Effect of acidification on micro structure and adsorption characteristics of coal
HE Jimin
YUAN Mei
LIU Dingling
TIAN Weilin
CHEN Lian
CAO Hongfei
Abstract：To investigate the changes in the microstructure of coal under acidification and the mechanism of their impact on coal ad-sorption characteristics,low-temperature nitrogen adsorption experiments,infrared spectroscopy experiments,and isothermal adsorp-tion experiments were conducted on coal samples before and after hydrofluoric acid treatment.The influence of acid solution on the pore structure and molecular structure of coal was deeply analyzed,and the evolution mechanism of coal adsorption characteristics under acidification was explored based on the experimental results.The results showed that after acid treatment,the average pore size and total pore volume of the coal sample increased,while the specific surface area decreased.The acid solution has the effect of ex-panding pores and increasing capacity of pores.Acidification can change the micro molecularstructure of coal.After acidification,the benzene ring structure of coal samples gradually developed towards multi substituted benzene rings,and the longer fatty chains and weaker hydrogen bond structures were destroyed.Besides,the content of oxygen-containing functional groups increased.In the isothermal adsorption experiment,the maximum adsorption capacity and adsorption rate of methane on coal samples decreased by 14.02%and 23.58%respectively after acidification.Furthermore,the adsorption potential theory indicated that the adsorption capa-city of coal samples for methane decreased and the adsorption space for methane decreases after acidification.
Keywords：coalbed methaneacidificationpore structurefunctional groupsadsorption characteristictheory of adsorption potential
Publication Date：2025-06-20
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：8( 1-8 )