This study analyzes the operation of Biomass System (BIO System) technology for the combustion of pellets from almond and olive trees within the circular economy model. Its aims are the reduction of greenhouse gas emissions as well as waste removal and its energy use by reintroducing that waste into the production process as technological nutrient. In order to do so, combustion efficiency under optimal conditions at nominal power was analyzed. In addition, a TESTO 350-XL analyzer was employed to measure CO and NOx emissions. High combustion efficiency values were obtained, 87.7% and 86.3%, for pellets from olive tree and almond tree, respectively. The results of CO and NOx emission levels were very satisfactory. Under conditions close to nominal power, CO emission levels were 225.3 ppm at 6% O2 for pellet from almond tree and 351.6 ppm at 6% O2 for pellet from olive tree. Regarding NOx emissions, the values were 365.8 ppm at 6% O2 and 333.2 ppm at 6% O2 for pellets from almond tree and olive tree, respectively. In general, these values were below those legally established by current legislation in European countries. Therefore, BIO System technology is a perfectly feasible option in terms of energy use and circular economy.