Abstract <p>The possibility of using atmospheric-pressure radiofrequency induction (RFI) plasma in argon for torrefaction of fuel pellets from high-moor peat to increase combustion efficiency is demonstrated. The component composition of the plasma flow has been determined by analyzing argon plasma emission spectra during peat surface treatment. The presence of OH radicals has been revealed, which have a destructive effect on natural peat polymers. As a result of polymer degradation, compacted fibrous structures that form the peat matrix acquired a loose surface. Thermogravimetric analysis methods established that during pyrolysis, the pellets have a smaller mass loss because of the removal of volatile components during plasma treatment, thereby reducing emissions into the atmosphere during combustion.</p>