| The use of animal waste as a fuel source has the potential to be a low cost, environmentally friendly fuel source, while at the same time solving animal waste disposal problems. In the current work it is proposed that the biomass be mixed with coal and co-fired in a 90:10 blend by mass. The high temperatures produced by the coal will allow the complete combustion of the biomass. In order to develop an animal biomass co-firing technology three tasks were undertaken: (1) a fuel property analysis, (2) boiler burner testing, and (3) reburn analyses.; Ultimate and Proximate analyses were performed. Notably coal contains 2.55 kg of ash/GJ ash, 0.180 kg of S/GJ, and 0.379 kg of N/GJ, while FB contains 44.2 kg of ash/GJ, 0.941 kg of S/GJ, and 2.504 kg of N/GJ, and LB contains 022.2 kg of ash/GJ, 0.547 kg of S/GJ, and 2.515 kg of N/GJ. TGA experiments were performed and the results fit to the parallel reaction model. The results revealed that biomass will lose volatiles at a lower temperature and a faster rate than coal. The coal pyrolyzed at 620 K while the FB pyrolyzed at 500 K and LB at 500 K. The experiments were repeated in air to determine the ignition behavior of coal, FB and LB.; For task 2, a 30 kW laboratory scale boiler burner was constructed, and used to evaluate the co-firing performance of the biomass and coal blends. The results showed a similar burnt mass fraction of 0.95 for coal and the blended fuels. The nitrogen emissions were also measured for both LB and FB blends and coal (0.15 kg/GJ), and the results showed no significant increase despite an increase of 8–20% nitrogen in the blended fuel.; The boiler burner was finally modified with a NH3 doped propane flame with 5% excess air (18 kW) in order to produce a NOx level of 600 ppm in the primary flame, and reburn injection ports to test the effectiveness of the coal, FB, and LB fuels as reburn fuels. The results indicated a 75% reduction when using pure biomass vs 30% for coal at reburn equivalence ratio of 1.05. |
