Solid superacidic and superbasic catalysts for enhanced biodiesel production through sequential esterification and transesterification
Journal
European Biomass Conference and Exhibition Proceedings
Journal Volume
2017
Journal Issue
25thEUBCE
Pages
1307-1317
Date Issued
2017
Author(s)
Abstract
Soybean oil containing free fatty acids (FFA, palmitic acid, 5.0 wt%) was converted to biodiesel by a two-step process in a catalytic fixed-bed batch reactor using three different catalysts. The solid superacidic SO 4 2- /ZrO 2 /Al 2 O 3 catalyst was prepared with 0.1-1.5 M H 2 SO 4 and calcined at 300-700 ¢XC. In addition, two solid superbasic catalysts, KF/CaO-Fe 3 O 4 and Na/NaOH/Al2O3, were synthesized with 5-25 wt% KF loading and 10-25 wt% NaOH, respectively, then calcined at 200-700 ¢XC. The efficiency of FFA removal by SO 4 2- /ZrO 2 /Al 2 O 3 in a 3 h reaction was much higher than Amberlyst IR 120 (80.0% compared to 30.0%), but lower than Amberlyst 15 (98.0%). As for biodiesel yield, optimal values of 83.0% and 100.0% were obtained using KF/CaO-Fe 3 O 4 and Na/NaOH/Al 2 O 3 , respectively. The transesterification mechanisms of soybean oil with FFA into biodiesel using solid superacid and superbasic catalysts were also proposed. We demonstrated the removal and conversion of FFA in soybean oil by first esterifying the oil over the SO 4 2- /ZrO 2 /Al 2 O 3 surface. The soybean oil was then converted into biodiesel via transesterification occurring at the surfaces of KF/CaO-Fe 3 O 4 and Na/NaOH/Al 2 O 3 . ? 2017, ETA-Florence Renewable Energies. All rights reserved.
Subjects
Biodiesel
Catalysis
Resource recovery
Soild superacidic/superbasic catalyst
Transesterification
SDGs
Type
conference paper