Bituminous Coal Research Articles

Modification of Microstructural and Fluid Migration of Bituminous Coal by Microwave–LN2 Freeze–Thaw Cycles: Implication for Efficient Recovery of Coalbed Methane

Modification of Microstructural and Fluid Migration of Bituminous Coal by Microwave–LN2 Freeze–Thaw Cycles: Implication for Efficient Recovery of Coalbed Methane

Characterizing carbonaceous aerosols in residential coal combustion: Insights from thermal/spectral carbon analyzer coupled with photoionization mass spectrometry analysis

This study aims to identify unique signatures from residential coal combustion in China across various combustion conditions and coal types. Using a Thermal/Spectral Carbon Analyzer with a Photoionization Time-of-Flight Mass Spectrometer (TSCA-PI-TOF-MS), we focus on the optical properties and organic mass spectra of the emissions. Bituminous coal emerged as the primary emitter of total carbon, releasing 729 μg C/mg PM2.5 under smoldering and 894 μg C/mg PM2.5 under flaming. Carbon fractions mainly comprised OC1 and OC2, except for anthracite's dominance of EC1 under smoldering. Pyrolysis carbon absorption shifted from 405, 445 and 532 nm during smoldering to near-infrared bands (635–980 nm) during flaming for both bituminous and anthracite coal. Conversely, clean coal exhibited an inverse trend, attributed to additives enhancing oxygen-containing organic compounds and long-chain hydrocarbons released in charring process. Sample of bituminous coal began charring at OC3 step, while anthracite began earlier at OC2 step, particularly pronounced under flaming. Clean coal displayed unconventional charring at OC1 step under smoldering condition, producing signature compounds like butenal, methylfuran, furanylalcohol, and naphthol. The mass spectra of bituminous coal featured characteristic peaks, including m/z 192 (methylphenanthrene), 206, 220 (alkylated phenanthrenes), and 234 (retene). Anthracite coal showed a potential tracer at m/z 223, shifting from OC1 in smoldering to OC2 in flaming. Clean coal under flaming condition exhibited elevated levels of aromatic compounds, indicating potential toxicity, with peaks at m/z 178 (phenanthrene), 228 (chrysene/benz[a]anthracene), 234 (retene), 242 (methylchrysene), and 252 (benzo[a]pyrene, benzo[k]fluoranthene). Results also showed that the broader mass spectra range in the OC3 and OC4 steps across all coal types suggests that high-temperature pyrolysis promotes diversity. These findings contribute to refined source apportionment of carbon emissions from residential coal combustion and provide the scientific basis for the formulation of air pollution prevention strategies, crucial for coal-dependent regions.

Prospects for systematization of lignite deposits to provide Ukraine with raw materials in the postwar period

The contribution of the mining industry to the economy of Ukraine and the current state of coal mining are analyzed on the basis of statistical data on balance sheet reserves of black coal by grade. The indicators of balance reserves and quality characteristics of lignite and associated minerals (coal clays) of the Dnipro Basin are specified. Prospects for the resumption of production are presented and a preliminary economic assessment of the attractiveness of the lignite application is made. The lignite reserves are partially recalculated taking into account the extraction of coal clays to increase the capacity of the country’s fuel and energy sector. The prospects for compiling a catalog of lignite raw materials are determined, taking into account the mining and geological conditions of occurrence and the quality characteristics of the mineral. The scientific novelty of the research is to catalog the deposits of the Dnipro Basin and rank them with a preliminary technical and economic assessment of lignite production. The practical significance is to create a ready catalog of lignite raw materials that will allow a potential investor to implement his or her economically viable project for the development of the deposit.

Synthesis of multi-layer graphene oxide from HCl-treated coke and Brazilian coals by sulfuric acid thermal exfoliation and ozone oxidation

This study involved the synthesis and characterization of graphene oxide (GO) from mineral coke and bituminous coal. HCl treated and non-HCl treated ultrafine powder obtained from both precursors were treated with H2SO4, followed by thermal treatment, and oxidation with ozone and ultra-sonication for GO production. The synthesized materials were characterized using Fourier transform infrared spectroscopy (FTIR), zeta potential (ZP), particle size distribution (PSD), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectroscopy. The results confirmed the exfoliation of the material primarily at the edges of its structure and the formation of multilayer graphene oxide (GO) from mineral coke and bituminous coal. Furthermore, it was found that carbonaceous materials with graphitic morphology are easier to exfoliate and oxidize, leading to the production of higher quality graphene oxide. Therefore, the GO synthesized from mineral coke exhibited the best quality in this study. The methodology used proposes an innovative approach, offering a faster, more economical, and environmentally friendly synthesis compared to the traditional Hummers' method, thereby adding value to other raw materials that can be utilized in this process, such as Brazilian coke and coal.

