Abies Wood Delignification by Hydrogen Peroxide at Mild Conditions in the Presence of Sulfuric Acid Catalyst

The influence of abies-wood delignification conditions in the medium "hydrogen peroxide - acetic acid - water - sulfuric acid catalyst" on the yield and composition of cellulosic product was studied. It was established that the content of residual lignin in cellulosic product and the yield of product are decreased with the growth of temperature, H2O2 and CH3COOH concentrations, liquid/wood ratio (LWR) and time of the process. The high yield of microcrystalline cellulose (49 % wt) with residual lignin content 3.4 % wt. was obtained at 100 degrees C, concentrations of H2O2 and CH3COOH4 % wt. and 30 wt, respectively, LWR 10, time 4 h. The oxidative delignification process is described by the first order equation. The rather high value of activation energy (82 kJ/mol) points on the absence of diffusion limitations at the used conditions of abies-wood oxidative delignification.