Processes
·
2022
·Vol. 10
·期 5
·823
·
IF 3.352
Bin Li,Xinjun Jing,Junsheng Yuan
The phase equilibria of the reciprocal quaternary system LiBr-Li2SO4-KBr-K2SO4-H2O and its ternary sub-systems LiBr-Li2SO4-H2O and KBr-K2SO4-H2O at 308.15 K were studied using the isothermal dissolution equilibrium method. Then, the solubility data of the equilibrium solutions were collected, and the phase diagrams were plotted. The phase diagrams of the ternary sub-systems at 308.15 K were compared with those at other temperatures. This study found that the phase diagram of the LiBr-Li2SO4-H2O system at 308.15 K consisted of an invariant point, two solid-phase crystallization regions of Li2SO4·H2O and LiBr·2H2O, and their corresponding solubility curves. The system generated two hydrated salts, which belonged to the hydrate type I phase diagram. The phase diagram of the KBr-K2SO4-H2O system at 308.15 K consisted of an invariant point, two univariant solubility curves, and two solid-phase crystallization regions of KBr and K2SO4, and no solid solution and double salts were formed. Thus, it belonged to a simple co-saturation type phase diagram. In the LiBr-Li2SO4-KBr-K2SO4-H2O system, K2SO4·Li2SO4double salt formed at 308.15 K, and the phase diagram consisted of three invariant points, five crystallization regions, and seven univariant solubility curves.Keywords:lithium bromide;potassium bromide;lithium sulfate;potassium sulfate;phase equilibrium
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2021
·
IF 2.694
Fei Yuan,Hua Li,Long Li,Yafei Guo,Shiqiang Wang,Tianlong Deng
Considering the significance of fundamental phase equilibrium data in resource exploitation from salt lake brines, the solid–liquid phase equilibria of the ternary system (KBO2 + K2SO4 + H2O) at 288.15, 308.15 K, and 0.1 MPa were investigated using the isothermal dissolution method. Along this line, the solubilities and physicochemical properties of densities were experimentally determined. Based on the experimental data, phase diagrams and the related physicochemical property diagrams against composition were plotted. It was found that there are one invariant point, two univariate solubility curves, and two crystalline regions corresponding to potassium metaborate hydrate (KBO2·1.33H2O) and arcanite (K2SO4) in the ternary phase diagrams at 288.15 and 308.15 K. In addition, they belong to the hydrate type I and neither double salt nor solid solution was formed. The distributive behaviors of density against the concentration of KBO2 in the equilibrium solution at two temperatures were similar. Moreover, the theoretical values of density were calculated, which were found to be consistent with the experimental values, further demonstrating the accuracy and reliability of this work.
研究领域:
化学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED POWDER TECHNOLOGY
·
2025
·
IF 4.2
Jingjing Zou,Yiping Sun,Shuo Liang,Zhongrui Shi,Guanghe Li,Chunbin Guo
This study introduces a novel process for recovering Al 2 O 3 from coal fly ash (CFA), utilizing potassium persulfate (K 2 S 2 O 8 ) as an activator, and explores the decomposition behavior of both crystalline and amorphous alumina phases within CFA. The experiment involved mixing K 2 S 2 O 8 with CFA in K 2 S 2 O 8 /Al 2 O 3 molar ratios ranging from 0.5:1 to 4:1, followed by calcination at varying temperatures and durations to optimize alumina extraction. The results indicated that the alumina extraction efficiency of 91 % was achieved with a molar ratio of 3:1 (K 2 S 2 O 8 /Al 2 O 3 ), calcination temperature of 405 °C, and reaction time of 2 h. X-ray photoelectron spectroscopy, scanning electron microscopy, and reaction kinetics were employed to analyze the reaction mechanism. The findings revealed that K 2 S 2 O 8 preferentially reacted with the amorphous alumina phase, leading to the breakage of Al–O–Si bonds. The release of SO 2 and O 2 during the reaction further facilitated the breakdown of the crystalline phase by disrupting aluminum–oxygen tetrahedra. Simultaneously, the silicon-oxygen tetrahedra decomposes and forms SiO 2 gel layer, wrapping the remaining aluminum oxygen octahedron, thus preventing further alumina extraction. This study contributes to a deeper understanding of the decomposition behavior of crystalline and amorphous alumina phases in CFA during sulfate roasting. The findings provide a theoretical foundation for refining alumina recovery processes and offer significant improvements to existing sulfate roasting methods.
