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Impacts of solid physical properties on the performances of a slurry external airlift loop reactor integrating mixing and separation

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Chinese Journal of Chemical Engineering 2023年第3期55卷 1-12页

作者： Tian Zhang Qingshan Huang shujun geng Aqiang Chen Yan Liu Haidong Zhang School of Chemical Engineering Hebei University of TechnologyTianjin 300130China Key Laboratory of Biofuels Qingdao Institute of Bioenergy and Bioprocess Technology(QIBEBT)Chinese Academy of Sciences(CAS)Qingdao 266101China Dalian National Laboratory for Clean Energy(DNL) Dalian 116023China Innovation Academy for Green Manufacture Institute of Process EngineeringCASBeijing 100190China Synthetic Biology Technology Innovation Center of Shandong Province Qingdao 266101China Shandong Energy Institute Qingdao 266101China

Solid physical properties are vital for the design, optimization, and scale-up of gas–liquid–solid multiphase reactors. The complex and interactional effects of the solid physical properties, including particle diameter, density, wettability, and sphericity, on the hydrodynamic behaviors in a new external airlift loop reactor(EALR) integrating mixing and separation are decoupled in this work. Two semi-empirical equations are proposed and validated to predict the overall gas holdup and liquid circulating velocity satisfactorily, and then the individual influence of such solid physical properties is further investigated. The results demonstrate that both the overall gas holdup in the riser and the liquid circulating velocity in the downcomer increase with the contact angle, but decrease with particle size, density, and sphericity.Additionally, the impact of the particle size on the liquid circulating velocity is also profoundly revealed on a micro-level considering the particle size distribution. Moreover, the axial solid concentration distribution is discussed, and the uniformity of the slurry is described by the mixing index of the solid particles. The results show that a more homogeneous mixture can be achieved by adding finer particles other than attaining violent turbulence. Therefore, this work lays a foundation for the design, scale-up, and industrialization of the EALRs.

关键词： Slurry reactor Hydrodynamics Particle Mixing Solid physical property

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Influences of fluid physical properties,solid particles,and operating conditions on the hydrodynamics in slurry reactors

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Chinese Journal of Chemical Engineering 2022年第4期35卷 51-71页

作者： He Yang Aqiang Chen shujun geng Jingcai Cheng Fei Gao Qingshan Huang Chao Yang Key Laboratory of Biofuels Qingdao Institute of Bioenergy and Bioprocess Technology(QIBEBT)Chinese Academy of Sciences(CAS)Qingdao 266101China Dalian National Laboratory for Clean Energy(DNL) Dalian 116023China Synthetic Biology Technology Innovation Center of Shandong Province Qingdao 266101China Key Laboratory of Green Process and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100080China Petrochemical Research Institute China National Petroleum Corporation(CNPC)Beijing 100083China

Slurry reactors are popular in many industrial processes,involved with numerous chemical and biological mixtures,solid particles with different concentrations and properties,and a wide range of operating conditions.These factors can significantly affect the hydrodynamic in the slurry reactors,having remarkable effects on the design,scale-up,and operation of the slurry reactors.This article reviews the influences of fluid physical properties,solid particles,and operating conditions on the hydrodynamics in slurry reactors.Firstly,the influence of fluid properties,including the density and viscosity of the individual liquid and gas phases and the interfacial tension,has been reviewed.Secondly,the solid particle properties(i.e.,concentration,density,size,wettability,and shape)on the hydrodynamics have been discussed in detail,and some vital but often ignored features,especially the influences of particle wettability and shape,as well as the variation of surface tension because of solid concentration alteration,are highlighted in this work.Thirdly,the variations of physical properties of fluids,hydrodynamics,and bubble behavior resulted from the temperature and pressure variations are also summarized,and the indirect influences of pressure on viscosity and surface tension are addressed systematically.Finally,conclusions and perspectives of these notable influences on the design and scale-up of industrial slurry reactors are presented.

