Experimental Study on Emission Characteristics during Combustion of Single Bamboo Pellet

Some specific bamboo pellets were combusted in a tube furnace individually in different constant air flow rates (3,4 and 5 L/min) and at various temperatures (800, 900, 1000, 1100 and 1200℃), in order to investigate the dynamic emission characteristics during various respective combustion processes. The results indicate that the increase of carbon monoxide(CO) amounts in 3 L/min air flow rate was caused by kinetic controlled combustion at 800 ℃ and by diffusion controlled combustion at 1100 and 1200 ℃. The yield and concentration of nitric oxide(NO) reach the maximums at 900 ℃, as well as the conversion rate from fuel-N to NO (9.17%). As combustion temperature increases, the yield and concentration of NO decline from the peak, and the conversion rate (from fuel-N to NO) falls to the lowest value (3.90%) at 1200 ℃ in 3 L/min air flow rate. When a bamboo pellet burns sufficiently almost none sulfur dioxide(SO2) was released , while the S element can be kept in the ash or discharged in high-temperature flue gas in the form of sulfate which is converted from fuel-S. In oxy-lean atmosphere, SO2 generates from the decomposition or oxidation of organic S during early devolatilisation, wheares more fuel-S probably are released in the forms of H2S and CaS.