Cofiring coal and dairy biomass in a 29Â kWt furnace

Results were obtained for burnt fraction, NOx and CO emission. Pure TXL produced 1505 ppm of CO at an equivalence ratio of 1.1. An 80:20 blend of TXL:LA-PC-SepSol-DB produced 4084 ppm of CO at the same equivalence ratio. The NOx emissions for equivalence ratio varying from 0.9 to 1.2 ranged from 0.4 to 0.13 kg/GJ for pure TXL coal. The corresponding NOx emissions are 0.8-0.10 kg/GJ for pure WYO coal. For 80:20 TXL:LA-SepS-DB blend they ranged from 0.375 to 0.05 kg/GJ over the same range. In general, the blends produced less NOx than pure coal under rich conditions even though the DB contained more nitrogen. This result is probably due to the fuel bound nitrogen in dairy biomass is mostly in the form of urea which reduces NOx to N2.