Article
Thermodynamics
Honggang Xing, Haozhe Jin, Xiaofei Liu, Rui Li, Mingxiang Wang, Hengyang Xiang, Chao Wang
Summary: This paper experimentally studies the heat transfer characteristics of heat exchange tubes with NH4Cl crystallization fouling. The results show that the local heat transfer coefficient varies with the circumferential angle and increases with fouling.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Thomas O. Jelly, Massimiliano Nardini, Marco Rosenzweig, John Leggett, Ivan Marusic, Richard D. Sandberg
Summary: This study investigates the impact of blade surface roughness on the aero-thermal performance of a high-pressure turbine vane using highly-resolved Large-Eddy Simulations. The study reveals that blade surface roughness affects boundary layer transition mechanisms, wall shear stress, blade surface heat flux, and turbulence kinetic energy and total pressure losses in the wake. However, the pressure-side surface of the blade remains relatively unaffected, even for the largest roughness amplitude.
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2023)
Article
Engineering, Environmental
Isaac A. Loge, Jakob R. Bentzon, Christopher G. Klingaa, Jens H. Walther, Benaiah U. Anabaraonye, Philip L. Fosbol
Summary: Crystallization fouling is a significant challenge in various industries, and understanding crystal formation is crucial for prevention and maintenance. The study demonstrates that deposition rates depend on detachment mechanisms and distribution characteristics. The influx of material and surface morphology govern deposition pattern.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Thermodynamics
Chenglei Xiong, Yongchang Chen, Chongfang Ma
Summary: A prediction model for crystallization fouling was proposed based on the Kern-Seaton model. The model can predict the changes in fouling resistance during the fouling process and is applicable to actual industrial processes, especially for turbulent flow. It provides a more convenient way to predict fouling in heat exchangers without requiring a large amount of measured data for fitting.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Thermodynamics
Baoqiang Yuan, Wei Wang, Wenjing Du
Summary: This study aims to evaluate the performance and applicability of different turbulence models near the pseudocritical point of fluids, and it found that these models have different sensitivities to molecular Prandtl numbers, buoyancy effects, and flow acceleration. Under forced convection conditions, appropriate turbulence models can be selected by limiting the flow acceleration number. However, none of the tested turbulence models showed generalizability under mixed convective conditions.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Physics, Multidisciplinary
Yaxuan Peng, Xuefei Xu, Yandong Liang
Summary: This study investigated the influence of an axial-electromagnetic field treatment device (AEFTD) with different electromagnetic frequencies on calcium carbonate (CaCO3) crystallization fouling on the tube side of a shell-and-tube heat exchanger. The results showed that the AEFTD effectively reduced fouling resistance and slowed down the growth rate of CaCO3 fouling. The application of the AEFTD enhanced heat transfer and favored the formation of vaterite instead of calcite, which facilitated the removal of fouling by turbulent flow.
Article
Thermodynamics
Amthal Al-Gailani, Olujide Sanni, Thibaut V. J. Charpentier, Richard Crisp, Jantinus H. Bruins, Anne Neville
Summary: The study found that the scale formed on surfaces mainly consists of two distinct regions: a smooth and flat layer, and a rough calcium carbonate layer, with copper and aluminum surfaces having a greater scaling tendency. Additionally, the complex effect of flow rate on scale formation was also discussed in the study.
APPLIED THERMAL ENGINEERING
(2021)
Article
Thermodynamics
Jure Berce, Matevz Zupancic, Matic Moze, Iztok Golobic
Summary: This study investigated calcium carbonate crystallization fouling in a corrugated plate heat exchanger, and demonstrated the use of temperature and flow measurements, coupled with infrared thermography, to monitor fouling. The results showed that fouling caused channel blockage and flow obstructions, resulting in significant flow redistribution within the channel. This approach provides valuable insights for heat exchanger fouling studies and lays the foundation for future research on dynamic operation and computational models.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Sadaf Rahimi, S. M. Peyghambarzadeh, H. Kazemi Esfeh, Shima Azizi, M. R. Malayeri
Summary: Deposit formation in heat exchangers is an undesirable process that can reduce their performance and efficiency. This research investigated the impact of fluid bulk temperature (Tb) on the deposition of CaCO3 solution under convective heat transfer and subcooled flow boiling conditions. The study found that Tb significantly influenced the mechanism of deposit formation, changing the fouling resistance curve and crystal type of the deposit layer. The results also showed that heat flux and fluid flow rate had different effects on fouling rate depending on Tb and heat flux levels.
