Textural analysis for better correlation of the char yield of pyrolysed lignocellulosic materials

A new empirical formula, based on the surface fractal dimension, the porosity, the botanical composition and the ash content of the precursor is proposed for the assessment of the char yield, Y (wt %) of lignocellulosic materials pyrolysed in a 600–900 °C temperature range. The following equation is proposed: Y ( wt % ) = D f ln ɛ [ L [ 0.59 − 2.74 × 10 − 4 ( t ° C − 600 ) ] + 0.22 C + A − 0.1 E [ 1 + 2 × 10 − 3 ( 600 − t ° C ) ] ] where Df, ɛ, L, C, A and E are parameters of the precursor, namely: fractal dimension, porosity (%) and percentage (wt%) of lignin, cellulose, ash and extractives, the t temperature, being in the Celsius grade. lues calculated by the formula fit satisfactorily with the experimental results, the gap being less than 0.5%.