The time-resolved mechanocatalytic partial depolymerization of cellulose is carried out at 500 rpm and a filling level of 20 % with 3 mm zirconia grinding balls for 3 % and 6 % acid content. The time range for the experiments with 6% acid content is up to 70 min and for the experiments with As expected, the temperature for an acid content of 3 % and 6 % increases with increasing grinding time (Figure ). At first, a sharp increase in temperature can be seen, which decreases with increasing grinding time and approaches a maximum. The acid loading has no influence on the temperature and the curves for 3 % and 6 % sulfuric acid content run parallel within the standard deviation. The limit is reached after 50 min at a temperature of around 85 °C. This shows that the selected grinding cycle intervals of 5 min grinding and 2 min cooling protect against overheating and subsequent reactions under the given reaction conditions.