APPLIED THERMAL ENGINEERING
(2023)
Article
Engineering, Chemical
Hong-Qing Jin, Hrushikesha Athreya, Aditi Kalle, Sophie Wang, Kashif Nawaz
Summary: The integration of a CO2 desorption model into CFD modeling allows for the prediction of scale formation and CO2 desorption with local and transient profiles of temperature, carbonate species concentrations, pH, and total alkalinity. Simulation results show that high steam temperatures increase seawater total alkalinity and accelerate scale formation. The thickness of the scale on the bottom tube reaches 0.30 μm and 5.24 μm for steam temperatures of 60 degrees C and 80 degrees C, respectively. High salinity leads to a larger CO2 desorption rate, with a 43% increase when seawater salinity increases from 35 to 55 g/kg. The effects of operating conditions on carbonate speciation and pH have been compared and analyzed. This model can be a useful tool for the design and optimization of thermal desalination systems.
Article
Thermodynamics
Hendrik Kiepfer, Paul Stannek, Marco Grundler, Hans-Joerg Bart
Summary: This study demonstrates the production process of a gasketed plate heat exchanger made of composite materials. The embossed polymer composites exhibit high thermal conductivity and comparable performance with metallic materials for the same wall thicknesses. However, the materials are susceptible to calcium sulfate fouling, which is attributed to flow maldistribution rather than the actual materials.
APPLIED THERMAL ENGINEERING
(2024)
Article
Engineering, Chemical
Kaleemullah Shaikh, Salim Newaz Kazi, Mohd Nashrul Mohd Zubir, Bushroa Abd Razak, Kokhoe Wong, Yew Hoong Wong, Wajahat Ahmed Khan, Shekh Abdullah, Md Shadab Alam
Summary: This study investigated the heat transfer and mitigation of CaCO3 fouling by applying zirconium coating layer on the heat exchanger surface. The results showed that the zirconium coated surface reduced fouling deposition and improved heat transfer.
JOURNAL OF THE TAIWAN INSTITUTE OF CHEMICAL ENGINEERS
(2023)
Review
Engineering, Chemical
Jure Berce, Matevz Zupancic, Matic Moze, Iztok Golobic
Summary: Fouling on heat exchangers, especially crystallization fouling, remains a significant challenge in heat transfer, despite numerous scientific investigations. Prediction and prevention of fouling are unresolved issues in process engineering, leading to economic losses and environmental damage.
Article
Thermodynamics
Zhiming Xu, Hongbo Fan, Zhimin Han
Summary: A local calculation method based on the crystallization fouling model is proposed to simulate the fouling process, and it is validated against experimental data. The local calculation method shows stronger correlation with experimental data in predicting fouling resistance, especially in complex channel structures. This method has an advantage in providing local fouling information compared to the integral calculation method.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Thermodynamics
Zhiming Xu, Yu Zhao, Jianjun He, Hongwei Qu, Yuchen Wang, Bingbing Wang
Summary: This study experimentally investigated the fouling characteristics of a heat transfer surface by CaCO3 with SCMC inhibitor, showing that increasing SCMC concentration, degree of substitution, and solution temperature can decrease fouling thermal resistance, while increasing solution mass flow can increase fouling thermal resistance. The effects of SCMC viscosity from 600 mpa.s to 15000 mpa.s on fouling thermal resistance were found to be negligible.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2021)
Review
Chemistry, Multidisciplinary
M. Schoenitz, L. Grundemann, W. Augustin, S. Scholl
CHEMICAL COMMUNICATIONS
(2015)
Article
Engineering, Chemical
Nathalie Gottschalk, Jan C. Kuschnerow, Henning Foeste, Wolfgang Augustin, Stephan Scholl
CHEMIE INGENIEUR TECHNIK
(2015)
Article
Biotechnology & Applied Microbiology
Charles Cunault, Christine Faille, Laurent Bouvier, Henning Foeste, Wolfgang Augustin, Stephan Scholl, Pascal Debreyne, Thierry Benezech
FOOD AND BIOPRODUCTS PROCESSING
(2015)
Article
Biotechnology & Applied Microbiology
Martin Schoenitz, Wolfgang Augustin, Stephan Scholl