Study of Palm Oil Shell Utilization as Metallurgical Coke with Variation of Bondcrete Additive

Coke, an essential ingredient in the steel and metallurgical industries, is typically derived from bituminous coal. However, in Indonesia, where bituminous coal is rare, coke production is dependent on coal imports due to the high moisture content of local coal. An alternative approach is to use biomass, such as palm oil processing waste, for "biomass coke" to produce a more environmentally friendly coke with lower greenhouse gas emissions. Palm kernel shell waste rich in lignocellulose proved suitable for this purpose due to its compressive strength and carbon content. Pyrolysis, a technique for creating porous micro-structured carbon from palm kernel shells, was used to produce this coke substitute, offering a more sustainable energy source with a lower carbon footprint than fossil fuels. Bio-coke exhibits low moisture content (5.84%) and ash content (13.20%) due to the moisture and ash reduction effects of bondcrete adhesive during combustion. It also demonstrates substantial compressive strength (14 mPa), a high calorific value (6795 cal/g), and a favorable pore structure with a large surface area, indicating a positive influence of bondcrete adhesive on coke properties without compromising energy potential.

Investigation into the role of carboxylic acid and phenolic hydroxyl groups in the plant biostimulant activity of a humic acid purified from an oxidized sub-bituminous coal.

Humic substances (HS) are increasingly being applied as crop plant biostimulants because they have been shown to increase plant productivity, especially under environmentally stressful conditions. There has been intense interest in elucidating the HS molecular structures responsible for eliciting the plant biostimulant response (PBR). The polar and weakly acidic carboxylic (COOH) and phenolic hydroxyl (ArOH) functional groups play major roles in the acid nature, pH dependent solubilities, conformation, and metal- and salt-binding capabilities of HS. Reports on the role played by these groups in the PBR of HS found growth parameters being both positively and negatively correlated with COOH and ArOH functionalities. To investigate the role of COOH and ArOH in HS biostimulant activity we used a humic acid (HA), purified from an oxidized sub bituminous coal to prepare HAs with COOH groups methylated (AHA), ArOH groups acetylated (OHA), and with both COOH and ArOH groups methylated (FHA). The original HA was designated (NHA). The four HAs were subjected to elemental, 13C-NMR, FTIR, and EPR analyses and their antioxidant properties were assessed using the trolox equivalents antioxidant capacity assay (TEAC). 13C-NMR and FTIR analysis revealed significant alkylation/acetylation. To determine the effects of alkylating/acetylating these functional groups on the HA elicited PBR, the HAs were evaluated in a plant bioassay on corn (Zea mays L.) seedling under nutrient and non-nutrient stressed conditions. Treatments consisted of the four HAs applied to the soil surface at a concentration of 80 mg C L-1, in 50 ml DI H2O with the control plants receiving 50ml DI H2O. The HA-treated plants, at both fertilization rates, were almost always significantly larger than their respective control plants. However, the differences produced under nutrient stress were always much greater than those produced under nutrient sufficiency, supporting previous reports that HA can reduce the effects of stress on plant growth. In addition, for the most part, the HAs with the alkylated/acetylated groups produced plants equal to or larger than plants treated with NHA. These results suggests that COOH and ArOH groups play a limited or no role in the HA elicited PBR. Alternatively, the HA pro-oxidant to antioxidant ratio may play a role in the magnitude of the biostimulant response.

Effects of Pre-Stretching Amount on Motion Characteristics and Screening Efficiency of Flip-Flow Screen Plates

This study systematically investigates the impact of pre-stretching amount (PSA) on the acceleration, motion status, and screening efficiency of the Flip-flow screen plate (FFSP). Initially, a nonlinear spring-multi-body model of the FFSP is established. Subsequently, the acceleration signals at the midpoint of the FFSP under various PSAs are measured and analyzed. The nonlinear stiffness coefficient of FFSP along the vertical direction is then determined and it is found that simplifying the nonlinear spring-multi-body system to a nonlinear spring-tri-body system under the experimental conditions can maintain the calculation error of FFSP’s acceleration within 30%. Phase and Poincaré mapping diagrams of the FFSP under different PSAs are subsequently created to illustrate the impact of PSA on the motion status of the FFSP. Finally, screening experiments are performed to study the optimal PSA for a kind of bituminous coal from Shanxi province.

