Science AI Journal
Engineering · Research topic

Open research questions in Coal Properties and Utilization

105 unresolved questions extracted from the limitations and future-work sections of 748 Coal Properties and Utilization papers in our library. Each links back to the study that raised it.

What the literature leaves open

  • The complexity of the coal rank and hydrocarbon generation–occurrence mechanism in the Mugua Area, - The lack of understanding of the accumulation and enrichment regularity of medium-rank deep CBM, - The need for a spatiotemporal synergistic coupling reservoir-controlling mechanism to determine the critical transition zone of the deep CBM occurrence state.

    Characteristics and Enrichment Regularity of Coalbed Methane in the No.8+9 Coal Seams of the Taiyuan Formation in the Mugua Area, Shenfu Gas Field · 2026 · DOI

  • Further study on the effect of local small reverse faults on gas escape, - Investigation of the relationship between formation temperature and gas release rate

    Characteristics and Enrichment Regularity of Coalbed Methane in the No.8+9 Coal Seams of the Taiyuan Formation in the Mugua Area, Shenfu Gas Field · 2026 · DOI

  • the complexity of the coal structure and its response to acidic environments - the difficulty in establishing a quantitative model that accurately describes the transformation process of coal samples - the need to minimize external interference and improve measurement reliability in the experiments

    Multiscale Damage and Fracture Characteristics of Coal Samples Induced by Acidity · 2026 · DOI

  • The study only considers the effects of acidity on coal samples, - The experiments were conducted in a controlled environment, - The study does not account for other factors that may influence the mechanical properties of coal, - The sample size is limited to three samples per pH condition, - The study only uses a specific type of coal from Shanxi Province, China

    Multiscale Damage and Fracture Characteristics of Coal Samples Induced by Acidity · 2026 · DOI

  • The need to preserve sample integrity during transportation and preparation. The challenge of simulating the temperature and pressure conditions in deep formations in the study area. The requirement for strict tolerances in drilling cylindrical plunger samples.

    Size-Dependent Pore Responses to Stress and Temperature of Anthracite Samples from the Qinshui Basin in North China Using NMR: Implications for Deep Coalbed Methane Exploitation · 2026 · DOI

  • The lack of understanding of pore size distribution characteristics of coal under high-temperature and high-stress conditions. The need to determine the difference in stress and temperature sensitivity of pores with varying sizes. The requirement for critical insights to optimize coalbed methane exploitation in deep anthracite reservoirs.

    Size-Dependent Pore Responses to Stress and Temperature of Anthracite Samples from the Qinshui Basin in North China Using NMR: Implications for Deep Coalbed Methane Exploitation · 2026 · DOI

  • further investigation of coal pore structures, - improvement of the MDFA-DeepLabv3+ model

    Deep Learning-Based Segmentation and Spatial Distribution Characteristics of Coal Matrix Pores in FIB-SEM Images · 2026 · DOI

  • Conventional characterisation techniques have inherent resolution constraints, - Prior methods are primarily divided into photoelectric radiation and fluid injection techniques, - There is a need for a more accurate and comprehensive method for evaluating coal matrix pore characteristics.

    Deep Learning-Based Segmentation and Spatial Distribution Characteristics of Coal Matrix Pores in FIB-SEM Images · 2026 · DOI

  • The lack of understanding of the influence mechanism of differences in hydrocarbon generation intensity of deep coalbed methane. The need to investigate the planar distribution characteristics of source rocks. The importance of analyzing the organic geochemical characteristics of coal samples.

    Influence mechanism of differences in hydrocarbon generation intensity of deep coalbed methane: a case study of the Daning-Jixian block · 2026 · DOI

  • Significant vertical heterogeneity in coal reservoirs. Insufficient conventional interval subdivision methods. Limited understanding of the cyclostratigraphic stratigraphic framework for the coal seam in this region.

    Vertical Heterogeneity of Deep Carboniferous Coal Reservoirs in the Northern Part of the Eastern Margin of the Ordos Basin · 2026 · DOI

  • The study only analyzed 26 samples from two wells, - The study used a limited number of measurement points for maceral analysis, - The repeatability limit for total sulfur determination is 0.10% for 1-4% sulfur

    Vertical Heterogeneity of Deep Carboniferous Coal Reservoirs in the Northern Part of the Eastern Margin of the Ordos Basin · 2026 · DOI

  • The paper identifies the challenge of low methane concentration and very large volumetric airflow rates in VAM. The study highlights the importance of considering air pre-treatment before ventilation air is introduced into VAM utilisation systems. The paper notes the need for site-specific sizing calculations for the actual airflow rate, dust concentration, and required outlet concentration.

    Characteristics of Dust in Ventilation Air from Hard Coal Mine Exhaust Shafts and Its Implications for VAM Utilisation Technologies · 2026 · DOI

  • The paper identifies a gap in the understanding of dust content in ventilation air quality for VAM utilisation technologies. There is a need for data on dust composition and particle size distribution. The study highlights the importance of considering air pre-treatment before ventilation air is introduced into VAM utilisation systems.

    Characteristics of Dust in Ventilation Air from Hard Coal Mine Exhaust Shafts and Its Implications for VAM Utilisation Technologies · 2026 · DOI

  • Further research is needed to investigate the effects of other factors on hydrocarbon generation intensity - Studies should be conducted to validate the results of this study in other coalbed methane reservoirs - Research should be done to improve the accuracy of hydrocarbon expulsion intensity estimates

    Influence mechanism of differences in hydrocarbon generation intensity of deep coalbed methane: a case study of the Daning-Jixian block · 2026 · DOI

  • However‌, existing studies on the outburst mechanisms of such working faces remain insufficient, resulting in low pertinence‌ and poor practical effectiveness of prevention measures.