FOOD AND BIOPRODUCTS PROCESSING
(2015)
Article
Biotechnology & Applied Microbiology
L. Gomes da Cruz, E. M. Ishiyama, C. Boxler, W. Augustin, S. Scholl, D. I. Wilson
FOOD AND BIOPRODUCTS PROCESSING
(2015)
Article
Thermodynamics
Robert Goedecke, Peter Droegemueller, Wolfgang Augustin, Stephan Scholl
HEAT TRANSFER ENGINEERING
(2016)
Article
Chemistry, Multidisciplinary
Sonja Joseph, Michael Rappolt, Martin Schoenitz, Vera Huzhalska, Wolfgang Augustin, Stephan Scholl, Heike Bunjes
Article
Engineering, Chemical
Shiyao Wang, Florian Schlueter, Nathalie Gottschalk, Stephan Scholl, D. Ian Wilson, Wolfgang Augustin
CHEMIE INGENIEUR TECHNIK
(2016)
Article
Thermodynamics
Karl Siebeneck, Johannes Lueken, Yan Lu, Ingmar Bialuch, Christian Stein, Wolfgang Augustin, Stephan Scholl
HEAT TRANSFER ENGINEERING
(2017)
Article
Thermodynamics
Martin Schoenitz, Jan Henrik Finke, Sebastian Melzig, Annika Hohlen, Nils Warmeling, Christel Mueller-Goymann, Wolfgang Augustin, Stephan Scholl
HEAT TRANSFER ENGINEERING
(2015)
Article
Thermodynamics
Florian Schlueter, Wolfgang Augustin, Stephan Scholl
Summary: Fouling is a major challenge for industries, and its quantification is commonly done through thermal fouling resistance. This contribution discusses an expanded approach to model and link fouling resistances, considering both experimental and analytical methods to understand local differences in fouling deposits within heat exchangers.
HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Florian Schlueter, Wolfgang Augustin, Stephan Scholl
Summary: This study presents experimental and analytical results of local investigations of a fouled counterflow double-pipe heat exchanger, with the aim of calculating different local fouling resistances in order to explain and eliminate apparent negative fouling resistances on a local basis. The research utilizes a holistic modeling approach to model and link local and integral fouling resistances, as well as thermal and mass-based methods.
HEAT AND MASS TRANSFER
(2022)
Article
Engineering, Chemical
Andreas Boettcher, Judith Petri, Arne Langhoff, Stephan Scholl, Wolfgang Augustin, Annika Hohlen, Diethelm Johannsmann
Summary: In situ study of emulsion polymerization fouling at hot interfaces using QCM-D was conducted. The fouling kinetics and surface stabilization were quantified with the QCM. It was observed that a film with a thickness of less than 1 µm can stabilize the surface against the deposition of thicker layers. Furthermore, the increase in resonance bandwidth prior to the main transition was attributed to the first contact of coagulum with the surface. The QCM-D technique proved effective in observing and quantifying the fouling at hot interfaces.
MACROMOLECULAR REACTION ENGINEERING
(2022)
Article
Thermodynamics
H. Wiese, H. Geissler, W. Augustin, S. Scholl
Summary: The individual steps in cleaning a fouled heat exchanger surface play a crucial role in determining the overall performance of the cleaning process. However, the complex mechanisms of the mutual supportive processes involved in cleaning are not fully understood yet. This study presents a stepwise approach to investigate the diffusion of the cleaning agent NaOH into a WPI gel under stationary and flow conditions. Temperature was found to affect both the diffusion step and the subsequent removal of proteins, but to different extents.
HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Niklas Jarmatz, Wolfgang Augustin, Stephan Scholl
Summary: Successfully dealing with complex fouling problems requires a good understanding based on a wide range of additional data. Process data can be utilized to better understand and predict fouling in an apparatus or a production plant. We propose a systematic approach to generate training data in a pipe fitting, which can be used before utilizing the entire data set of the production plant for fouling prediction. The temperature-based detection of heat transfer resistance and particle deposition in the pipe fitting provides reproducible results for model training.
HEAT AND MASS TRANSFER
(2023)
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)