Macromolecular insights into the influence of bituminous coal matrix deformation on CH4-N2 competitive adsorption and diffusion

Competitive adsorption and two-component diffusion of CH4/N2 play a crucial role in the production of N2-enhanced coalbed methane (N2-ECBM). However, the complex production and geological conditions as well as the heterogeneity and anisotropy of the coal can easily result in different degrees of deformation of the coal. Therefore, the competing adsorption and diffusion properties of CH4/N2 in bituminous coal matrix under uniaxial tension and compression strains were studied by macromolecule simulation. The results show that the partial pressure effect of N2 increases the difficulty of CH4 adsorption. Compared to the compression strain, the tension strain has less influence on the gas adsorption potential energy, while the corresponding potential energy distribution has more overlap. Besides, the thermodynamic correction factor (Γ) is positive correlated with the bulk CH4 mole fraction (y(CH4)) and decreasing y(CH4) increases the effect of CH4 displacement by N2. On the other hand, compared to the pores before adsorption, the number of pore throats and smaller pores in the gas-containing coal matrix increases, and the compression strain reduces the flexibility of the coal molecule. More importantly, strain has a dual effect on adsorption-induced coal matrix swelling and gas diffusion, with CH4 diffusion having an inhibitory effect on N2 diffusion. Furthermore, the order of strain influence on the interactions between gases is N2-N2 > CH4-CH4 > CH4-N2 and CH4-N2 tends to cluster compared to pure gases. These results provide important clues for the optimal design of the N2-ECBM technology in deformed bituminous coal reservoirs.

Anchorage performance of a new rebar bolt under different surrounding rock strength and borehole depth

The theory and technology of rock bolting are fundamental research topics for strata control in civil and mining engineering. Rebar bolts are commonly used for roadway primary support in underground coal mine. To adapt to deep resource mining, a new left threaded rebar bolt has been developed. Compared to conventional rebar bolts, the result of installation test showed that the new bolt reduced of 41.5% and 57.9% in stirring resistance force and torque, respectively. In laboratory pullout tests, PVC and aluminum sleeves were used to simulate weak and medium strength surrounding rocks. The average peak pullout force, displacement at the peak load and energy absorption increased by 27%, 107% and 108%, respectively, using PVC sleeve; and increased by 113%, 109% and 212%, respectively, using aluminum sleeve. Field tests were conducted under soft coal, hard coal and medium strength rock geo-conditions. Different borehole depths were selected to precisely calculate the average anchorage performance of the new bolt. Results showed that the average peak pullout force of the new bolt increased by 37%, 38% and 28%, respectively, under different surrounding rock conditions. Moreover, based on on-site test results, the pullout curves in field-testing were summarised and classified into 6 different patterns, which were discussed from a viewpoint of causality mechanism. The research findings validate that the newly developed bolt has better anchorage performance compared to conventional rebar bolts, making it a new anchorage material for deep resource mining.

Multiscale Pore Structure Evolution of Different Rank Coals Induced by Chelating Agent Intrusion

Summary China’s coalbed methane (CBM) reservoirs are characterized by low permeability (<1 md). Stimulation with conventional acids is facing the problems of secondary precipitation, high corrosion rates, and fines migration. Chelating agent intrusion was proposed as a promising alternative for conventional acids, while the pore structure evolution induced by it needs to be further clarified. In this study, coal samples with three different ranks were selected and treated with L-glutamic acid N, N-diacetic acid (GLDA). Low-temperature Ar and N2 adsorption tests, mercury intrusion porosimetry (MIP), and scanning electron microscope (SEM) analyses were applied to investigate nanoscale to macroscale pore structure changes. X-ray fluorescence (XRF) spectroscopy tests were conducted to determine the mineralogical change of coal. The results show that chelating agent intrusion can widen fracture width, connect micropores, and create void space in macropores by dissolving carbonate minerals, while the nanoscale pore volumes (PVs) showed a slight decrease due to clay minerals collapse. The fractal dimensions Dm calculated by the MIP results of lignite, bituminous coal, and anthracite coal decreased by 0.2735, 0.1734, and 0.1444, respectively. It is indicated that a pore structure with a diameter of >100 nm of the coal became more unified, which favors the seepage of gas/water. The chelating agent intrusion shows a significant effect on lignite, followed by bituminous and anthracite coal. However, the metal element reduction rate of anthracite coal presents the highest, followed by bituminous coal and lignite. There can be a risk that a long intrusion time would loosen the skeleton of lignite, leading to further reservoir damage. Therefore, bituminous and anthracite coal samples are preferred, as the skeletons of higher-rank coals are more compact. These research findings introduced a potential stimulation method for enhancing CBM recovery and provided references for field application.

