Transportation Fuels from Renewable Hydrogen and Green Carbon Dioxide - A Technical, Economic and Environmental Evaluation

Transportation Fuels from Renewable Hydrogen and Green Carbon Dioxide – A Technical, Economic, and Environmental Evaluation12.04.2017D. Bongartz1, A. Bardow6,2, J. Burre1, S. Deutz2, L. Doré3, K. Eichler4, T. Grube5, B. Heuser4, L. Hombach3, S. Pischinger6,4, M. Robinius5, D. Stolten6,5, L. Schulze Langenhorst1, G. Walther3, A. Mitsos6,1*1: Process Systems Engineering (AVT.SVT), RWTH Aachen University, 52074 Aachen, Germany2: Chair for Technical Thermodynamics, RWTH Aachen University, 52072 Aachen, Germany3: Chair of Operations Management, RWTH Aachen University, 52072 Aachen, Germany4: Institute for Combustion Engines, RWTH Aachen University, 52074 Aachen, Germany5: Electrochemical Process Engineering (IEK-3), Forschungszentrum Jülich, 52425 Jülich, Germany6: JARA-ENERGY, 52056 Aachen, GermanyThe desire to reduce greenhouse gas emissions from the transportation sector along with the increasing penetration of fluctuating renewable power sources in several countries have led to an increasing interest in the production of synthetic fuels from electricity [1]. Most of these processes employ water electrolysis in order to produce hydrogen. Apart from direct use in fuel cell electric vehicles, hydrogen can also be reacted with CO2 to form various gaseous or liquid organic fuels that are more compatible with existing infrastructure and engines. Several pathways are being suggested in literature that use CO2 from different sources [2] and lead to different fuels [3]. However, comprehensive comparisons to assess the benefits and drawbacks of these options including both fuel production and use in transportation are still scarce. In this contribution, we present a detailed technical, environmental, and economic evaluation of several pathways that are considered promising. This includes direct application of hydrogen in a fuel cell vehicle, and conversion of hydrogen and CO2 to combustion engine fuels like methane, methanol, and different methyl ethers, some of which can also be used as blend components with conventional fuels [4]. The CO2 used is assumed to be a byproduct of biogas upgrading, which is already being done at a number of operating biogas plants in order to obtain biomethane of higher purity [3]. The pathways are evaluated with respect to their well-to-wheel efficiency and greenhouse gas emissions, and fuel cost. A technical analysis is conducted based on detailed process simulations in order to highlight what causes the differences in the performance of the different pathways, and an outlook is given on the potential for improved production processes.References:[1] M. Bailera, P. Lisbona, L.M. Romeo, S. Espatolero. Renew. Sust. Energ. Rev. 69: 292–312, 2017. [2] G. Reiter, J. Lindorfer. J. CO2 Util. 10: 40–49, 2015.[3] W. Wang, S. Wang, X. Ma, J. Gong. Chem. Soc. Rev. 40: 3703–3727, 2011. [4] L. Lautenschütz, D. Oestreich, P. Seidenspinner, U. Arnold, E. Dinjus, J. Sauer. Fuel 173: 129–137, 2016