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Spray and mixing characteristics of liquid jet in a tubular gas-liquid atomization mixer
Lingzhen Kong, Jiaqing Chen, Tian Lan, Huan Sun, Kuisheng Wang
Chinese Journal of Chemical Engineering    2021, 34 (6): 1-11.   DOI: 10.1016/j.cjche.2020.08.016
Abstract106)      PDF(pc) (1293KB)(63)       Save
For the design and optimization of a tubular gas-liquid atomization mixer, the atomization and mixing characteristics of liquid jet breakup in the limited tube space is a key problem. In this study, the primary breakup process of liquid jet column was analyzed by high-speed camera, then the droplet size and velocity distribution of atomized droplets were measured by Phase-Doppler anemometry (PDA). The hydrodynamic characteristics of gas flow in tubular gas-liquid atomization mixer were analyzed by computational fluid dynamics (CFD) numerical simulation. The results indicate that the liquid flow rate has little effect on the atomization droplet size and atomization pressure drop, and the gas flow rate is the main influence parameter. Under all experimental gas flow conditions, the liquid jet column undergoes a primary breakup process, forming larger liquid blocks and droplets. When the gas flow rate (Qg) is less than 127 m3·h-1, the secondary breakup of large liquid blocks and droplets does not occur in venturi throat region. The Sauter mean diameter (SMD) of droplets measured at the outlet is more than 140 μm, and the distribution is uneven. When Qg > 127 m3·h-1, the large liquid blocks and droplets have secondary breakup process at the throat region. The SMD of droplets measured at the outlet is less than 140 μm, and the distribution is uniform. When 127 < Qg < 162 m3·h-1, the secondary breakup mode of droplets is bag breakup or pouch breakup. When 181 < Qg < 216 m3·h-1, the secondary breakup mode of droplets is shear breakup or catastrophic breakup. In order to ensure efficient atomization and mixing, the throat gas velocity of the tubular atomization mixer should be designed to be about 51 m·s-1 under the lowest operating flow rate. The pressure drop of the tubular atomization mixer increases linearly with the square of gas velocity, and the resistance coefficient is about 2.55 in single-phase flow condition and 2.73 in gas-liquid atomization condition.
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Meltblown fabric vs nanofiber membrane, which is better for fabricating personal protective equipments
Junwei Wu, Hongjia Zhou, Jingyi Zhou, Xiao Zhu, Bowen Zhang, Shasha Feng, Zhaoxiang Zhong, Lingxue Kong, Weihong Xing
Chinese Journal of Chemical Engineering    2021, 36 (8): 1-9.   DOI: 10.1016/j.cjche.2020.10.022
Abstract81)      PDF(pc) (2768KB)(134)       Save
The coronavirus disease 2019 (COVID-19) pandemic has led to a great demand on the personal protection products such as reusable masks. As a key raw material for masks, meltblown fabrics play an important role in rejection of aerosols. However, the electrostatic dominated aerosol rejection mechanism of meltblown fabrics prevents the mask from maintaining the desired protective effect after the static charge degradation. Herein, novel reusable masks with high aerosols rejection efficiency were fabricated by the introduction of spider-web bionic nanofiber membrane (nano cobweb-biomimetic membrane). The reuse stability of meltblown and nanofiber membrane mask was separately evaluated by infiltrating water, 75% alcohol solution, and exposing under ultraviolet (UV) light. After the water immersion test, the filtration efficiency of meltblown mask was decreased to about 79%, while the nanofiber membrane was maintained at 99%. The same phenomenon could be observed after the 75% alcohol treatment, a high filtration efficiency of 99% was maintained in nanofiber membrane, but obvious negative effect was observed in meltblown mask, which decreased to about 50%. In addition, after long-term expose under UV light, no filtration efficiency decrease was observed in nanofiber membrane, which provide a suitable way to disinfect the potential carried virus. This work successfully achieved the daily disinfection and reuse of masks, which effectively alleviate the shortage of masks during this special period.