Coal-based hard carbon anode for high-performance sodium ion batteries via coal-based graphene oxide as a multi-functional binder

Coal-based hard carbon for sodium ion batteries (SIBs) was successfully prepared using Shenfu bituminous coal (SFC) by one-step pyrolysis method. In the present work, we reported a novel method to fabricate carbon electrodes for SIBs from coal-based hard carbon with coal-based graphene oxide (CGO) as a multi-functional conductive binder to realize dual functional utilization of coal. As compared to traditional binder (CMC), electrodes with the CGO binder exhibits significantly increased reversible capacity and rate capability. This work provides a facile method for coal-based carbon materials used in SIBs.

Effect of oxygen concentration on the heat release behaviour of bituminous coal over the complete spontaneous combustion process

Effect of oxygen concentration on the heat release behaviour of bituminous coal over the complete spontaneous combustion process

Molecular simulation of competitive adsorption of CO2/N2/O2 gas in bituminous coal

The main cause of coal spontaneous combustion is the oxidation and temperature rise of coal. Injecting composite inert gas for fire prevention and extinguishing is one of the important methods to prevent coal spontaneous combustion. A large number of studies have macroscopically investigated the fire prevention and extinguishing effects of CO2/N2 and their synergistic actions. However, there is currently a lack of research at the molecular level on the competitive adsorption mechanism between mixed inert gases (CO2, N2) and O2 molecules in coal. Therefore, this study conducted adsorption experiments using Qian Yingzi(QYZ) bituminous coal and compared them with the simulation data of the Wiser coal model to verify the reliability of the Wiser model. Subsequently, employing grand canonical Monte Carlo (GCMC) and molecular dynamics (MD) methods, the competitive adsorption behavior of different proportions of binary mixed component gases (CO2/O2, CO2/N2, O2/N2) at a temperature of 303.15 K was investigated from five perspectives: adsorption capacity, adsorption selectivity coefficient, potential energy distribution, competitive adsorption heat, and interaction energy. The results indicate that among the competitive component gases, CO2 exhibits the strongest adsorption effect on the entire system, which is closely correlated with the distribution range of adsorption energy sites. The adsorption heat and adsorption amount of CO2 consistently exhibit a negative correlation, whereas the relationship between the adsorption heat of N2 and O2 and the adsorption amount shows a positive correlation. Their adsorption capacities depend on the pressure and the proportion of the two gases. Based on the isothermal adsorption curve of CO2/N2, it is recommended that the gas pressure during actual inert gas injection be less than 2.5 MPa. Under this pressure, the competitive adsorption effect is no longer significant, providing a certain theoretical basis for high-pressure injection. Moreover, the preliminary determination of the optimal injection ratio range is from 4:6–3:7. Furthermore, a systematic logical framework for selecting underground inert gas composition is proposed, and an underground mobile inert gas infusion process is adopted. The actual gas composition for infusion is determined based on cost factors in practical engineering. The research results can provide guidance for the selection of gas injection parameters for mixed inert gas fire prevention and extinguishing in goaf.

Research on the pressure relief law of diamond beaded rope saw cutting seam: a numerical investigation

As a new technology to mitigate the high outburst risk of the low permeability coal seam, it is essential to delve deeper into the law and mechanism of pressure relief associated with the diamond beaded rope saw slotting. The paper presents a numerical calculation model under small size that is based on the superimposed beam theory and the contact surface model. The model is compared with the experimental results of similar models in the laboratory to verify its applicability for simulating the numerical calculation of stress distribution in coal seam cut by diamond beaded rope saw. The study then goes on to investigate the influence of coal seam inclination, working face length, coal seam hardness, and seam advancing distance on the pressure relief effect of diamond beaded rope saw cutting seam under engineering scale. The mechanism of the diamond beaded rope saw cutting seam is also analyzed. The results indicate that the diamond beaded rope saw effectively reduces pressure in low permeability coal seams, with the impact range extending to the slit area. Additionally, stress concentration was observed at the front of the slit. Increasing the inclination of the coal seam, working face length, and advancing distance of the cutting seam enhances the pressure relief effect of the diamond beaded rope saw. The latter two factors’ influence is reflected in the direction along the working face and the direction of mining advance, respectively. The efficacy of pressure relief through this particular method is comparatively better in soft coal than in hard coal. This research is significant in promoting the widespread application of diamond beaded rope saws in the pressure relief of coal seam cutting.

