Fast, High Quality and Low-Cost Biodiesel Production using Dolomite Catalyst in an Enhanced Microwave System with Simultaneous Cooling

Abstract

In this study, biodiesel production with canola oil and methanol in the presence of dolomite catalyst was examined in a multimode Enhanced Microwave System (EMS) with simultaneous cooling worked under constant, continuous microwave (MW) power and isothermal conditions. The experiments were carried out in the EMS utilizing the "one variable at a time" method to estimate optimum values of five experiment parameters named methanol-to-oil molar ratio (n_m/n_o), amount of catalyst (% wt of oil), temperature (T,°C), reaction time (t, min) and absorbed MW power (P_a,W). The optimum values of these parameters were obtained as 9, 5%, 65°C, 120 min., 48 W, respectively. At the end of the study in EMS, an experiment was repeated in the Conventional Heating System (CHS) at the optimum conditions. Accordingly, it was found that the yield of biodiesel in EMS (99.1%) during the same period was 30.2% higher than in CHS (76%). Faster, higher-quality, and lower-cost biodiesel production was accomplished when compared to the CHS. Energy and production cost saving were accomplished by 58.2 % and production rate was increased by 30.4% in EMS. Furthermore, selective and homogenous heating effect on catalyst's local surface temperature and strong vibrational effect of MW on dipoles provided advantages in terms of catalyst activity and different methyl ester content. This showed that biodiesel with different properties can be produced using same oil in the EMS.