Synthesis of reusable biobased nano-catalyst from waste sugarcane bagasse for biodiesel production

The purpose of this study is to synthesize biobased nano-catalyst using waste sugarcane bagasse to produce biodiesel from an inexpensive waste feedstock - palm fatty acid distillate (PFAD). Waste sugarcane bagasse (SCB) was converted into biochar, followed by sulfonation using chlorosulfonic acid as a sulfonating reagent. Four sulfonation variables; sulfonation time, sulfonation temperature, SCB-biochar and volume of chlorosulfonic acid were optimized to achieve the best sulfonating conditions. The optimum sulfonating conditions were recorded to be; 300 degrees C sulfonating temperature, 2 g of SCB-biochar, 200 mL of ClSO3H and 5 h sulfonating time via response surface methodology (RSM) optimization technique. The surface area for the sugarcane bagasse (SCB) was 98 m(2) g(-1) while the SCB-biochar was 310 m(2) g(-1) and 298 m(2) g(-1) for the SCB-SO3H. The pore volumes recorded were 0.09 cm(3) gm(-1) for SCB, 1.18 cm(3) gm(-1) for SCB-biochar and 1.17 cm(3) gm(-1) for SCB-SO3H. Similarly, the pore diameters for SCB, SCB-biochar and SCB-SO3H were 1.95 nm, 3.92 nm and 3.21 nm, respectively. The acid densities were 0.03 mmol g(-1) for SCB, 1.44 mmol g(-1) for SCB-biochar and 5.63 mmol g(-1) for SCB-SO3H catalyst. The FAME production process was optimized; reaction time (1.5 h), reaction temperature (60 degrees C), catalyst concentration (2 wt%) and methanol:PFAD molar ratio (10:1). The optimized conditions alongside the optimized sulfonation parameters gave a FAME yield of 98.6%. CHNS analyzer was utilized for the reusability test and SCB-SO3H was used for seven reaction cycles. Hence, the gained results exposed a promising feasibility of the application of waste biomass and feedstock, as an alternate option for the synthesis of a heterogeneous acid catalyst and biodiesel production. (C) 2020 Elsevier B.V. All rights reserved.