A critical analysis of thermochemical cellulosic biorefinery capital cost estimates

This analysis quantifies the impact of capital cost estimation methodologies and probability distributions on the 20-year net present values (NPV) of six thermochemical cellulosic biofuel pathways. It reviews the methodologies and distributions employed in the open literature, and compares the latter with those reported for existing energy projects. A sensitivity analysis calculates the impact of methodology choice on the NPV of each pathway scenario and an uncertainty analysis calculates the impact of probability distribution choice on the same. The sensitivity analysis finds that the choice of pessimistic or optimistic estimation methodology changes NPV by up to $300 million. The uncertainty analysis finds that the representation of capital cost by asymmetrical probability distributions increases the standard deviations of the 20-year NPV cumulative distribution functions by up to 35% relative to symmetrical distributions. Finally, recommendations are given to improve capital cost calculations in cellulosic biofuel techno-economic analyses. (C) 2015 Society of Chemical Industry and John Wiley & Sons, Ltd