As a result of dispersion analysis of the experimental data the mathematical model of process thermo-chemical activation of lignin, formed during catalytic delignification of birch wood, the potassium hydroxide on the values of the parameters of porous structure of  nanoporous carbon materials was obtained. It was determined that the process in optimal conditions allows to obtain of the lignin based carbon materials with specific surface of more than 2500 m²/g and a pore volume of 1.4 cm³/g. The obtained nanoporous carbon materials possess high sorption capacity for benzene (1.1 g/g), exceeding the capacity of domestic and foreign commercial carbon sorbents in 3-6 times.