Optimization of One-Stage Processes of Microcrystalline Cellulose Obtaining by Peroxide Delignification of Wood in the Presence of TiO2 Catalyst

The traditional method for obtaining microcrystalline cellulose (MCC) from wood raw material is multi-stage and it is based on the integration of environmentally hazardous processes of pulping and bleaching of cellulose and acid hydrolysis of amorphous part of cellulose. The paper describes an improved one-stage catalytic method of microcrystalline cellulose obtaining from softwood and hardwood based on peroxide delignification of wood in acetic acid-water medium under the mild conditions (100 °C, atmospheric pressure) in the presence of an environmentally safe solid catalyst TiO 2 . Experimental and mathematical optimization of the processes of MCC preparation by peroxide catalytic delignification of various types of wood was carried out. The following optimal modes of obtaining MCC with the yield 36.3–42.0 wt.% of abs. dry wood and residual lignin content ≤1.0 mas.%, hemicellulose ≤6.0 mas.% was established: for aspen – 5 wt.% H 2 O 2 , 25 wt.% CH 3 COOH, hydromodule = 10; for birch – 5 wt.% H 2 O 2 , 25 wt.% CH 3 COOH, hydromodule = 15; for abies – 6 wt.% H 2 O 2 , 30 wt.% CH 3 COOH, hydromodule = 15; for larch – 6 wt.% H 2 O 2 , 30 wt.% CH 3 COOH, hydromodule = 15.