Article
Thermodynamics
Yu. Yu. Bozhko, R. K. Zhdanov, K. V. Gets, O. S. Subbotin, V. R. Belosludov
Summary: The paper presents the calculated results of the P-T diagram for freons R23 and R34a, as well as a 90%R23+10%R134a mixture, in the ice phase-liquid phase-gas phase-hydrate phase equilibrium. It is shown that R134a forms a stable CS-II hydrate phase in the temperature range of 260-280 K and pressure range of 0.0267-0.21 MPa, while R23 forms a stable CS-I hydrate phase in the temperature range of 260-280 K and pressure range of 0.238-0.75 MPa. The calculations are consistent with the known experimental data. Additionally, it is found that the addition of 10% R134a to the freon mixture results in the formation of CS-II hydrate phase within the temperature range of 260-280 K and pressure range of 0.0167-0.15 MPa.
JOURNAL OF ENGINEERING THERMOPHYSICS
(2023)
Article
Meteorology & Atmospheric Sciences
Jeremy J. Harrison, Martyn P. Chipperfield, Christopher D. Boone, Sandip S. Dhomse, Peter F. Bernath
Summary: The phase out of ozone-depleting substances led to the rise in the use of HFCs, powerful greenhouse gases, which are now controlled under the Montreal Protocol. Research using ACE-FTS v4.0 data investigates the global distribution and trends of HFC-134a, showing a nearly linear increase in abundance.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2021)
Article
Environmental Sciences
Zhiwei Zhu, Yuncheng Cao, Zihan Zheng, Nengyou Wu, Duofu Chen
Summary: This study applied the van der Waals-Platteeuw model to investigate the formation of CH4-H-2 hydrates in marine serpentinization environments, taking into account the effects of salinity. The model accurately predicted the three-phase equilibrium temperature and pressure for CH4-H-2 hydrates in pure water and provided theoretical insights for gas hydrate research in areas with marine serpentinization.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Chemistry, Physical
Ningru Sun, Yanjun Li, Nianxiang Qiu, Joseph S. Francisco, Shiyu Du
Summary: Hydrate Based Gas Separation (HBGS) technology is being developed as a solution for air pollution caused by flue gas. The study shows that the presence of H2S, SO2, and N2O in mixed gases can promote the formation of CO2 hydrate, and the ratio between CO2 and impurity gases can predict the gas recovery yield under different conditions.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Engineering, Chemical
Zucheng Cheng, Weiguo Liu, Shaohua Li, Sijia Wang, Yingying Liu, Xiang Sun, Cong Chen, Lanlan Jiang, Yongchen Song
Summary: This study evaluated the performance of SDS in the separation efficiency of simulated biogas. The experimental results showed that higher driving forces led to a significant increase in gas capture, dominated by the CH4 component. Hydrate growth mainly occurred in the liquid phase, and the separation factor was positively correlated with the induction time. Gas capture per unit volume of solution could be improved at higher gas-liquid ratios, while high-pressure failure behavior was observed. The defoamer had no significant effect on hydrate generation kinetics and separation efficiency.
SEPARATION AND PURIFICATION TECHNOLOGY
(2022)
Article
Engineering, Environmental
Gyeol Ko, Joonseop Lee, Yongwon Seo
Summary: The feasibility of hydrate-based sulfur hexafluoride (SF6) separation was examined by measuring the three-phase equilibria of SF6 + N-2 hydrates, constructing a pressure-composition diagram, identifying the hydrate type using powder X-ray diffraction, and measuring the dissociation enthalpy with a high-pressure micro-differential scanning calorimeter. Experimental results demonstrated the selective capture of SF6 in the hydrate phase, with the hydrate-based method requiring lower initial concentration and pressure compared to the liquefaction method.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Thermodynamics
R. K. Zhdanov, K. V. Gets, Yu. Yu. Bozhko, O. O. Subboting, V. R. Belosludov
Summary: In this study, we used molecular dynamics to investigate the nucleation and growth process of methane and propane gas hydrate from a homogeneous solution. Our aim was to understand the impact of hydrate seed on the growth rate and structure of the resulting hydrate in the presence of sea salt. We characterized the process by calculating the number of long-lived hydrogen bonds, the amount of hydrate and hydrate-like cavities, and the order parameter of intermolecular torsion angles. The results showed that the kinetics of hydrate formation were similar in pure water and seawater. However, a seed crystal of hydrate not only increased the growth rate, but also resulted in a structure closer to cubic structure II hydrate.