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Green biomanufacturing promoted by automatic retrobiosynthesis planning and computational enzyme design
Ziheng Cui, Shiding Zhang, Shengyu Zhang, Biqiang Chen, Yushan Zhu, Tianwei Tan
Chinese Journal of Chemical Engineering    2022, 41 (1): 6-21.   DOI: 10.1016/j.cjche.2021.08.017
Abstract75)      PDF(pc) (4649KB)(168)       Save
Biomanufacturing, which uses renewable resources as raw materials and uses biological processes to produce energy and chemicals, has long been regarded as a production model that replaces the unsustainable fossil economy. The construction of non-natural and efficient biosynthesis routes of chemicals is an important goal of green biomanufacturing. Traditional methods that rely on experience are difficult to support the realization of this goal. However, with the rapid development of information technology, the intelligence of biomanufacturing has brought hope to achieve this goal. Retrobiosynthesis and computational enzyme design, as two of the main technologies in intelligent biomanufacturing, have developed rapidly in recent years and have made great achievements and some representative works have demonstrated the great value that the integration of the two fields may bring. To achieve the final integration of the two fields, it is necessary to examine the information, methods and tools from a bird’s-eye view, and to find a feasible idea and solution for establishing a connection point. For this purpose, this article briefly reviewed the main ideas, methods and tools of the two fields, and put forward views on how to achieve the integration of the two fields.
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Dynamics of self-organizing single-line particle trains in the channel flow of a power-law fluid
Xiao Hu, Jianzhong Lin, Dongmei Chen, Xiaoke Ku
Chinese Journal of Chemical Engineering    2021, 34 (6): 12-21.   DOI: 10.1016/j.cjche.2020.10.009
Abstract72)      PDF(pc) (1392KB)(53)       Save
The formation of self-organizing single-line particle train in a channel flow of a power-law fluid is studied using the lattice Boltzmann method with power-law index 0.6≤n≤1.2, particle volume concentration 0.8%≤Φ≤6.4%, Reynolds number 10≤Re≤100, and blockage ratio 0.2≤k≤0.4. The numerical method is validated by comparing the present results with the previous ones. The effect n, Φ, Re and k on the interparticle spacing and parallelism of particle train is discussed. The results showed that the randomly distributed particles would migrate towards the vicinity of the equilibrium position and form the ordered particle train in the power-law fluid. The equilibrium position of particles is closer to the channel centerline in the shear-thickening fluid than that in the Newtonian fluid and shear-thinning fluid. The particles are not perfectly parallel in the equilibrium position, hence IH is used to describe the inclination of the line linking the equilibrium position of each particle. When self-organizing single-line particle train is formed, the particle train has a better parallelism and hence benefit for particle focusing in the shear-thickening fluid at high Φ, low Re and small k. Meanwhile, the interparticle spacing is the largest and hence benefit for particle separation in the shear-thinning fluid at low Φ, low Re and small k.
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Concentration of mixed acid by electrodialysis for the intensification of absorption process in acrylic acid production
Hanxiao Du, Lixin Xie, Jie Liu, Shichang Xu
Chinese Journal of Chemical Engineering    2021, 36 (8): 10-18.   DOI: 10.1016/j.cjche.2020.07.020
Abstract71)      PDF(pc) (2636KB)(100)       Save
The absorption process in acrylic acid production was water-intensive. The concentration of acrylic acid before distillation process was low, which induced to large amount of wastewater and enormous energy consumption. In this work, a new method was proposed to concentrate the side stream of absorption column and thus increase the concentration in bottom product by electrodialysis. The influence of operating conditions on concentration rate and specific energy consumption were investigated by a laboratory-scale device. When the voltage drop was 1 V·cP-1 (1 cP=10-3 Pa·S), flow velocity was 3 cm·s-1 and the temperature was 35 ℃, the concentration rates of acrylic acid and acetic acid could be 203.3% and 156.6% in the continual-ED process. Based on the experimental data, the absorption process combined with ED was simulated, in which the diluted solution from ED process was used as spray water and the concentrated solution was feed back to the absorption column. The results shown that the flow rate of spray water was decreased by 37.1%, and the acrylic acid concentration at the bottom of the tower was increased by 4.56%. The ions exchange membranes before and after use 1200 h were tested by membrane surface morphology (scanning electron microscope), membrane chemical groups (infrared spectra), ion exchange capacity, and membrane area resistance, which indicated the membrane were stable in the acid system. This method provides new method for energy conservation and emission reduction in the traditional chemical industry.
