Study of semi-coke characteristics obtained by slow pyrolysis of nut shells at different temperatures of the heating medium

Characteristics of the semi-coke obtained by slow pyrolysis of nut shells were studied. The shells of four types of nuts (walnuts, pine nuts, hazelnuts, and peanuts) were used as the studied samples. The process was implemented in a batch installation using indirect heating of the sample at heating medium temperatures of 400–600 °C. Proximate characteristics were determined for the obtained solid-phase products (semi-coke) and their morphological structure was studied. A nonlinear increase in the carbon content and, as a result, the calorific value was observed with a rise of the carbonification degree of the semi-coke samples (due to an increase in the heating medium temperature). A significant change in the morphology of the semi-coke particles obtained at higher temperatures was also recorded.