AbstractOverpressure is widespread in the Permian and Triassic successions of the petroliferous Junggar Basin, northwestern China, with pressure coefficients up to 2.1. This study investigates the origin, distribution, and evolution of overpressure in the central Junggar Basin using well logs, measured pore pressures, basin modeling, geochemical parameters, and density–sonic cross plots. Overpressured intervals show consistent log responses, with higher acoustic travel time and lower resistivity than normally pressured mudstone. Mudstone density within the overpressured sections remains nearly constant, implying that overpressured mudstone have undergone normal compaction. Mudstone data from the overpressured intervals depart markedly from the normal compaction trend defined by normally pressured mudstone on density–sonic cross plots, indicating that disequilibrium compaction is unlikely to be the dominant overpressure mechanism in Permian and Triassic. Source rocks in these strata are dominated by Type II kerogen with a subordinate Type III component, and the vertical patterns of TOC and Rock-Eval S1+S2 broadly coincide with the distribution of overpressure. Most Permian and Triassic units in the central Junggar Basin occur below the top overpressure surface at depths commonly greater than 5000 m, where formation temperatures exceed 122 ℃ and thermal maturity is higher than 0.8% Ro. Under these conditions, the source rocks are capable of generating large volumes of hydrocarbons, which can provide sustained pore-pressure buildup. Basin modeling that incorporates a hydrocarbon-generation pressurization scheme further suggests three stages of pressure increase and two stages of pressure decrease in the Permian source rocks, and the inferred pressure-release episodes are broadly synchronous with hydrocarbon charging. These findings indicate that hydrocarbon generation is the dominant mechanism for overpressure in the Permian and Triassic strata of the Junggar Basin. Pressure buildup associated with hydrocarbon generation and pressure-release caused by hydrocarbon charging is the dominant mechanism controlling overpressure evolution in the Permian and Triassic strata of the Junggar Basin.

Carbon dioxide sequestration in saline aquifers is a promising strategy for mitigating climate change, but the long-term stability of stored CO2 depends on pore-scale interfacial dynamics between CO2 and brine. This study investigates CO2-brine interfacial mass transfer mechanisms and remobilization behavior during unsaturated brine imbibition using micro-CT scanning to resolve pore-scale processes. Results demonstrate that residual CO2 bubbles remain stable without significant remobilization at low capillary number, but interfacial mass transfer can induce isolated CO2 remobilization below the critical capillary number, leading to saturation reductions exceeding 20%. Post-remobilization pressure patterns vary among cores due to differences in CO2 trapping patterns, with CO2 singlets in single pores exhibiting the highest stability. Systematic analysis of bubble expansion and contraction reveals that contraction primarily occurs at pore throats with good connectivity, while expansion is dominant in poorly connected pores with CO2 singlet and ganglion distributions. Two mass transfer coefficients-slice-averaged and per-bubble-are measured, showing magnitudes of 10- 8 to 10- 7 m/s. While flow velocity does not exhibit a clear trend in coefficient magnitude, it induces a transition from Fickian to nonFickian mass transfer. Additionally, the study examines the interfacial evolution of CO2 clusters, ganglia, and singlets, highlighting that CO2 preferentially dissolves at pore throats, causing non-equilibrium phenomena such as bubble collapse, expansion, recession, and reconnection. These processes increase interfacial curvature and local capillary pressure, reducing bubble stability within pores. This research provides insights into pore-scale mechanisms governing CO2-brine interfacial mass transfer, offering implications for predicting sequestration efficiency and optimizing storage strategies.

Printed circuit heat exchanger (PCHE) has great potential to replace traditional intermediate heat exchangers in lead-bismuth eutectic (LBE) cooled fast reactors. In this study, a PCHE with novel layout is presented. An asymmetric channel configuration is proposed to mitigate the significant thermal resistance imbalance between LBE and water. A segmented Log-mean temperature difference method integrated with two-phase boiling correlations is employed for thermal design, while mechanical integrity is assessed in accordance with American Society of Mechanical Engineers standards. Parametric analysis reveals that increasing LBE inlet velocity or reducing channel diameter improves compactness but elevates pressure drop on both the LBE and water side. Dual-objective optimization yields an optimal design achieving a unit volumetric heat transfer rate of 354 MW & sdot;m- 3, which is 48 times higher than shell-and-tube exchangers, while maintaining a lowest hot-side pressure drop of 29.4 kPa. The final asymmetric PCHE occupies only 2.1% of the volume and 2.9% of the mass of a traditional shell-and-tube heat exchanger. Additionally, its volume and mass are both reduced to 51.0% compared to those of a symmetric PCHE. These results demonstrate that the proposed asymmetric channel layout offers superior compactness, and low flow resistance, making it highly suitable for nuclear applications.

