Kinetics, comprehensive characteristics, and product analysis of peanut shell pyrolysis activated by a small amount of KCl

摘要

? 2023Simultaneous conversion of peanut shell (PS) by pyrolysis into energy and useful chemicals is essential for its maximum utilization. The pyrolysis kinetics of PS and KCl-activated PS (KCl-PS) were studied using isoconversional and integral master plots methods. The power law (P4) model was found to be the most appropriate pyrolysis mechanism, and KCl-PS had a lower average activation energy than PS. When 1.56 wt KCl was used to activate PS pyrolysis, enhanced gas products and bio-oil with lower oxygen content were produced, and the BET surface area of biochar increased significantly from 1.02 m2/g to 503.45 m2/g. This may be because potassium reacts with oxygen-containing functional groups to form K2CO3, which promotes the cracking of labile aliphatic compounds (e.g., CdbndO, CH, C-O, and OH groups). The exploratory factor analysis extracting three factors also showed that compared with PS, KCl-PS scored higher on the pyrolysis factor of labile aliphatic compounds and the factor including temperature and residual mass, but lower on the factor describing energy change.