淮南煤与内蒙古煤配煤煤灰熔融特性及气化反应性研究OA北大核心CSTPCD

Huainan coal ash cannot be directly used in an entrained-flow gasifier due to its high ash melting temperature.In this study,Huainan coal(ZA coal)was blended with two kinds of Inner Mongolia coal(ZB coal and ZC coal)with low ash melting temperature,respectively,to investigate the influence of coal blending on coal ash melting temperature.The blending ratio(mass ratio)was 1∶9,2∶8,3∶7,4∶6,5∶5,6∶4,7∶3,8∶2,9∶1,respectively.The ash melting temperatures of single coal and blending coal were determined using an ash melting tem-perature auto-analyzer in a weakly reducing atmosphere.The effect of coal blending on the ash fusibility was discussed based on the thermodynamic equilibrium calculation results(by Fact-Sage).The CO2 gasification reactivity of char was measured using a thermogravimetric analyzer(TGA),and the reaction kinetics were analyzed.The results indicate that the high ash melting temperature of ZA coal is primarily due to the formation of mullite at high temperatures.When ZA coal is blended with ZB coal or ZC coal,the content of mullite decreases,while the content of low-melting-point minerals such as anorthite and magnesium cordierite increases,leading to a re-duction in the ash melting temperature.The average CO2 gasification rates of ZA coal char,ZB coal char,and ZC coal char are 2.54%/min,3.49%/min,and 4.19%/min,respectively,indica-ting that ZA coal char has the lowest gasification reactivity with CO2.While the ZC coal char has the highest average reaction rate,indicating that its gasification is easy to happen.Compared to the single coal,the gasification process of blended coal exhibits an initial promoting effect fol-lowed by an inhibitory effect.The activation energies for the CO2 gasification reactions of the three kinds of coal char range from 336.8 kJ/mol to 405.0 kJ/mol.The activation energies of AB2 coal(the mass ratio of ZA coal to ZB coal is 2∶8)char and AC3 coal(the mass ratio of ZA coal to ZB coal is 3∶7)char are consistent with those of ZB coal char and ZC coal char,indicating that coal blending can reduce the activation energy of the incorporated ZA coal char.