Techno-economic assessment of biodiesel production from canola oil through ultrasonic cavitation

Abstract

The immiscibility of oil and alcohol is a severe issue in biodiesel production as it causes a low mass transfer rate and long reaction time. This problem can be overcome by incorporating the intensification method, which significantly increases the contact surface area of oil and alcohol through various techniques. In recent years, ultrasonic cavitation has emerged as one of the most effective ways for this purpose. However, it is still unclear whether this technology will provide the industry with an economically profitable process. This paper attempts to assess the potential of ultrasonic cavitation from a techno-economic viewpoint. Two plants based on the conventional mechanical stirring and ultrasonic cavitation processes were designed using Aspen HYSYS V8.4. Total investment, costs of products, net present value, and internal rate of return were used to compare the two processes together. The total investment in the ultrasonic cavitation process was lower than that of the mechanical stirring process by approximately 20.8%. Compared to the conventional process, using ultrasonic reactors also caused products’ costs to reduce by 5.2%. Owing to a positive net present value and an internal rate of return of 18.3%, the ultrasonic cavitation process was a better choice. Moreover, ultrasonic cavitation resulted in a meaningful decrease in both consumed energy and the production of wastes. The overall energy consumption was reduced by 6.9% when ultrasonic cavitation was employed. The amount of waste produced in the ultrasound-assisted process was one-fifth of that in the mechanical stirring process.