Pretreated residual biomasses in fluidized beds for chemical looping gasification: Analysis of devolatilization data by statistical tools

Previously, this research group performed devolatilizations of different wheat straw pellets in fluidized beds, as a preliminary investigation for chemical looping gasification (European research project CLARA, G.A.817841). Performances were there evaluated by: (i) integral-average parameters (gas yield, carbon conversion, and H2/CO molar ratio); (ii) syngas composition at the peak of gas release during unsteady-state devolatilizations of individual pellets. In this work, results were statistically analyzed by linear model regressions with the software R, assessing influences from: devolatilization temperature (700–900 °C), oxygen-carriers as bed-materials, biomass pretreatments (torrefaction, torrefaction-washing). For both integral-average and peak parameters, the temperature increase significantly augmented gas yield, carbon conversion and H2/CO ratio. In comparison to previous deterministic studies of this group, the effects of oxygen-carriers and biomass pretreatments emerged more clearly. In addition, statistically-proved linear models were provided, for future simulations of devolatilizations of the investigated biomasses in chemical looping gasification from 700 °C to 900 °C.