JOURNAL OF ENGINEERING THERMOPHYSICS
(2023)
Article
Engineering, Environmental
Mingjin Si, Le Kuai, Erguang Huo, Lize Li, Mengna Bai
Summary: This study investigates the thermal decomposition and interaction mechanism of HFC-134a/HFC-32 mixture using ReaxFF reactive molecular dynamic simulations and density functional theory calculations. The results show that the hydrogen bond formed between HFC-134a and HFC-32 inhibits the decomposition of HFC-134a, leading to better thermal stability of the HFC-134a/HFC-32 mixture. The findings are beneficial for the screening of ORC working fluid and ensuring the safe operation of the ORC system.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2022)
Article
Thermodynamics
Qiang Zhang, Junjie Zheng, Baoyong Zhang, Praveen Linga
Summary: Coalbed methane recovery is crucial for coal mine safety, reducing greenhouse gas emissions, and economic benefits. Gas hydrate technology can effectively separate CH4 from N2-rich coal mine gas. The synergistic effect of sII hydrate promoters and amino acids was examined for enhancing hydrate formation kinetics, separation performance, and CH4 recovery. Amino acids showed significant promotion effects, particularly for the propane system, and improved kinetics by over 10 times. CP-amino acid systems demonstrated excellent separation performance, increasing CH4 content from 30% to 70%. THF-amino acid systems achieved the highest CH4 recovery of up to 50.27%. The impact of amino acids varied depending on the system, and two possible mechanisms, including interfacial tension alteration and amino acid hydrophobicity, were discussed. These insights provide a basis for optimizing the hydrate process for coalbed methane recovery and other applications.
Article
Engineering, Environmental
Junghoon Mok, Wonjung Choi, Yongwon Seo
Summary: This study investigated the thermodynamic stability and kinetic growth behavior of HFC-152a hydrate, finding that HFC-152a hydrate has a higher hydration capacity in the presence of NaCl. The results suggest that HFC-152a may be a superior candidate for the HBD process.
Review
Energy & Fuels
Yanhong Wang, Xuemei Lang, Shuanshi Fan, Shenglong Wang, Chi Yu, Gang Li
Summary: CO2 replacement of NGH is crucial in energy development, and while it faces challenges of low recovery efficiency and slow replacement rates, coupling with depressurization or thermal stimulation can significantly enhance CH4 recovery.
Article
Energy & Fuels
Huiru Sun, Bingbing Chen, Guojun Zhao, Yuechao Zhao, Mingjun Yang
Summary: Water-gas two-phase flow plays a crucial role in inducing methane hydrate decomposition, with higher water-gas flow rate ratio and faster depressurization rate leading to improved energy recovery and efficient avoidance of ice generation. The combination of piecewise depressurization with water-gas flow was identified as the most effective mode for gas recovery from hydrate reservoirs in the experimental scale.
Article
Chemistry, Multidisciplinary
Xiluo Hao, Chengfeng Li, Qingguo Meng, Jianye Sun, Li Huang, Qingtao Bu, Congying Li
Summary: The three-phase coexistence line of CO2 hydrate was determined using molecular dynamics simulations. The influence of the water model on the equilibrium prediction was found to be greater than that of the CO2 model. Adjusting the parameters based on the solubility of CO2 in water improved the accuracy of the simulations.
Review
Energy & Fuels
Aijaz Abbasi, Fakhruldin Mohd Hashim
Summary: Hydrocarbon fluid flow is affected by changes in temperature, pressure, and composition, with solid precipitation posing severe issues in oil and gas production and transmission systems. Hydrate formation, a common solid precipitation problem, presents a significant risk in high-pressure natural gas transportation.
PETROLEUM SCIENCE AND TECHNOLOGY
(2022)
Article
Energy & Fuels
Ye Zhang, Gaurav Bhattacharjee, Mohana Dharshini Vijayakumar, Praveen Linga
Summary: Gas storage technologies are important for energy security and resilience. The use of clathrate hydrates, specifically Solidified Natural Gas (SNG), for natural gas storage is attractive due to its non-explosive nature and high volume density. Recent research has shown that the additive 1,3-dioxolane (DIOX) can improve the thermodynamic and kinetic performance of hydrate formation.
