Experimental Study on the Mechanism of Radial Change of Simulated Enrichment Nutrient Solution Injection into Coal Seams

This paper deals with enhanced coal bed methane recovery and geological CO2 storage, combined with the dual effect of increasing coal-bed methane and achieving carbon emission reduction. Coal of different particle sizes were loaded into acrylic tanks of a certain height, and peristaltic pumps were used to enrich nutrient solution and CO2 into different layers of coal seams, to monitor the liquid phase pH, COD, OD600 , aromatic structure, HCO3 - , three-dimensional fluorescence data of the upper, middle, and lower layers, and the specific surface area of coal Poreginseng. The following conclusions were drawn: (1) the reaction with CO2 resulted in a lower pH than that without CO2 , with weak acidity and higher concentration of HCO3- ions. The OD600 concentration and activity of the bacterial solution were stronger. Most of the solution was dominated by Clostridium acidophilum, and the three-dimensional fluorescence results are also shown. (2) Coal samples with small particle sizes had a larger surface area, more contact area with bacterial liquid, and a more complete reaction, so the physical property transformation of coal reservoirs with small particle sizes was more obvious, and the COD change was the largest. (3) The upper and middle layers were exposed to more bacterial fluid and CO2 , resulting in a more complete degradation reaction.