研究领域:
材料科学
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环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2021
·
IF 6.158
Boqian Li,Shu Li,Ludong Yi,Haosheng Sun,Jun Qin,Jun Wang,Dawei Fang
Diazinon (DZN), a broad-spectrum and highly effective organophosphorus pesticide, is widely being used in agricultural production and household environments. However, massive DZN effluent can be generated during the DZN production process, which will cause devastating effects on the ecosystem and damage human health due to the improper dispose of pesticide effluent before discharging. In this work, hydrodynamic cavitation (HC), a new advanced oxidation technology, was used to degrade DZN in wastewater for the first time. The influences of DZN initial concentration (5.0–15 mg/L), solution pH (4.0–10), temperature (30–50 °C) and some orifice plate geometric parameters (orifice numbers and orifice half angles) on the degradation effect of DZN were investigated. It can be observed that the DZN in solution can be effectively degraded in orifice plate HC system based on three orifices with 45° convergent half angle and the degradation ratio can reach 50.52 % under the operation conditions of 150 min treatment time, 30 °C temperature and pH = 4.0 acidity. Subsequently, the studies of intensifying DZN degradation were also carried out through adding different inorganic oxidants such as potassium peroxodisulfate (K 2 S 2 O 8 ), potassium periodate (KIO 4 ) and sodium perchlorate (NaClO 4 ). The maximum DZN HC degradation extent (81.92 %) can be achieved in the presence of K 2 S 2 O 8 under the optimized conditions. The generated intermediate products in DZN HC degradation process are some low-toxic and low-active substances. And that, these intermediate products can be further mineralized to H 2 O, CO 2 and inorganic ions. On the basis of cavitational yield, the energy consumption analysis has been performed. Overall, this work demonstrates that the HC combined with oxidant K 2 S 2 O 8 may be a promising strategy for the large-scale treatment of organophosphorus pesticide wastewater.
研究领域:
环境科学
·
农药化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Tong Liu,Zhican Xie,Peng Zhou,Zhaokun Xiong,Heng Zhang,Zhicheng Pan,Yang Liu,Bo Lai
Transition metal activation of sulfite (S(IV)) is a promising wastewater treatment technology . In this study, the activation of potassium pyrosulfite (PPS) with ferric iron (Fe 3+ ) is proposed firstly to degrade carbamazepine (CBZ). PPS has the advantages of low cost, non-toxicity and acidic solution, which makes it unnecessary to adjust the pH. The results showed that the Fe 3+ cycle was realized during the reaction process, and the degradation trend of CBZ was consistent with the formation rate of Fe 2+ and the decay rate of S(IV). Moreover, oxygen (O 2 ) plays a decisive role in the system and was the initiator of free radical chain reactions. The existence of sulfite radical (SO 3 •− ), sulfate radical (SO 4 •− ) and hydroxyl radicals (HO • ) in Fe 3+ /PPS system was proved by electron paramagnetic resonance (EPR), quenching experiments and terephthalic acid (TA) photoluminescence probing technique. The contribution of SO 4 •− and OH • to the removal of CBZ in Fe 3+ /PPS system is 64% and 35%, respectively. In addition, intermediates of CBZ were identified by Liquid Chromatography–Tandem Mass Spectrometry (LC–MS/MS) and possible removal pathways were also proposed. Finally, the effects of PPS concentration, Fe 3+ concentration, initial pH, anions and humic acid (HA) were also investigated.
