Article
Energy & Fuels
Xingxun Li, Ming Liu, Qingping Li, Weixin Pang, Guangjin Chen, Changyu Sun
Summary: This study investigated the formation and depressurization-induced dissociation behaviors of methane hydrate in porous media using a high-pressure transparent micro-packed bed reactor. The results revealed the effect of methane bubble dispersion on hydrate formation, observed hydrate reformation during depressurization, and demonstrated the impact of fluid extraction rate on hydrate reformation. The dissociation process of hydrate and fluid migration phenomena in the pore spaces were also visualized.
Article
Engineering, Environmental
Mirian E. Casco, Sven Gratz, Dirk Wallacher, Nico Grimm, Daniel M. Tobbens, Malina Bilo, Natascha Speil, Michael Froba, Lars Borchardt
Summary: The study investigated methane hydrate formation process in confinement through high-pressure methane sorption experiments on two wet materials with similar pore size distributions, B-PMO (hydrophobic) and MCM-41 (hydrophilic). The results showed that external water and 'core water' inside the pore were rapidly consumed in the first step to form bulk-like hydrate, while adsorbed water was slowly consumed in the second step to form less stable confined hydrates.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Energy & Fuels
Yimao Shen, Zhi Li, Jingtao Hu, Yue Zhang, Tianduo Li, Guangjin Chen
Summary: Gas hydrate technology is a promising gas storage method with great potential. The addition of additives such as THF and TBAB can significantly improve the gas storage performance of the fixed bed. Using diesel oil to establish gas channels in the bed can also enhance the gas mass transfer. However, the simultaneous addition of diesel oil and THF may lead to competition between the two accelerators, resulting in less significant improvement in gas storage density.
Article
Engineering, Chemical
Nan Li, Jing-Yu Kan, Chang-Yu Sun, Guang-Jin Chen
Summary: CO2 sequestration in marine sediments as solid hydrates is a potential method for capturing and storing anthropogenic CO2. This study simulated hydrate formation from liquid CO2 in marine sediments and investigated the factors that affect the kinetics of hydrate formation. The results showed that rapid initial hydrate formation increases mass transfer resistance and slows down hydrate growth. Low temperature and high pressure conditions result in a higher water conversion ratio.
CHINESE JOURNAL OF CHEMICAL ENGINEERING
(2022)
Article
Chemistry, Multidisciplinary
Nikhil H. Margi, Ganapati D. Yadav
Summary: Successful synthesis of pseudoionone using a solventless flow process and a heterogeneous catalyst overcame the drawbacks of the traditional process, achieving nearly solventless conditions with high conversion and selectivity.
NEW JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Physical
Zhi Li, Bei Liu, Yinghua Gong, Guangjin Chen, Tianduo Li
Summary: In this study, the impact of wax crystal on the formation of methane hydrate was examined using molecular dynamics technique. The results showed that small wax crystals promoted the formation of hydrate while large wax crystals inhibited it. These findings contribute to a better understanding of the interaction between wax and hydrate.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Energy & Fuels
Peng Xiao, Guang-Jin Chen, Chang-Yu Sun, Li-Wei Cheng, Xing Huang
Summary: Morphology observation is an important approach for studying hydrate formation mechanisms. The study found that under reciprocating impact, forming and fracturing of hydrate shells significantly improved hydrate formation, and the memory effect during re-formation affected nucleation rate and gas storage capacity.
Article
Energy & Fuels
Andre Bolt, Ibrahim Dincer, Martin Agelin-Chaab
Summary: New designs of helical methane/natural gas reactors are proposed in this study, which utilize the Sabatier reaction for renewable production of methane. The study develops three models with different diameters and the same volume, and suggests optimizing the reactor design by varying specific parameters. The reactor model with a diameter of 0.0381 m achieves a reactant conversion of 75% and a yield of 87%, while the model with a cross-sectional diameter of 0.0254 m demonstrates the most effective cooling at a coolant temperature of 200 degrees C.
Article
Energy & Fuels
Ruifang Huang, Yusheng Zhao, Yiming Ma
Summary: Experiments on methane hydrate formation in the presence of different sediments (montmorillonite, talc, and silica sand) reveal that montmorillonite and talc severely inhibit the formation of methane hydrates, while silica sand slightly promotes it. The inhibiting effect of montmorillonite and talc is attributed to the release of cations, resulting in alkaline solutions that are unfavorable for methane hydrate formation. The experiments provide important insights into the understanding of massive methane hydrate formation with low amounts of sediments.
