Techno-economic analysis of alternative fuel production routes –Uncertainty and Global Sensitivity Analysis

Kurzfassung

Motivation The defossilization of the transport sector is subject to worldwide research. Several routes and alternative fuel options are investigated. A standardized techno-economic analysis may aid the evaluation and comparison of different production routes. Especially when comparing different routes and process designs it is elemental to know the uncertainty of the performance indicator to be compared. Additionally, it is important to identify the main contributors to the uncertainty. Hence, this work focuses on a methodology for uncertainty and global sensitivity analysis in the context of alternative fuel production routes. Methodology Process modelling is conducted in a flowsheet simulator (Aspen Plus) providing stream and unit data for the techno-economic analysis. This data is further processed in DLR’s Techno-Economic Process Evaluation Tool TEPET. It already gives a good indication about eventual production costs and options for further process optimization. The validity of assumed cost improvements is often questionable. In this work this tool is extended from calculating the specific net production costs to analyzing the uncertainty and global sensitivity. The uncertainty analysis is conducted via Monte-Carlo simulation, which is a widely accepted approach for estimating uncertainties. The aim of the uncertainty analysis is to quantify the uncertainty. For allocating the uncertainty to a specific input parameter, a global sensitivity analysis is conducted. In comparison to local sensitivity analysis, most often a once-at-a-time method, global sensitivity analysis investigates the whole parameter space. This is especially important when the underlying model is not linear. Different estimators for estimating the global sensitivity will be compared. An exemplary process route for the production of alternative fuels (Biomass-to-Liquid, Power-to-Liquid or equivalent) will be used to show the results of the uncertainty and global sensitivity analysis. Results This work focuses on developing methodological advances in the techno-economic analysis in terms of uncertainty and global sensitivity analysis. One exemplary process route to produce alternative fuels (Biomass-to-Liquid, Power-to-Liquid or equivalent) will be investigated. For this route, the uncertainty of the net production costs will be quantified and allocated to the specific input parameter using global sensitivity analysis. Different estimators for global sensitivity analysis will be compared regarding their performance to give recommendations for standardization.