Article
Engineering, Environmental
Jia Lin, Ting Ren, Yuanping Cheng, Jan Nemcik
Summary: CO2 geo-sequestration in unminable coal seams shows promise in reducing greenhouse gas emissions and enhancing coal bed methane recovery, but faces challenges in permeability reduction effects post-injection.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2021)
Article
Geosciences, Multidisciplinary
Qinghe Niu, Mingwei Hu, Bing Leng, Xiang He, Wenjie Su, Wei Wang, Qizhi Wang, Jiangfang Chang, Zhongmin Ji, Xiaofei Qi
Summary: Guaranteeing CO2 injectivity is crucial for CO2-enhanced coalbed methane recovery (CO2-ECBM), however, the injectivity decreases significantly due to the dynamic change of anisotropic permeability of coal. Anisotropic permeability tests and CO2 injectivity simulation tests were conducted to evaluate CO2 injectivity in coal. The results show that permeability is highest in the parallel face cleat direction, followed by parallel butt cleat direction, and lowest in the vertical bedding direction. Increasing CO2 injection pressure temporarily enhances injectivity, but there is a limited increment. CO2 fracturing by phase transition may be a promising method for enhancing CO2 injection.
FRONTIERS IN EARTH SCIENCE
(2023)
Article
Thermodynamics
Zhenzhi Wang, Xuehai Fu, Jienan Pan, Ze Deng
Summary: By conducting experiments on four coal samples with different CH4 saturations, the change of coal strain during N2/CO2-ECBM was studied. The results show that the adsorption swelling rate decreases with increasing saturation, and the order of swelling rate is CO2 > N2 > CH4. The ratio of strain induced by CO2, CH4, and N2 adsorption is approximately 9.52 : 4.05 : 1. During N2-ECBM, the volume shrinkage strain caused by nitrogen injection increases with the increase of methane saturation, and the shrinkage percentage follows the order of medium- > low- > high-rank coal. Replacing injected N2 with CO2 reduces the swelling strain rate compared to CH4 adsorption. In the process of desorption with stepwise depressurization, the strain rate in N2-ECBM follows the order of test 2 < test 3 < test 4, but there is no obvious regularity in CO2-ECBM. The application of CO2-ECBM is more effective in high-rank coal reservoirs. CO2/N2 alternate injection method can improve the injectability of CO2, especially in high-rank coal.
Article
Energy & Fuels
Jun Tang, Yonghan Long, Lei Zhang, Shipan Zeng, Shixiang Tian, Cun Zhang
Summary: Coal seam gas extraction is vital for green mining, and enhanced coalbed methane recovery (ECBM) through gas injection has been proposed as an effective and eco-friendly method. The study investigates the impact of coal rank on CO2-ECBM efficiency using different coal types - lignite, bituminous coal, and anthracite. The results show that lignite and anthracite display higher rates of CO2 and CH4 outflow, as compared to bituminous coal. Additionally, coal rank influences permeability and CH4 production, with differences observed in the two phases.
Review
Energy & Fuels
Weiguo Liang, Jiwei Yan, Beining Zhang, Dongsheng Hou
Summary: Coal bed methane (CBM) is a primary clean energy source found in coal seams, but its recovery ratio is very low due to strong adsorption and low permeability. A theory of enhanced CBM recovery by energy stimulation, including SCCO2 fracturing and thermal fracturing, has been proposed. Experimental results show that SCCO2 has higher transportation capacity than gaseous CO2 in coal beds, and total permeability decreases as its content increases in the system with CH4.