Anaerobic microbial oxidation of hydrocarbons is a key biogeochemical process influencing hydrocarbon compositions and the carbon cycle in subsurface systems. In this study, the microbial oxidation of propane within the Ch-7 shale of the Ordos Basin was investigated through intramolecular carbon isotope analysis of thermally desorbed gases. The results show that samples affected by microbial activity exhibit elevated ΔC-T values (3.9‰–7.9‰), Δ13Ccentral values ranging from –27.2‰ to –22.9‰, and Δ13Cterminal values from –31.1 to –30.5‰, significantly higher than non-degraded samples. These isotopic characteristics indicate that microorganisms preferentially oxidize the central carbon atom in propane, while the terminal carbon retains its original isotopic signature. The distinct position-specific isotopic patterns serve as sensitive indicators of microbial degradation in shale reservoirs. Furthermore, sedimentological data suggest that microbial degradation potential is closely linked to the sand supply from different sedimentary facies. Toward deeper lacustrine settings, reductions in sandy interlayer thickness and grain size, along with enhanced nanoconfinement effects, restrict nutrient diffusion and microbial mobility, resulting in limited degradation despite favorable thermal conditions. This study confirms that intramolecular-level isotopic techniques provide powerful tools for identifying microbial processes in low-permeability shales and contribute to a better understanding of shale oil and gas reservoir evolution.

The continuous ortho-para hydrogen conversion plate-fin heat exchanger (C-PFHE) is a vital component in hydrogen liquefaction systems. However, limited research exists on quantitatively analyzing the effects of cold-side fin performance on flow, heat transfer, and ortho-para hydrogen conversion performance in the hot-side catalyst-filled channel. This study developed a one-dimensional mathematical model to simulate the characteristic of heat transfer, flow resistance, and ortho-para hydrogen conversion. We investigate three hybrid fin configurations: plain-plain, plain-perforated, and plain-serrated, utilizing principles of thermodynamics and field synergy to assess how variations in cold-side fin performance influence hot-side functionality. Results demonstrated that enhanced cold-side heat transfer improves overall heat transfer of hot-side and increases synergy between the heat transfer coefficients of across both sides. For engineering applications, employing a low Reynolds number with a plain-serrated hybrid fin C-PFHE is recommended for achieving optimal performance. Additionally, improving hot-side heat transfer boosts the para-hydrogen conversion rate. Two novel quantitative correlations are established: one between the hot-side j-factor and the cold-side j-factor, and the other between the hot-side j-factor and the para-hydrogen conversion ratio, with errors of ±1.5% and ±6%, respectively. These correlations offer theoretical guidance for designing new C-PFHE structures and enable rapid evaluation of impacts on hot-side performance.

In the context of the global energy transition and carbon neutrality, CO2 plume geothermal systems, as a CCUS technology that can synergistically achieve geothermal development and carbon storage, show broad application prospects. This study focuses on the Quantou Formation reservoir in the Songliao Basin. A three-dimensional heterogeneous model is constructed to compare four injection schemes: pure CO2 continuous injection, CO2-water alternating injection with 1-year cycles, CO2-water alternating injection with 2-year cycles, and CO2-water alternating injection with 3-year cycles. The impact of different injection rates on the system's heat extraction and storage performance is analyzed. The results indicate that the alternating injection strategy can significantly improve the overall system performance. At a flow rate of 40 kg/s, the system lifespan is extended to 26.8 years, an increase of 25.8% compared to pure CO2 injection; at a flow rate of 50 kg/s, the cumulative heat extraction reaches 2.83 & times; 1015 J. Thermal quality analysis shows that 30 kg/s is the optimal flow rate for intermittent injection, achieving a balance between thermal extraction and sustainability. In terms of CO2 storage, pure CO2 injection has a faster short-term storage rate, storing 1.5 & times; 1010 kg over 15 years at 50 kg/s, whereas alternating injections, although initially lagging, achieve a comparable long-term storage volume. However, alternating injection can cause periodic fluctuations in reservoir pressure, and the local high pressure formed during the water injection phase may affect the integrity of the caprock.

