Article
Engineering, Environmental
Caifeng Huang, Min Xu, Xunfeng Li, Xiulan Huai
Summary: Rare-earth-ion-doped Ca(OH)(2) materials can lower the dehydration temperature, and have higher dehydration rate and stability, making them suitable for stable high-density solar thermal energy storage.
CHEMICAL ENGINEERING JOURNAL
(2023)
Review
Engineering, Chemical
Peng Cen, Xue Bian, Zhannian Liu, Manyi Gu, Wenyuan Wu, Baokuan Li
Summary: Rare earth elements play an indispensable role in modern high technology, making the efficient exploitation and utilization of rare earth resources crucial. Current industrial processes are chemical and energy intensive, leading to negative impacts on the environment, thus further improvement towards cleaner production is necessary.
MINERALS ENGINEERING
(2021)
Article
Chemistry, Applied
Sheng Chang, Mei Li, Kai Gao, Dongliang Zhang, Haijun Duan, Linlin Ma, Zheng Ruan
Summary: The study investigated the mechanism of phthalic acid as a dicarboxylic acid collector in the flotation separation of fluorite and rare earth minerals. Experimental data showed that phthalic acid could efficiently separate the two minerals under weakly acidic conditions. The adsorption mechanism analysis revealed the formation of stable polycyclic calcium phthalate complex on the surface of fluorite.
JOURNAL OF RARE EARTHS
(2022)
Article
Engineering, Chemical
Sebastian Simu, Adriana Ledeti, Elena-Alina Moaca, Cornelia Pacurariu, Cristina Dehelean, Dan Navolan, Ionut Ledeti
Summary: This study analyzes the thermal stability and decomposition kinetics of ethinylestradiol (EE), a widely used synthetic derivative of estradiol. The results show that the main decomposition process of EE in the temperature range of 175-375 degrees Celsius is a single-step process, unaffected by the heating rate of the sample.
Article
Green & Sustainable Science & Technology
Sara Ait Hak, Anasse Sraidi, Khaoula Khaless, Rachid Benhida
Summary: Phosphogypsum (PG), a primary by-product of wet process phosphoric acid production, presents challenges to the fertilizer industry. This study explores the leaching of rare earth elements (REEs) from PG and establishes a strong correlation between REEs concentration and leaching efficiency. Nitric acid and hydrochloric acid are effective leaching agents, with calcium sulfate solubility playing a pivotal role. Kinetics investigations indicate that the diffusion of REEs through the product layer is the rate-controlling step.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Chemistry, Analytical
Mohammad Nahid Siddiqui, Halim Hamid Redhwi, Dimitris S. Achilias
Summary: In this study, the thermal degradation of polymers is simulated using the random chain-scission model. By combining experiments and mathematical models, kinetic parameters with physical meaning are obtained for comparing the thermal stability of different polymers. The research shows that the dominant degradation mechanism for several polymers in the range of 30% to 90% relative degree of degradation is random scission.
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
(2022)
Article
Chemistry, Physical
Haibo Wan, Zhen Huang
Summary: The thermal degradation of nylon-6 tennis string nylon wastes was studied using multiple heating-rate thermogravimetric analyses in different atmospheres. Kinetic analysis methods were used to calculate activation energy and evaluate thermodynamic parameters during the thermal degradation process.
Article
Polymer Science
Adrian Olejnik, Paulina Kosmela, Lukasz Piszczyk
Summary: Thorough thermogravimetric analysis was conducted on bio-based polyurethane-polyisocyanurate (PUR-PIR) foams in both nitrogen and oxygen atmosphere. It was found that foams using biopolyol exhibit enhanced stability in both oxidative atmosphere and nitrogen compared to purely petrochemical foams, with relationships between thermal stability and foam structure established. Enhanced stability in oxygen can be attributed to higher cross-linking density and possibly the presence of more aromatic compounds in the biopolyol structure.
JOURNAL OF POLYMER SCIENCE
(2021)
Article
Thermodynamics
Laipeng Luo, Zhiyi Zhang, Chong Li, Nishu, Fang He, Xingguang Zhang, Junmeng Cai
Summary: In analyzing kinetic reactions of solid-state reactions like lignocellulosic biomass pyrolysis, the accuracy of determining the kinetic mechanism function using the master plots method depends strongly on the variation degree of the frequency factor with conversion and the conversion dependency of activation energy. Failure to consider these factors when utilizing the master plots method may lead to misestimating the kinetic mechanism function.
Article
Green & Sustainable Science & Technology
Pollyana R. Carvalho, Samuel L. S. Medeiros, Raul L. Paixao, Igor M. Figueredo, Adriano L. A. Mattos, M. Alexsandra S. Rios
Summary: Thermogravimetric pyrolysis of carnauba straw and carnauba stalk was studied and the kinetic parameters, FTIR spectra, and molar ratios were obtained, which were in good agreement with other reported biomasses.
