Non-isothermal and isothermal co-pyrolysis characteristics of coal gangue/coal slime and pine sawdust: Thermogravimetric analyzer and fixed bed pyrolysis reactor study

• Published in: International journal of hydrogen energy Vol. 59; pp. 1230 - 1243
• Main Authors: Niu, Yonghong, Han, Shuang, Hu, Yuyang, Yang, Man, Han, Fengtao
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.03.2024
• Subjects: Biomass; Co-pyrolysis characteristics; Coal gangue; Coal slime; Kinetics; Coal gangue; Co-pyrolysis characteristics; Biomass; Kinetics; Coal slime
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2024.01.353

The generation and accumulation of coal gangue (CG) and coal slime (CS) are a serious cause of environmental pollution. The co-pyrolysis of CG/CS and pine sawdust (PS) is an effective method to reduce pollution and waste generation. In this work, the co-pyrolysis characteristics of CG/CS and PS were analyzed by the thermogravimetric analyzer and fixed bed pyrolysis reactor. The kinetics analysis showed that the activation energies decreased with the PS mixing ratio increased for CG/PS blends and CS/PS blends in the second pyrolysis stage. The synergistic effect on yield is quantified by comparing the results of the co-pyrolysis of CG/CS and PS blends with weighted results from the pyrolysis of CG, CS and PS individually. The results revealed that when the mixing ratio of CG:PS was 1:1, the difference between the experimental and calculated yields (2.9 %) and the H2 yield (320 ml/g) were maximum. Among the CS/PS blends, these values are maximum when the mixing ratio of CS:PS is 3:1 (2.5 % and 450 ml/g). Furthermore, the alkali and alkaline earth metals K and Ca in the co-pyrolysis char catalyze the decomposition of the –OH functional group. •CG/CS and PS co-pyrolysis was studied by non-isothermal and isothermal conditions.•The alkali and alkaline earth metals in the co-pyrolysis char had a catalytic effect.•CG/PS1-1 and CS/PS3-1 mixing ratio had the highest hydrogen yield.