Catalytic performance of potassium in lignocellulosic biomass pyrolysis based on an optimized three-parallel distributed activation energy model

Abstract

The pyrolysis kinetics of extractive tobacco stem and pretreated samples with different KCl impregnation ratios were investigated by the thermogravimetric experiment and an optimized three-parallel distributed activation energy model (DAEM). The significant fitting deviation for the cellulose pyrolysis and the unrealistic partial fitting curve for the hemicellulose pyrolysis were mitigated during the optimization process by applying the Avrami-Erofeev-DAEM and reducing the latent interferences. The optimized parameters with good fitting qualities (about 2%) were obtained. Furthermore, based on the experimental results (changes in reaction intensity and temperature), model calculations (differences in reaction order, activation energy, volatiles fraction, etc.), and the maximum residual error analysis (with a high catalytic reaction rate) regarding different KCl-to-biomass ratios, it was found that KCl kinetically promoted the hemicellulose pyrolysis, which can be utilized as the theoretical support for the industrial application.

Keywords: Biomass pyrolysis; Distributed activation energy model; Potassium; Tobacco stem.