The Chang 8 Member in the Longdong area of the Ordos Basin hosts significant petroleum resources, demonstrating substantial potential for tight oil exploration and development. Astronomical forcing exerts a discernible influence on the evolution of its petroleum system. To elucidate the impact of Milankovitch orbital cycles on organic enrichment and the development of source rocks, reservoirs and cap rocks, we conducted a high-resolution cyclostratigraphic analysis of the Chang 8 Member stratigraphy. This study utilized gamma-ray (GR) well log series as the primary dataset. This lacustrine succession preserves distinct Milankovitch cycles, including similar to 405 ka long eccentricity, similar to 125 ka short eccentricity, obliquity, and precession periods, with eccentricity cycles showing particularly strong expression. These diagnostic eccentricity signals provided the framework for delineating high-frequency sequences. Subsequent astronomical tuning and base-level reconstruction constrain the depositional age of the Chang 8 Member to 242.22-241.23 +/- 1.4 Ma. During this interval, the lacustrine system exhibited a pronounced trend of base-level fall followed by rise, punctuated by higher-frequency fluctuations. Milankovitch cycles govern the development of high-quality reservoirs and cap rocks and organic enrichment by modulating climate and lake-level fluctuations. These orbital forcings drive weathering processes, control fluvial sediment supply and lacustrine accommodation space, and influence biological productivity. Our results demonstrate a pronounced association between the long eccentricity cycle (similar to 405 ka) and enhanced reservoir quality development, while the short eccentricity cycle (similar to 125 ka) exhibits a stronger correlation with organic matter enrichment, cap rocks, and source rock formation. Ultimately, the interplay of eccentricity cycles jointly governs the formation of the hydrocarbon system within the continental Chang 8 Member.

Printed circuit heat exchanger has great potential to replace traditional steam generators in molten salt-cooled high temperature reactor. In this study, an improved asymmetric-layout printed circuit steam generator (PCSG) is presented, where solar salt serves as the hot-side working fluid and water as the cold-side one. To accurately simulate phase-change heat transfer process of water (encompassing subcooled liquid, saturated liquid-steam, and superheated steam stages), a segmented Log-Mean Temperature Difference method integrated with Kandlikar's boiling heat transfer correlations is adopted. Mechanical integrity of the PCSG is verified in accordance with the American Society of Mechanical Engineers standards to ensure operational safety. Parametric analysis reveals that increasing the solar salt inlet velocity or expanding the water-side channel diameter enhances the PCSG's compactness but concurrently leads to higher pressure drops on both sides. Multi-objective optimization is performed using the genetic algorithm, followed by decision-making method, considering both two-objective (hot-side pressure drop and volume) and three-objective (hot-side pressure drop, cold-side pressure drop, and volume) scenarios. Compared to conventional shell-and-tube steam generators, optimized PCSG reduce height to 44.8-49.4 % and cold-side surface heat flux to 16.3-26.8 %, thus avoiding dryout in water or steam channels. This suggests that PCSG represent a promising alternative to conventional shell-and-tube steam generators. This study provides an efficient design approach for compact and safe PCSG in molten salt-cooled high-temperature reactors systems.

The abatement of NOx from diesel vehicle exhaust is of great importance for improving the atmospheric environment. Cu-SSZ-39 zeolites possess the potential for application in the diesel vehicle aftertreatment system. Phosphorus (P) and hydrocarbons (HCs) present in the exhaust have negative impacts on the catalysts. To enhance the resistance of Cu-SSZ-39 catalysts to P and HCs, various rare earth metals were doped. Loading of 1 wt% Ce on the Cu-SSZ-39 catalyst improves the resistance to P and HCs simultaneously. The promotion mechanism was investigated through H2-temperature programmed reduction (H2-TPR), ultraviolet visible diffuse reflectance spectroscopy (UV-vis-DRS), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), X-ray photoelectron spectroscopy (XPS), energy dispersive spectroscopy (EDS) and theoretical calculation. On the one hand, Ce species can act as sacrificial sites, preferentially binding with P. On the other hand, Ce doping induces the formation of CuO species, promoting the oxidation of C3H6 and preventing the consumption of NH3 from the reaction with C3H6. Ce acting as bi-functional sites enhances the P and HCs resistance of Cu-SSZ-39 catalysts, further brightening its practical application. (c) 2024 Chinese Society of Rare Earths. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

