Roadmap to economically viable hydrogen liquefaction U. Cardella a,b , L. Decker a,* , H. Klein b a Linde Kryotechnik AG, D€ attlikonerstrasse 5, 8422 Pfungen, Switzerland b Institute of Plant and Process Technology, TU Mu ¨ nchen, 85748 Garching, Germany article info Article history: Received 29 September 2016 Received in revised form 7 January 2017 Accepted 10 January 2017 Available online xxx Keywords: Hydrogen Liquefaction Roadmap Efficiency Costs Mobility abstract The distribution of hydrogen in liquid state has several advantages because of its higher volumetric density compared to compressed hydrogen gas. The demand for liquid hydrogen (LH 2 ), particularly driven by clean fuel cell applications, is expected to rise in the near future. Large-scale hydrogen liquefaction plants will play a major role within the hydrogen supply chain. The barriers of built hydrogen liquefiers is the low exergy efficiency and the high specific liquefaction costs. Exergy efficiency improvements, however, are limited by economic viability. The focus of this paper is to present a roadmap for the scale- up of hydrogen liquefaction technology, from state-of-the-art plants to newly developed large-scale liquefaction processes. The work is aimed at reducing the specific liquefaction costs by finding an optimal trade-off between capital costs and operating costs. To this end, two developed hydrogen liquefaction processes were optimized for specific energy con- sumption and specific liquefaction costs, showing the potential to reduce the specific liquefaction costs by 67% for a 100 tpd LH 2 plant compared to a conventional 5 tpd LH 2 plant while achieving a specific energy consumption between 5.9 and 6.6 kWh per kg LH 2 with technology that is or will be available within 5 years. The results make liquid hydrogen a viable distribution route for hydrogen for mobility. © 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Introduction Air pollution and global warming coming along with global- ization, a growing world population and its ambition for higher living standard menace the future of mankind. For the last 200 years mobility, heating and power generation relied mainly on combustion of hydrocarbons causing carbon diox- ide, soot and other pollutants. Carbon dioxide with more than 80% share is by far the main greenhouse gas (GHG) [1]. Transport, being responsible for one third of total GHG emission in the US [1] and about 20% in the EU, is the only major sector in the EU where greenhouse gas emissions are still rising [2]. Any technological progress in combustion en- gines has been outbalanced by an increasing individual mobility and the demand for larger and heavier vehicles. In recent years, focus has therefore been set on individual cars accounting for about 75% of all CO 2 emissions coming from transport [2]. Hydrogen has come into focus as a potential future energy carrier as it reacts in a fuel cell with atmospheric oxygen releasing only electric energy, heat and water. Fuel cells can * Corresponding author. Fax: þ41 52 304 0580. E-mail addresses: umberto.cardella@tum.de (U. Cardella), lutz.decker@linde-kryotechnik.ch (L. Decker), harald.klein@apt.mw.tum.de (H. Klein). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/he international journal of hydrogen energy xxx (2017) 1 e10 http://dx.doi.org/10.1016/j.ijhydene.2017.01.068 0360-3199/© 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Please cite this article in press as: Cardella U, et al., Roadmap to economically viable hydrogen liquefaction, International Journal of Hydrogen Energy (2017), http://dx.doi.org/10.1016/j.ijhydene.2017.01.068