Article
Geosciences, Multidisciplinary
Beichen Yu, Dongming Zhang, Bin Xu, Weijing Xiao, Chongyang Wang, Weihang Du
Summary: Understanding the desorption and seepage behaviors of CO2 and CO2-CH4 gas mixture in coal is crucial for CO2 geological sequestration and enhanced coalbed methane recovery. Experimental results showed that the permeability of coal to CO2 increased with pore pressure, while decreased with sigma(1) and sigma(3). CO2 desorption increased with pore pressure and the Dubinin-Astakhov model captured the desorption behavior accurately. The seepage volume of CO2 was significantly larger than the desorption volume. For the CO2-CH4 gas mixture, the seepage volume decreased exponentially over time, while the desorption volume increased exponentially. Regardless of seepage or desorption tests, the concentration of CH4 in the gas mixture was always higher than that of CO2.
NATURAL RESOURCES RESEARCH
(2022)
Article
Energy & Fuels
Zhenzhi Wang, Ze Deng, Xuehai Fu, Hao Chen, Jienan Pan, He Zhou
Summary: The study found that increasing gas content in N-2-ECBM recovery leads to volume shrinkage and decreased permeability in specimens, but CH4 desorption during N-2-IS can enhance permeability.
Article
Energy & Fuels
Zhengdong Liu, Xiaosong Lin, Yuanping Cheng, Rui Chen, Liuyang Zhao, Liang Wang, Wei Li, Zhenyang Wang
Summary: This study investigates the diffusion characteristics of coal and reveals the differences between granular coal and coal mass. It proposes different shape units and gas diffusion paths for coal matrix and establishes improved diffusion models based on Fick's Second Law of Diffusion. The study compares the desorption laws and gas diffusion coefficients of coal with different forms and suggests that tectonic coal seams may be more suitable for CO2 storage.
Article
Engineering, Environmental
Zawar Hussain, Na Chang, Jingqiu Sun, Simeng Xiang, Tehreem Ayaz, Hao Zhang, Haitao Wang
Summary: In this study, modified coal fly ash showed good removal efficiency for various carcinogenic dyes, with a maximum removal efficiency of 96.03%. Langmuir and Freundlich models were suitable for adsorption isotherm analysis at different dye concentrations, indicating that the adsorption behaviors of all four dyes were better described by pseudo-second-order kinetics. (Less than three sentences)
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Article
Geosciences, Multidisciplinary
Jinfeng Liu, Christopher J. Spiers
Summary: The permeability evolution in coal reservoirs during CO2-enhanced coalbed methane (ECBM) production is greatly affected by the swelling/shrinkage effects caused by the sorption and desorption of CO2 and CH4. The study shows that the permeability of methane and CO2 is influenced by the coupled effects of self-stress, change in effective stress coefficient, sorption-induced closure of transport paths, and heterogeneous gas penetration and equilibration dependent on diffusion.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geochemistry & Geophysics
He Yang, Dejun Miao, Zhen Liu, Dawei Zhao, Mingrui Zhang
Summary: Hydraulic flushing drilling technology can improve the efficiency of coalbed methane extraction and reduce coal and gas outburst disasters. By expanding the borehole diameter and increasing strain around the borehole, permeability of the coal seam can be improved. Determining the pressure relief range based on radial strain law can guide drilling arrangements effectively.
Article
Geochemistry & Geophysics
Weidong Xie, Meng Wang, Hongyue Duan
Summary: Adsorbed gas is crucial in shale gas reservoirs, and this study focused on the adsorption characteristics of coal-measure shale gas in the Taiyuan-Shanxi Formations. Results showed that organic matter and mineral composition influenced the adsorption characteristics, with organic matter possessing a strong adsorption capacity for CH4 due to its complex pore structure.
Article
Engineering, Multidisciplinary
Guanglei Zhang, P. G. Ranjith, Herbert E. Huppert
Summary: Injecting nitrogen (N2) can reverse the decline in coal permeability caused by CO2 adsorption, providing a promising option for zero emissions from deep coal seams.
Article
Thermodynamics
Wei Yang, Yihan Wang, Fazhi Yan, Guangyao Si, Baiquan Lin
Summary: This paper investigates the microstructural changes of high gas content coal samples after pyrolysis at different temperatures and their effects on gas adsorption capacity. The results show that the methane adsorption capacity of coal samples decreases as the pyrolysis temperature increases. The content of C=C, -OH, C=O, -CH2 in coal molecules also decreases gradually.
