Experimental assessments of pyrolytic and fluid-dynamic interactions between pretreated residual biomasses and fluidized beds made up of oxygen carriers for chemical looping gasification

•Study of 3 oxygen carriers (OCs) and torrefied/washed wheat straw + 2 wt% CaCO3.•Devolatilizations of pretreated wheat straw in fluidized-bed OCs (700–900 °C)•Study of bubbling fluidization quality of biomass ashes/OC mixings at 700–1000 °C.•Pretreatments, OCs, and temperature influenced syngas and fluidization quality.