Parameters of high temperature steam gasification of original and pulverised wood pellets

Experiments on gasification of chars obtained from original and pulverised wood pellets were conducted in atmosphere of water steam and nitrogen under temperatures of 800, 900 and 950 °C. Molar flow rates of carbon containing product gases were measured and approximated using different models with respect to extents of carbon conversion in char of the pellets. Comparison of the random pore, grain and volumetric models revealed the best applicability for approximations of the random pore model. Apparent activation energies obtained as a result of application of the models to the data from experiments with char of original pellets were higher in comparison to those of pulverised pellets, except for a grain model. Approximations under 800 °C showed relatively big deviations from experimental data on the beginning of char gasification. This is attributed to catalytic effects from alkali metals in the pellets.

► The steam gasification of chars of original and pulverised wood pellets is considered.
► The chars were obtained by pyrolysis in different charring conditions.
► Three models were applied to predict parameters of char gasification.
► The grain and random pore models showed the best applicability for the predictions.
► Volumetric model was inept at fitting the data of the char gasification experiments.