Diffusion mechanism and environment pollution abatement of coalbed gas

Coalbed gas is a kind of special gas of containing mass of CH₄, which is the host-coal rocks formed then reserved in the coalbed in the process of coalification. The gas direct diffuse into the air in exploiting coal because less study on diffusion mechanism of coalbed gas. It could make the risk of gas explosion,environment pollution and the resources wasted. Then, it is provided significance of theory and practice in study on diffusion mechanism and pollution prevention and control of the coalbed gas. The premise of the diffusion is the gas concentration gradient. The important parameter of diffusion capability is diffusion coefficient. According to Fick Law, establishing model of diffusion gas, dQ/dt=-D·A·dc/dx.It can be calculated that diffusive flux and diffusivity by Q=D·(C-C0)/H·S·t and Vd=Q/S´·t=D(C-CO)/H·Φ. Take full advantage of the coalbed gas is the best way to prevent pollution. Extracting the gas before exploiting coal could avoid the risk of the gas explosion, it can meliorate the unreasonable structure of energy and reduce the environment pollution.