Renewable hydrogen production by solar-powered methanol reforming.

The present study demonstrates the possibility of generating hydrogen by methanol steam reforming at temperatures of 235–260 °C inside a non-concentrating solar collector, ideally for stationary fuel cell systems. In contrast to the current state-of-the-art, the solar collector provides all heat required for heating and evaporation of the reactants, endothermic reaction, and compensation of heat losses, without any external heat supply (such as from combustion of fuel or electric heating) and without the need for concentration of sunlight (as in conventional parabolic trough systems). Without the need for solar concentration, the system is simpler and more compact than conventional systems, and it can utilize all direct and indirect incident sunlight. The solar collector-reactor achieves hydrogen generation up to 6.62 L STP min −1 per m 2 collector area (equivalent to 1088 W m −2 LHV) under 1 sun, with solar-to-hydrogen efficiencies up to 78% and total energetic efficiencies (considering solar and fuel input) up to 43%. [ABSTRACT FROM AUTHOR]