| OCR Text |
Show address simultaneously several areas of concern relating to waste disposal, and control of greenhouse and noxious gas emissions. This is due to the fact that fuels derived from biomass are renewable and contain low concentrations of sulphur [9] . Among the biomass waste materials that can be used in this way are: domestic refuse, waste paper, wood waste, agricultural wastes such as straw, and sewage sludges. The use of these fuels can be highly cost effective, particularly if the cost associated with conventional disposal are taken into account. However, biomass wastes tend to have low energy densities, and their compositions can be significantly different from more conventional fuels. They can contain large fractions of non-combustibles and furthermore they can be difficult to handle. The combustion technology required to co-fire these biomas~ wastes with coal has not yet been developed, and effects related to emissions of NOx, SOx and unburned hydrocarbons, particulates and the incidence of slagging, fouling and corrosion, are as yet unquantified [8]. These aspects have lead. the EC to initiate the "Clean Coal Technology" programme with the specific objective to support experiments on the co-firing of coal with biomass wastes. As a part of this programme, the IFRF is studying the co-firing of a range of bituminous coals with straw, waste paper and sewage sludge. In the following paragraphs are presented the preliminary results of experiments firing three different bituminous coals with straw and waste paper. The objectives of this research programme are to determine the effects of co-firing a range of biomass waste materials with pulverised coal from the viewpoint of combustion behaviour, gaseous pollutant emissions, slagging and fly ash quality [10]. The full study consists of co-firing high and medium-volatile bituminous coals with straw, waste paper containing a maximum of 50/0 plastics and municipal sewage sludge. The present study concentrates on straw and some preliminary results are presented. Co-firing of coal with municipal sewage sludge will form the subject of the second phase of the programme. The experiments were executed on IFRF semi7industrial boiler furnace simulator at 2.5 MW fuel input. The internal combustion chamber, dimensions 2x2x6.3m, is refractory lined and equipped with flexible cooling loops. The experimental facility also consisted of a straw /paper shredder and feeding system. The overall facility is shown in Figure 9. The pulverised coals were prepared in the IFRF coal handling and preparation facility. |