Article
Engineering, Environmental
Kesiany M. de Souza, Marcelo J. S. de Lemos, Roberta dos R. Ribeiro, Ana Maria G. Marin
Summary: The transition to a carbon-free economy has led to the development of innovative technologies for permanent P&A of mature oil wells, such as the use of thermites in Thermal P&A technology. This study presents a comprehensive kinetic analysis of the Fe2O3-2Al thermite reaction using DSC data. Multiple kinetic methods were employed to calculate the activation energies for each reaction stage, revealing significant variations with the extent of conversion. Different models were used to describe the reaction stages, with the first stage following a contracting sphere mechanism and the second stage following a random nucleation mechanism. The modeled data showed good agreement with the experimental data for the first stage, but larger deviations were observed for the second stage.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Thermodynamics
E. A. Kammar, E. A. M. Gad, M. A. Mousa
Summary: NixCo1-xFe2O4 spinel nanoparticles were prepared using different methods and showed catalytic activity in the thermal decomposition of ammonium perchlorate, with NiCoF-gl exhibiting the highest catalytic activity. The addition of nanosized ferrites decreased the decomposition temperatures of AP.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Biochemistry & Molecular Biology
Bruno Ekawa, Herminio P. Diogo, Ricardo A. E. Castro, Flavio J. Caires, M. Ermelinda S. Eusebio
Summary: This study investigated the coamorphous formation of valsartan with 4,4'-bipyridine and trimethoprim in binary systems and evaluated it based on the glass transition temperature. The results showed that Val-Bipy (with hydrogen bonding) had a lower deviation, while Val-Tri (with ionic bonding) had a higher deviation.
Article
Environmental Studies
Zhili Zuo, Jinhua Cheng, Haixiang Guo, Benjamin Craig McLellan
Summary: China's rare earths industry is generally secure, with the technology subsystem showing saturated growth and the politics subsystem experiencing a significant decline. From 2006 to 2019, the industry experienced fluctuation driven by resources, economy, and politics. Changes in the security value of subsystems, particularly in technology and politics, have been significant, with all variables considered in the path model influencing the security index directly or indirectly.
Article
Materials Science, Ceramics
Shuhao Yang, Andre Anderko, Richard E. Riman, Alexandra Navrotsky
Summary: This study evaluates the thermodynamic properties of rare earth oxyfluorides (REOF) with varying RE elements and investigates the phase transitions of YbOF. It is found that REOF compounds are energetically stable relative to the binary oxides and fluorides, and the RE-O interactions contribute to their thermodynamic stabilities. REOF with small cations possess the monoclinic structure as the more energetically stable phase at room temperature.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Peng Cen, Wenyuan Wu, Xue Bian
GREEN PROCESSING AND SYNTHESIS
(2016)
Article
Materials Science, Multidisciplinary
Peng Cen, Wenyuan Wu, Xue Bian
METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
(2017)
Article
Materials Science, Multidisciplinary
Peng Cen, Wenyuan Wu, Xue Bian
METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
(2018)
Article
Engineering, Chemical
Peng Cen, Xue Bian, Wenyuan Wu, Baokuan Li
Summary: The current metallurgical process for bastnaesite concentrates needs to be updated for cleaner and more efficient production. A novel beneficiation-metallurgy combination process is proposed, which can significantly reduce chemical reagent usage and energy consumption, while also inhibiting fluorine waste generation. Recovery rates for rare earths, fluorine, and calcium are high under optimum conditions, indicating economic benefits and sustainability.
SEPARATION AND PURIFICATION TECHNOLOGY
(2021)
Review
Chemistry, Physical
Ming Cai, Xue Bian, Feng Xie, Wenyuan Wu, Peng Cen
Summary: This review article focuses on the development of cerium-based catalysts for NH3-SCR technology, including the components, preparation methods, catalytic performance, and reaction mechanisms of these catalysts. The review highlights the modification effects of various metal elements, various synthesis methods, and the physicochemical properties of the catalysts, particularly in relation to catalytic performances in the presence of SO2 and H2O. The aim is to provide technical guidance and insights for the application of NH3-SCR in NOx control.
Review
Engineering, Chemical
Peng Cen, Xue Bian, Zhannian Liu, Manyi Gu, Wenyuan Wu, Baokuan Li
Summary: Rare earth elements play an indispensable role in modern high technology, making the efficient exploitation and utilization of rare earth resources crucial. Current industrial processes are chemical and energy intensive, leading to negative impacts on the environment, thus further improvement towards cleaner production is necessary.
MINERALS ENGINEERING
(2021)
Article
Chemistry, Physical
Peng Cen, Kastriot Spahiu, Mikhail S. Tyumentsev, Mark R. St J. Foreman
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2020)
