Article
Chemistry, Physical
Armin Afrough
Summary: In geological porous materials, free induction decay can exhibit both single-exponential and non-exponential decay behaviors. Numerical simulations show different effects of mass diffusion in these two regimes. This finding warns against the common single-exponential assumptions in surface magnetic resonance methods for surveying underground water aquifers.
EUROPEAN PHYSICAL JOURNAL E
(2021)
Article
Microbiology
Yajun Zhang, Yusheng Lin, Xin Lv, Aoshu Xu, Caihui Feng, Jun Lin
Summary: This study investigates the mechanisms responsible for T-2 signals of biofilm growth by cultivating biofilms in different media and measuring T-2 relaxation. The results show that T-2 relaxation distribution is strongly influenced by bacterial cell density and biofilm development stage, with peak time and peak percentage serving as indicators of biofilm growth states.
Article
Energy & Fuels
Guodong Zhang, Bingjie Liu, Lu Xu, Runcheng Zhang, Yan He, Fei Wang
Summary: Porous media have been found to significantly enhance hydrate nucleation and growth kinetics, with specific mechanisms still unclear. This study revealed the formation of rime-like hydrates, hydrate fibers, and hydrate chunks on porous surfaces, shedding light on hydrate nucleation and growth in these conditions. The presence of surface micro bulges and two-way convection in inner pores was found to increase gas-liquid contact area and provide numerous nucleation sites, leading to faster hydrate nucleation.
Article
Engineering, Environmental
Yu Feng, Yang Zhao, Yuze Han, Yanzhen Liu, Lunxiang Zhang, Jiafei Zhao, Lei Yang, Yongchen Song
Summary: The formation and dissociation behavior of CO2 hydrates in the presence of clay particles were investigated using low-field nuclear magnetic resonance. It was found that montmorillonite particles significantly promoted the conversion of water into hydrate, while illite particles had a weaker promoting effect. According to the DLVO theory, the total interaction potential between montmorillonite particles was much higher than that between illite particles.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Physical
Matteo Boventi, Michele Mauri, Francesca Alexander, Stuart L. James, Roberto Simonutti, Franca Castiglione
Summary: The porous topology of Type II Porous Liquids (PLs), prepared using Noria-OEt as an empty molecular host dissolved in 15-crown-5 solvent, is investigated with 129Xe NMR Spectroscopy. Xenon NMR parameters, such as chemical shifts and T1 relaxation times, measured in PLs solutions prepared at various Noria-OEt concentrations, are related to the intrinsic microporous structure of the material. The experimental data are interpreted on the basis of a multiple-site model for xenon atoms within the multiple PLs cavities. Diffusion NMR experiments show a similar mobility of xenon in PLs compared with the pure solvent.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Energy & Fuels
Shashika Gajanayake, Ranjith Pathegama Gamage, Pabasara Wanniarachchige
Summary: This study aims to investigate the formation characteristics of hydrate in a porous medium under different confining conditions, focusing on the effect of confining pressure on hydrate nucleation, growth, and saturation. The experimental results demonstrate the random nature of hydrate formation and the direct relationship between pressure decrease and hydrate saturation. Higher confining pressure conditions contribute to greater hydrate saturation within the porous medium.
Article
Energy & Fuels
Yulia F. Chirkova, Andrey S. Stoporev, Roman S. Pavelyev, Mikhail A. Varfolomeev
Summary: In recent years, interest in gas hydrates has grown due to their potential as an energy source and environmentally friendly alternative to storing and transporting natural gas. This study compared the effectiveness of sulfonated castor oil (SCO) and sodium dodecyl sulfate (SDS) as promoting reagents in the formation and decomposition of methane and methane-propane hydrates in a porous medium. The results showed that SCO significantly improved the water conversion rate in methane hydrates due to enhanced mass transfer in the presence of surfactants, while the effect on methane-propane hydrates was limited. Both SCO and SDS accelerated hydrate formation, but SCO required less supercooling. These findings suggest that SCO is comparable to SDS in promoting activity in porous media with varying water saturation.
