The depolymerization of acid-impregnated cellulose in planetary ball mills was investigated under the perspective of the influence of reaction parameters. Several process, technological and chemical parameters were examined. It was found that with a higher rotation frequency v(rot), smaller milling balls and a milling ball filling degree Phi(MB) of approximately 0.3, the highest solubility could be reached and the milling time could be reduced. The use of milling vessels with larger diameter was beneficial. Variation of the milling ball material showed huge influence and a linear correlation between solubility and density of the milling ball material was observed. Kinetic investigations indicate that the degradation of the impregnated cellulose follows a first order model. (C) 2015 Elsevier B.V. All rights reserved.