No abstract

The combustion performance of a small sample of Judy Creek North coal was evaluated in a pilot-scale, pulverized-fired research boiler. The coal, which contained 22% total moisture and was moderately reactive, handled and pulverized easily, ignited readily and produced a bright, stable flame. The coal ash did not slag or sinter on high-temperature boiler surfaces and low-temperature corrosion due to sulphuric acid was not detected on probe surfaces controlled at 104 ° C, 120 °C and 138 °C. The coal produced moderate levels of nitric oxide (about 0.56 lbs/ m 10 6 Btu). Sulphur oxide emissions were considerably less than theoretical because about 40% of the input sulphur was retained in the boiler ash and fly ash. The resistivity of the fly ash, being generally between 10 9 and 10 10 - ohm-cm, indicates that the performance of cold electrostatic precipitators will be good. The combustion, fouling and emission characteristics of Judy Creek North coal were similar in many respects to those of a Sundance reference coal.

No abstract

Fast reactor fuel has been reprocessed at Dounreay since 1960. This paper describes the operation of the reprocessing and waste management facilities associated with the reprocessing of the prototype fast reactor (PFR) since the start of operation on this project in 1980.

Pilot-scale (75 kg/hr) combustion trials using a pulverised western Canadian bituminous coal of low sulphur content have shown that the fly-ash resistivity can be significantly modified by adding SO 3 , H2 SO4 , NH2 S020H and NH 3 to flue-gases as fly-ash conditioning agents. The measured fly-ash resistivity(11) when using these conditioning agents was found to decrease exponentially, from its original lçvel (R0 ) to a limiting value (RSat) as the concentration of the conditioning _agents was increased: Log (R) - Log (Rsat) = e -k(c) Log (Ro)- Log (Rsat) For each conditioning agent k is a constant and (c) is the gas-phase concentration of the conditioning agent. The dissociation products (SO 3 and NH 3 ) of NH2SO2OH act independently and cumulatively in their effect on the resistivity of the fly-ash from Luscar coal. The resistivity reductions produced by SO 3' H 2 SO 4 and NH2 SO2OH were accompanied by increases in precipitator efficiency from the base level of 85%. Maximum efficiencies were recorded at additive concentrations in the range 10-15 ppm S0 3 : Emax( SO3) = 99% at 13 ppm SO 3 Emax(H2 SO4 ) = 98% at 10 ppm SO3 Emax( NH2S020H)= 95% at 10 ppm SO 3 Ammonia was not found to be an effective conditioning agent with this coal: Emax(NH3) = 90% at 45 ppm NH3