Article
Engineering, Chemical
Atsushi Iizuka, Sachiko Hayashi, Hideo Tajima, Fumio Kiyono, Yukio Yanagisawa, Akihiro Yamasaki
SEPARATION AND PURIFICATION TECHNOLOGY
(2015)
Article
Energy & Fuels
Masahiro Abe, Shiori Hirata, Hiroyuki Komatsu, Kazuaki Yamagiwa, Hideo Tajima
Article
Energy & Fuels
Masahiro Abe, Hiroyuki Komatsu, Kazuaki Yamagiwa, Hideo Tajima
Article
Engineering, Chemical
Hideo Tajima, Miki Hattori, Hikaru Akagami, Hiroyuki Komatsu, Kazuaki Yamagiwa
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2018)
Article
Energy & Fuels
Masahiro Abe, Hiroyuki Komatsu, Kazuaki Yamagiwa, Hideo Tajima
Article
Engineering, Chemical
Hideo Tajima, Yasuhiro Oota, Kazuaki Yamagiwa
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2014)
Article
Engineering, Chemical
Hiroyuki Komatsu, Kenta Maruyama, Kazuaki Yamagiwa, Hideo Tajima
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2019)
Article
Chemistry, Multidisciplinary
Hideo Tajima, Hiroki Ui, Mai Minagawa, Motoshi Suzuki, Aoi Kikuchi, Shou-ichi Nanba, Youji Taguchi
SEPARATION SCIENCE AND TECHNOLOGY
(2020)
Article
Engineering, Chemical
Ryosuke Ezure, Yuto Matsumoto, Shun Takano, Mana Shimizu, Hiroyuki Komatsu, Kazuaki Yamagiwa, Hideo Tajima
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2020)
Article
Energy & Fuels
Masahiro Abe, Ryosuke Nakamura, Hiroyuki Komatsu, Kazuaki Yamagiwa, Hideo Tajima
Summary: The study found that additives with fatty-acid groups with the same chain length as the main saturated FAME in the mixture significantly improved the separation effect; cyclic structures and hydroxy groups in palmitate derivatives were essential for preventing crystal growth and liquid contamination; Span40 was the most effective additive for mixtures containing approximately 50 wt% methyl palmitate.
Article
Engineering, Chemical
Ryosuke Ezure, Tomoya Sagawa, Tatsuya Horiguchi, Yuma Arai, Hiroyuki Komatsu, Kazuaki Yamagiwa, Hideo Tajima
Summary: Gas hydrate slurries prepared using solid hydrates and water are effective secondary refrigerants with high latent heat of fusion that can help reduce global warming. The flow properties of R-134a and R-32 gas hydrate slurries were investigated, showing that they behaved as pseudoplastic fluids in good flow states and dilatant fluids in poor flow states. The relative viscosities of the slurries were estimated using Happel's equation based on apparent particle hold-up, and in turbulent flow, both slurries acted as pseudoplastic fluids with good flow characteristics.
CHEMICAL ENGINEERING SCIENCE
(2021)
Article
Energy & Fuels
Hideo Tajima, Masahiro Abe, Hiroyuki Komatsu, Kazuaki Yamagiwa
Summary: The study demonstrated the additive winterization of biodiesel derived from various edible oils, showing effective separation and purification. However, there is room for improvement in certain aspects, especially under high stearate conditions. Proper mechanical separation methods such as filtration can increase the separation factor and liquid recovery rate.
Article
Engineering, Chemical
Ryosuke Ezure, Yuma Arai, Daiki Nakano, Hiroyuki Komatsu, Hideo Tajima
Summary: Hydrate-based gas separation is a method of separating gas mixtures based on their thermodynamic properties. This study proposes a new process for gas absorption and desorption under constant pressure with rising temperature. Theoretical calculations and experimental verification showed that SF6 can be concentrated up to 90% using this process.
