Name : The 46th Conference of Coal Science
Number : 46
Location : [in Japanese]
Date : November 26, 2009 - November 27, 2009
Pages 58-59
The evolution of HF during temperature-programmed pyrolysis of 3 sub-bituminous coals and subsequent char combustion has been examined with a fixed-bed quartz reactor. A slight amount of HF is formed in the pyrolysis up to 1000℃ and thus HF yield is only <1% in every case, whereas the retention of F in char is 65-85%. Most of the F is retained even when 10-16% of the pyrolyzed chars are gasified with H_2O at 1000℃. On the other hand, HF formation from the chars during combustion at 1000℃ proceeds considerably at high burn-off of >95% after the apparently complete release of CO_2. The F 1s XPS spectra after HF yields of 40-50% reveal the existence of C-F forms, and the proportion is estimated to be as high as 97-99mol%.
