Effects of volatiles and active AAEMs interaction with char on char characteristics during co-pyrolysis

The interactions between volatile substances (volatiles and volatile alkali and alkaline earth metals) released from pyrolysis and char have a crucial influence on the co-gasification process. The influence mechanism of volatiles-char interaction and volatile substances-char interaction in the co-pyrolysis of coal (RSM) and corn stover (RCS) was studied. The findings indicated that volatiles-char interaction suppressed the progression of specific surface area (SSA) and pore structures of char. Volatile active alkali and alkaline earth metals (Ac-AAEMs) of RCS/RSM attenuated the unfavorable effects of volatiles and facilitated the progression of pore structures and SSA of coal/RCS char. Besides, volatiles could react with char through small aromatic ring structures and oxygen-containing groups. The presence of volatile Ac-AAEMs could inhibit the depletion of small aromatic ring structures and oxygen-containing groups caused by volatiles-char interaction. Among them, RCS volatile Ac-AAEMs suppressed the consumption of 11% oxygen-containing groups. RSM volatile Ac-AAEMs inhibited the depletion of 4% oxygen-containing groups. Finally, RCS volatiles-char interaction could inhibit the reactivity of RSM char. The existence of RCS volatile Ac-AAEMs could alleviate the inhibition of volatiles and significantly promote the reactivity of RSM char. Nevertheless, the volatiles and volatile Ac-AAEMs from RSM exhibited minor impacts on RCS char reactivity.

Automated summary

The influence of volatiles-char interaction and volatile substances-char interaction on the co-pyrolysis of coal and corn stover was studied. It was found that volatiles-char interaction suppressed the progression of specific surface area and pore structures of char, while active alkali and alkaline earth metals in corn stover alleviated the unfavorable effects of volatiles. Volatiles could react with char through small aromatic ring structures and oxygen-containing groups, and the presence of volatile active alkali and alkaline earth metals inhibited their depletion.