Process design and supply chain optimization of supercritical biodiesel synthesis from waste cooking oils

A small scale biodiesel production facility based on the Mcgyan process is simulated in HYSYS and a follow-up techno-economic analysis is performed. Two feedstocks are analyzed: a soybean oil and waste cooking oil analogs. It is found that the soybean oil based process is not economical at such small scales, whereas the waste oil case has an NPV of $618K with an internal rate of return of 80%. The economic feasibility of a distributed system of small scale biodiesel production facilities in Greater London using waste vegetable cooking feedstock is also investigated. It is found that this system is feasible with a total of 20 installed facilities and an NPV of $1.1MM. A scheme is then implemented which reduces the total capital expenditure per facility based on the mass production of similar facilities. As expected, this scheme reduces the total capital cost of the system. Finally, a Monte Carlo scheme is implemented to study how the variability in economic parameters affects the system. It is found that the system is most sensitive to the sale price of biodiesel but that in all cases a positive NPV is returned. These analyses support the feasibility of small scale locally based biofuel production from locally sourced feestocks. (C) 2013 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.