FTIR studies of potassium catalyst-treated gasified coal chars and carbons

Abstract

The catalytic effect of K 2CO 3, KHCO 3, KOH, K 2SO 4 and KCl during steam gasification of coal and carbon chars has been evaluated by gravimetric measurements at 750 °C. The order of catalytic activity found was KOH~ K 2 CO 3 > KHCO 3 > KNO 3 > K 2 SO 4 with almost no activity for KCl. Transmission i.r. spectra were obtained on thin wafers of KBr mixed with carbon and coal char samples after impregnation, devolatilization and partial gasification. All catalytically activated salts presented two characteristic bands at 1050 and 1400 cm −1 while no such bands appeared in the case of catalytically inactive KCl. Furthermore, such bands were also present in a different carbon substrate impregnated with K 2CO 3 and in an oxygen-exposed intercalate (C 8K). The bands appeared at the same frequencies as those of KHCO 3 in pure, carbon impregnated, devolatilized, and partially gasified form.