Article
Engineering, Environmental
Hyung Jin Yoon, Sungyong Mun, Ki Bong Lee
Summary: This study demonstrated that the CO2 sorption performance of CaO-based sorbents can be maximized through simple mechanical ball-milling, and the used sorbents can be successfully reactivated using this method. The research highlighted the critical role of CaO particle size in affecting CO2 sorption performance, showing that reducing particle size can significantly improve sorption capacity.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Engineering, Environmental
Hyung Jin Yoon, Chan Hyun Lee, Ki Bong Lee
Summary: In this study, mass transfer enhanced CaO pellets were prepared by utilizing CO2 evacuation to form channels, which significantly improved the initial stage of CO2 sorption and accelerated the sorption kinetics. The enhanced mass transfer not only increased the CO2 sorption uptake at different temperatures, but also had a positive effect on CO2 release after capture. The fast CO2 sorption and regeneration kinetics of the new pellets significantly enhanced the energy efficiency of continuous CO2 capture processes.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Vyacheslav V. Rodaev, Svetlana S. Razlivalova, Alexander Tyurin, Vladimir M. Vasyukov
Summary: A nanofibrous CaO sorbent for high-temperature CO2 capture was successfully fabricated by calcination of electrospun composite filaments. The sorbent showed excellent CO2-uptake capacity and has potential applications in calcium-looping technology.
Article
Engineering, Environmental
Yongqing Xu, Cong Luo, Huiying Sang, Bowen Lu, Fan Wu, Xiaoshan Li, Liqi Zhang
Summary: The study prepared NaCl-modified CaO-based sorbents through simultaneous hydration and impregnation, and investigated their cyclic CO2 capture capacity. The results showed that NaCl could tailor the temperature sensitivity of the sorbents and enhance their carbonation activity, particularly at higher temperatures.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Vyacheslav V. Rodaev, Svetlana S. Razlivalova, Alexander I. Tyurin, Vladimir M. Vasyukov
Summary: A Zr-doped CaO sorbent with an average filament diameter of about 160 nm was fabricated using electrospinning. The sorbent showed an initial CO2 uptake capacity of 12.1 mmol/g, a specific surface area of 79 m(2)/g, an indentation Young's modulus of 520 MPa, and a hardness of 1.6 MPa. After 50 carbonation/decarbonation cycles, the sorbent still exhibited a decent CO2 uptake capacity of 9.7 mmol/g due to the uniform distribution of CaZrO3 in the CaO nanofibers.
Article
Energy & Fuels
Tao Jiang, Hao Zhang, Yujun Zhao, Changlei Qin, Shengping Wang, Xinbin Ma
Summary: The excessive emission of anthropogenic CO2 has led to the greenhouse effect, causing serious problems to the environment and human society. To address this issue, Al-promoted CaO-based solid sorbents were produced on a kilogram scale per batch using a simple co-precipitation technique, which improved the CO2 sorption performance of the sorbents. The optimized preparation conditions resulted in the successful synthesis of a 6-kg sorbent powder with favorable CO2 capture performance, and pelletization methods were used to further enhance the sorbent pellets' CO2 sorption capability and anti-attrition resistance.
