INFLUENCE OF ALKALINE MINERAL MATTERS ON NITROGEN CONVERSION IN CO-COMBUSTION OF COAL AND STRAW

To investigate the influence of Na and Mg on NO release characteristics during co-firing of biomass and coal,combustion tests of mixed samples consist of different proportioned deashing straw and demineralized coal added with single NaOH or MgO at different ratios were conducted,by means of thermogravimetric differential thermal analysis(TG-DTA) and gas chromatogram and mass spectra(GC-MS).Results show that,adding Na into demineralized coal can catalyze the NO reduction,but the addition of Mg affects little on the NO reduction.With raising Na-addition proportion,the NO releasing of deashing straw first declinces and then increases.However,after addition of Mg,the release of NO is on the contrary.As the Na,Mg addition increasing,catalysis on NO reduction is enhanced,but it tends to be stable when the addition of Na and Mg is up to 2.5% and 1.2%,respectively.