New materials technologies for hydrogen generation

A thermochemical cycle is described that demonstrates the use of biomass or lignite-derived synthesis gas to reduce New Zealand ironsand, which is subsequently steam-oxidised to generate pure hydrogen. The redox reactions for this cycle have been thermodynamically modelled, giving an indication of the temperature ranges required to achieve water splitting and the potential sensitivity of the process to partial pressures Of CO(2). A fixed bed reactor showed reproducible oxide reduction behaviour over 10 redox cycles but only achieved limited conversion to 64% residual Fe(3)O(4) (18%Fe). Fluidised bed reactor studies carried over a comparable timeframe using CO/N(2) Mixtures demonstrated a high degree of reduction to 76%Fe.