Article
Engineering, Environmental
Gina Bang, Kyung-Min Kim, Seongmin Jin, Chang-Ha Lee
Summary: The presence of other gas species in practical conditions complicates sorption-based processes. This study focuses on understanding the dynamic CO2 sorption behavior of MgO-based sorbent under practical conditions. It was found that elevated pressures significantly enhance sorption performance, while temperature has no significant influence. H2O enhances CO2 sorption kinetics and initial CO2 sorption, while CO hinders them.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Engineering, Environmental
Chongcong Li, Xingli Gong, Hao Zhang, Yan Zhang, Mingjun Yang, Bingbing Chen
Summary: This study sought to use organic acid-rich torrefaction condensate (TC) as a replacement for commercial acetic acid (AC) in the acidification treatment of CaO sorbent to enhance its CO2 capture performance. The modified sorbents with TC exhibited better cyclic stability compared to the AC-modified ones. The presence of carbon deposition from TC, which acted as a spacer and protective overlay to slow down the sintering of CaO particles, was believed to be the reason for the improved cyclic stability.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Energy & Fuels
Yuning Chen, Yun Long, Jian Sun, Shengbin Bai, Yijie Chen, Zhanliang Chen, Chuanwen Zhao
Summary: By incorporating varying amounts of cellulose in the outer shell of calcium looping pellets, researchers were able to improve the mechanical properties of the pellets and enhance CO2 capture performance. The addition of cellulose reinforced the cement-based outer shell and promoted accessibility of CO2 to the highly reactive core, resulting in superior CO2 capture capacity.
Article
Engineering, Environmental
Azra Nawar, Majid Ali, Asif Hussain Khoja, Adeel Waqas, Mustafa Anwar, Mariam Mahmood
Summary: In this study, waste eggshells were used to synthesise structure modified CaO with organic acids for efficient CO2 capture. Among the modified sorbents, citric acid modification showed the highest CO2 uptake, making it a promising candidate for economical CO2 capture.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2021)
Article
Engineering, Chemical
Zhikun Zhang, Ziyan Yang, Siteng Zhang, Di Zhang, Boxiong Shen, Zhichuan Li, Jiao Ma, Lina Liu
Summary: This study reports a method to prepare a novel stable CaO-based sorbent by utilizing municipal solid waste incineration (MSWI) bottom ash. The stabilizer derived from the bottom ash promoted the dispersion of CaO and increased the surface area and pore size of the sorbents. The addition of Al2O3 and SiO2 from the bottom ash reacted with CaO to maintain the porous structure of the sorbents. The optimum carbonation temperature for the sorbents was found to be 700 degrees C, and after 20 cycles, the highest CO2 uptake was achieved by the BAS(20 wt%)/CaO sorbent, with a value of 0.14 gCO2/gsorbent.
SEPARATION AND PURIFICATION TECHNOLOGY
(2023)
Article
Engineering, Environmental
Bao-Qi Feng, Han-Qing Chen, Chao Ping, Xiang Huang, Wen-Long Liu, Bao-Xia Dong, Yun-Lei Teng
Summary: The study shows that inert additive-doped CaO-based CO2 adsorbents can be synthesized in one pot by the mechanochemical method, producing methane instead of CO2 emission. The prepared CaO@C and CaO@MgO@C composites exhibit high CO2 adsorption capacity and superior cycling stability, with much lower activity losses after 30 cycles compared to conventional adsorbents. This work provides a novel, simple, solution-free, and sustainable strategy for synthesizing effective CaO-based CO2 adsorbents.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Engineering, Environmental
Wenfei Yue, Chuigang Fan, Wenli Song, Songgeng Li
Summary: This study investigates the effects of different precipitated CaCO3 precursors on the physical properties and CO2 capture performance of CaO sorbents. The results show that the presence of additives affects the crystal composition and porosity of the CaCO3 precursor, and CaO sorbents derived from CaCO3 modified with 8 mmol/L CTAB exhibit higher CO2 capture capacity than other sorbents.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2022)
Article
Engineering, Chemical
Marco Balsamo, Fabio Montagnaro
Summary: The capture of CO2 from industrial flue gas by CaO in fluidized bed calcium looping processes is an effective way to reduce greenhouse gas emissions. This study developed an expression for the diffusivity of the product layer that takes into account the carbonation time using fractal-like dynamics concepts. The proposed fractal model based on the canonical random pore model demonstrated superior accuracy in predicting CO2 diffusion in the product layer under realistic operating conditions.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Engineering, Chemical
Zhihong Xu, Tao Jiang, Hao Zhang, Yujun Zhao, Xinbin Ma, Shengping Wang
Summary: Novel MgO-doped CaO sorbent pellets exhibit excellent CO2 adsorption capacity and adsorption rate due to the homogeneous dispersion of MgO and its effects on the physical structure of sorbents, effectively inhibiting sintering of CaO and retaining adsorption capacity during multiple cycles. Mesopores and macropores contribute to significant volume changes during operation cycles. Ca2Mg1 sorbent pellets show favorable CO2 capture capacity, average adsorption rate, and conversion rate of CaO after 30 cycles.
