Changing the Structure of Brown Coal by Alkaline Activation with Thermal Shock

Resumo

The solid thermolysis products (STPs) of brown coal formed upon alkaline activation with thermal shock (TS)—the rapid introduction of coal with KOH into a reactor heated to t_TS ≤ 850°С—were studied. It was established that the structural fragmentation of coal (C–O and C–C bond heterolysis) dominated at t_TS ≤ 400°С. With an increase in t_TS to 850°С, the formation of subnanopores (≤1 nm) occurred simultaneously the growth of polyarenes and their condensation into polyarylenes, and it was limited by the diffusion of KOH (or K) and formed the final porous structure of STPs.