Article
Energy & Fuels
Xiaodan Zhu, Alejandro D. Rey, Phillip Servio
Summary: Natural gas, recognized as a green energy resource, has the potential to generate energy with fewer pollutants and carbon dioxide emissions compared to coal and petroleum. It is also considered a competitive candidate for carbon dioxide sequestration. However, the instability of gas hydrates during exploration poses a major barrier to methane gas extraction and carbon dioxide sequestration. This study investigates the stability limits and piezo effect of structure I (sI) methane gas hydrates at 0 K using a multiscale approach, providing valuable insights for engineering correlations and fundamental understanding.
Article
Energy & Fuels
Masakazu Matsumoto, Hideki Tanaka
Summary: The structure selectivity of mixed gas hydrates and group 14 clathrates is examined using statistical mechanical theories and the empirical rule on the topological constraint of the Frank-Kasper phases. The most stable structure is revealed by the generalized phase diagram, and the method developed here can estimate the phase behaviors of clathrate compounds in a wide range of thermodynamic conditions.
Article
Chemistry, Physical
Anshul Gupta, Gino Baron, Patrice Perreault, Silvia Lenaerts, Radu-George Ciocarlan, Pegie Cool, Paulo G. M. Mileo, Sven Rogge, Veronique Van Speybroeck, Geert Watson, Pascal Van der Voort, Maarten Houlleberghs, Eric Breynaert, Johan Martens, Joeri F. M. Denayer
Summary: Clathrates, as a promising material for hydrogen storage, have advantages such as low cost, reversible reaction, environmentally friendly nature, and low risk of flammability, despite the lower capacity predicted by simulations. The ability to tailor the properties of clathrates and the rapid technological advancements in this field provide immense opportunities for customization and growth. This review aims to analyze the current developments in solid-state hydrogen storage materials, focusing on hydrogen clathrates, and presents a global overview for future research.
ENERGY STORAGE MATERIALS
(2021)
Review
Chemistry, Multidisciplinary
Jyotirmoy Ghosh, Gaurav Vishwakarma, Rajnish Kumar, Thalappil Pradeep
Summary: Through multiple studies in a simulated interstellar environment, we have discovered several molecules' clathrate hydrates (CHs). These CHs play an important role in the chemical processes of the interstellar medium, contributing to the chemical evolution and formation of planetary systems as well as the origin of life.
ACCOUNTS OF CHEMICAL RESEARCH
(2023)
Article
Chemistry, Physical
Hideki Tanaka, Masakazu Matsumoto, Takuma Yagasaki
Summary: This study proposes substitution schemes for methane-carbon dioxide (CH4-CO2) hydrates and investigates the advantages and efficiencies of the substitution under three-phase and two-phase coexistence conditions. The study finds that although substitution is feasible in three-phase coexistence, its working window in temperature-pressure space is narrower compared to the two-phase coexistence condition. It also suggests a significant endothermic substitution in the medium pressure range.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Ove Andersson, Paulo H. B. Brant Carvalho, Ulrich Haussermann, Ying-Jui Hsu
Summary: The glass transitions (GTs) were studied in different samples and with different guest molecules. The results show that the GTs are associated with the water network and deuteration leads to an increase in the glass transition temperature.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Multidisciplinary Sciences
Michael Benedict Davies, Martin Fitzner, Angelos Michaelides
Summary: Through molecular dynamics simulations, researchers have found that many different substrates can promote the formation of pristine I-c, I-c can be selectively nucleated even with mild supercooling, the water contact layer's resemblance to a face of ice is the key factor determining the polytype selectivity and nucleation temperature, and substrate lattice match to ice is not indicative of the polytype obtained.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Chemistry, Physical
