Lujaji, Frank C.Boateng, Akwasi A.Schaffer, Mark A.Mullen, Charles A.Mkilaha, IddiMtui, Peter L.2016-07-122016-07-122016-04Lujaji, F.C., Boateng, A.A., Schaffer, M.A., Mullen, C.A., Mkilaha, I.S. and Mtui, P.L., 2016. Pyrolysis oil combustion in a horizontal box furnace with an externally mixed nozzle. Energy & Fuels, 30(5), pp.4126-4136.http://hdl.handle.net/20.500.11810/3097Full text can be accessed at http://pubs.acs.org/doi/ipdf/10.1021/acs.energyfuels.6b00318Combustion characteristics of neat biomass fast-pyrolysis oil were studied in a horizontal combustion chamber with a rectangular cross-section. An air-assisted externally mixed nozzle known to successfully atomize heavy fuel oils was installed in a modified 100 kW (350"000 BTU/h nominal capacity) burner to explore full utility for pyrolysis oil (bio-oil) combustion in a furnace. Combustion experiments were conducted at air/fuel equivalence ratios of 0.46, 0.53, and 0.68 (116, 88, and 47% excess air, respectively) and compared to diesel fuel flames (control) at the two higher air/fuel equivalence ratios. In these experiments, the fuel flow rate was maintained at a constant energy input (equivalent of 24 kWth). The results revealed that, while the externally mixed nozzle could effectively atomize and ensure stable combustion of neat bio-oil at the set heat rate, this comes with a penalty associated with a lower peak flame temperature and, hence, heat flux. The formation of carbon monoxide (CO) decreases with an increasing air/fuel equivalence ratio for bio-oil combustion. The levels of carbon dioxide (CO2) and nitrogen oxides (NOx) increase with an increasing air/fuel equivalence ratio for bio-oil combustion and were slightly higher than that generated by diesel. Hydrocarbon emissions do not follow any defined trend with an increasing air/fuel equivalence ratio for bio-oil, as typically observed for diesel fuels as a result of the oxygenated nature of bio-oil.enJournal Article10.1021/acs.energyfuels.6b00318