Abstract
Water in coal pores can generate strong steam explosions when treated with microwave irradiation. In order to improve the sensitivity of coal reservoirs to microwaves, we used varying concentrations of NaCl on the pore solution, which further increased the effect of microwaves on permeability enhancement. In our experiments, we selected 3 ratios of water content and 5 different concentrations of NaCl. The changes of coal water content and permeability before and after irradiation were compared. In addition, changes in coal surface temperature and internal thermal power were analyzed through thermal imaging and random sphere numerical modeling. Results showed that the increase of the proportion of solution mass and the ion concentration in the solution improved the overall dielectric properties of coal rock samples. After microwave irradiation, the average reduction rate of water content in coal rock samples increased with the increase of ion concentration in the solution. Both the average surface temperature of the coal rock samples and the average electromagnetic heating power gradually increased; this increases the temperature rise rate and maximum temperature of coal rock samples under the same irradiation time, which is conducive to better rapid accumulation of steam pressure, thereby improving the pore structure more effectively. Finally, the maximum growth rate of permeability reached 466.18%. This work provides a novel train of thought to enhance coal permeability by using microwave irradiation.
Highlights
Recent development of clean energy technologies, the impact of Covid-19, and the significant reduction in coal demand by OECD countries have resulted in reduction in global coal consumption
The International Energy Agency (IEA) predicted that the use of coal will continue to decline in the future [2]
The purpose of the present research was to investigate the influence of the increase of ion mass ratio and ion concentration on coal permeability when this material was exposed to microwave irradiation
Summary
Recent development of clean energy technologies, the impact of Covid-19, and the significant reduction in coal demand by OECD countries have resulted in reduction in global coal consumption. 1 1 1 1 1 the permeability under microwave irradiation by increasing the water content of coal. The temperature of lignite significantly increased when ferroferric oxide was used as absorbent In this case, the temperature of the sample reached 800°C after 3 minutes of irradiation at the same microwave power. The conversion efficiency of microwave irradiation into heat was enhanced in 64% Based on these data, we consider increasing the ion concentration of the aqueous solution present in coal in order to improve its ability to absorb microwaves. The purpose of the present research was to investigate the influence of the increase of ion mass ratio and ion concentration on coal permeability when this material was exposed to microwave irradiation. We used physical and numerical experiments in order to clarify the mechanism of permeability improvement when microwave steam explosion is used
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