Article
Energy & Fuels
Xin Zheng, Limin Wang, Zhi Li, Weixin Pang, Qingping Li, Guangjin Chen, Bei Liu
Summary: This study investigated the dissociation and re-formation of methane hydrates in silica-slit and bulk water using molecular dynamics simulations. The results showed that methane hydrates dissociate layer-by-layer with the generation of nanobubbles. The hydrophilic quartz surface was found to facilitate the formation and stable existence of ordered structures of interfacial water molecules. In the process of hydrate regeneration, intact/semi hydrate cages were beneficial for re-formation, while long-time decomposition induced large nano-bubbles that hindered memory effect and prolonged the induction time. The loci of hydrate re-crystallization were determined by the concentration of dissolved methane gas and the diffusion of water molecules.
Article
Chemistry, Physical
Marziyeh Zare, Vandad Talimi, Sohrab Zendehboudi, Majid Abedinzadegan Abdi
Summary: This study explores the formation of methane hydrate in a stirred reactor using a computational fluid dynamics (CFD) model. The results demonstrate that the model accurately predicts hydrate formation and reveal that increasing subcooling, gas volume fraction, pressure, and stirring rate lead to more hydrate formation.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Environmental Sciences
S. M. Al -Salem, H. J. Karam, M. M. Al-Qassimi
Summary: Pyrolysis of end of life tyres is a promising alternative to incineration or classical product recovery. The analysis showed that there was not much difference in the maximum conversion rate between different tyre grades, and the difference was attributed to the release of free radicals. The pyro-gas from the pyrolysis of end of life tyres contained abundant light hydrocarbon products, which could be utilized in oil and gas ventures.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2022)
Article
Engineering, Environmental
Chanjuan Liu, Zhen Long, Yong He, Xuebing Zhou, Deqing Liang
Summary: This study investigates the growth and storage performance of CO2 hydrates under different conditions, and finds that the water film on silica gel particles is the main factor affecting gas storage efficiency. Silica gels with 30% water saturation can achieve the highest CO2 storage capacity. In addition, it is found that SDS can increase the CO2 storage volume ratio under high water saturation and reduce the volume ratio decay in repeated tests.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Physical
Gianmarco Parolin, Alessia Borgogna, Gaetano Iaquaniello, Annarita Salladini, Stefano Cerbelli
Summary: The study investigates a new setup using a semi-batch annular fixed-bed membrane reactor, where a permeselective membrane allows for lower reaction temperatures and overcoming equilibrium limitations. The research found non-trivial dynamical behavior of the reactor due to catalyst deactivation and spatial concentration gradients triggered by hydrogen permeation, with a localized reaction front developing near the membrane in the early stage of the process. Dimensionless analysis of reactor efficiency dependence on pressure and catalyst activity was carried out, identifying optimal working pressure at high Damkohler values. Different operating modes of the membrane reactor in various regions of the pressure-Damkohler parameter space were identified and interpreted.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Shyamal Roy, Dilip Kumar Mondal, Sauvik Chatterjee, Avik Chowdhury, Tuhin Suvra Khan, M. Ali Haider, Subhash Mandal, Debraj Chandra, Michikazu Hara, Asim Bhaumik
Summary: In this study, a novel catalyst was synthesized via excess solution impregnation, which can selectively reduce CO2 into methane. The research found that under appropriate process conditions, the catalyst achieved a high CO2 conversion efficiency.
MOLECULAR CATALYSIS
(2022)
Article
Engineering, Chemical
Florian Filarsky, Carsten Schmuck, Heyko Juergen Schultz
CHEMIE INGENIEUR TECHNIK
(2019)
Article
Engineering, Chemical
Katja Jaehrling, Heyko Juergen Schultz
CHEMIE INGENIEUR TECHNIK
(2019)
Article
Engineering, Chemical
Sven Wolinski, Mathias Ulbricht, Heyko Juergen Schultz
CHEMIE INGENIEUR TECHNIK
(2019)
Article
Engineering, Chemical
Joscha Priessen, Thomas Kreutzer, Gizem Irgat, Malte Behrens, Heyko Juergen Schultz
Summary: The study investigated the influence of different internal geometries on solid flow in rotary drums, finding that sectional internal geometries significantly increased mean residence times and holdups, with axial dispersion coefficients comparable to literature data.
