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 kW(th) 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 unbumt 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. (C) 2014 Elsevier B.V. All rights reserved.