Economic Comparison of Continuous and Batch Production of Biodiesel Using Soybean Oil

Continuing depletion of fossil fuel reserves and increasing environmental concerns have encouraged engineers and scientists to look for alternative, clean, and renewable fuels that can reduce fossil-fuels’ negative environmental impact and secure the energy supplies. Biodiesel has been considered as one of the best candidates for these renewable fuels. For its production, transesterification reaction of triglycerides is recognized as a feasible pathway. This reaction can be carried out in continuous or batch reactors, however, most of the other unit operations, like decanters and distillation columns, are operated continuously. Most of the studies of biodiesel production have been done in continuous models. In this paper, we evaluate batch and continuous processing options for biodiesel production from the economical point of view. The economic feasibility of biodiesel as well the plants configuration not only depends on technical design aspects but also on other important factors such as seasonal variation of feedstock, transportation costs, and storage costs of material. Therefore, our comparison involves size of the market, transportation distance from supplier to producer facility, and feedstock availability of soybean oil by the allocation of supply of raw material. It was found that based on these aspects, batch processing shows interesting results and should be considered for production rather that continuous production as it is done today. Moreover, a sensitivity analysis provides more insights of the flexibility of batch processing when scheduling variation is considered. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 11–24, 2013