Article
Chemistry, Physical
Ricardo Vieira, Ildefonso Marin-Montesinos, Joao Pereira, Rita Fonseca, Marina Ilkaeva, Mariana Sardo, Luis Mafra
Summary: This study presents a comprehensive solid-state NMR analysis of physisorbed CO2 on silica surfaces, successfully distinguishing three physisorbed CO2 species with different proportions, and revealing that approximately 55% of CO2 in the hybrid silicas is physisorbed. By employing various analytical methods, a deeper understanding of the distribution and properties of weakly interacting CO2 has been achieved.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Crystallography
Hao Bian, Lu Ai, Klaus Hellgardt, Geoffrey C. Maitland, Jerry Y. Y. Heng
Summary: This study investigated the melting behavior of natural gas hydrates formed in porous mineral sediments. Hydrate phase equilibria for methane and water mixtures were studied using high-pressure differential scanning calorimetry in silica particles with controlled pore sizes. It was found that as the pore size decreased, there were significant decreases in dissociation temperature, consistent with the Gibbs-Thomson equation. Additionally, a strong, essentially logarithmic dependence on pressure for melting behavior was observed, which led to a proposed modification of the Gibbs-Thomson equation to include this effect.
Article
Thermodynamics
Jiwoong Seol
Summary: In this study, the thermodynamic promotion effect of nitroalkane large guest molecules (LGMs) on CH4 hydrates was investigated. The structural analysis confirmed the formation of different hydrate types with different LGMs. All nitroalkanes improved the equilibrium temperatures, with tBuNO2 showing the strongest promotion effect. The structural and thermodynamic results of this study provide valuable information for the development of CH4 storage and transport technologies.
JOURNAL OF CHEMICAL AND ENGINEERING DATA
(2023)
Article
Construction & Building Technology
Ziyou Yu, Rodrigo de Oliveira-Silva, Yiannis Pontikes, Dimitrios Sakellariou
Summary: The effect of adding Fe(III) ions on spin relaxation and pore structure in metakaolin-based geopolymers was studied using low-field 1H nuclear magnetic resonance (LF NMR). The results showed that Fe(III) affected spin relaxation and pore size, with the former being related to Fe(III) ion content and the latter increasing significantly after reaching 2.0 wt% iron content.
CEMENT AND CONCRETE RESEARCH
(2023)
Article
Chemistry, Physical
Arezoo Azimi, Jafar Javanmardi, Amir H. Mohammadi
Summary: A thermodynamic model based on the dissociation enthalpy of clathrate hydrate and water activity in porous medium is introduced to predict the stability conditions of clathrate hydrates. The model is capable of predicting the dissociation conditions of simple and mixed-clathrate hydrates in various porous media and under a wide range of operating conditions, confirming that the inhibition effect of porous medium increases as pore diameter decreases.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Nanoscience & Nanotechnology
Neil Robinson, Eric F. May, Michael L. Johns
Summary: Solid-fluid interactions are crucial for porous materials in various chemical processes, but the opaque nature of these systems hinders detailed characterization of interfacial phenomena. A low-magnetic-field two-dimensional H-1 nuclear spin relaxation measurement provides insights into adsorbate identity and interfacial dynamics, showcasing distinct relaxation responses correlated with adsorbate acidity. This approach offers a molecular-level perspective on interactions within optically opaque porous media.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Energy & Fuels
Dnyaneshwar R. Bhawangirkar, Vishnu Chandrasekharan Nair, Siddhant Kumar Prasad, Jitendra S. Sangwai
Summary: The study investigated methane hydrate formation and dissociation in the presence of different concentrations of Krishna-Godavari basin sediment samples, revealing thermodynamic and kinetic characteristics. The inhibition effect during methane hydrate formation increased with sediment concentration, while stable temperature range during dissociation also increased. This research contributes to a better understanding of the KG basin reservoir and future methane gas exploration.
