煤表面含氧官能团对矿井气体吸附特性的模拟研究

基于密度泛函理论模拟方法,从原子层次上模拟计算4种典型矿井气体(CO、CO2、CH4及N2)对煤表面含氧官能团的吸附行为,探究4种气体对煤表面官能团的吸附机理。对4种气体对煤表面6种常见的官能团结构单元:酚羟基、羧基、羰基、醚键、醇羟基和烷基(Ph-OH、-COOH、-C=O、-O-、R-OH及R)吸附行为进行模拟,通过吸附能、吸附构型、前线轨道的计算分析;结果表明煤与4种气体的吸附强度存在CO2>N2>CO>CH4的关系,并且各气体分子在煤表面模型上各含氧官能团的吸附强弱顺序为:羧基>醇羟基>酚羟基>羰基>醚键>烷基。

Simulation Study on Adsorption Characteristics of Mine Gases by Oxygen Functional Groups on Coal Surface

Based on the density functional theory simulation method, the adsorption behaviors of four typical mine gases(CO, CO2,CH4 and N2) on the surface oxygen-containing functional groups of coal are simulated from the atomic level. The adsorption mechanism of four kinds of gases on coal surface functional groups is investigated. Four kinds of gases simulate the adsorption behavior of six common functional group structural units on the coal surface: phenolic hydroxyl group, carboxyl group, carbonyl group, ether bond, alcoholic hydroxyl group and alkyl group. The results show that the adsorption energy, adsorption configuration and frontier orbit are calculated and analyzed. The adsorption strength of coal and four gases exists: CO2>N2>CO >CH4, and the order of adsorption of oxygen-containing functional groups on each coal surface model is: carboxyl group > alcoholic hydroxyl group> phenolic hydroxyl group> carbonyl group> Ether bond > alkyl group.