Chemical looping combustion and gasification of swine manure with a Cu-Based oxygen carrier

• Energy valorization of the swine manure in CLC and CLG has been performed. • High combustion and CO 2 capture efficiencies (87–99 %) are reached in iG-CLC. • Syngas yield ranged between 0.4 and 0.7 Nm 3 /kg of swine manure in CLG. • NO and NH 3 concentration decrease with increasing the temperature (CLC) or λ (CLG). • Low tar content of around 1.3 g/kg of swine manure was obtained in CLG. The thermochemical conversion of swine manure by using Chemical Looping Combustion (CLC) and Chemical Looping Gasification (CLG) is an interesting option to obtain bioenergy and solve some environmental issues related to this waste. In this work, experimental tests using swine manure as fuel and a Cu-based oxygen carrier (14 wt% CuO) in a 0.5kW th continuous unit have been performed. For CLC conditions, the effect of the temperature (800–900 °C) and the fluidization agent (CO 2 or steam) on the combustion and CO 2 capture efficiencies was evaluated. In general, high combustion (97–99 %) and CO 2 capture (87–99 %) efficiencies were achieved, which improved by increasing the operating temperature. For CLG conditions, the effect of the oxygen-to-fuel ratio (λ = 0.2, 0.3 and 0.4) on the gas product distribution, CO 2 capture efficiency and tar composition was studied using steam and CO 2 as fluidizing agents at 900 °C. The CO 2 capture potential improved by increasing the oxygen-to-fuel ratio. Regarding the tar distribution, naphthalene was the main product followed by benzene, acenaphthylene, indene and phenanthrene. Additionally, for both processes, CLC and CLG, the distribution of nitrogenous compound emissions (N 2 , NH 3 , N 2 O, NO 2 and NO) was analyzed. It was observed that the N-swine manure was mainly converted into inert N 2 .