Techno-economic and environmental assessment for enhancementbiodiesel production process using rotating tube reactor and dry washing

Abstract

The study aims at exploring the potential use of rotating tube reactor (RTR) and performing economic analysis as wells as addressing the challenges associated with the utilization of different feedstocks including of refined palm oil (RPO) and waste cooking oil (WCO) for biodiesel production. The type of feedstock strongly influenced the optimum reaction temperature. For instance, RPO can produce biodiesel in the RTR at room temperature while WCO required the external heat source for biodiesel production at 65°C. In addition, two transesterification steps of WCO were required to achieve 95.16%. Simulation results found that the process intensification using RTR and dry washing gave the highest biodiesel yield and lowest energy consumption for both RPO and WCO feedstocks (B1 and B2 cases) based on 100 L/day of biodiesel production. However, the economic analysis revealed that A2 (RPO, RTR-wet washing) case demonstrated the lowest manufacturing cost and highest net present value of 61.6 and 232.7 thousand USD, respectively. On the other hand, the CO2 emission obtained from the process intensification cases was higher than the conventional process because the specific energy consumption of RTR was measured from the lab scale. Sensitivity analysis confirmed the significant impact of oil and biodiesel prices on the economic feasibility for biodiesel production. Furthermore, the minimum biodiesel selling price of 1.3 USD/kg was required to achieve economically viable for all plant processing capacities from 4,000 to 30,000 L/day based on the A2 case. This can be concluded that RTR is a promising reactor for biodiesel production based on both economic and environmental consideration.