9 - Use of carbohydrates for hydrogen storage

Abstract

Renewable carbohydrates are a promising hydrogen carrier because of its renewable abundance, low cost, high hydrogen storage density (e.g., >8% H2 mass% and >100kg of H2/m3), carbon-neutrality, and high safety. Theoretical yield and high-purity hydrogen production from carbohydrates becomes possible with a new technology called in vitro synthetic pathway biotransformation (SyPaB). Hydrogen production catalyzed by SyPaB has several distinguishable advantages: the highest chemical energy efficiency (122%), the highest product yield (~12moles of H2 per mole of hexose), fast reaction rate, and clean products (only H2 and CO2). The remaining major challenges are how to further decrease costs of enzymes and cofactors, increase their stability, and increase hydrogen production rates. Various potential applications of SyPaB-based hydrogen production include local hydrogen-generating stations as the most feasible application, and sugar fuel cell vehicles as the most ambitious application. These great applications and their potential markets are strong motivation to solve those challenges and bring about a new carbon-neutral hydrogen economy.