Effect of some natural minerals on transformation behavior of sulfur during pyrolysis of coal and biomass

摘要

The effect of tourmalines, Na-bentonite and medical stone on the retention of total sulfur, pyritic sulfur, sulfate sulfur and organic sulfur were investigated in a fixed bed reactor. The result shows that during Longma coal pyrolysis, adding tourmalines, Na-bentonite and medical stone all make the total sulfur retention and organic sulfur retention increase obviously. Interestingly, the results also indicate that adding tourmaline 1 (T1), tourmaline 2 (T2), Na-bentonite and medical stone all could make sulfate sulfur retention decrease obviously. Furthermore, when temperature is below 650 C during coal pyrolysis, adding tourmaline1 (T1) makes pyritic sulfur retention higher; while adding Na-bentonite, tourmaline 2 (T2) or medical stone makes pyritic sulfur retention lower. Besides that, the results also show that adding tourmaline 2 (T2) is beneficial for sulfur to convert into H_2S and then escape, while adding medical stone is not only good for sulfur to turn into H_2S, but also is good to turn into COS during LM coal pyrolysis. For co-pyrolysis of LM coal and biomass, the results show that during co-pyrolysis of LM coal and wheat straw or sawdust, adding tourmaline 1 (T1) influences the total sulfur retention differently with temperature increases. Furthermore, adding tourmaline 1 (T1) also could influence the emission of H_2S and COS to a certain degree during co-pyrolysis of coal and biomass.