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Struggling as in past, write a glorious future together—CJChE’s 40th anniversary
Weiyang Fei, Guangsheng Luo
Chinese Journal of Chemical Engineering    2022, 41 (1): 1-1.   DOI: 10.1016/j.cjche.2022.01.006
Abstract68)      PDF(pc) (1176KB)(180)       Save
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Numerical simulation and experimental study of the characteristics of packing feature size on liquid flow in a rotating packed bed
Xifan Duan, Zhiguo Yuan, Youzhi Liu, Hangtian Li, Weizhou Jiao
Chinese Journal of Chemical Engineering    2021, 34 (6): 22-31.   DOI: 10.1016/j.cjche.2020.09.063
Abstract67)      PDF(pc) (920KB)(33)       Save
Rotating packed bed has high efficiency of gas–liquid mass transfer. So it is significant to investigate fluid motion in rotating packed bed. Numerical simulations of the effects of packing feature size on liquid flow characteristics in a rotating packed bed are reported in this paper. The particle image velocimetry is compared with the numerical simulations to validate the turbulent model. Results show that the liquid exists in the packing zone in the form of droplet and liquid line, and the cavity is droplet. When the radial thickness of the packing is less than 0.101 m, liquid line and droplets appear in the cavity. When rotational speed and radial thickness of the packing increase, the average diameter of the droplets becomes smaller, and the droplet size distribution becomes uniform. As the initial velocity of the liquid increases, the average droplet diameter increases and the uniformity of particle size distribution become worse. The droplet velocity increases with the radial thickness of the packing increasing, and gradually decreases when it reaches the cavity region. The effect of packing thickness is most substantial through linear fitting. The predicted and simulated values are within ±15%. The cumulative volume distribution curves of the experimental and simulated droplets are consistent with the R-R distribution.
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Knowledge expression, numerical modeling and optimization application of ethylene thermal cracking: From the perspective of intelligent manufacturing
Kexin Bi, Shuyuan Zhang, Chen Zhang, Haoran Li, Xinye Huang, Haoyu Liu, Tong Qiu
Chinese Journal of Chemical Engineering    2021, 38 (10): 1-17.   DOI: 10.1016/j.cjche.2021.03.033
Abstract63)      PDF(pc) (7201KB)(221)       Save
Applications of process systems engineering (PSE) in plants and enterprises are boosting industrial reform from automation to digitization and intelligence. For ethylene thermal cracking, knowledge expression, numerical modeling and intelligent optimization are key steps for intelligent manufacturing. This paper provides an overview of progress and contributions to the PSE-aided production of thermal cracking; introduces the frameworks, methods and algorithms that have been proposed over the past 10 years and discusses the advantages, limitations and applications in industrial practice. An entire set of molecular-level modeling approaches from feedstocks to products, including feedstock molecular reconstruction, reaction-network auto-generation and cracking unit simulation are described. Multi-level control and optimization methods are exhibited, including at the operational, cycle, plant and enterprise level. Relevant software packages are introduced. Finally, an outlook in terms of future directions is presented.