The supercritical carbon dioxide Brayton cycle (SCO2-BC) represents a transformative advancement in power generation, offering exceptional efficiency and compactness, particularly for renewable energy integration. Among the heat exchanger technologies suited for SCO2-BC, printed circuit heat exchangers (PCHEs) stand out due to their superior thermal performance and adaptability under extreme conditions. This review critically examines recent advancements in the thermal-hydraulic characteristics and dynamic performance of PCHEs in SCO2 systems. Key topics include flow and heat transfer behaviors under steady and dynamic conditions, innovative heat transfer structures, and performance evaluation using thermodynamic laws. Key breakthroughs include novel channel designs such as airfoil fins, pseudo-boiling theory, and artificial intelligence-driven performance predictions, which represent groundbreaking enhancements in efficiency. Persistent challenges-such as unifying heat transfer mechanisms, characterizing thermal inertia, and optimizing transient off-design performance-are also highlighted. Future research directions emphasize channel design optimization, flexibility/ safety enhancements, and comprehensive evaluation criteria. This work consolidates current understanding and guides future PCHE development for advanced energy applications.

Sedimentary structures induced by water seepage are described from modern beach bars within the Zhoushan Archipelago in China, including two unique types, herein referred to as: 1) seepage tubes; 2) seepage beads. Their formation is related to water seepage in sandy sediments, where the seepage tubes are formed by the downward seepage of pore water in sandy sediment, while the seepage beads are formed by the vertical superposition of multiple beaded horizontal seepage layers. The results show that unique terrain and rapid water ingress and retreat related to tides control the formation of these sedimentary structures. The seepage-induced sedimentary structures can be divided into vertical vadose belts that develop seepage tubes, horizontal undercurrent belts with seepage beads, and water-table variation belts with both seepage tubes and seepage beads appearing alternately. These sedimentary structures are hitherto undescribed and contribute to an improved understanding of similar sedimentary structures in the geological record.

Accurate characterization of the CO2-oil mixtures phase behavior will be advantageous for CO2 enhanced oil recovery (EOR) and reservoir production design for CO2 geologic storage projects. Relevant properties which include density, oil swelling factor, solubility and minimum miscibility pressure (MMP) of CO2-oil are typically measured in the laboratory using the conventional time-consuming pressure-volume-temperature (PVT) method. In this study, the phase behavior of CO2-oil mixtures was characterized inside a porous medium at reservoir temperature and pressure using nuclear magnetic resonance imaging (MRI). This research method realizes direct observation and in situ measurement compared with PVT method, effectively reducing the experimental operating pressure and the pressure-loading limit of the measurement equipment. The CO2-oil mixture equilibrium pressures correlated exponentially with the corresponding proton density (M0) and relaxation rates (1/T1, 1/T2); thus, the MRI multiparameter method was first applied to estimate MMP by only measuring several equilibrium pressure points and extrapolating to zero. The CO2 solubility and saturated liquid density linearly decreased as 1/ T1 increased but linearly increased as 1/T2 increased, which indicates that these parameters can be estimated based on the magnetic resonance (MR) relaxation rates. The results demonstrate the remarkable advantage and feasibility of applying MRI techniques for in situ measuring of the physical properties of fluids in porous media within the laboratory.

Accumulations of large volumes of CO2 related to mantle degassing, metamorphic reactions or magmatic processes have been found in many oil-gas bearing basins around the world . The Huangqiao area of the Lower Yangtze Plate hosts the largest CO2 gas field on mainland China. Throughout geological history, a significant influx of deep mantle-derived CO2 fluid occurred in this area. Understanding the timing of these CO2 charge and their effects on crude oil reservoirs is crucial for interpreting the distribution of present-day resources. The Cenozoic was long believed to be the only period during which CO2 charging occurred in the Huangqiao area, primarily because evidence of earlier CO2 fluid charges had been scarce. To address this, a comprehensive study utilizing petrography, cathodoluminescence, fluorescence and Raman spectrum of fluid inclusions, in-situ U-Pb dating, and basin modeling was conducted to elucidate the timing and interactions between crude oil and deep mantle-derived CO2 in the Permian Qixia Formation of the Huangqiao area. Three distinct phases of calcite veins were identified and dated: 251.7 ± 1.8 Ma, 124.16 ± 1.46 Ma, and 97.68 ± 1.20 Ma to 96.75 ± 0.25 Ma. The earliest CO2 charge, occurring around 251.7 ± 1.8 Ma, corresponds to a period when supercritical CO2 extracted low molecular-weight hydrocarbons from the S1g source rock. This timing aligns with the mass extinction event (251.4 ± 0.3 Ma), a rapid rise in atmospheric CO2 levels, and volcanic activity in the Permian Gufeng and Longtan Formations of the Lower Yangtze Plate, suggesting that the CO2 influx was volcanically driven. Between 124.16 ± 1.46 Ma and 96.75 ± 0.25 Ma, significant portions of the CO2 and crude oil within the Qixia Formation escaped due to tectonic uplift and erosion associated with the collision between the Yangtze Plate and the North China Plate. This research provides the first documentation of early mantle-derived CO2 fluid charges and their role in crude oil extraction from source rocks during transport from the mantle to the Earth's crust. Additionally, the study reconstructs the processes of CO2 and oil accumulation and leakage from the Indosinian to the Yanshanian periods, offering new insights into the evolution of hydrocarbon reservoirs in the Huangqiao area of Lower Yangtze Plate.