Article
Engineering, Environmental
Luke Forster, Carmine D'Agostino, Margot Anabell Llosa-Tanco, Vincenzo Spallina, Camilla Brencio, Fausto Gallucci, Matthew Lindley, Sarah J. Haigh, David Alfredo Pacheco-Tanaka
Summary: The carbonization temperature of Al-CMSM significantly affects pore size, hydrophilicity, permeance, and permselectivity. Lower carbonization temperatures produce more hydrophilic membranes with higher water permeance. Water permeance is higher than CH4 permeance due to the larger kinetic diameter of CH4 and the enhanced adsorption-diffusion transport mechanism in hydrophilic pores.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Engineering, Chemical
Qing Han, Mengqing Shi, Linkai Han, Di Liu, Mingwei Tong, Yuxin Xie, Zhonghua Xiang
Summary: Developing highly efficient bifunctional oxygen electrocatalysts is crucial for zinc-air flow batteries. Metal-organic frameworks (MOFs) and covalent organic polymers (COPs) have emerged as promising alternatives due to their designable and controllable atomic-level structures. However, their catalytic performances are limited by conductivity and catalytic activity. In this study, nanosheet FeNi-MOF and iron phthalocyanine rich COP hybrid materials are assembled through the pi-pi stacking effect to create highly efficient bifunctional electrocatalysts. The resulting catalyst exhibits superior catalytic performance and stability, making it a promising candidate for zinc-air flow batteries.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Daria Grigorash, Dmytro Mihrin, Rene Wugt Larsen, Erling H. Stenby, Wei Yan
Summary: The article introduces a new approach to describe the cross-association between molecules, allowing for the simulation of weakly bound molecular complexes with different conformations in mixtures. By incorporating this approach into the equation of state, accurate predictions of vapor-liquid equilibrium and liquid-liquid equilibrium can be made. The new method is validated through experiments on alcohol and acid mixtures, with the results compared to experimental data, demonstrating its accuracy and reliability.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Mohammed Al-Sharabi, Daniel Markl, Vincenzino Vivacqua, Prince Bawuah, Natalie Maclean, Andrew P. E. York, Axel Zeitler
Summary: This study used terahertz pulsed imaging to investigate the transport process of different solvents into ceramic catalytic materials. The results showed that the heating rate of the samples influenced the water transport rate, while the viscosity of 1-octanol slowed down its transport.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Chukwunonso Anyaoku, Sati Bhattacharya, Rajarathinam Parthasarathy
Summary: This study aimed to enhance understanding of settling dynamics in viscoelastic fluids by developing a semi-empirical correlation and a dimensionless ratio, which accurately described the characteristics of settling suspensions.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Antti I. Koponen, Janika Viitala, Atsushi Tanaka, Baranivignesh Prakash, Olli-Ville Laukkanen, Ari Jasberg
Summary: This study focuses on the development of foam application chemicals for the paper and board industry. The research explores the rheology of the polyvinyl alcohol foam used in the process. Measurements were conducted to determine the foam viscosity and slip flow. The results suggest that slip flow contributes significantly to the total flow rate, and the obtained viscosity and slip models provide a solid foundation for industrial processes.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Dalei Sun, Jinghui Cai, Yating Yang, Zhiwu Liang
Summary: In this study, Fe-doped alpha-Bi2O3 catalysts with different Fe/Bi molar ratios were synthesized and utilized in the carbonylation of isobutyl amine with CO2. The results showed that Fe doping significantly enhanced the catalytic abilities of alpha-Bi2O3.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Yuan Tian, Xinxin Wang, Yanrong Liu, Wenping Hu
Summary: This paper predicts the solubility of nitrogen gas in ionic liquids (ILs) using two quantitative structure-property relationship (QSPR) models. By combining machine learning methods and ionic fragments contribution method, the accuracy and reliability of the prediction models are improved.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Liwang Wang, Wei Liu, Pan Yang, Yulong Chang, Xiaoxu Duan, Lingyu Xiao, Yaoming Hu, Jiwei Wu, Liang Ma, Hualin Wang
Summary: This study investigates the effective phase interfacial area (ae) of hydro-jet cyclones at different injection angles. The results show that a 45 degrees upward incidence angle yields the most favorable flow field characteristics for efficient mass transfer. The significant enhancement in ae of the hydro-jet cyclones offers the advantage of reducing equipment volume and cost savings.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Chuanjun Wu, Jiangzhi Chen, Jiyue Sun, I-Ming Chou, Shenghua Mei, Juezhi Lin, Lei Jiang
Summary: In this study, the solubility of H2S hydrate in water was measured using Raman spectroscopy. The results showed that the solubility increases with temperature under certain equilibrium conditions, and the solubility also depends on pressure and temperature under different equilibrium conditions. A thermodynamic model based on the van der Waals-Platteeuw theory was developed to predict the solubility, demonstrating its accuracy.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Lorenzo Brivio, Serena Meini, Mattia Sponchioni, Davide Moscatelli
Summary: This study investigates the influence of three main parameters and proposes a kinetic model to predict the optimal operating conditions for high yield of dimethyl terephthalate (DMT) in the chemical recycling process of polyethylene terephthalate (PET).