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Large-scale simulations of CO2 diffusion in metal-organic frameworks with open Cu sites
Tongan Yan, Minman Tong, Qingyuan Yang, Dahuan Liu, Yandong Guo, Chongli Zhong
Chinese Journal of Chemical Engineering    2022, 42 (2): 1-9.   DOI: 10.1016/j.cjche.2021.08.013
Abstract61)      PDF(pc) (2295KB)(280)       Save
Understanding CO2 diffusion behavior in functional nanoporous materials is beneficial for improving the CO2 adsorption, separation, and conversion performances. However, it is a great challenge for studying the diffusion process in experiments. Herein, CO2 diffusion in 962 metal-organic frameworks (MOFs) with open Cu sites was systematically investigated by theoretical methods in the combination of molecular dynamic simulations and density functional theory (DFT) calculations. A specific force field was derived from DFT-D2 method combined with Grimme's dispersion-corrected (D2) density functional to well describe the interaction energies between Cu and CO2. It is observed that the suitable topology is conductive to CO2 diffusion, and 2D-MOFs are more flexible in tuning and balancing the CO2 adsorption and diffusion behaviors than 3D-MOFs. In addition, analysis of diffusive trajectories and the residence times on different positions indicate that CO2 diffusion is mainly along with the frameworks in these MOFs, jumping from one strong adsorption site to another. It is also influenced by the electrostatic interaction of the frameworks. Therefore, the obtained information may provide useful guidance for the rational design and synthesis of MOFs with enhanced CO2 diffusion performance for specific applications.
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A review of conventional and renewable biodiesel production
P. Vignesh, A.R. Pradeep Kumar, N. Shankar Ganesh, V. Jayaseelan, K. Sudhakar
Chinese Journal of Chemical Engineering    2021, 40 (12): 1-17.   DOI: 10.1016/j.cjche.2020.10.025
Abstract56)      PDF(pc) (2712KB)(221)       Save
The need for sustainable fuels has resulted in the production of renewables from a wide range of sources, in particular organic fats and oils. The use of biofuel is becoming more widespread as a result of environmental and economic considerations. Several efforts have been made to substitute fossil fuels with green fuels. Ester molecules extracted from processed animal fats and organic plant materials are considered alternatives for the use in modern engine technologies. Two different methods have been adopted for converting esters in vegetable oils/animal fats into compounds consistent with petroleum products, namely the transesterification and the hydro-processing of ester bonds for the production of biodiesel. This review paper primarily focuses on conventional and renewable biodiesel feedstocks, the catalyst used and reaction kinetics of the production process.
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Recent advances in cardiovascular stent for treatment of in-stent restenosis: Mechanisms and strategies
Hang Yao, Yuwei He, Jinrong Ma, Lang Jiang, Jingan Li, Jin Wang, Nan Huang
Chinese Journal of Chemical Engineering    2021, 37 (9): 12-29.   DOI: 10.1016/j.cjche.2020.11.025
Abstract56)      PDF(pc) (3856KB)(209)       Save
Treatments of atherogenesis, one of the most common cardiovascular diseases (CVD), are continuously being made thanks to innovation and an increasingly in-depth knowledge of percutaneous transluminal coronary angioplasty (PTCA), the most revolutionary medical procedure used for vascular restoration. Combined with an expanding balloon, vascular stents used at stricture sites enable the long-time restoration of vascular permeability. However, complication after stenting, in-stent restenosis (ISR), hinders the advancement of vascular stents and are associated with high medical costs for patients for decades years. Thus, the development of a high biocompatibility stent with improved safety and efficiency is urgently needed. This review provides an overview of current advances and potential technologies for the modification of stents for better treatment and prevention of ISR. In particular, the mechanisms of in-stent restenosis are investigated and summarized with the aim to comprehensively understanding the pathogenesis of stent complications. Then, according to different therapeutic functions, the current stent modification strategies are reviewed, including polymeric drug eluting stents, biological friendly stents, prohealing stents, and gene stents. Finally, the review provides an outlook of the challenges in the design of stents with optimal properties. Therefore, this review is a valuable and practical guideline for the development of cardiovascular stents.
