Mine gas hydration kinetics in coal based on impedance method

To explore the application of hydrate technology in preventing coal and gas outburst,the impedance monito- ring experiment devices of mine gas curing process is used to study the effect of four kinds of different pore and fractal distributions on mine gas hydration process. Meanwhile, the impedance characteristic curve of mine gas hydration process in coal is obtained. The growth rate and gas content of mine gas hydrate are calculated. The results show that impedance value increases in the upper layer and it decreases in the middle and lower layers of the experimental reac- tor. Mine gas hydrate mainly forms in the upper and middle layers of the experimental reactor. Under the same thermo- dynamic conditions, the gas hydrate formation rate in the four experimental systems is 0． 180,0． 083,1． 747 and 0． 448 cm3 / min respectively. The gas fraction is 1. 9×10-3 ,6. 3×10-3 ,2. 1×10-3 and 1. 6×10-3 mol / cm3 respectively. The above data indicates that the mine gas hydration rate is quicker in the coal which contains more pore and fractures due to the high gas content in mine gas hydrate. The gas content of unit volume mine gas hydrate is different with the varying pore and fractures in coal and the quantity of mine gas hydrate is larger in the coal with more pore and frac- tures. Based on the theory of homogeneous occupy,the mine gas hydrate contains more hollow cages in the coal with more pore and fractures.