Article
Thermodynamics
Chaolin Zhang, Enyuan Wang, Bobo Li, Xiangguo Kong, Jiang Xu, Shoujian Peng, Yuexia Chen
Summary: CO2-ECBM recovery has the triple benefits of recovering clean resources, ensuring coal mine safety, and achieving CO2 geological sequestration. The study reveals that during CO2-ECBM recovery, the reservoir pressure remains high, methane recovery efficiency increases, but CO2 sequestration efficiency decreases with increasing injection pressure. A displacement index is proposed to reflect the synergistic effect of methane recovery and CO2 sequestration, and a dynamic pressure injection mode is suggested to enhance recovery and sequestration efficiency.
Editorial Material
Thermodynamics
J. Ilja Siepmann, Ramesh L. Gardas, David A. Kofke, Ronny Pini, Gabriele Sadowski, Cara E. Schwarz, Jiangtao Wu
JOURNAL OF CHEMICAL AND ENGINEERING DATA
(2021)
Editorial Material
Thermodynamics
J. Ilja Siepmann, Ramesh Gardas, David A. Kofke, Carlos Nieto de Castro, Eugene Paulechka, Ronny Pini, Gabriele Sadowski, Cara E. Schwarz
JOURNAL OF CHEMICAL AND ENGINEERING DATA
(2022)
Article
Engineering, Chemical
Nerine Joewondo, Valeria Garbin, Ronny Pini
Summary: This paper presents a mathematical model that describes the dissolution of spherical bubbles in two-dimensional regular pore networks. The study reveals that network connectivity affects the dissolution time, and the solute concentration field influences the bubble dissolution or growth process.
TRANSPORT IN POROUS MEDIA
(2022)
Article
Chemistry, Physical
Adam Ward, Ronny Pini
Summary: In this study, a traditional analysis was carried out on a set of dynamic breakthrough experiments of the CO2/He system adsorbing onto activated carbon by fitting a 1D dynamic column breakthrough model. Uncertainties in the fitted model parameters were quantified using Bayesian inference techniques, and the robustness of the modeling was assessed by propagating these uncertainties through the dynamic model. It was found that uncertainties in the adsorption isotherm parameters were the main cause of variability in the modeling outputs, and several recommendations were made for practitioners using Bayesian statistical tools.
ADSORPTION-JOURNAL OF THE INTERNATIONAL ADSORPTION SOCIETY
(2022)
Article
Energy & Fuels
Humera Ansari, Shuwei Gong, J. P. Martin Trusler, Geoffrey Maitland, Ronny Pini
Summary: This study presents a hybrid pore-scale model for gas adsorption in shale, using surrogate surfaces to simulate the behavior. The reliability of the model is verified through comparisons with experimental data. The proposed model can reduce the experimental burden and has general applicability.
Article
Thermodynamics
Junyoung Hwang, Hassan Azzan, Ronny Pini, Camille Petit
Summary: The excess adsorption of CO2, CH4, N-2, and H-2 on ZIF-8 was measured in different temperature and pressure ranges, and the adsorption isotherm models were analyzed, along with the microstructure of the adsorbent.
JOURNAL OF CHEMICAL AND ENGINEERING DATA
(2022)
Article
Environmental Sciences
Zitong Huang, Takeshi Kurotori, Ronny Pini, Sally M. Benson, Christopher Zahasky
Summary: This article presents a method for quantifying the heterogeneous multiscale permeability in geologic porous media using positron emission tomography (PET) imaging. By utilizing a trained convolutional neural network (CNN) based on experimental data, accurate and computationally efficient permeability inversion maps can be generated. The results demonstrate the effectiveness of this approach by comparing the network-predicted permeability maps with experimental data.
