In this study in which the Taguchi method was used, the optimization of sulphur removal by H2O2/H2SO4 solutions was carried out over lignite with higher content of sulphur from Artvin/Yusufeli, Turkey. In experiments, the ranges of experimental parameters were between 0.25 and 6.0 mol L-1 for H2O2 concentration, 0.25-4 mol L-1 for H2SO4 concentration, 10-60 degrees C for reaction temperature, 0.01-0.08 g mL(-1) for solid-to-liquid ratio, 15-120 min for reaction time, 200-300 rpm for stirring speed and 710-120 mu m for particle size. The optimum conditions for these parameters have found to be 60 degrees C of temperature, 0.06 g mL(-1) of solid-to-liquid ratio, 60 min of reaction time, 250 rpm of stirring speed and -250 + 180 mu m of particle size. A statistical experimental arrangement, L-25(5(6)) was prepared to determine optimum sulphur removal and ash removal ratios. The obtained yields were 97.85% in removal of total sulphur, 56.54% in removal of pyritic sulphur, 21.33% in removal of organic sulphur and 61.52% in removal of ash. According to variance analysis, it was seen that all parameters were effective in removal of pyritic and total sulphur, reaction temperature, solid-to-liquid ratio, reaction time, stirring speed, H2O2 and H2SO4 concentrations in removal of organic sulphur, and other parameters except acid concentration in removal of ash. (c) 2006 Elsevier Ltd. All rights reserved.