Paulo H. B. Brant Carvalho, Mikhail Ivanov, Ove Andersson, Thomas Loerting, Marion Bauer, Chris A. A. Tulk, Bianca Haberl, Luke L. L. Daemen, Jamie J. J. Molaison, Katrin Amann-Winkel, Alexander P. P. Lyubartsev, Craig L. L. Bull, Nicholas P. P. Funnell, Ulrich Haussermann
Summary: From crystalline tetrahydrofuran clathrate hydrate, three distinct polyamorphs can be derived. THF-CH undergoes pressure-induced amorphization to form high-density amorphous (HDA). HDA can be converted to a densified form, VHDA, upon heat-cycling, and decompression of VHDA produces recovered amorphous (RA). The structure of amorphous THF hydrates is different from crystalline THF-CH and liquid THF center dot 17H(2)O solution.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Trinidad Mendez-Morales, Hadrian Montes-Campos, Martin Perez-Rodriguez, Manuel M. Pineiro
Summary: This study uses molecular simulations to estimate the hydrogen storage ability of hydroquinone clathrates. The results show that hydrogen diffusion is limited by interfacial phenomena, and the distribution of multiple guest molecules can be computed.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Chemistry, Multidisciplinary
Alexandra L. Volkwyn, Delia A. Haynes
Summary: This study demonstrates that crystalline hydrates of organic molecules can be obtained through sublimation under vacuum. The crystals obtained from sublimation consist of both hydrated and anhydrous forms. Moreover, increasing the amount of water in the sublimation system results in a higher water content in the sublimed crystals. Competition studies show the transfer of water between hydrate and anhydrous forms during sublimation, indicating the presence of strong hydrogen bonds between water and the solid hydrate.
Article
Materials Science, Multidisciplinary
Paulo H. B. Brant Carvalho, Amber Mace, Ove Andersson, Chris A. Tulk, Jamie Molaison, Alexander P. Lyubartsev, Inna M. Nangoi, Alexandre A. Leitao, Ulrich Haeussermann
Summary: The high-pressure structural behavior of noble gas clathrate hydrates Ar•6.5H2O and Xe•7.2H2O was investigated by neutron powder diffraction at 95K, revealing pressure-induced amorphization at different pressures. Molecular dynamics simulations provided insight into the role of guest species in stabilizing or destabilizing the clathrate structures under pressure.
Article
Chemistry, Multidisciplinary
Alexandra L. Volkwyn, Delia A. Haynes
Summary: This study investigates the sublimation process of organic molecules with known crystalline hydrates under vacuum and finds that the hydrate crystals can be grown through sublimation. The results show that the water content and the conversion between hydrates and anhydrous forms are influenced by the amount of water present. Sublimation crystallization of hydrates is possible if there is a strong hydrogen bond to water in the solid hydrate.
Article
Chemistry, Physical
Gaurav Vishwakarma, Bijesh K. Malla, Soham Chowdhury, Sakshi Pradip Khandare, Thalappil Pradeep
Summary: Acetaldehyde in dilute solution can form geminal diol under normal atmospheric conditions. This study discovers the existence of stable acetaldehyde clathrate hydrate (CH) in ultrahigh vacuum at cryogenic temperatures. The formation of CH was confirmed using infrared spectroscopy and mass spectrometry. This finding suggests the possibility of stable CH phase for acetaldehyde in interstellar and cometary environments.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Energy & Fuels
Dehuan Yang, Rongtao Yan, Feng Cheng, Di Lu, Changfu Wei, Huihui Tian
Summary: The low-field NMR method was used to investigate the impact of various experimental conditions on the hydration number during methane hydrate dissociation. It was found that the NMR signal peak value of water was not affected by sediment dry density, gas pressure, and salt concentration, but was significantly influenced by temperature. A relationship among NMR signal peak value, substance content, pressure, and temperature was established to estimate the hydration number of pore hydrates. The experimental results showed that the hydration number of methane hydrates remained practically unchanged during dissociation in fine-grained sediments, and was minimally influenced by experimental conditions.