WATER RESOURCES RESEARCH
(2022)
Article
Chemistry, Physical
Hassan Azzan, Ashwin Kumar Rajagopalan, Anouk L'Hermitte, Ronny Pini, Camille Petit
Summary: This study aims to develop a novel method for characterizing the adsorption properties of individual shaped adsorbents using a small amount of material. The researchers used an experimental dynamic sorption setup and mathematical models to study mass transport, and utilized a derivative-free optimizer to predict model parameters. By testing and validating the method on adsorbents with different properties, it was demonstrated that this approach can rapidly and quantitatively characterize adsorption properties.
CHEMISTRY OF MATERIALS
(2022)
Editorial Material
Thermodynamics
Ronny Pini, Daniel W. Siderius, J. Ilja Siepmann
JOURNAL OF CHEMICAL AND ENGINEERING DATA
(2022)
Article
Engineering, Chemical
Adam Ward, Ronny Pini
Summary: The design of adsorption systems for CO2/N-2 separation in carbon capture applications is challenging and requires multiobjective optimization. Traditional methods using NSGA-II are time-consuming, while a Bayesian optimization algorithm called TSEMO can provide the same solution with significantly less computational time. The use of TSEMO algorithm has led to the design of an efficient carbon capture system. However, when coupled with a data-driven machine learning framework, NSGA-II outperforms the Bayesian approach in terms of computational performance.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Article
Engineering, Chemical
Anna-Maria Eckel, Rebecca Liyanage, Takeshi Kurotori, Ronny Pini
Summary: Dissolution trapping is an important mechanism for carbon dioxide storage in deep saline aquifers. Previous experiments mainly focused on 2D systems and did not reflect the subsurface CO2/brine system accurately. In this study, we use X-ray computed tomography to investigate the evolution of the convective mixing process in 3D porous media and observe the impact of hydrodynamic dispersion on longitudinal mixing. Our findings suggest that the finger pattern and counter-current flow structure enhance the spread of solute compared to unidirectional dispersion.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Engineering, Chemical
Nerine Joewondo, Valeria Garbin, Ronny Pini
Summary: This study investigates the dissolution of CO2 bubbles in a two-dimensional porous network. The experimental results show the dissolution, growth, or a combination of these processes for different initial liquid supersaturation levels. The pore-network model complements the experimental observations and provides insights into the interplay between inter-and intra-pore diffusive fluxes.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2023)
Article
Green & Sustainable Science & Technology
Evans Anto-Darkwah, Takeshi Kurotori, Ronny Pini, Avinoam Rabinovich
Summary: Characterizing subsurface reservoirs is crucial for environmental engineering technologies. This study presents a method to accurately model coreflooding experiments by estimating the permeability distribution and relative permeability of core samples, considering varying flow rates. The method improves previous approaches by achieving mm-scale accuracy. The application of the method to limestone core samples demonstrates its effectiveness in estimating saturation distribution and core pressure drop.
Article
Engineering, Environmental
Diana Iruretagoyena, Paul Fennell, Ronny Pini
Summary: This study investigated the adsorption of carbon dioxide on a commercial hydrotalcite (HT) and compared it with zeolite 13X (Z13X) using gravimetric analysis. The results showed that HT had higher adsorption capacities and surface area coverage at low pressures compared to Z13X. However, HT exhibited hysteresis and deactivation effects, indicating the need for further research on its regenerability. The CO2 adsorption isotherms of HT were successfully fitted to the Freundlich model.
CHEMICAL ENGINEERING JOURNAL ADVANCES
(2023)
Article
Engineering, Chemical
Adam Ward, Ke Li, Ronny Pini
Summary: We assessed dual-adsorbent beds for post-combustion CO2 capture using a model-based approach. We developed a process model and evaluated the performance of 2,850 combinations of adsorbents from a database of promising materials. We identified nine categories of process behavior and observed a reduction in energy penalty of the separation by approximately 20%.
SEPARATION AND PURIFICATION TECHNOLOGY
(2023)