Significantly enhances caking index of long‐flame coal under tetralin‐glycerol/H₂ system

Abstract

For alleviating of the shortage of coking coal resource and efficient cleaning and utilization of low-rank coal, hydro-plasticization of low-rank coal was carried out. However, the caking property of low-rank coal cannot be obviously improved under mild conditions in the traditional tetralin-H 2 system. This study is to investigate the feasibility of mixed tetralin-glycerol as a solvent in the process of low-rank coal hydro-plasticization. The solvent ratios of tetralin-glycerol, reaction pressure, and atmosphere were varied to evaluate their effects on hydro-plasticization. The results show that the caking index (G RI ) of long-flame coal increases from 0 to 78 at mild conditions, and the hydrogen transfer mechanism might be directly from H 2 to coal rather than through hydrogen-donor solvents in the mixed solvent case. The solvent extraction and the G RI of modified coals were measured and found that the G RI of modified coal has a good linear relationship with PAA yield, and its R 2 is .985.