Biomass minimum ignition temperature prediction through differential study of thermogravimetric analysis

With the global goal of minimising energy dependence on fossil fuels, biomass is taking on a crucial role, not only as an energy source, but also as a means of reducing greenhouse gas emissions and incorporating the use of new biofuels. However, the storage of processed biomass in dust form introduces several inherent hazards, e.g. the formation of fires due to self-ignition or the deposition of this powdery material on hot surfaces, thus reaching the minimum ignition temperature of dust layer. These hazards are not only observed in the industrial safety area but are also associated with the process of generating energy from biomass in controlled environments. In order to quantify these critical risks, this study focuses on correlating the devolatilization temperature ranges of the main polymers of biomass from the differential analysis of thermogravimetric curves (DTG) to obtain a prediction of the minimum ignition temperature of dust layer. This parameter has been experimentally determined according to UNE - EN ISO/IEC 80079-20-2:2016. Six samples of lignocellulosic biomass of different origin and composition were studied. The Fraser-Suzuki deconvolution method was used to determine the percentage of hemicellulose, cellulose, and lignin in order to establish a correlation between the composition and the flammability tendency of the samples. The results of the study underline the effectiveness of differential analysis of thermogravimetric curves as a fast and accurate tool for predicting the minimum ignition temperature of dust layer in lignocellulosic biomasses. This novel method, which requires only 60 mg and has an average error of 1.10% compared to experimental temperatures, improves the understanding of the combustibility of lignocellulosic biomasses by providing a more complete thermal record than that reported by international standard test methods. Therefore, its implementation would provide an improvement in terms of preventive and environmental risk management strategies related to combustible dust accumulation.