Effect of primary air and coal properties on the formation of fine mode particles during low NOx gasification-combustion of coal in a self-sustaining furnace

Gasification-combustion technology can reduce NOx while the formation characteristics of fine mode PM is unclear. This research studied the impact of the excess air coefficient (αg) of the gasifier and the properties of coal on the formation and evolution of fine mode PM. The experiment was conducted on a self-sustaining furnace consisting of a gasifier where pyrolysis/gasification occurs and a combustion chamber where burnout of gasification gas and char occurs. The results showed that fine mode PM and NOx can be synergistically reduced by optimizing αg during gasification-combustion. A low or high αg can lead to a high furnace temperature in the gasifier or combustion chamber, respectively. Elimination of high temperature is crucial to reduce element vaporization which promotes the formation of fine mode PM. Additionally, an optimized combination of furnace temperature and reducing atmosphere in the gasifier can decrease NOx. The optimal αg was 0.32 for bituminous coal (BC). Fine mode PM generated from gasification-combustion of BC, lean coal (LC), and semi-char (SC) mainly consists of Ca, Si, Fe, and S. The vaporization of element from LC and BC primarily occurs during char combustion in the combustion chamber, while the vaporization of element from SC occurs almost equally in the gasifier and combustion chamber.

Low-carbon fuel reburning for CO2 and NOx reduction in pulverized coal firing system

Using low- or zero-carbon fuels is necessary to reduce CO2 emissions. Gas reburning technology can be applied to existing coal boilers to reduce not only CO2 but also NOx emissions. In this study, we confirmed the gas reburning effect using lab-scale equipment based on the consumption coal used in real-scale boilers, with the aim of practical application. Bituminous coal was used as the reference fuel, and sub-bituminous coal was blended to determine whether coal blending has an effect on NOx emissions. This was conducted to optimize the coal blending ratio and gas reburning technology for NOx emission reduction and quantify the NOx reduction by the two methods. Blending sub-bituminous coal reduced the unburned carbon (UBC) content, because of its high volatile matter content. Moreover, NOx emissions decreased as the ratio of sub-bituminous coal increased. In terms of the reburning effect, although UBCs increased with the addition of methane, NOx emission decreased by up to 96.05 %. The conversion ratio, defined as the NOx formation ratio of the total fuel N injection, was used to separate the NOx reduction effects of the two methods. Thus, gas reburning in the ammonia co-firing system of coal-fired power plants can significantly reduce NOx emissions.

Investigation on the Gas Emission Law of Water-Containing Coal across the Rank Range.

Water commonly occurs in coal reservoirs, and it can block the gas flow channels. This has a significant influence on methane transportation within coal. To reveal the gas emission law of water-containing coal across the rank range, three typical coal samples with different coal ranks covering lignite to anthracite were selected in this work. The initial velocity of gas emission (ΔP) under the effect of moisture was measured, and the combination of scanning electron microscopy and mercury injection method was adopted to study the pores and fracture characteristics within coal. Distribution features of oxygen-containing groups in coal were explored by X-ray photoelectron spectroscopy. The microscopic influence mechanism of the water content on ΔP in coal was also comprehensively elucidated. The experimental results show that the moisture content has an obvious inhibitory effect on the ΔP of coal, but the degree of influence on different coal rank samples was different. As the pore space of anthracite (sample XJ) is developed with numerous gas transportation channels, the ΔP has less changes at the lower moisture content (<4.36%). When the moisture content is >4.36%, a large number of water molecules will band together to form water clusters, hindering the gas release, thus greatly reducing the ΔP. However, the change of lignite (sample SL) shows an inverse trend to that of anthracite. Its ΔP is sensitive to the moisture content due to the small number of pores and low porosity. In addition, a great number of oxygen-containing groups in lignite can also provide good surface hydrophilicity for water molecules, and even a small amount of the moisture content (<3.21%) can block most of the pore and facture channels within coal, leading to the remarkable decrease in ΔP. For bituminous coal (sample ML), the distribution of pores and oxygen-containing groups is the most uniform, and the ΔP decreases linearly with the increase in the moisture content.

