Kinetic study of Lignin Dissolution in Kraft Pulping Process of Wheat Straw by Glycerol

In this study، the kinetic of the lignin dissolution in paper pulping process of wheat straw by Glycerol was carried out under the reflux conditions in the presence and absent of 2% NaOH as catalyst، at 200°C and selected time 0 to 180 min. Obtained results showed with an increasing in paper pulping process time، the residual lignin in pulp، carbohydrate yield and recovery decreases in the presence and absent of catalyst. We presented rate equations versus residual lignin in paper pulp for each phase of lignin dissolution. Investigations showed the kinetic of lignin dissolution in this condition is first-order reaction and rate constants in each phase of lignin dissolution are 3×10-3، 6×10-4 and 4×10-3، 1×10-3 respectively.