    Deformation characteristics and outburst mechanism of coal mass ahead of working faces under dynamic disturbance induced by roof fracturing · 2026 · DOI

  • How different representations of fractures affect the predicted displacement response remains insufficiently understood, particularly when discrete fracture network (DFN) and equivalent continuum medium (ECM) models are compared under identical initial and boundary conditions.

    Hot Flue Gas-Enhanced Coalbed Methane Recovery: Comparative Discrete Fracture Network and Equivalent Continuum Modeling · 2026 · DOI

  • As coal mining moves toward greener and more intelligent practices, future research should focus on integrating inhibition technology with sustainable concepts, and on bridging theoretical mechanism studies with engineering applications.

    A Bibliometric Review of Chinese Research on Coal Spontaneous Combustion Inhibitors in Years 1990–2025 · 2026 · DOI

  • However, the evolution of coal oxidation characteristics under different degrees of thermal damage remains unclear.

    Evolution and mechanism of oxidation characteristics of coal with different degrees of thermal damage in coalfield fire zones based on multi-method joint characterization · 2026 · DOI

  • Carbon-centered radicals (R ), which were scarcely detectable before irradiation, formed rapidly under UV exposure, indicating photoinduced cleavage of activated C–H and C–C bonds.

    Ultraviolet-enhanced oxidative activation of pre-oxidized coal during storage: radical evolution and mechanistic insights into low-temperature oxidation · 2026 · DOI

  • Coal exposed to air and solar radiation during open storage and transportation undergoes progressive low-temperature oxidation; however, the molecular mechanism by which ultraviolet (UV) irradiation activates the radical network of pre-oxidized coal remains unclear.

    Ultraviolet-enhanced oxidative activation of pre-oxidized coal during storage: radical evolution and mechanistic insights into low-temperature oxidation · 2026 · DOI

  • Surfactants are widely applied in mine dust control; however, the intrinsic mechanism by which microscopic physicochemical properties determine macroscopic wetting performance remains not fully elucidated, limiting the rational design of high-efficiency reagents.

    A multiscale study on the molecular mechanisms of surfactants that enhance the wettability of coal dust and the efficiency of droplet coagulation · 2026 · DOI

  • However, comprehensive studies on pore structure characteristics and flow mechanisms in deep coalbed methane reservoirs are lacking.

    Review and Outlook of Pore Structure Characteristics and Flow Mechanisms in Deep Coalbed Methane Reservoirs: Advances and Perspectives · 2026 · DOI

  • Nonetheless, the exact origin of cleats remains unclear, and various hypotheses exist.

    Cleat and Fracture Systems in Coal with Implications for Strength, Hydrofracking, and Gas–Water Flow Mechanisms: A Critical Review · 2025 · DOI

  • However, there is currently limited research on the internal factors that govern the methane adsorption capacity and methane production mechanisms in coals with varying degrees of metamorphism.

    Methane Adsorption Behavior and the Constraint Mechanism of Microbial Degradation in Coals of Varying Ranks · 2025 · DOI

  • However, the occurrence characteristics of initial free and adsorbed methane and the influence of the initial free methane content on deep CBM production remain elusive.

    Occurrence Characteristics of Initial Free and Adsorbed Methane under Pressure-Preserved Coring Conditions and the Influence of Initial Free Methane on Deep Coalbed Methane Production · 2025 · DOI

Most-cited papers in Coal Properties and Utilization

Most recent work

Find a gap in your own Coal Properties and Utilization sub-topic

This page shows what the Coal Properties and Utilization literature already flags as unresolved. To narrow it to your specific question, search the Research Gap Finder: the search is free with a free account and lists the papers closest to your topic first. Unlocking that topic (50 credits, charged once) fills the comparison table from our 4.5M-paper local library and writes the gaps from its rows.

Open the Research Gap Finder →

Related topics in Engineering

Human auditory perception and evaluation
606 open questions
Urban Design and Spatial Analysis
499 open questions
Spatial Cognition and Navigation
457 open questions
Perovskite Materials and Applications
433 open questions
Traffic and Road Safety
426 open questions
Concrete and Cement Materials Research
409 open questions
Digital Transformation in Industry
378 open questions
Advancements in Battery Materials
362 open questions
105 open questions have been extracted from the limitations and future-work passages of 748 Coal Properties and Utilization papers in our 4.5M-paper local library. Each one below links back to the study that raised it, so you can read the original claim in context.

Tools for your next paper

Gaps & Literature SearchFind open questions in any field — 120,000+ open gaps mined from our own library.Pre-CheckIs your paper ready? A Tier 1–5 acceptance probability in seconds.Journal FinderA ranked shortlist of target journals from a 17,500-venue index.Duplicate Publication CheckerCheck prior-publication & salami-slicing risk across 8 sources.Citation GeneratorFreeA DOI or title → APA, MLA, Vancouver, Chicago, BibTeX, RIS. No signup.Graphical Abstract MakerFreeTurn your findings into a colorblind-safe graphical abstract.

Compare the category — Honest roundups of the AI research tools, ours listed alongside the alternatives.

Command palette

Jump anywhere, run any action.