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Recent advances in amino acid-metal coordinated nanomaterials for biomedical applications
Shaobo Wang, Yunchao Zhao, Zeyu Zhang, Yalong Zhang, Linlin Li
Chinese Journal of Chemical Engineering    2021, 38 (10): 30-42.   DOI: 10.1016/j.cjche.2021.03.013
Abstract55)      PDF(pc) (9998KB)(207)       Save
Metal and amino acid (AA), as two kinds of entities, have been widely involved in biomaterials and nanomedicines. Recently, the marriage of them has developed new nanoformulations, amino acid-metal coordinated nanomaterials (AMCNs), which show great biomedical application potential in cancer therapy, antibacterial applications, biomedical imaging, etc. With the respective characteristics of metal and AA with rich biological and chemical properties, AMCNs can not only act as drug carriers with specific tumor targeting ability, but also realize synergistic therapy and imaging-guided therapy. Although the design and synthesis of amino acid-metal coordinated nanomaterials have been in-depth investigated, there are few systematic reviews on their biomedical application. In this review, we give a comprehensive summary of recent progresses in the design, fabrication, and biomedical applications of AMCNs. We also propose the future outlooks and challenges in aforementioned field. We expect that this review would contribute some inspiration for future research and development for amino acid metal coordinated nanomaterials.
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Measurement methods of particle size distribution in emulsion polymerization
Shuaifeng Zhang, Qinghua Zhang, Jianzhuang Shang, Zaisha Mao, Chao Yang
Chinese Journal of Chemical Engineering    2021, 39 (11): 1-15.   DOI: 10.1016/j.cjche.2021.03.007
Abstract51)      PDF(pc) (3445KB)(183)       Save
The particle size distribution of polymer always develops in emulsion polymerization systems, and certain key phenomena/mechanisms as well as properties of the final product are significantly affected by this distribution. This review mainly focuses on the measurement methods of particle size distribution rather than average particle size during the emulsion polymerization process, including the existing off-line, on-line, and in-line measurement methods. Moreover, the principle, resolution, performance, advantages, and drawbacks of various methods for evaluating particle size distribution are contrasted and illustrated. Besides, several possible development directions or solutions of the in-line measurement technology are explored
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Machine learning of materials design and state prediction for lithium ion batteries
Jiale Mao, Jiazhi Miao, Yingying Lu, Zheming Tong
Chinese Journal of Chemical Engineering    2021, 37 (9): 1-11.   DOI: 10.1016/j.cjche.2021.04.009
Abstract51)      PDF(pc) (1626KB)(263)       Save
With the widespread use of lithium ion batteries in portable electronics and electric vehicles, further improvements in the performance of lithium ion battery materials and accurate prediction of battery state are of increasing interest to battery researchers. Machine learning, one of the core technologies of artificial intelligence, is rapidly changing many fields with its ability to learn from historical data and solve complex tasks, and it has emerged as a new technique for solving current research problems in the field of lithium ion batteries. This review begins with the introduction of the conceptual framework of machine learning and the general process of its application, then reviews some of the progress made by machine learning in both improving battery materials design and accurate prediction of battery state, and finally points out the current application problems of machine learning and future research directions. It is believed that the use of machine learning will further promote the large-scale application and improvement of lithium-ion batteries.
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Low-temperature conversion of methane to oxygenates by supported metal catalysts: From nanoparticles to single atoms
Geqian Fang, Jian Lin, Xiaodong Wang
Chinese Journal of Chemical Engineering    2021, 38 (10): 18-29.   DOI: 10.1016/j.cjche.2021.04.034
Abstract49)      PDF(pc) (7633KB)(187)       Save
Direct cost-effective conversion of abundant methane to high value-added oxygenates (methanol, formic acid, acetic acid, etc.) under mild conditions is prospective for optimizing the structure of energy resources. However, the CH bond of products is more reactive than that of high thermodynamic stable methane. Exploring an appropriate approach to eliminate the “seesaw effect” between methane conversion and oxygenate selectivity is significant. In this review, we briefly summarize the research progress in the past decade on low-temperature direct conversion of methane to oxygenates in gas-solid-liquid phase over various transition metal (Fe, Cu, Rh, Pd, AuPd, etc.) based nanoparticle or single-atom catalyst. Furthermore, the prospects of catalyst design and catalysis process are also discussed.
