The energy value and economic efficiency of solid biofuels produced from digestate and sawdust

Primary energy sources have limited deposits and their exploitation has a negative impact on the environment. Biofuels production is an efficient and profitable method of environmentally-friendly energy production in terms of economic reasons. In recent years use of renewable energy sources (RES) in the Polish energy balance can be noticed. The main sector in which can be observed a dynamic growth is the biomass market, with the solid biofuel market in particular. The aim of this research was to perform an economic and energy analysis of briquettes and pellets production. The obtained results of economic analyzes have shown that the individual production of solid biofuels from digestate is more profitable than using sawdust as a substrate. The costs of producing solid biofuels from solid fraction of digested pulp, as well as their calorific value, make the discussed substrate to be used to produce energy. The calorific value of the solid biofuel produced from the digested pulp solid fraction (DSF) can be compared to the calorific value of biofuel generated from sawdust. The digested pulp can be considered as an alternative to the sawdust in the production of solid biofuels.