Biomass combustion with CO2 capture by chemical looping with oxygen uncoupling (CLOU)

•CLOU process with biomass successfully demonstrated for the first time•A 1.5 kW CLC continuous unit with a Cu-based oxygen carrier was used.•Full combustion of biomass, with no tars in outlet gas stream, was obtained.•100% of CO2 capture efficiency reached at 935 °C with low solid inventory

Economic benefits can be expected in the future if CO2 capture and storage are implemented in energy generation from biomass combustion. The aim of this work is to investigate the combustion of biomass in a chemical looping with oxygen uncoupling (CLOU) process with inherent CO2 separation. The performance of biomass combustion in a continuously operated 1.5 kWth CLOU unit is presented. Particles prepared by spray drying containing 60 wt.% CuO were used as an oxygen carrier. Milled pine wood chips were used as fuel. The work focused on the effect of fuel reactor temperature on the CO2 capture and the combustion efficiency of the CLOU process with biomass. Under CLOU operation, biomass combustion was complete to CO2 and H2O without the presence of any unburnt material, including tars. Moreover, high carbon capture efficiencies were achieved using very low oxygen carrier inventories and without a carbon separation unit. This is the first time that the CLOU concept has been demonstrated in a continuous CLC unit using biomass as fuel.

Graphical abstractThe use of biomass in the 1.5 kWth CLOU unit.Figure optionsDownload full-size imageDownload as PowerPoint slide