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Research progress on preparation and purification of fluorine-containing chemicals in lithium-ion batteries
Xiaobin Liu, Zhenguo Gao, Jingcai Cheng, Junbo Gong, Jingkang Wang
Chinese Journal of Chemical Engineering    2022, 41 (1): 73-84.   DOI: 10.1016/j.cjche.2021.09.007
Abstract49)      PDF(pc) (3577KB)(155)       Save
With the development of digital products, electric vehicles and energy storage technology, electronic chemicals play an increasingly prominent role in the field of new energy such as lithium-ion batteries. Electronic chemicals have attracted extensive attention in various fields. Characteristics of high-end electronic chemicals are high purity and low impurity content, which requires a very strict separation and purification process. At present, crystallization is a key technology for their separation and purification of electronic chemicals. In this work, the representative fluorine-containing compounds in cathode and anode materials, separator and electrolyte of lithium-ion batteries are introduced. The latest technologies for the preparation and purification of four kinds of fluorine-containing battery chemicals by crystallization technology are reviewed. In addition, the research prospects and suggestions are put forward for the separation of fluorine-containing battery chemicals.
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Theoretical insights on the hydration of quinones as catholytes in aqueous redox flow batteries
Jipeng Li, Huan Xu, Jingqi Wang, Yujun Wang, Diannan Lu, Jichang Liu, Jianzhong Wu
Chinese Journal of Chemical Engineering    2021, 37 (9): 72-78.   DOI: 10.1016/j.cjche.2021.06.016
Abstract48)      PDF(pc) (2544KB)(230)       Save
Quinones have been widely studied as a potential catholyte in water-based redox flow batteries (RFBs) due to their ability to carry both electrons and protons in aqueous solutions. The wide variety of quinones and derivatives offers exciting opportunities to optimize the device performance while poses theoretical challenges to quantify their electrochemical behavior as required for molecular design. Computational screening of target quinones with high performance is far from satisfactory. While solvation of quinones affects their potential application in RFBs in terms of both electrochemical windows, stability, and charge transport, experimental data for the solvation structure and solvation free energies are rarely available if not incomplete. Besides, conventional thermodynamic models are mostly unreliable to estimate the properties of direct interest for electrochemical applications. Here, we analyze the hydration free energies of more than 1,400 quinones by combining the first-principles calculations and the classical density functional theory. In order to attain chemical insights and possible trends, special attention is placed on the effects of "backbones" and functional groups on the solvation behavior. The theoretical results provide a thermodynamic basis for the design, synthesis, and screening of high-performance catholytes for electrical energy storage.
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Thermodynamic modeling and phase diagram prediction of salt lake brine systems II. Aqueous Li+-Na+-K+-SO42- and its subsystems
Huan Zhou, Peng Wu, Wenxuan Li, Xingfan Wang, Kuo Zhou, Qing Hao
Chinese Journal of Chemical Engineering    2021, 34 (6): 134-149.   DOI: 10.1016/j.cjche.2020.11.040
Abstract46)      PDF(pc) (2146KB)(66)       Save
It is still a challenging task to accurately and temperature-continuously express the thermodynamic properties and phase equilibrium behaviors of the salt-lake brine with multi-component, multi-temperature and high concentration. The essential subsystem of sulfate type brine, aqueous Li+-Na+-K+-SO42- and its subsystems across a temperature range from 250 K to 643 K are investigated with the improved comprehensive thermodynamic model. Liquid parameters (ΔgIJ, ΔhIJ, and ΔCp,IJ) associated with the contributions of Gibbs energy, enthalpy, and heat capacity to the binary interaction parameters, i.e. the temperature coefficients of eNRTL parameters formulated with a Gibbs Helmholtz expression, are determined via multi-objective optimization method. The solid constants ΔfGk°(298.15) and ΔfHk°(298.15) of 11 solid species occurred in the quaternary system are rebuilt from multi-temperature solubilities. The modeling results show the accurate representation of (1) solution properties and binary phase diagram at temperature ranges from eutectic points to 643 K; (2) isothermal phase diagrams for Li2SO4-Na2SO4-H2O, Li2SO4-K2SO4-H2O and Na2SO4-K2SO4-H2O ternary systems. The predicted results of complete structure and polythermal phase diagram of ternary systems and the isothermal phase diagrams of quaternary system excellently match with the experimental data.
