GASEOUS EMISSIONS DURING AGRICULTURAL BIOMASS COMBUSTION IN A 50 KW MOVING STEP GRATE BOILER

Results of the study examining carbon monoxide and nitric oxide concentrations while burning different types of agricultural biomass: coffee husk pellets alone or in combination with wheat straw pellets and cherry stones, sewage sludge pellets, corn stover briquettes and a mixture of rye straw briquettes and miscanthus briquettes were presented. The combustion was performed in a 50 kW boiler type Biowarmer with a cast-iron moving step grate. The temperature in the combustion chamber did not exceed 800 degrees C. For all biomass types, only brittle slag was generated in the furnace, which was easily broken by a reciprocating movement of the grate. Carbon monoxide concentration in the flue gas except for the case of sewage sludge pellet firing did not exceed the permitted value of 3000 mg/m(3) and nitric oxide concentration 515 mg/m(3), both presented for 10% O-2 concentration in the flue gas based in dry gas. Hydrocarbon concentrations for all test runs were close to zero.