| OCR Text |
Show • to determine volatile-release profiles, burning profiles, and char reactivity. Fundamental combustion properties, including pyrolysis and char oxidation rates, will be determined using the PETC Drop Tube Furnace as part of Level 3 evaluations. Pilot-scale combustion experiments will be conducted in the new PETC Fuels Evaluation Facility (FEF). The FEF is presently under construction, and a late 1988 commission date is planned. Initially, only relatively small quantities «1 ton) of some of the advanced coal-cleaning products will be available for evaluation. This dictated that the FEF be designed for a relatively low firing rate, on the order of 30-50 pounds of fuel per hour (approximately 500,000 Btu/hr), to allow long enough duration (6- to 12-hr) tests to be conducted to make the minimum number of desired measurements. Long-term (i.e., >24-continuous-hr) tests will be conducted, -when possible, to delineate some aspects of the combustion behavior of the new fuels. Ash deposi tion (slagging and fouling) and fly ash erosion are examples of fuel-dependent phenomena where long-term testing will allow a more precise assessment of the commercial value of these fuels. The Fuels Evaluation Facility will allow ranking of the combustion performance of the deeply beneficiated fuels in their various forms in relation to one another and to the parent coal feedstocks. The facili ty will be equipped to make the following evaluations: o transport, handl ing, and storage character istics of the var ious fuel forms (dry powders and coal-water mixtures) o combustibility (flame stability and carbon conversion efficiency) o ash deposition characteristics [deposition rates, deposit heat transfer properties (emissivity and thermal conductivity), and deposit response to soot blowing (deposit strength and minimum jet impact pressure required)J o fly ash properties (erosiveness, resistivity, and collectibility by baghouses and electrostatic precipitators) o emiss ions of cr iter ia (SO 2, NOx, THC, CO, and particulates) and non-criteria (PAH and trace elements) pollutants Available public domain single- and mul ti-dimensional numer ical combustion codes (e.g., 1-DICOG and COMO) may be used to model chemical and physical processes during combustion and to aid in scale-up predictions. In addition, comparative estimates of utility boiler (oil- and coal-designed) performance when firing the parent and clean coals may be made using a recently developed public domain boiler heat transfer model [1J coupled with pilot-scale data. A companion project is under way in which the storage, handling, and transport properties of dry, ul trafine coal-based fuels are being investigated at the light-industrial scale. The ability to further process the clean coal products into dry powders or into coal-water mixtures is being studied in the PETC Fuel Rheology Laboratory. |
