Study of Light Gas Generation Behavior during the Thermal Chemistry Conversion Process of Cattle Manure

High Resolution Image Download MS PowerPoint Slide To investigate the thermal chemistry conversion behavior of cattle manure as a biomass fuel, the effect of three reaction ambiences (N 2, air, and CO 2 ) and four temperatures (350, 550, 750, and 950 °C) was studied on a fixed-bed reactor. The tested final products were divided into three categories: nitrogen-containing species (NO, NO 2, HCN, NH 3 ), carbon-containing species (HCN, CH 4, CO, CO 2 ), and others (SO 2, HCl). As the temperature increased, HCN and NO always increased, while NH 3 and NO 2 increased first and then decreased. This tendency was the same in all three ambiences. HCN was found to be the major component among the four measured nitrogen-containing species, with a maximum mass ratio of 17% under N 2 ambience at 950 °C. CO 2 and CO are the two major carbon-containing species. The oxygen for CO 2 or CO formation can be from either cattle manure itself or the surrounding air. As the temperature increased, the contribution to CO 2 formation from the internal oxygen became larger than that from the external oxygen in both N 2 and air ambiences. At 950 °C, the CO 2 mass ratio in N 2 ambience was 55%, while it was only 35% from the external oxygen. Under CO 2 ambience, the presence of CO 2 can boost CO formation by gasification. The SO 2 –S and HCl–Cl mass ratios present no apparent relation with ambience. As the temperature increased, the SO 2 –S and HCl–Cl mass ratios decreased in all three ambiences. The sulfur in cattle manure is mainly organic, while the chlorine exists mainly in inorganic forms, such as NaCl and KCl.