to oil molar ratio (MeOH: Oil) of 5.5:1, reaction time of 2.25 h, and 0.475 wt.% (KOH weight/ oil weight) KOH loading.