Experimental Study On Gas Adsorption Modification Of Coal Particles After Microwave Irradition

Coal seam gas threats the safety production of coal mine at any moment.Simultaneously, coal seam gas has very important application prospect as a clean efficient energy. In order to study the influence law of coal adsorption gas characteristics and mechanism under microwave irradiation, and further understand the influence of the applied field, the microwave generator was used to treat coal particles under the microwave irradiation conditions of different power and time. By using high pressure-change temperature adsorption desorption experiment system to do the isothermal adsorption experiment and testing industrial analysis parameters of the different coal samples. As well by using the SEM and low field NMR to determine the surface morphology and pore distribution characteristics of each experimental coal sample. By unitting the change law of granular coal gas adsorption characteristics and the coal samples pore structure under microwave irradiation and clarifiing coal particles on the adsorption characteristics of microwave irradiation and the mechanism of the pore structure changes. This paper achieved the following conclusions:( 1) By using high pressure-change temperature adsorption desorption experiment system to do isothermal adsorption experiment of particles coal which was irradiated by microwave, the research showed that the limiting adsorbed amount improved significantly after microwave irradiation, and the coal samples limiting adsorbed amount appeared two "inflection point" with the increase of microwave irradiation. The general trend was first increase and then decrease, then increased continuouslty. But the adsorption constant b has not obvious change with the increase of microwave irradiation.(2)By using SEM and low field NMR, we determined the surface morphology and surface morphology characteristics of coal samples. By SEM we can observe the surface holes change of coal samples before and after microwave irradiation. The surface morphology of coal samples changed significantly with the increase of microwave irradiation. By low field NMR, we tested the pore volume and distribution of the coal samples. The research showed that with the increase of microwave irradiation, the pore volume and distribution of the coal samples changed significantly,especially for the microporous which plays a decisive role in coal absorbing gas. The total pore and micropore volume changed with the increase of microwave irradiation.And in the process appeared two "inflection point", the general trend was first increase and then decrease, then increased continuouslty.(3)This paper comparativly analysised the different action mechanisms under the online and offline field. The research showed that the microwave irradiation mainly reflected in the heat effect for coal particles. Because of the heat effect, which changed the pore volume and distribution of the coal samples, thus influenced and determined the desorption characteristic change of the particles coal. By the gas desorption experiment of coal particles which was irradiated by microwave, this paper verified the rationality of the above conclusion.