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Hongju Lin, Fanhui Liao, Yanchang Chu, Mingyu Xie, Lun Pan, Yuanyuan Wang, Lijian Leng, Donghai Xu, Le Yang, Gangfeng Ouyang
Summary: A honeycomb NiCo/C-Na catalyst with a micro-meso-macroporous structure has been fabricated and shown to have significantly higher catalytic activity for the decarboxylation of fatty acids. It also proves to be efficient in upgrading sludge HTL bio-crude, resulting in a biofuel with decreased viscosity and increased density.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Xiaoxian Li, Rui Li, Min Lin, Mingde Yang, Yulong Wu
Summary: A series of coated non-noble metal porous carbon catalysts were synthesized and applied to the aqueous-phase deoxygenation of algal bio-oil. One of the catalysts showed excellent deoxygenation selectivity and catalytic activity at 250 degrees C. The catalyst exhibited good hydrothermal stability and the reaction mechanism was proposed based on product analysis and active site analysis.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
M. V. Chudakova, M. V. Popov, P. A. Korovchenko, E. O. Pentsak, A. R. Latypova, P. B. Kurmashov, A. A. Pimenov, E. A. Tsilimbaeva, I. S. Levin, A. G. Bannov, A. V. Kleymenov
Summary: A series of catalysts with different potassium contents were prepared using solution combustion synthesis and characterized using various techniques. The results showed that the potassium content affected the phase composition and texture of the catalysts. The addition of a small amount of potassium resulted in a change in particle size distribution, leading to higher hydrogen yield. The Ni-1%K2O/Al2O3 catalyst exhibited the highest hydrogen yield at temperatures of 675 and 750 degrees Celsius.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Aliakbar Roosta, Nima Rezaei
Summary: In this study, we modified the electrolyte cubic plus association equation of state (e-CPA EoS) and integrated it with two electrical conductivity models to estimate the electrical conductivity of 11 monovalent electrolyte solutions in water. The modified e-CPA model demonstrated better performance and the hybridization with electrical conductivity models resulted in two predictive models for estimating the electrical conduction of dilute and concentrated electrolyte solutions. These predictive models showed relative average percentage deviations (AARD) of 11.15% and 13.87% over wide ranges of temperature and electrolyte concentration.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Haoren Niu, Jianzheng Wang, Qingzhu Jia, Qiang Wang, Jin Zhao, Fangyou Yan
Summary: A study developed two quantitative structure-property relationship models for the complexation performance of alpha- and beta-cyclodextrins and validated their stability and predictive ability through internal and external validation. The models showed robustness and satisfactory performance, as demonstrated by the experimental results and model validations. These models can effectively predict the binding constants between cyclodextrins and various types of molecules, providing valuable tools for cyclodextrin design.
CHEMICAL ENGINEERING SCIENCE
(2024)