研究领域:
环境科学
·
废水处理技术
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产品关联
DOI
高影响因子
MOLECULES
·
2023
·Vol. 29
·期 1
·141
·
IF 4.6
Yayuan Zheng
This paper explores the kinetics of the crystallization of potassium sulfate in a stirred bed crystallizer through experimental investigation. Employing classical nucleation theory, the homogeneous and heterogeneous nucleation mechanisms of potassium sulfate were investigated. The induction time and critical nucleation parameters, including the surface tension (γ), critical nucleation radius (r*), critical nucleation free energy (ΔG*), and critical nucleation molecule number (i*), were meticulously determined under varying temperatures and supersaturation ratios. The experimental findings revealed that as the temperature and supersaturation ratio increased, the induction time, critical nucleation free energy, critical nucleation radius, and critical molecule number decreased whereas the nucleation rate increased. The crystalline shape remains relatively unaltered with respect to temperature and supersaturation ratio, yet the particle size (D10, D50, D90) increases as the supersaturation and temperature increase. The variations in the measured nucleation parameters align well with the predictions of classical nucleation theory. Furthermore, the kinetic equations of crystal nucleation and the growth rate in a stirred crystallization system were fitted using population balance equations. The results demonstrate that the growth rate increases with increasing supersaturation and stirring rates. Additionally, the effects of the parameters in the nucleation rate equation suggested that the suspension density exerted the greatest influence, followed by the supersaturation ratio and stirring rate. This extensive research provides invaluable theoretical guidance for optimizing the crystallization process and designing industrial crystallizers.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
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2022
·
IF 4.644
Nengyuan Zeng,Yuling Liu,Yuanshen Cheng,Chong Luo,Hongdong Zhao
The efficient copper removal of the in the multi-layer copper interconnect copper film chemical mechanical planarization (CMP) process is one of the important indicators for high production efficiency of integrated circuit process. The chemical corrosiveness of polishing slurries to copper is the key factor affecting the copper removal rate. Since the copper polishing slurries are relied too much on the synergistic effect of complexing agent and oxidant for the copper chemical dissolution to achieve efficient removal of copper film, the planarization and corrosion of copper CMP cannot be well improved. In this paper, it was found that adding potassium sulfate (K 2 SO 4 ) in polishing slurries can improve the copper removal effect of CMP. In this paper, the mechanism of the effect enhancement of K 2 SO 4 was explored with series of characterization experiments. Firstly, the influence of K 2 SO 4 on the increase of electrochemical corrosion degree of copper electrode was studied by electrochemical method. Secondly, based on X-ray photoelectron spectroscopy (XPS) and laser scanning confocal microscope (LSCM), it was determined that the copper surface oxide formation increased after electrochemical corrosion caused by K 2 SO 4 . Finally, the efficiency of copper polishing removal of K 2 SO 4 in polishing slurries was verified by CMP experiments, and the dynamic oxidation enhancement mechanism of K 2 SO 4 in polishing slurries for CMP copper removal was analyzed.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Yu Xie,Wangyang Wang,Jiale Cui,Hui Li,Kang Cheng,Qinghong Zhang,Ye Wang
The oxidative coupling of methane (OCM) into C 2−3 hydrocarbons is still limited to a few types of catalysts with low product yield. Herein, we reported our discovery that a K 2 SO 4 -promoted TiO 2 catalyst can effectively catalyze the OCM reactions with a C 2−3 yield of up to 26 %, which is comparable to the classical Mn-NaWO x /SiO 2 catalyst. Besides, this catalyst not only exhibits promising stability for at least 200 h without signs of deactivation under typical OCM conditions but also demonstrates high sulfur-resistance performance, outperforming most reported catalysts. We have evidenced that K + ions are responsible for increasing the surface basicity of rutile TiO 2 , thus benefiting C 2−3 selectivity. The presence of SO 4 2− can prevent the formation of potassium titanates, which catalyze the over-oxidation of CH 4 . The surface lattice oxygen species are confirmed to be the active sites for selective CH 4 activation, while the chemisorbed oxygen species catalyze the combustion of CH 4 to CO 2 .
研究领域:
化学工程
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Yangchen Zhu,Fei Wang,Beihai Zhou,Huilun Chen,Rongfang Yuan,Yiyue Zhang,HuanHuan Geng,Yuxin Liu,Hao Wang
Sulfadiazine (SDZ) entering the environment has an adverse impact on animal, plant, and human health, it is important to find effective ways to remove SDZ from the aquatic environment. This work comprehensively explored the degradation of SDZ by MoS 2 in photocatalysis and Fe 2+ activation of potassium peroxodisulfate (PDS) from both theoretical and experimental aspects. The PDS/Fe 2+ /MoS 2 system had a faster PDS conversion rate and a higher degradation efficiency for SDZ compared with PDS/Fe 2+ and PDS/MoS 2 . The degradation rate of the PDS/Fe 2+ /MoS 2 system to SDZ reached 97.1% within 60 mins. The degradation rate is higher under acidic conditions compared with alkaline conditions. Free radical capture experiments and EPR tests showed that the degradation of SDZ was the result of a variety of free radicals, among which the SO 4 · − , 1 O 2 and h + played a major role. The chemical morphology and composition of MoS 2 , as well as the changes in the concentration of Fe ions in different valence states were explored and the changes in the O-O and, S-O bond lengths, and differential charge density of PDS in the MoS 2 and, Fe 2+ /MoS 2 systems were calculated by DFT. The results showed that both MoS 2 and Fe 2+ significantly increased the conversion rate of PDS. The activation of PDS on the Fe-modified MoS 2 surface had stronger active sites. MoS 2 can promote the cycle of Fe 3+ /Fe 2+ and the conversion of PDS. According to the intermediate products measured by LC-MS/MS, as well as the frontier molecular orbitals and Fukui function diagrams of SDZ and SDZ* calculated by quantum chemistry, four degradation paths of SDZ were speculated and confirmed the existence of the self-sensitized photodegradation process of SDZ in the system.