Article
Chemistry, Physical
Shengli Liu, Wenxiu Zhang, Huanhua Wu, Jiaheng Wang, Yongqi Yuan, Sikai Wang, Jinxiang Liu
Summary: Clathrate hydrate is a promising candidate for hydrogen storage, and the addition of natural gas can reduce the formation pressure and improve energy density. Through calculations and simulations, we estimated the hydrogen storage capacity of H2-CH4 binary hydrate and studied its thermodynamical and mechanical stability. The binary hydrate can maintain its structure under moderate temperature and pressure, and exhibits a self-preservation effect at -270 K, making it suitable for hydrogen storage and transport. These findings enhance our understanding of mixed hydrate as a viable hydrogen storage technology for achieving a sustainable hydrogen economy.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Engineering, Chemical
Chandan Sahu, Anirbid Sircar, Jitendra S. Sangwai, Rajnish Kumar
Summary: This study investigates the impact of organic aliphatic amines on CO2 hydrate kinetics and finds that the additives significantly promote nucleation time, with decylamine showing the best CO2 absorption performance. The study also proposes a suitable well design for enhanced CO2 sequestration as solid hydrates in subsea sediments.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Review
Chemistry, Physical
Subhadip Das, Kavya Mrudula Tadepalli, Sudip Roy, Rajnish Kumar
Summary: This article reviews the existing theories on nucleation and growth of gas hydrates, discusses the factors affecting decomposition, and explores the analysis techniques used to quantify such mechanisms. Molecular Dynamics simulations play a significant role in understanding these processes.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Crystallography
Paulo H. B. Brant Carvalho, Amber Mace, Inna Martha Nangoi, Alexandre A. Leitao, Chris A. Tulk, Jamie J. Molaison, Ove Andersson, Alexander P. Lyubartsev, Ulrich Haeussermann
Summary: The high pressure structural behavior of H-2 and Ne clathrate hydrates was investigated, and the transitions of H-2 and Ne hydrates under different pressure and temperature conditions were observed.
Article
Energy & Fuels
Kavya Mrudula Tadepalli, Rajnish Kumar
Summary: This study aims to understand the impact of ammonia on CO2 hydrates and its effect on methane recovery through molecular dynamics simulations. The results indicate that with optimized concentrations, ammonia can enhance the sequestration of CO2.
Article
Materials Science, Multidisciplinary
Asaf Pesach, Long Nguyen, Federico A. Gorelli, Roberto Bini, Refael Hevroni, Mark Nikolaevsky, Antonio M. dos Santos, Christopher A. Tulk, Jamie J. Molaison, Reuben Shuker, Aviva Melchior, El'ad N. Caspi, Ran Salem, Guy Makov, Eran Sterer
Summary: This study investigates the metallization mechanism of SnO under high pressure using combined experimental and computational methods. It is found that pressure induces polaron delocalization, with electron-phonon coupling and lattice distortion being key factors. Additionally, the pressure-induced charge transition and dome-shaped superconductivity transition are observed.
RESULTS IN PHYSICS
(2022)
Article
Engineering, Chemical
Lagnajita Paul, Namrata Gaikwad, Rajnish Kumar
Summary: Hydrate-based desalination is a promising and environmentally friendly technique for producing fresh water from saline water. This research investigated the kinetics of hydrate formation in saline water and compared the utility of CO2 and N-2 as hydrate formers for desalination work.
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
(2023)
Editorial Material
Energy & Fuels
Rajnish Kumar, Praveen Linga
Article
Thermodynamics
Bhavikkumar Mahant, Omkar Singh Kushwaha, Rajnish Kumar
Summary: This study reports the synthesis and application of a surfactant derived from Cocos nucifera (CDS) for methane gas hydrate formation. The CDS surfactant showed competitive growth of methane gas hydrates and proved to be a promising substitute for kinetic promotion. Morphology studies and property evaluations were conducted to comprehensively evaluate the synthesized surfactant.
