Process analysis and optimization of biodiesel production from vegetable oils

The dwindling resources of fossil fuels coupled with the steady increase in energy consumption have spurred research interest in alternative and renewable energy sources. Biodiesel is one of the most promising alternatives for fossil fuels. It can be made from various renewable sources, including recycled oil, and can be utilized in lieu of petroleum-based diesel. To foster market competitiveness for biodiesel, it is necessary to develop cost-effective and technically sound processing schemes, to identify related key design criteria, and optimize performance. The overall goal of this work was to design and optimize biodiesel (Fatty Acid Methyl Ester ?FAME?) production from vegetable oil. To achieve this goal, several interconnected research activities were undertaken. First, a base-case flow sheet was developed for the process. The performance of this flow sheet along with the key design and operating criteria were identified by conducting computer-aided simulation using ASPEN Plus. Various scenarios were simulated to provide sufficient understanding and insights. Also, different thermodynamic databases were used for different sections of the process to account for the various characteristics of the streams throughout the process. Next, mass and energy integration studies were performed to reduce the consumption of material and energy utilities, improve environmental impact, and enhance profitability. Finally, capital cost estimation was carried out using the ICARUS Process Evaluator computer-aided tools linked to the results of the ASPEN simulation. The operating cost of the process was estimated using the key information on process operation such as raw materials, utilities, and labor. A profitability analysis was carried out by examining the ROI (Return of Investment) and PP (Payback Period). It was determined that the single most important economic factor is the cost of soybean oil, which accounted for more than 90% of the total annualized cost. Consequently, a sensitivity analysis was performed to examine the effect of soybean oil cost on profitability. It was determined that both ROI and PP quickly deteriorate as the cost of soybean oil increases.