SEPARATION AND PURIFICATION TECHNOLOGY
(2023)
Article
Engineering, Chemical
Tomoya Sagawa, Ryosuke Ezure, Hiroyuki Komatsu, Hideo Tajima
Summary: The flow pattern and rheological properties of SF6 hydrate slurry were investigated in this study. Three flow patterns, namely homogeneous flow, heterogeneous flow, and moving-bed flow, were observed as the flow velocity changed. Experimental relationships based on the Turian-Yuan equation were developed to predict the flow velocities at which the flow patterns change with an error of approximately 10%. The rheological properties of SF6 hydrate slurry exhibited Newtonian tendency at low solid fractions and pseudoplastic tendency at high solid fractions. The relative viscosity of the slurry could be estimated within 25% error using the Krieger-Dougherty model.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2023)
Article
Engineering, Chemical
Hiroyuki Komatsu, Tatsuya Horiguchi, Nobuyuki Sakamoto, Hideo Tajima
Summary: The rheological properties of tetra-n-butylammonium bromide (TBAB) and tetra-n-butylphosphonium bromide (TBPB) semi-clathrate hydrate (SCH) slurries with polyvinyl alcohol (PVA) were measured using a viscometer to evaluate the anti-agglomeration effect of PVA. Adding PVA changed the rheological properties of slurries to a Bingham fluid even under CO2 bubbling conditions. TBAB and TBPB hydrate slurries exhib-ited a stronger dilatant trend with yield stress and more aggregates with increasing solid fraction, and TBPB had higher frictional force and aggregability compared to TBAB hydrate slurries.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Engineering, Chemical
Yunfei Yu, Xue Yang, Chenchen Zhang, Jie Chen, Wei Lin, Jianqiang Meng
Summary: This study reports an environmentally friendly and simple approach for preparing double-network (DN) ion gel membranes with high strength and excellent gas separation performance. By optimizing crosslinking density, mass ratio, and the type and content of free ionic liquid, the mechanical and gas separation properties of the DN membrane are improved.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Si-qi Jiang, Qiang Gao, Xi-guang Li, Chao-zhu Deng, Jun Qiu, Xiang-nan Zhu
Summary: A dual-strengthening pretreatment method is proposed to remove PVDF more efficiently and enhance the leaching of LiCoO2. Experimental results show that dual-strengthening pretreatment can effectively remove PVDF and significantly improve the leaching efficiency compared to single pretreatment methods.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Zengchi Hu, Xiaoyu Wang, Xiaohui Zhang, Xue Li, Jiangbin Xia
Summary: The rapid fabrication of high-performance composite membranes based on CMPs using simple and low-cost methods is challenging. In this study, three CMPs-based composite membranes were rapidly fabricated with adjustable size using unidirectional diffusion synthesis. The microstructural design enhanced the rejection rates of the membranes and they showed strong hydrolytic resistance, thermal stability, and acid-base resistance. Electrostatic adsorption and the adjustable microstructures significantly varied the repellence of the membranes to different charged molecules.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Farzaneh Rouhani, Matineh Ayedi, Nasser Safari
Summary: Introducing defects into porous metal-organic frameworks is important for improving their adsorption performance. Quasi-MOFs, an underutilized variant of large-scale, fundamentally deficient MOFs, have been found to have substantial amounts of unsaturated metal sites to offset the drawbacks of MOFs. In this study, a quasi-MOF was produced using a water-stable MOF and demonstrated significantly improved phosphate adsorption capability due to the presence of defect sites.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Valentin Reungoat, Morad Chadni, Louis M. M. Mouterde, Fanny Brunissen, Florent Allais, Helene Ducatel, Irina Ioannou
Summary: This study focuses on the recovery of sinapic acid using liquid-liquid extraction assisted by a hollow fiber membrane contactor from an aqueous feed obtained through the hydrolysis of mustard bran. The screening of solvents of different chemical nature showed that all tested solvents had an extraction efficiency of more than 80% for pH < 5. Four solvents were selected for use in the hollow fiber membrane contactor, and the volatile solvents showed higher mass transfer coefficients compared to non-volatile solvents. The extraction efficiency was intensified by increasing the initial concentration of sinapic acid and the feed-to-solvent ratio. CPME was found to have optimal recovery efficiency at a phase ratio of 8:1, yielding 0.9 g of sinapic acid per liter of CPME used.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Takahiro Sakamoto, Takafumi Hanada, Hayate Sato, Mayu Kamisono, Masahiro Goto
Summary: The emergence of the battery society has led to a high demand for battery metals, resulting in a strain on their supply. This study introduces a novel technique using a hydrophobic deep eutectic solvent (DES) for leaching and recovering battery metals from low-grade nickel laterite ores. The DES enables selective leaching and recovery of the metals, offering a promising pathway for the extraction of critical battery metals.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Rongrong He, Jiarui Chen, Chunyao Zhang, Dan Lu, Lin Zhang, Tao He