CHEMICAL ENGINEERING & TECHNOLOGY
(2021)
Article
Engineering, Chemical
Joscha Priessen, Torben Kawka, Malte Behrens, Heyko Juergen Schultz
Summary: The study investigates the effect of sectional internals on the solid bed cross section in rotary drums. It is found that the sections can improve mixing kinetics and enhance the mixing performance of particulate systems. Additionally, the impact of sectional internals on phase interfaces of the cross section is analyzed, showing varying degrees of influence depending on the number of sections.
Article
Biochemistry & Molecular Biology
Florian Filarsky, Julian Wieser, Heyko Juergen Schultz
Summary: This paper describes the development of a rapid gas hydrate production process, which uses coupled spraying with stirring for the fastest hydrate formation and highest gas uptakes. Extensive experimental series using different gas compositions were conducted, achieving high storage capacities, formation rates, and separation efficiencies.
Article
Engineering, Chemical
Joscha Priessen, Torben Kawka, Jasmina Alisic, Malte Behrens, Heyko Juergen Schultz
Summary: This study experimentally investigated the impact of sectional internals commonly used in industrial rotary drums on the axial solid transport, finding that increasing the number and length of sections can increase the mean residence time of the solids in the drum. However, as the number and length of sections increase, the effects of parameter changes on axial dispersion decrease.
Article
Engineering, Chemical
Joscha Priessen, Fernando Barths, Malte Behrens, Heyko Juergen Schultz
Summary: This study analyzed the impact of the length of axially segmented lifters on the process behavior of industrial rotary drums, particularly on axial solid transport. Experimental measurements showed a significant influence of lifter length on mean residence times, drum capacity, and axial dispersion, with different flow patterns observed. Novel design recommendations for lifter length and the installation of front side walls at the lifter blades were derived from the findings.
Article
Biochemical Research Methods
Julia Seithuemmer, Melda Oeztuerk, Dennis S. Wunschik, Joscha Priessen, Heyko J. Schultz, Michael Dornbusch, Jochen S. Gutmann, Kerstin Hoffmann-Jacobsen
Summary: In this study, an aliphatic-aromatic polyester with two different classes of pendant hydroxyl groups was synthesized enzymatically using lipase catalysis. The addition of hexane diol as a third monomer was required for the polycondensation to occur. The reaction conditions were optimized to incorporate the aromatic diol and enhance the hydroxyl group density. Post-polymerization with glycerol further improved the polymer properties. The resulting material with aromatic building blocks and enhanced polymer chain reactivity has potential applications in coatings and adhesives.
BIOTECHNOLOGY JOURNAL
(2022)
Article
Engineering, Chemical
Marian Matzke, Cheryl Behrens, Niklas Jongebloed, Dominik Steins, Mathias Ulbricht, Heyko Juergen Schultz
Summary: In this study, flow fields in stirred tank reactors were investigated using a fluorescence tracer method. The method proved to be a promising supplement to fluid investigation methods, with little effort required for both the experiment and data analysis steps.
CHEMIE INGENIEUR TECHNIK
(2022)
Article
Engineering, Chemical
Lisa Marie Radeke, Alexander Lindner, Niklas Jongebloed, Mathias Ulbricht, Heyko Juergen Schultz
Summary: The grinding fineness of spiral jet mills can be optimized by reducing the product outlet diameter and installing a particle trap ring. The study investigates the influences of these factors on flow conditions and grinding performance, aiming to improve the classifying efficiency of spiral jet mills. Analysis of velocity fields and experimental grinding results show the potential for optimization through these modifications.
CHEMIE INGENIEUR TECHNIK
(2023)
Article
Engineering, Chemical
Heyko Juergen Schultz
Summary: This contribution presents an important overview of the latest trends, developments, and innovations in mixing technology showcased at ACHEMA 2022. Mixing technology is a crucial aspect in chemical and process engineering, especially in the context of sustainability, which is one of the key topics of ACHEMA. The article covers process solutions for different viscosity ranges, stirring technology for liquid-phase systems, static and solid-state mixers, as well as novel mixing systems ranging from laboratory to industrial scale.
CHEMIE INGENIEUR TECHNIK
(2023)
Article
Engineering, Chemical
Marian Matzke, Ekaterina Ranft, Leon Dominkovic, Mathias Ulbricht, Heyko Juergen Schultz
Summary: This study investigates the flow fields of two-stage impellers, which consist of different types of impellers on one shaft, using stereo particle image velocimetry. Based on torque measurements, diameters for different impellers are determined to achieve matching power input of each turbine. Proper implementation of both selected impellers results in flow fields that differ significantly from those induced by single-stage impellers or two-stage setups with identical impellers.
CHEMIE INGENIEUR TECHNIK
(2023)