Hydrocarbons (HCs), as major poisoning substances, have a crucial influence on NH3-SCR catalysts. In this work, the effects of C3H6 on fresh and hydrothermally aged Cu-SSZ-39 catalysts with different copper contents were investigated. All catalysts suffered a deactivation above 250 °C, especially between 300∼400 °C, which was mainly related to the reaction between NH3 and C3H6. However, the hydrothermally aged and the high-copper-loaded Cu-SSZ-39 catalysts could achieve a recovery of NH3-SCR performance at high temperatures. Such activity recovery was attributed to the oxidation of C3H6 by CuxOy species, which therefore inhibited the reaction between NH3 and C3H6. As a result, more NH3 could be available for the NH3-SCR reaction and the Cu-SSZ-39 catalysts could maintain a good catalytic activity. Based on these findings, we proposed that high loaded Cu-SSZ-39 catalysts with a little CuOx formed are preferred for application.

The development of shape-stabilized phase change materials (PCMs) for solar-thermal energy storage faces a trade-off: while conventional petroleum or mineral-derived systems achieve high energy density, they raise concerns about resource depletion and environmental impact. Here, we address this challenge by applying a circular economy approach, transforming waste coffee grounds and beeswax (BW) into a fully bio-based composite PCM that combines sustainable attributes with performance characteristics relevant for practical applications. A hierarchically porous carbon aerogel, prepared by carbonization of coffee waste, serves as a structural support for vacuum-impregnated BW and demonstrates a PCM loading capacity of 78.8 %. The composite exhibits a phase change enthalpy of 135.3 J/g at 48.7°C and maintains 98.2 % of its capacity after 500 thermal cycles. Under thermal stress conditions (70°C, 4 h), the material shows no detectable leakage. Additionally, the biochar framework enables dual functionality: efficient solar absorption and heat storage, yielding an 89.0 % solar-thermal conversion efficiency under a light intensity of 100 mW/cm2. The real-time temperature profile shows that phase transition aligns with variations in solar input, as evidenced by a stable 48°C plateau during energy storage. By marrying waste valorization with leak-proof thermal storage, this work establishes a promising and scalable approach for developing next-generation bio-based energy materials. The coffee ground-derived composites combine renewable feedstock, straightforward preparation, and long-term cyclic durability, suggesting their potential as candidate materials for solar thermal harvesting and storage applications.

Printed circuit heat exchanger (PCHE) is widely recognized as the most promising heat exchanger for supercritical CO2 (SCO2) Brayton cycle. Stress assessment is critical to ensuring the safety and longevity of PCHE. This study addresses a critical gap in the thermal-mechanical stress assessment of PCHE for SCO2 Brayton cycles by developing novel quantitative models to predict equivalent stresses at semicircular channel tips. Unlike conventional ASME codes, which overlook thermal stress, the pseudo-2D ANSYS Workbench model integrating both thermal and mechanical stresses, was used to offer a comprehensive evaluation. Key structural parameters (channel diameter, plate thickness, ridge thickness) and operational parameters (pressure, temperature difference) were analyzed. The results reveal that mechanical stress is most sensitive to cold-side pressure, while thermal stress correlates linearly with temperature gradients. Dimensional analysis yielded predictive formulas for thermal stress (+/- 13.3 % error) and mechanical stress (+/- 14.3 % error), validated against finite element method results. A backpropagation neural network further improved prediction accuracy (errors <10 %). The proposed models streamline PCHE design verification and dynamic control optimization, ensuring safer and more efficient SCO2 cycle operation. This research advances sustainable energy systems by providing reliable tools for PCHE stress assessment, with potential applications in solar, nuclear, and waste heat recovery systems.

