Storage is currently a major obstacle to the promotion of hydrogen energy. Hydrogen storage in abandoned coal mines can achieve the effective use of underground space while meeting the growing demand for energy storage facilities, which can bring economic and environmental benefits. However, research in this area has been limited to the conceptual discussion stage, without establishing a scientific evaluation method for the potential of modifying and utilizing abandoned coal mine space. In this study, based on the analytic network process (ANP), the Apriori algorithm is introduced to mine the association rules for various influencing factors. First, the Apriori algorithm is applied to mine association rules between indicators, eliminate unnecessary influence relationships, simplify the network structure model, and optimize the ANP weight calculation results; second, the solution method of judgment matrix is improved with triangular fuzzy numbers, and the index weight is solved by fuzzy nine marks instead of the method of nine scale, which is convenient for experts to give the fuzzy scale while better reflecting the opinions of experts. Finally, the ANP algorithm is applied to rank the weights of the obtained influencing factors, discuss the main factors with higher weights, and analyze the feasibility of converting candidate coal mines into hydrogen storage facilities using the derived evaluation method in the case study. The evaluation methods and conclusions presented in this study provide analytical tools and a decision basis for analyzing the feasibility of converting underground space of abandoned coal mines into hydrogen storage facilities and assessing the economic indicators.

Gas pressure is one of the major factors to characterize the outburst danger of coal seams. Generally, the process of gas pressure determination is complicate and cannot ensure the accuracy of results, which may cause a wrong identification of outburst danger. This paper discussed and revealed a positive correlation between initial gas emission and gas pressure, which provides a new approach to identify the outburst danger by initial gas emission. Through theoretical analysis and numerical simulation, the liner equation of gas pressure and initial gas emission was deduced. Laboratory experiments under adsorption and desorption of CO₂ and N₂ were performed using coal samples from Weishe coal mine. The data of initial gas emission under different gas pressure were recorded, and the fitting curves were obtained. The results show a positive correlation between initial gas emission and gas pressure, and the curve of N₂ was below the CO₂. Especially, while the adsorption gas pressure was under 0.663 and 0.675 MPa, the difference of corresponding initial gas emission was only 0.01 L/s, which indicates the high degree of correlation. The results validated the theoretical and practical feasibility to identify the coal and the gas outbursts through initial gas emission.