Synthesis and characteristics of carbon-based synfuel from biomass and coal powder by synergistic co-carbonization technology

A synergistic co-carbonization method based on the use of corn stalk (CS), wood shavings (WS) and bituminous coal (BC) is proposed as a green and low-cost technology. The preparation parameters included a co-carbonization temperature of 600 °C, a co-carbonization time of 30 min, and a biomass/coal ratio of 4/6. The high calorific value (HCV) and bulk density of the CS/BC synfuel were 29.81 MJ kg−1 and 495 kg m−3, respectively, and those of the WS/BC synfuel were 30.11 MJ kg−1 and 485 kg m−3, respectively. The results indicated that the microcrystalline structure was ordered and that the proportion of the graphitic structure increased during the synergistic co-carbonization process. In addition, the co-carbonization process changed the contents of the functional groups on the surface. The amount of aromatic C–O increased during the synergistic co-carbonization process. Decreases in the O-containing functional groups and increases in the graphitic carbon content in the synfuel demonstrated that the interactions of the biomass volatiles with the bituminous coal generated a more regular structure for the carbon-based synfuel and changed the carbon type of the synfuel. This work provides a mechanism for the biomass and coal interactions occurring during the preparation of carbon-based synfuels.

Study on the influence of different thermal coals on the mixed‐burning characteristics of ventilation air methane and pulverized coal

AbstractTo effectively utilize ventilation air methane (VAM), it is proposed to pass it into the boiler of the coal‐fired power plant for mixed combustion. However, the different types of thermal coal utilized present distinct characteristics when mixed with VAM. In this paper, lignite, bituminous coal, and anthracite are selected to study the CH4 conversion rate, system ignition temperature, and NO emission characteristics of the VAM‐pulverized coal coupled system on a fluidized bed experimental platform. The experimental results show that the ignition temperatures of VAM are 748, 736, and 732 °C when the CH4 concentration is 0.25, 0.5, and 0.75%. After the addition of thermal coal, the ignition temperature decreased significantly. When the CH4 concentration is 0.25%, the ignition temperature of the lignite‐VAM system is the lowest, which is 450 °C. Anthracite has the strongest catalytic effect on CH4 combustion. When the heating rate is 5 °C /min, the reaction rate of CH4 is the fastest in the anthracite‐VAM coupled system. Under laboratory conditions, the peak NO concentration in the coal‐VAM coupled system was lignite &gt; bituminous coal &gt; anthracite at different CH4 concentrations, and the CH4 in VAM had a reducing action on the NO generated during mixed combustion, with a stronger reducing effect observed as the CH4 concentration increased. The results of this study can lay the foundation for the industrial application of the mixed combustion of VAM and thermal coal, and be of great significance for solving the practical problems caused by the change of boiler coal types. © 2024 Society of Chemical Industry and John Wiley &amp; Sons, Ltd.

Influence of plasma breakdown on pores and fractures in bituminous coal: A new characterization method of breakdown energy

Plasma technology has a potential application prospect in the field of coal seam permeability enhancement. However, the relationship between plasma breakdown energy and the improvement effect of coal pores and fractures is lack of in-depth research. This study proposed a novel method for characterizing the plasma breakdown energy, and three testing techniques, namely, particle size distribution, mercury intrusion porosimetry (MIP) and low-field nuclear magnetic resonance (NMR), were utilized to examine the pore and fracture distribution of coal samples obtained from Jiulong Mine under varying breakdown energy conditions. The influence between breakdown energy and pores and fractures development is revealed. The results show that: (1) The degree of coal sample fragmentation increases with the increase of plasma breakdown energy. (2) Different breakdown energy induced the development of different pore distribution patterns. At lower breakdown energy, an increase in the volume of macropores dominates. As the breakdown energy increases, there is a rapid increase in the volume of mesopores, a slight increase in minipores, and the least increase in micropores, indicating that plasma treatment primarily improves pores with diameters greater than 100 nm. The test results of the three techniques were mutually verified. (3) Compared with capacitance energy and voltage, the effective breakdown energy obtained by the integral method has a more significant linear relationship with the particle size distribution, total pore volume, and average pore diameter, indicating that the effective breakdown energy is more suitable for characterizing the crushing effect of plasma. During the plasma breakdown process, the expansion stress and thermal stress formed by the effective breakdown energy exceeded the local tensile strength of coal, leading to the generation and development of pores and fractures, which in turn led to the rupture of the coal body. The larger the breakdown energy, the larger the crushing circle formed around the ion channel, the finer the coal is crushed, and the more pore fractures are developed. These nascent pores and fractures provide channels for gas transport, which is extremely favorable for coal mine gas extraction. The research conclusions provide theoretical support for the application of plasma in fracturing and permeability enhancement in coal seams.