Efficiency and gases emissions with incineration of composite and one-component biofuel briquettes in room heater

In accordance with the technical standard ČSN EN 13229 "Inset appliances for heating including open fires fired by solid fuels - Requirements and test methods" was performed the basic assessment of thermal efficiency and emission parameters of prototype of combustion accumulation stove SK-2 with upper after-burning and nominal heat output of 8 kW. Verified gradually were the bio-briquettes of diameter 65 mm from mixture of wheat straw and 20% m/m of brown coal, wheat straw and 5% m/m of brown coal, wheat straw, mixture of wheat straw and 10% m/m of water and molasses solution, Ecobiopal created with the fermented blend of 33% m/m of digested clean water plant sludge and 67% m/m of wood chopped material, blend of wheat straw and 15% m/m of sugar beet pulp, mixture of timothy hay and 25% m/m of brown coal, timothy grass hay, meadow hay, mixture of meadow hay and 25% m/m of brown coal. The lowest CO emissions, when the limit value of 3000 mg/m3N at 13% of O2 has not been exceeded, determined for more strict 1st class and the highest efficiency at nominal heat performance, i.e. higher or equal to 70% (Class I) have been reached by the briquettes produced from mixture of wheat straw and 15% m/m of sugar beet pulp, timothy hay and mixture of meadow hay with addition of 25% m/m of brown coal. Further were measured NOx and HCl emissions. NOx values were significantly lower than limit values determined for similar combustion of solid biofuel. Higher differences of HCl emissions correlate with various Cl content in fuels. Only the wheat straw briquettes with share of 25% m/m of brown coal have exceeded the limit value by 16%. Other fuels have shown considerably lower values. The results have proved better heat-technical and emission parameters of blended briquettes and are significant also for solid biofuels and solid recovered fuels standardization as well as for increasing efficiency method detection and ecological parameters optimization including HCl emissions.