Characterizing the Complexity Assembly of Pore Structure in a
Here we identify the pore structure in a coal matrix as a dual-complexity system consisting of original complexity and behavioral complexity independent to each
Coal/PAN interconnected carbon nanofibers with excellent energy storage
Section snippets Oxidization of raw coal. All reagents were of analytical grade and directly used without any purification. The industrial and elemental analysis of raw coal (from Kuche County, Xinjiang, China) are shown in Table 1. 10 g Kuche coal powder was added into 250 mL concentrated sulfuric acid at a time in the ice water
Time
In research on coalbed methane, there is no accurate and reasonable description of the gas transport behavior in a coal matrix over the entire time and pressure scale. The classical Fick diffusion model is inadequate to describe the transport behavior of methane in a coal matrix. It is also very controversial to use the Darcy flow model to simulate the gas
Characterizing the Complexity Assembly of Pore Structure in a Coal
The pore structure in a coal matrix is a dual-porosity system where fractures and pores coexist and feature scale-invariance properties, which would affect the occurrence and migration of coalbed methane (CBM) significantly. Therefore, it is of fundamental importance to well define complexity types and effectively characterize their
Evolution of coal permeability during gas/energy storage
Enhanced coalbed methane recovery and CO2 geo-storage in coal seams are severely limited by permeability decrease caused by CO2 injection and associated coal matrix swelling.
Preparation of porous carbon materials from biomass
1. Introduction. Hydrogen energy is considered as a promising sustainable resource under the increasingly tense situation of energy and environment [1].However, there are some key problems restrict the further progress of hydrogen energy, especially the challenge of hydrogen storage [2], [3] recent years, plenty of efforts have been
Characterization of Coal Pore Structure and Matrix
In this work, we modeled a continuous pore size distribution from nanopores to microfractures and determined the optimal pore size range for calculating
Dynamical modeling of coupled heat and mass transfer process of
Accordingly, gas transport in coal seams occurs at two scales: gas desorption within the porous coal matrix and gas flow through the coal fractures [7]. Due to the complexity of governing mechanisms, it is challenging to accurately model the dynamical behavior of gas desorption and flow in coal seams though it is one key issue for coalbed
Recent advances in porous carbons for electrochemical energy storage
Porous carbons are widely used in the field of electrochemical energy storage due to their light weight, large specific surface area, high electronic conductivity and structural stability. Over the past decades, the construction and functionalization of porous carbons have seen great progress. This review summarizes progress in the use of
Pore structure characterization and its significance
In the stage of high metamorphism, the abnormally rapid temperature rise promotes the pyrolysis of alicyclic and side chains, and a large number of interchain
Functional combination of methylene blue and porous
The separation of CH 4 and N 2 is an important technology for the effective utilization of low-concentration CBM. To improve CH 4 /N 2 separation properties of coal-based porous carbons, Shaanxi long-flame coal was hydrothermally treated followed by KOH activation for the preparation of porous carbons. The impact of hydrothermal
Hierarchically structured porous materials: synthesis strategies and
As mentioned above, since hierarchically structured porous materials can provide an efficient solution to the practical problems of energy storage, such as capacity loss, poor rate capability, volume expansion and limited cycle life, encountered in commercial application of reversible batteries and supercapacitors, their synthesis and
Impact of Effective Stress and Matrix Deformation on the Coal
The coal has a natural dual porosity structure that consists of the coal matrix and the fracture in which there are numerous inorganic minerals, mainly kaolinite, pyrite and illite, as shown in Fig. 1.More than 95 % of the gas occurs as adsorbed gas in the sorption space of the abundant micro-pores (Gray 1987).The gas migrates by diffusion in
Porous carbon nanosheets from coal tar pitch for zinc ion hybrid
The preparation process of PCNSs can be found in the Fig. 1a. First, as the temperature rises, the coal tar pitch melted and coated the mixture of KHCO 3 and KHC 2 O 4.Then, KHCO 3 and KHC 2 O 4 began to decompose and react with the carbon matrix to activate it and make pores. The decomposed reactions of KHCO 3 and KHC 2 O 4 are
Characterizing the Complexity Assembly of Pore Structure in a
The pore structure in a coal matrix is a dual-porosity system where fractures and pores coexist and feature scale-invariance properties, which would affect
Robust coal matrix intensifies electron/substrate interaction of
The intermittent characteristic of renewable energy offers important opportunities for electrochemical energy storage and conversion [3]. RR activity significantly [25]. Consequently, a robust and porous coal matrix should be able to enhance catalytic performance of nonprecious metals. Additionally, it is worth noting that
Study on gas transport behavior in coal matrix based on free gas
CBM mining has the potential to not only alleviate the energy crisis but also reduce greenhouse gas emissions and coal mine accidents (Yan et al Numerical modeling and experimental validation of anomalous time and space subdiffusion for gas transport in porous coal matrix. Int. J. Heat Mass Tran., 100 (2016), pp. 747-757,
Improved Porosity and Permeability Models with Coal Matrix
Coal permeability is an important parameter in coalbed methane (CBM) exploration and greenhouse gas storage. A reasonable theoretical permeability model is helpful for analysing the influential factors of gas flowing in a coalbed. As an unconventional reservoir, the unique feature of a coal structure deformation determines the state of gas
Evolution of coal permeability during gas/energy storage
Permeability is one of the important reservoir parameters for the geological storage of CO2 or hydrogen in coal seams, as it can directly affects the gas
A New Coal-Permeability Model: Internal Swelling Stress and
We have developed a new coal-permeability model for uniaxial strain and constant confining-stress conditions. The model is unique in that it explicitly considers fracture–matrix interaction during coal-deformation processes and is based on a newly proposed internal swelling stress concept. This concept is used to account for the impact
N-doped porous carbon from direct KOH activation of Victorian
Coal, as a low-cost precursor for carbon materials, has been explored for alternative utilizations in many areas, such as energy storage and absorption [11], [12], [13]. Victoria has more than 430 billion tons of Australian brown coal reserves, which account for up to 20% of the known low-rank coal reserves globally [14].
