Determination of Key Groups of Coal Spontaneous Combustion and Risk Prediction Based on Ultrasonic Extraction.

In order to accurately investigate the key microstructures in the spontaneous combustion exothermic process of coal, an ultrasonic extraction method was employed to extract the coal, and the complex microscopic groups within it were stripped and studied. On this basis, Fourier transform infrared spectroscopy and differential scanning calorimetry were employed to assess the content of microscopic groups and the exothermic characteristics of the raw and extracted coal samples. The findings indicated that toluene and methanol demonstrated a notable capacity for extracting aromatic and aliphatic hydrocarbon compounds from coal, whereas -methyl pyrrolidone (NMP) and ethylenediamine (EDA) exhibited a pronounced effect on oxygen-containing functional groups and hydroxyl groups.

Characterization of Pore Structures with Mercury Intrusion Porosimetry after Electrochemical Modification: A Case Study of Jincheng Anthracite.

Quantitative characterization of the change in the cleat and pore structures and fractal dimensions in anthracite after electrochemical modification is crucial for better understanding of the modification effect. Thus, lump anthracite samples were electrochemically modified in our manufactured device with 0, 0.5, 1, and 2 V/cm potential gradients.

Effect of Cyclical Microwave Modification on the Apparent Permeability of Anthracite: A Case Study of Methane Extraction in Sihe Mine, China.

The application of cyclical microwave modification for accelerating the extraction of coalbed methane (CBM) from anthracite is limited. In this study, the apparent permeability of anthracite samples before and after each microwave treatment (three in total) for 120 s was measured by a self-built permeability-testing platform. Microcomputed tomography (micro-CT) technology and image-processing technology were employed to analyze the 3D micron-scale pore structures, especially the quantitative characterization of connected pores and throats.

Effect of Electric Potential Gradient on Methane Adsorption and Desorption Behaviors in Lean Coal by Electrochemical Modification: Implications for Coalbed Methane Development of Dongqu Mining, China.

The application of electrochemical modification for accelerating methane extraction in lean coal seams is limited due to the lack of experimental and theoretical research studies. Therefore, electrochemical modification with different electric potential gradient values was selected to modify lean coals in this study; meanwhile, the amount of methane adsorption and the methane desorption ratio were tested and analyzed. The results showed that the maximum amount of methane adsorption in coal samples decreased after electrochemical modification and the decrease in methane adsorption increased with an increase in electric potential gradient.

Effect of Pressure and Temperature on CO/CH Competitive Adsorption on Kaolinite by Monte Carlo Simulations.

The adsorption of CO and CO/CH mixtures on kaolinite was calculated by grand canonical Monte Carlo (GCMC) simulations with different temperatures (283.15, 293.15, and 313.