Liu Yinhe,Che Defu,Xu Tongmo
(School of Energy and Power Engineering,Xi'an Jiaotong University,Xi'an 710049,China)
Abstract:An experiment was carried out to investigate effects of minerals on sulfur dioxide release and the mechanism of sulfur retention by calcium during temperature-programmed combustion of a high rank coal by TG£¯EGA method at 10¡ãC£¯min. The major results are as follows.Demineralization causes the profiles of sulfur dioxide evolution to change from bimodality to single peak with two shoulders and increases the conversion of coal sulfur to sulfur dioxide.The absorption-desorption mechanism was developed to elucidate effects of minerals on sulfur release.Calcium can promote sulfur dioxide release in low temperature.Different calcium forms appear different effects on sulfur release.Calcium sulphate can serve as an inert component to change the sulfur dioxide evolution profiles without any sulfur retention.Calcium carbonate and calcium oxide can change sulfur release profile and reduce sulfur dioxide release.In addition, calcium oxide is more effective than calcium carbonate on sulfur retention.Calcium effect on sulfur dioxide reduction is governed by the present sulfur dioxide absorption-desorption£¯oxidation mechanism.
Keywords:sulfur dioxide;demineralization;calcium;coal combustion;thermogravimetry