Molecular simulation study on adsorption of C2H4 in bituminous coal

Abstract

C2H4 is used as an indicator gas to evaluate the spontaneous combustion process of coal, and the adsorption of C2H4 by coal will cause the decrease of C2H4 gas volume fraction in mine air, which in turn affects the accuracy of the assessment of the spontaneous combustion process of coal. In order to reveal the microscopic mechanism of C2H4 adsorption in bituminous coal, a molecular model of Wiser bituminous coal was constructed, and the adsorption process of C2H4 in the molecular model of bituminous coal at temperature of 293.15-313.15 K and pressure of 0.1-3 MPa was simulated using Monte Carlo method, and the changes of adsorption heat, adsorption potential energy and adsorption entropy during the adsorption process were analyzed. The results showed that the adsorption of C2H4 in bituminous coal molecules first increased rapidly with increasing pressure and then leveled off; the higher the temperature, the lower the adsorption of C2H4 when the pressure was the same; Langmuir-Freundlich model has the best fitting effect on C2H4 adsorption process, and the maximum adsorption a of C2H4 decreases with increasing temperature; the average heat of adsorption of C2H4 under different temperature conditions is 35.29-37.65 kJ/mol, indicating that the adsorption of C2H4 in bituminous coal is physical adsorption; the adsorption potential energy and entropy of C2H4 decreased

Keywords

• coal spontaneous combustion
• c2h4
• bituminous coal
• adsorption
• monte carlo
• molecular simulation