The intramolecular isotopic compositions of associated propane in shale oil from the Chang-7 sub-member of the Yanchang Formation in the Ordos Basin were firstly determined by an improved GC-Pyrolysis-GC-IRMS method, which was calibrated by the quantitative isotopic 13C NMR method. The results show that the Delta C-T values (S13CCentral-S13Cterminal) of associated C3 are ranging from 1.3 %o to 2.9 %o, the S13CCentral values range from -34.2 %o to -31.8 %o, while the S13Cterminal values vary between -35.6 %o and -34.9 %o. The molecular carbon isotopes of propane suggest that the associated gas originates from the sapropelic organic matter (OM) at the early maturation stage, while the intramolecular carbon isotopic compositions of associated C3 indicate that the associated propane is dominated by n-propyl reaction pathway with contribution more than 75 %. The intramolecular isotopic compositions of C3 derived from typical humic and sapropelic OM shows that the compositions of normal and isomeric groups within the kerogen structures could influence the chemical compositions in generated hydrocarbons. OM with high proportion of normal groups prefers to generate liquid hydrocarbons, while OM with high proportion of isomeric groups tends to generate gaseous hydrocarbons at the same maturation stage. This study demonstrates that the intramolecular isotopic composition of associated C3 in shale oil can reflect the chemical structure of kerogen of source rock, and may further assess the shale oil potential.

Backward Monte Carlo method of the complicated and exact three-dimensional turbine with the spectral emission and reflection characteristics of the turbine blades materials and the spectral absorption and emission characteristics of combustion gas is established. The factors affecting the accuracy of the radiation temperature measurement are analyzed. The results show that reducing the distance from the probe to the target surface can reduce the effect of the environment on the measurement accuracy. Increasing the temperature and emissivity of the target surface can improve the measurement accuracy. The reflection characteristics of the surfaces have little influence on the radiation temperature measurement, so the blades can be considered as diffuse reflectors in order to improve the calculation efficiency. The temperature measurement accuracy decreases rapidly as the temperature of the combustion gas increases. The temperature measurement accuracy decreases with the increase of total gas pressure and H2O concentration. When measuring the temperature of rotating blades, the apparent emissivity of the target surface is inversely proportional to the measurement accuracy.

The hydrogen precooler is a critical component of hydrogen refueling stations (HRS), requiring high heat transfer efficiency, compactness, and pressure resistance. The printed circuit heat exchanger (PCHE) excels in highpressure environments. However, in practical engineering applications, the refrigerant's operating pressure on the cold side is relatively low. Consequently, a hybrid PCHE incorporating a plate-fin structure on the cold side offers greater potential. This study evaluates the performance of three innovative hybrid PCHEs (semicircleplain, semicircle-perforated, and semicircle-serrated) compared to conventional PCHEs (semicircle- semicircle) for 35 MPa and 70 MPa HRS using a segmented thermal design method coupled with a stress check. Channel geometrical parameters are optimized to minimize volume and pressure drop. Results show that hybrid PCHEs outperform conventional PCHEs, with the semicircle-serrated hybrid PCHE achieving the best performance. Its superior performance is attributed to the serrated fins, which enhance synergistic performance between local heat transfer coefficient and local heat transfer temperature difference and reduce thermal resistance, significantly lowering the required heat transfer area. At the optimal point, hybrid PCHE volume is reduced by 68.82 % (35 MPa HRS) and 33.33 % (70 MPa HRS), while pressure drops are reduced by 48.94 % and 83.73 %, respectively. This study provides valuable insights into optimizing PCHE designs for future hydrogen refueling infrastructure.

The pore network in shale could influence the proportion of adsorbed gases and total gas content and thus is significantly important for the exploration and development of shale gas. The Lower Cambrian Niutitang Formation shale has been proved that have impressive shale gas exploration prospect. Ten Niutitang Formation shale samples were collected from the Micangshan-Hannan Uplift of the Southern Shaanxi area. The TOC is between 0.68% to 2.51%, averaging at 1.54%, and the mineral compositions are dominated by quartz, feldspar, and clay. The pore types comprise intergranular pore, inter-crystalline pore in clay matrix and pyrite aggregates, and organic pore. Quantitative pore structure investigation and impact factors were conducted. The pore area and pore volume are mainly contributed by macropores and mesopores, respectively. TOC, quartz and carbonate contents can jointly influence the pore space. The development of micropore in shale samples is closely related to organic matter, and which is associate with the content of quartz.