Process simulation and economic analysis of dolomite catalyst based biodiesel production from Nepalese Jatropha Curcas

Abstract

This study presents a detailed design, cost estimation and sensitivity analysis to determine the commercial viability of a Jatropha biodiesel plant with Nepal as a representative case. Here, we present a biodiesel production process utilizing dolomite PB-20, an inexpensive solid catalyst, that allows easy retrieval of catalysts for reuse and easier product separation compared to the conventional liquid catalyst based production process. The transesterification and the subsequent separation processes were simulated using Aspen Plus to determine the amount of raw materials, the sizes of the equipment's and the total utility required for producing 43 million liters biodiesel per year. The total capital cost and the production cost for the plant of this scale was calculated to be $23 million and $51 million respectively. Similarly, the final biodiesel selling price was calculated to be $1.23/l. The selling price of the biodiesel was found to be highly sensitive to the purchase cost of the Jatropha oil. A 25% reduction in the Jatropha oil purchase cost from the base case price of $0.97/l will lower the biodiesel selling price to $1.00/l making it competitive with petro-diesel (current selling price of $1.02/l). The economic viability of the dolomite catalyst based biodiesel production plant and thus, the adoption of biodiesel as a substitute for petro-diesel is strongly dependent on the purchase cost of the Jatropha oil. This study illustrates the potential of dolomite catalyst based biodiesel production process and provides an important reference value for a more detailed policy level study to develop appropriate biofuel policies and to make investment decisions.