Synthetic porous carbons for clean energy storage and conversion
2.2. Pore structure engineering. Porous carbon electrode materials are essential components of energy storage and conversion systems, all the pore structure characteristics comprising pore size, size distribution, tortuosity and connectivity play a key role in affecting the electrochemical performance.
Nanomechanical properties of CH4-containing coal during CO2 storage
The mechanical properties of the storage medium are one of the key factors ensuring the safety of CO 2 storage. The Grand canonical Monte Carlo and Molecular Dynamic were conducted in this paper to investigate the micromechanical characteristics of storage medium after CO 2 storage in the coal molecular layer and
Numerical investigation of local thermal non
When cryogenic nitrogen flows through float coal porous media, the initial temperature difference between fluid and coal matrix will result in complex heat and mass transfer due to very small thermal conductivity of float coal matrix, which may be different from those discovered in the field of heat transfer enhancement, such as energy storage
From longan peel waste to energy storage: Porous
Fig. 1 illustrates the process for producing porous activated carbon, referred to as LP 2, and its selenium composite, Se@LP 2, starting from longan peel waste (LPw) as the carbon precursor itially, LPw obtained from a local market was thoroughly washed with water and ethanol to remove impurities. After washing, the LPw was dried at
Mechanical property alterations across coal matrix due to water
Coal matrix is known to be a polymer-like porous medium with developed pores instead of rigid grain-packed brittle material. Coal matrix can swell or shrink in response to CO 2 adsorption or desorption due to gas sorption-induced surface energy alternation and the induced structural changes can weaken coal strength and trigger
Coal Matrix Deformation and Pore Structure Change in
A coal seam is a kind of typical heterogeneous unconventional natural gas reservoir, developed abundantly in pores and fractures [ 1, 2 ]. Pores in the coal matrix are the main space that adsorbs coalbed methane (CBM),
Visualisation of [11C]CO2 storage in coal with positron emission
Depleted coal seam gas reservoir has the largest storage capacity and efficiency due to the longer interaction time between CO 2 and coal matrix, better sweeping efficiency, and late CO 2 breakthrough. This work directly investigates in-situ CO2 flow dynamics in coal by using [11 C]CO2 as the tracer during PET imaging for the first time.
Shape-stabilized phase change materials based on porous
Shape-stabilized phase change materials based on porous supports for thermal energy storage applications. Author links open overlay panel Xiubing Huang 1, Xiao Chen 1, Ang Li, Dimberu Atinafu, Hongyi Gao, Wenjun Dong 1 W m −1 K −1 to 50.8 W m −1 K −1 due to the uniform distribution of thermal conductive medium in the
Numerical modeling and experimental validation of
Coal seams differ significantly from conventional gas reservoirs in that most gas in coal seams is originally adsorbed on the surface area of porous coal matrix rather than stored as a free gas [2]. Accordingly, the dynamic process of gas transport in coal seams occurs at two scales: gas adsorption and desorption within the coal matrix and
Effective combination of Fe2O3 with hierarchical porous carbon
Herein, the well-designed hybrid materials composed of Fe2O3 nanoparticles embedded in hierarchical porous carbon matrix (HPCs/Fe2O3) were prepared by a two-step approach, involving a salt template route followed by hydrothermal treatment. The hierarchical porous structure not only serves as a buffer matrix to
Pore structure and compressibility of coal matrix with
The results from TG-MS showed that moisture and partial volatiles were removed from the coal matrix, and pore structure almost remained unchanged during the low heat treatment (25~200°C). The micropores and transition pores consisted of more than 80% of the total pore volume based on the MIP.
Effective combination of Fe2O3 with hierarchical porous carbon
Herein, the well-designed hybrid materials composed of Fe 2 O 3 nanoparticles embedded in hierarchical porous carbon matrix (HPCs/Fe 2 O 3) were prepared by a two-step approach, involving a salt template route followed by hydrothermal treatment.The hierarchical porous structure not only serves as a buffer matrix to
Robust coal matrix intensifies electron/substrate interaction of
The coal-matrix electrocatalyst CNNi-700 yields a high FE CO of 97% as well as an industrial j CO of 223 mA cm –2 in the flow cell. Third, with the support and protection of the robust coal matrix, the electrochemical performance of CNNi-700 remains steady after the long-term electrolysis, demonstrating its outstanding durability.
A review on the applications of porous materials in solar energy
In a numerical work, Ming et al. [60] used porous material as an energy storage layer in the solar chimney power plant system and they considered soil as the porous material. The porosity of the layer was selected as 0.6. They observed that the temperature distributions at the surface and inside the porous layer varied significantly
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