FRONTIERS OF CHEMICAL SCIENCE AND ENGINEERING
(2021)
Article
Engineering, Chemical
Ri Zhang, Shasha Zhang, Mengyan Ding
Summary: A thin liquid film method is proposed to evaluate sand erosion in annular flow. This method considers the direct interaction between the liquid film and gas core, as well as the entrainment and deposition of droplets. The erosion rate is calculated by considering the effects of liquid entrainment and particle velocity decay. The method is fully verified by comparing with experimental data.
Article
Engineering, Chemical
Yu Suo, Xianheng Su, Wenyuan He, Xiaofei Fu, Zhejun Pan
Summary: This research investigates the mechanical properties of sandstone-shale composite through orthogonal experimental method and discrete element simulation. The results show that different lithologies and thickness ratios can affect the strength and fracture mode of the composite rock samples.
Article
Engineering, Chemical
Maurizio Troiano, Andrea El Hassanin, Roberto Solimene, Alessia Teresa Silvestri, Fabrizio Scala, Antonino Squillace, Piero Salatino
Summary: This study investigates the potential of Fluidized Bed Finishing (FBF) for square flat AlSi10Mg specimens manufactured via Laser-Powder Bed Fusion (L-PBF) additive manufacturing technology. The results show that good finishing can be achieved using rotation-assisted tests, with a maximum reduction of surface roughness by 67%. Steel particles are found to be the most effective bed material.
Review
Engineering, Chemical
Ningbo Song, Wanzhong Yin, Jin Yao
Summary: Seawater's dissolved salts and minerals have various effects on the flotation process, including influencing the characteristics and behavior of flotation factors, as well as affecting the surface of sulfide minerals. In most cases, seawater has adverse effects on the flotation of sulfide minerals, but these effects can be mitigated by adjusting the reagents.
Article
Engineering, Chemical
Kaiqiao Wu, Shuxian Jiang, Victor Francia, Marc-Olivier Coppens
Summary: In rectangular and cylindrical annular fluidized beds, pulsating gas flow can create regular bubble patterns, overcoming challenges seen in conventional units. This study provides new opportunities for modularization of fluidized bed operations.
Article
Engineering, Chemical
Shuo Li, Huili Zhang, Jan Baeyens, Miao Yang, Zehao Li, Yimin Deng
Summary: The paper assesses the behavior of cohesive Geldart C-type particles when fluidized by air with the aid of vibration. It determines that mechanical vibration is a simple and effective method to improve the fluidity of cohesive particles during fluidization.
Article
Engineering, Chemical
Zhenfei Feng, Qingyuan Zhang, Shanpan Liang, Zhenzhou Li, Fangwen Guo, Jinxin Zhang, Ding Yuan
Summary: A new micro/mini-channel heat sink (MCHS) with a combined structure of longitudinal and transverse vortex generators is designed, using Al2O3 nanofluid as the working medium. The study explores the effects of transverse vortex generator shape and longitudinal vortex generator angle on the hydraulic and thermal characteristics, comprehensive performance, entropy generation, and exergy efficiency. The results show that the triangular transverse vortex generator improves the comprehensive performance and exergy efficiency. Combined with the longitudinal vortex generator, the MCHS achieves the best comprehensive performance, entropy generation, and exergy efficiency when the Reynolds number is 742.
