Highly microporous carbon materials with high apparent surface areas (up to 2400 m(2).g(-1)) were obtained by heat treatment of mixtures of demineralized Kraft lignin and sodium hydroxide, The application of a statistical tool, the response surface methodology, was used to determine the optimum operation conditions for preparing activated carbon able to adsorb large quantities of organic compounds. For that purpose, three parameters were varied: temperature of activation, sodium hydroxide and demineralized Kraft lignin percent mass ratio, and nitrogen flow rate. This carbon was tested for the adsorption of methylene blue that is a model compound for the most usual organic pollutant behavior, such as dyes. The adsorption of methylene blue was 93.2 g/100 g activated carbon, and this has a high microporosity and a specific surface area of 2610 m(2).g(-1). The optimum preparation conditions of this best activated carbon were determined at 755 degrees C, 22.4% Kraft lignin, and 200 cm(3) N(2).min(-1).