Performance of NiAl2O4 spinel derived catalyst + dolomite in the sorption enhanced steam reforming (SESR) of raw bio-oil in cyclic operation

The production of H2 from raw bio-oil with high yield and purity requires the development of reforming technologies with low energy requirements, minimized CO2 emissions, and stable and regenerable catalysts. This work studies the performance (activity, selectivity, stability and regenerability) in the sorption enhanced steam reforming (SESR) of raw bio-oil of a catalyst prepared by reduction of a NiAl2O4 spinel together with dolomite as CO2 sorbent. The reaction runs were carried out in a fluidized-bed reactor under the following conditions: 550–700 °C; space time, 0.15 and 0.30 gcatalyst·h/goxygenates; dolomite/catalyst mass ratio, 10 and 20; steam/carbon (S/C) molar ratio, 3.4; time on stream, 50 and 300 min. The highest H2 yield (>92 %) and purity (>99 %) in the CO2 capture period are obtained in the 600–650 °C range and with a dolomite/catalyst mass ratio of 10, due to synergy between catalyst and sorbent activity. The catalyst/sorbent system can be regenerated (4 h in air at 850 °C and subsequent reduction at 900 °C) and used in the successive reaction-regeneration cycles. The results are of relevant interest to progress towards scale-up of this process, which combines sustainable production of high purity H2 from biomass with CO2 capture.