研究领域:
环境科学
·
化学工程
·
理论化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Chemistry
·
2018
·
IF 1.726
Yinke Zhang,Hang Xu,Mengfan Jia,Zhuang Liu,Deqiang Qu
Response surface methodology (RSM) was selected to optimize a desulfurization process with metal based ionic liquids ([Bmim]Cl/CoCl2) and potassium monopersulfate (PMS) together to remove benzothiophene (BT) from octane (simulating oil). The four experimental conditions of PMS dosage, [Bmim]Cl/CoCl2 dosage, temperature, and reaction time were investigated. The results showed that the quadratic relationship was built up between BT removal and four experimental variables with 0.9898 fitting coefficient. The optimal conditions were 1.6 g (20 wt%) PMS solution, 3.2 g [Bmim]Cl/CoCl2, 46°C, and 23 min, which were obtained based on RSM and experimental results. Under the optimal condition, predicted sulfur removal rate and experimental sulfur removal rate were 96.7% and 95.4%, respectively. The sequence of four experimental conditions on desulfurization followed the order temperature > time > [Bmim]Cl/CoCl2 dosage > PMS solution dosage.
研究领域:
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
THEORETICAL FOUNDATIONS OF CHEMICAL ENGINEERING
·
2023
·Vol. 57
·期 3
·391-402
·
IF 0.8
Zheng Dan
Abstract This work presents a novel approach for the growth of potassium sulfate (K 2 SO 4 ) from supersaturated solutions by reaction-extractive crystallization in a fluidized-bed crystallizer (FBC), in which K 2 SO 4 is transformed into potassium chloride and sulfuric acid based on a reactive extraction-crystallization process using triisooctylamine (TOA) in n -octanol as the extraction system. This paper uses the moment transformation method to solve the population balance equations of K 2 SO 4 in the extractive crystallization process, and the crystallization kinetic parameters are obtained by nonlinear regression. The kinetic equations of crystal nucleation, growth, and agglomeration rate in the crystallization process of potassium sulfate are determined, and experiments verify the reliability of the kinetic parameters. The results show that in a specific range, higher supersaturation and fluidization rate are conducive to the nucleation, growth, and aggregation of K 2 SO 4 . Suspension density promotes crystal nucleation and growth but has the opposite effect on accumulation. At the same time, based on the constant calculation equation of particle number and the constant calculation equation of mass, the extraction crystallization coupling mathematical model of the crystal in the fluidization state is established. The effects of suspension density, Reynolds number, extraction rate, feeding rate, and extraction concentration on potassium sulfate’s nucleation, growth, and aggregation rate were studied by combining model calculation with experimental research. A process coupling model of the potassium sulfate extraction crystallization process in a fluidized bed was proposed. The model agrees with the experimental results, which have specific guiding significance for industrial production.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2018
·Vol. 45
·期 2
·757-768
·
IF 1.674
Li Qiang,Wang Lifang,Zhang Li,Xie Hongyong
In this study, rapid degradation of Tetrabromobisphenol A (TBBPA) is explored by using photocatalysis of homo/heterogeneous UV/TiO 2 /potassium persulfate (KPS) systems in alkaline solutions. The experimental results show increasing pH values and decreasing the initial concentration of TBBPA could increase the degradation degree, while the loading amount of TiO 2 and dosage of potassium persulfate have optimum values to increase the degradation degree. TBBPA can be almost completely degraded and 70% of TOC removal efficiency is achieved in the UV/TiO 2 /KPS homo/heterogeneous photocatalysis, much more than the UV/KPS system and UV/TiO 2 system. Roles of radicals \(\text{SO}_{\text{4}}^{ \cdot - }\) and OH · in the photocatalysis systems are discussed based on experimental measurements. The significant TOC removal efficiency and increased bromide ion concentration yield show that there exist synergistic effects in the UV/TiO 2 /KPS homo/heterogeneous photocatalysis, which can mineralize TBBPA into inorganic small molecules relatively thoroughly, thus much less intermediates are formed in the UV/TiO 2 /KPS homo/heterogeneous photocatalysis.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）