Synthesis of Green Heterogeneous Bifunctional Zeolite-A/Biochar Catalyst for the Production of Biodiesel from Waste Cooking Oil

Abstract

Green heterogeneous bifunctional catalyst is sustainable for the production of biodiesel owning to its reusability, eco-friendly, and bifunctionality. In this work, a green heterogeneous bifunctional Zeolite-A/Biochar (Z-A/BC) catalyst was synthesized for the production of biodiesel from waste cooking oil (WCO) through one-pot esterification-transesterification reaction. The functional group, elemental composition, crystallographic structure, and morphology of the synthesized catalyst were characterized using FT-IR, EDX, XRD, and SEM, respectively. Furthermore, the catalytic proficiency of the synthesized catalyst was tested by optimizing methanol to oil ratio, catalyst amount, temperature, and reaction time. The maximum biodiesel yield (86.22%) was achieved at 2.5% wt. of catalyst amount, 10:1 of methanol to oil molar ratio, 70 °C of reaction temperature, and 240 min of reaction time. The synthesized Z-A/BC catalyst showed apparent catalytic efficiency than its parent materials Z-A (69.42%) and BC (74.27%). The recyclability of Z-A/BC catalyst was also found to be 86.22, 82.98, 79.08, 62.87, and 76.84% for 1^st, 2^nd, 3^rd, 4^th, and 5^th cycles, sequentially which is cost effective. Furthermore, the physicochemical properties such as density, ash content, FFA, acid value, saponification value, and kinematic viscosity of the produced biodiesel were analyzed by comparing with standards. These results showed good agreement with ASTM and EN14214 biodiesel standards. Therefore, the produced biodiesel using heterogeneous bifunctional Z-A/BC catalyst from WCO could be used as an alternative engine fuel with/without blending with commercial diesel.

Graphical Abstract