Effects of NaOH-Na₂SO₃-thiourea-urea Treatment on Enzymatic Saccharification of Poplar (Populus simonii var.) Branch

Abstract

In this study, NaOH-Na₂SO₃-thiourea-urea aqueous solution was used to treat refiner mechanical pulp (RMP) prepared from poplar (Populus simonii var.) branch at temperature in the range of 120 to 140 °C for the modification of the enzyme saccharification, and the single factor tests were applied to determine the optimal conditions. As the results, a combination of the NaOH dosage of 4%, the Na₂SO₃ dosage of 12%, the CS(NH₂)₂ dosage of 13%, the CO(NH₂)₂ dosage of 16%, the treating temperature of 130 °C, the keeping time of 60 min, the soaking time of 15 min, and the pulp consistency of 20% was chosen as the optimal condition for the enzymatic saccharification. The glucose conversion of RMP cellulose obtained by the NaOH-Na₂SO₃-thiourea-urea treatment was 70.2%, which was higher than that (63.7%) by the NaOH-thiourea-urea treatment.