Article
Engineering, Chemical
Kostas Giannis, Christoph Thon, Guoqing Yang, Arno Kwade, Carsten Schilde
Summary: This study presents a 3D convolutional neural network (3D-CNN) methodology for generating realistic 3D models of particles. The method trains on 2D projections of particle images to predict their 3D shapes, and evaluates the accuracy of the predictions using Fourier shape descriptors (FSDs). This methodology has wide applications in particle shape analysis.
Article
Engineering, Chemical
Zheng-qing Zhou, Lu-jia Chai, Yu-long Zhang, Ya-bin Wang, Ze-chen Du, Tian-yi Wang, Yu-zhe Liu
Summary: The dynamic oxidation and shell-breaking processes of aluminum nanoparticles (ANPs) during heating were studied using in situ transmission electron microscopy. The results revealed that the changes in shell thickness can be divided into three stages, and the active aluminum content of ANP decreased before shell-breaking.
Article
Engineering, Chemical
Fulei Chen, Huaqing Ma, Zihan Liu, Lianyong Zhou, Yongzhi Zhao
Summary: A particle breakage model based on the particle replacement scheme, using the polyhedral model to describe particles, is proposed in this work to accurately describe the breakage of a large number of particles. Additionally, a fast-cutting algorithm is proposed to reproduce the size distribution of progeny particles determined by the breakage model. The validation and simulation results show satisfactory accuracy, efficiency, and stability of the algorithm.
Review
Engineering, Chemical
Matteo Errigo, Christopher Windows-Yule, Massimiliano Materazzi, Dominik Werner, Paola Lettieri
Summary: Gas-solid fluidized-bed systems have advantages in terms of chemical reaction efficiency and temperature control, making them widely used in industrial applications. However, the design, scale-up, and optimization of these complex units are limited by the lack of deep physical understanding. Non-invasive and non-intrusive diagnostic techniques provide a way for researchers to study these systems without affecting the flow field or directly contacting the medium under study.
Article
Engineering, Chemical
Saeed Fateh, Mohammad Behshad Shafii, Mohammad Najafi, Cyrus Aghanajafi
Summary: Applying a magnetic field to ferrofluids alters their flow characteristics and enhances heat transfer. Through visualization and quantitative investigation, it is found that the magnetic field influences the flow patterns and velocity profiles, improving fluid mixing and vorticity magnitude.
Article
Engineering, Chemical
Lei Gao, Bingbing Wei, Xiaochuan Hu, Zaifeng Yao, Yiwen Fang, Xuejian Gao
Summary: In this study, a numerical model of sand triaxial test was established using discrete element software PFC3D, and an indoor triaxial test was conducted to calibrate the numerical model. The influence of microscopic parameters on the macroscopic mechanical response of sand was analyzed. The results showed that the friction coefficient had the greatest impact on the peak strength and residual strength of the sand's stress-strain curve, and it was positively correlated. The normal tangential stiffness ratio was negatively correlated, while the porosity and boundary flexibility stiffness had minimal influence on it.
Article
Engineering, Chemical
Xuan Liu, Jie Gong, Kai Jiang, Xiaojuan Lai, Yu Tian, Kang Zhang
Summary: This study aimed to improve the performance of lignite coal water slurries (CWSs) by synthesizing a series of three-arm amphiphilic block copolymers. By controlling the relative molecular weight, hydrophilic/hydrophobic ratio, and ionic group content, the apparent viscosity of CWSs was significantly reduced and the static stability was improved. Thermogravimetric testing and XPS analysis were conducted to reveal the mechanism behind the improved performance.
Article
Engineering, Chemical
Lanka Dinushke Weerasiri, Daniel Fabijanic, Subrat Das
Summary: Fluidization at low pressure offers significant benefits for the fine chemical industry. This study investigates the behavior of bubbles and bed expansion under low pressure conditions. It is found that lower pressure leads to larger bubbles, increased bubble quantity, and higher aspect ratio. The predictability is affected by the inhomogeneous fluidization, but low pressure fluidization can generate similar bubble sizes with lower fluidizing mass compared to atmospheric pressure.