Investigation on pulp production using γ-valerolactone organosolv process from birch wood

In this study, the possibility of using γ-valerolactone as a green organic solvent for production of pulp from birch wood was investigated. The variables of cooking condition were different L/W (3 and 5), temperature (170 and 180°c), and time (60, 120 and 180 minutes) in the constant ratio of γ-valerolactone to water 50/50.The amount of yield, rejects, kappa number, viscosity and degree of polymerization of different cooking conditions were determined. Based on the results, the L/W ratio 5, temperature 170 ° C and time 180 minutes with 59.58% yield, 0% rejects, 45.06 kappa number, 1158 viscosity and 3633 degree of polymerization was selected as the optimal treatment for γ-valerolactone cooking. After measuring the insoluble and soluble lignin in acid, the mono saccharides in the pulp and spent liquor were ascertained by high-performance anion-exchange chromatography (HPAEC-PAD) and the hydroxy methyl furfural, furfural and organic acids in liquor measured by high performance liquid chromatography (HPLC) and the mass balance of the pulp compositions produced by the γ-valerolactone-water process was calculated based on the dry weight of wood and pulp. The molar mass distribution of pulp was measured by gel permeation chromatography (GPC). The 50,100 and 2000 degree of polymerization of optimum treatment were 1.536, 7.690 and 55.683. Also degree of polymerization index were calculated 12.53. The results of this research show the success in the production of pulp from birch wood by clean γ-valerolactone process and increasing in cooking time compare to temperature has been advantage.