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Eco friendly adsorbents for removal of phenol from aqueous solution employing nanoparticle zero-valent iron synthesized from modified green tea bio-waste and supported on silty clay
Shaimaa T. Kadhum, Ghayda Yassen Alkindi, Talib M. Albayati
Chinese Journal of Chemical Engineering    2021, 36 (8): 19-28.   DOI: 10.1016/j.cjche.2020.07.031
Abstract44)      PDF(pc) (3705KB)(147)       Save
The present research investigated a novel route for the synthesis of nanoparticle zero-valent iron (NZVI) utilizing an aqueous extract of green tea waste as a reductant with ferric chloride. Also, the supported nanoparticle zero-valent iron was synthesized using natural silty clay as a support material (SC-NZVI). The NZVI and SC-NZVI were characterized by infrared spectroscopy (FTIR), scanning electron microscope (SEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), and zeta potential (ζ). The interpretation of the results demonstrated that the polyphenol and other antioxidants in green tea waste can be used as reduction and capping agents in NZVI synthesis, with silty clay an adequate support. Additionally, the experiments were carried out to explore phenol adsorption by NZVI and SC-NZVI. To determine the optimum conditions, the impact of diverse experimental factors (i.e., initial pH, adsorbent dose, temperature, and concentration of phenol) was studied. Langmuir, Freundlich, and Tempkin isotherms were used as representatives of adsorption equilibrium. The obtained results indicated that the adsorption processes for both NZVI and SC-NZVI well fitted by the Freundlich isotherm model. The appropriateness of pseudo_first_order and pseudo_second_order kinetics was investigated. The experimental kinetics data were good explained by the second-order model. The thermodynamic parameters (ΔH0, ΔS0, and ΔG0) for NZVI and SC-NZVI were determined. The maximum removal rates of phenol at optimum conditions, when adsorbed onto NZVI and SC-NZVI, were found to be 94.8% and 90.1%, respectively.
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The development road of ammonium phosphate fertilizer in China
Dehua Xu, Benhe Zhong, Xinlong Wang, Xue Li, Yanjun Zhong, Zhengjuan Yan, Jingxu Yang, Xiaobin Li, Yumei Wang, Xiaohou Zhou
Chinese Journal of Chemical Engineering    2022, 41 (1): 170-175.   DOI: 10.1016/j.cjche.2021.08.015
Abstract43)      PDF(pc) (1058KB)(26)       Save
Ammonium phosphate fertilizer is the compounds containing nitrogen and phosphorus that are usually produced through the neutralization reaction of phosphoric acid and ammonia. At present, there are a variety of products, such as slurry monoammonium phosphate (MAP), diammonium phosphate (DAP), industrial grade MAP, water soluble MAP, water soluble ammonium polyphosphate (APP) and so on. After more than 60 years of development, China’s ammonium phosphate fertilizer industry has experienced the road of from scratch and from weak to strong. The successful development of the slurry MAP technology ended the history that the high concentration phosphate fertilizer cannot be produced by using the medium and low grade phosphate ore. The continuous, stable and large-scale production of DAP plant provides sufficient guarantee for DAP products in China. The development of new ammonium phosphate fertilizer products, such as industrial grade MAP, water soluble MAP, water soluble APP, provides technical support for the transformation and upgrading of phosphorus chemical enterprises. In this paper, the production methods, the development history and the latest research progress of ammonium phosphate fertilizers were reviewed.
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