ENERGY CONVERSION AND MANAGEMENT
(2022)
Article
Chemistry, Multidisciplinary
Asheesh Kumar, Nagu Daraboina, Praveen Linga, Rajnish Kumar, John A. Ripmeester
Summary: Gas hydrates, such as sH and sI hydrates, have potential for gas separation applications, with sH hydrates requiring large molecules and help-gas molecules to form stable structures. Testing different compositions showed that CO2 lean mixtures form sH hydrates, while CO2-rich mixtures form sI hydrates, indicating a structure transition pattern across gas mixtures. Furthermore, it was observed that the CO2 lean mixture initially forms sI hydrate and gradually converts to the thermodynamically stable sH hydrate, providing insights into a suitable gas separation mechanism for this gas mixture.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2022)
Article
Chemistry, Multidisciplinary
Kavya Mrudula Tadepalli, Suman Chakrabarty, Pramod Patil, Rajnish Kumar
Summary: Oligomers of PDMS (M1), polyFast (M2), modified PVEE (M3 and M4), and two new molecules with cyclic cores (M5 and M6) were studied for their ability to thicken sc-CO2 without a cosolvent at 377 K and 55 MPa. PDMS and polyFast behaved as expected, with PDMS not improving viscosity and polyFast significantly enhancing it. M3 and M4 did not significantly improve viscosity even with the introduction of a styrene component, but solubility in the fluid was improved. M5 and M6, however, showed enhanced viscosity similar to polyFast due to their structural advantage and pi-pi interactions. The synthesis of these molecules was found to be moderately easy.
Article
Chemistry, Physical
Gaurav Vishwakarma, Bijesh K. Malla, K. S. S. V. Prasad Reddy, Jyotirmoy Ghosh, Soham Chowdhury, Sharma S. R. K. C. Yamijala, Sandeep K. Reddy, Rajnish Kumar, Thalappil Pradeep
Summary: Restricted migration of CO2 from clathrate hydrate cages to amorphous solid water matrix was observed in the presence of tetrahydrofuran (THF) under ultrahigh vacuum and cryogenic conditions. This cage-matrix exchange may create a more conducive environment for chemical transformations in interstellar environments.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Engineering, Chemical
Namrata Gaikwad, Hyunho Kim, Gaurav Bhattacharjee, Jitendra S. Sangwai, Rajnish Kumar, Praveen Linga
Summary: This study experimentally investigated the formation of sH hydrate with methane and cyclooctane for possible applications in gas storage. The study found that the slow kinetics of sH hydrate formation can be improved by using low tryptophan concentrations. Raman analysis confirmed the presence of methane and cyclooctane in the sH hydrate cages.
ACS ENGINEERING AU
(2023)
Review
Chemistry, Multidisciplinary
Jyotirmoy Ghosh, Gaurav Vishwakarma, Rajnish Kumar, Thalappil Pradeep
Summary: Through multiple studies in a simulated interstellar environment, we have discovered several molecules' clathrate hydrates (CHs). These CHs play an important role in the chemical processes of the interstellar medium, contributing to the chemical evolution and formation of planetary systems as well as the origin of life.
ACCOUNTS OF CHEMICAL RESEARCH
(2023)
Article
Engineering, Environmental
Rahul Sarkhel, Chandan Sahu, Rajnish Kumar, Jitendra S. Sangwai
Summary: This study investigates the kinetics of CO2 hydrate formation and dissociation in the presence of CO2-philic additives. The results show that the additives, particularly DDP at a concentration of 0.5 wt%, significantly enhance the formation and dissolution rates of CO2 hydrates.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2023)
Article
Chemistry, Physical
Gaurav Vishwakarma, Bijesh K. Malla, K. S. S. V. Prasad Reddy, Jyotirmoy Ghosh, Soham Chowdhury, Sharma S. R. K. C. Yamijala, Sandeep K. Reddy, Rajnish Kumar, Thalappil Pradeep
Summary: Restricted migration limits chemical transformations within interstellar and cometary ices. We found that CO2 can migrate from clathrate hydrate cages to amorphous solid water in the presence of tetrahydrofuran under ultrahigh vacuum and cryogenic conditions. This migration may create a more conducive environment for chemical transformations in interstellar environments.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