Summary: Researcher has developed a method to quantify the charge density in nanofiltration (NF) membrane separation layer and applied it in NF membranes that can separate Mg2+ and Li+. The results showed that overcompensated amine groups played a major role, and there was a linear relationship between charge density and coating bi-layers or PAH layers.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Zhijian Zhang, Min Chen, Zhe Lin, Zhichao Yang, Yafeng Du, Zhihui Chen, Zhenhao Yang, Kongyin Zhao, Ligang Lin
Summary: Membrane technology plays an important role in molecular/ion separation processes, but faces challenges such as membrane fouling. This study introduces a new ion-crosslinking method to fabricate copper alginate hydrogel membranes with improved mechanical strength and antimicrobial capabilities. The membranes exhibit excellent separation performance and enhanced long-term molecule/ion separation through improved anti-swelling properties. Molecular dynamics simulations and life cycle analysis highlight the pore structure and environmental friendliness of the hydrogel membranes. These findings provide valuable insights for developing sustainable hydrogel membranes with stable performance and high separation efficiency.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Dongmei Liu, Aiying Guo, Yanling Qi, Zhixin Ji, Hongjuan Li, Zhiwei Zhang, Xinyue Zhang, Kunze Wu, Aijun Cai
Summary: In this study, a stable magnetic Mg/Mn-layered double oxide-doped biochar composite (MgMnLDO-MBC) was prepared and successfully used for the removal of antibiotics and bacteria from wastewater. The composite exhibited enhanced surface areas, adsorption sites, and free radicals, leading to improved catalytic activity. The effects of different factors on the removal efficiency were evaluated, and the composite showed good reusability.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Feng Wang, Zhaoyong Bian, Yaru Zhang, Wenchao Yu, Qiang Zhang, Hui Wang
Summary: In this study, a nanofibrous layered structure of Ff-Ti3C2Tx-Co3O4 was prepared by self-assembling nanofibrous Co3O4 with lamellar fluorine-free MXene (Ff-Ti3C2Tx). The Ff-Ti3C2Tx-Co3O4 exhibited excellent catalytic activity for degradation, resistant to ionic interference, and maintained high removal efficiency of sulfamethoxazole (SMX) in municipal wastewater. The rapid SMX degradation involved fast electron transfer in redox cycles with PMS and the generation of 1O2 via PMS ->center dot O2 -> 1O2. This work provides new insights into antibiotic degradation mechanisms and electron transfer based on PMS activation.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Weipeng He, Jiacheng Luo, Yujie Wu, Tianhao Luo, Chen Tang
Summary: This study comparatively evaluated the role of cationic, anionic, and nonionic polyacrylamides (PAMs) in ballasted flocculation of clay suspensions under different aluminum sulfate (AS) coagulant dosages. The selection of PAMs and AS dosage had a significant influence on the size and shear resistance of ballasted floc aggregates.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Lixian Wang, Lizhi Zhao, Didi Si, Zhixin Li, Huiqin An, Hui Ye, Qingping Xin, Hong Li, Yuzhong Zhang
Summary: Metalloporphyrin-based nanozymes integrated with poly (vinylidene fluoride) membrane show high catalytic activity and reusability for the decolorization of Congo Red dye in continuous flow process.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Yongfei Ma, Chenyu Zeng, Yongzhen Ding, Jiayi Tang, Ondrej Masek, Zhikang Deng, Rui Mu, Zulin Zhang
Summary: In this study, sludge-derived biochar (SBC) was functionalized with various iron salts to enhance its adsorption ability for sulfamethoxazole (SMX) and magnetic collection performance. Ball milling was further employed to treat the optimal iron salt functionalized SBC (MSBC), resulting in ball milled SBC (BMSBC) with improved adsorption performance for SMX. The dominant driving mechanism for SMX adsorption onto BMSBC was confirmed to be multiple physicochemical forces, including 7C-7C conjugation, pore filling, H-bonding, Fe-O complexation, and electrostatic interactions. BMSBC exhibited favorable adsorption ability for SMX in actual waters and could be easily collected within 1 min due to its magnetic sensitivity.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Jinglin Tan, Xiaohui Mao, Wenjihao Hu, Hongbo Zeng
Summary: This study investigates the influence of PDMS chain architectures on surface properties and reveals that PDMS coatings with looped structures exhibit superior hydrophobicity, self-cleaning, and water sliding compared to coatings with linear structures. Additionally, both looped and linear PDMS coated stainless steel mesh/polyester fibers show efficient separation of oil/water mixture.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Wei-Liang Chen, Chih-Chia Cheng, Chien-Hsing Lu, Jem-Kun Chen
Summary: This study designs a novel sandwich-structured capacitor that reduces the absorption time of pollutants using dielectrophoresis force. By coating graphene oxide on polystyrene microspheres as adsorbents and encapsulating them within the capacitor, the adsorption rate is significantly enhanced. Additionally, frequency manipulation allows for the recycling of adsorbents and concentration of dyes, minimizing secondary pollution.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)