关键词： Multiphase reactors Fluid physical properties Particle Operating conditions Bubble column Airlift loop reactor

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CFD study on double-to single-loop flow pattern transition and its influence on macro mixing efficiency in fully baffled tank stirred by a Rushton turbine

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Chinese Journal of Chemical Engineering 2019年第5期27卷 993-1000页

作者： Quanhong Zhu Hang Xiao Aqiang Chen shujun geng Qingshan Huang Key Laboratory of Biofuels Qingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of SciencesQingdao 266101China Dalian National Laboratory for Clean Energy Dalian 116023China Key Laboratory of Green Process and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China

For a fully baffled tank stirred by a Rushton turbine (RT), the flow pattern will change from double- to single-loop as the off bottom clearance (C) of the RT decreases from one third of the tank diameter. Such a flow pattern transition as well as its influence on the macro mixing efficiency was investigated via CFD simulation. The transient sliding mesh approach coupled with the standard k-s turbulence model could correctly and efficiently reproduce the reported critical C range where the flow pattern changes. Simulation results indicated that such a critical C range varied hardly with the impeller rotation speed but decreased significantly with increasing impeller diameter. Small RTs are preferable to generating the single-loop flow pattern. A mechanism of the flow pattern transition was further proposed to explain these phe no mena. The discharge stream from the RT deviates down wards from the horizontal direction for small C values;if it meets the tank wall first, the double-loop will form;if it hits the tank bottom first, the single-loop will form. With the flow pattern transition, the mixing time decreased by about 35% at the same power input (P), indicating that the single-loop flow pattern was more efficient than the double-loop to enhance the macro mixing in the tank. A comparison was further made between the single-loop RT and pitched blade turbine (PBT, 45°) from macro mixing perspective. The single-loop RT was found to be less efficient than the PBT and usually required 60% more time to achieve the same level of macro mixing at the same P.

关键词： Rushton turbine Flow pattern Transition Simulation Mechanism Mixing

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Process Intensification in Pneumatically Agitated Slurry Reactors

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Engineering 2021年第3期7卷 304-325页

作者： shujun geng Zai-Sha Mao Qingshan Huang Chao Yang Key Llaboratory of Biofues Qingdao Institute of Eioenergy and Bioprocess TednologyChinese ALcadermy of SsciencesQingdao 266101China Dalian Narional Labor atary or dlean Energy Dalian lustitue of chemical PhysitsChinese Academy of SciancesDalian 11623China Key Laboratary of areen Proces and Engireering Iistitue of Poess Eingireeringhinese Academy of SdercesBeijing 100190Ohina

Pneumatically agitated slurry reactors,including bubble column reactors and airlift loop reactors(ALRs),are important gas-liquid-solid multiphase reactors.These reactors have been widely applied in many processes,especially in the biological fermentation and energy chemical industry,due to their low shear stress,good mixing,perfect mass-/heat-transfer properties,and relatively low costs.To further improve the performance of slurry reactors(i.e.,mixing and mass/heat transfer)and to satisfy industrial require-ments(e.g.,temperature control,reduction of back-mixing,and product separation),the process intensi-fication of slurry reactors is essential.This article starts by reviewing the latest advancements in the intensification of mixing and mass/heat transfer in these two types of reactors.It then summarizes process-intensification methods for mixing and separation that allow continuous production in these slurry reactors.Process-intensification technology that integrates directional flow in an ALR with simple solid-liquid separation in a hydrocyclone is recommended for its high efficiency and low costs.This arti-cle also systematically addresses vital considerations and challenges,including flow regime discrimina-tion,gas spargers,solid particle effects,and other concerns in slurry reactors.It introduces the progress of numerical simulation using computational fluid dynamics(CFD)for the rational design of slurry reactors and discusses difficulties in modeling.Finally,it presents conclusions and perspectives on the design of industrial slurry reactors.

关键词： Slurry reactors Pneumatic agitation Bubble column Airlift loop reactor Process intensification Solid particles

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Influences of top clearance and liquid throughput on the performances of an external loop airlift slurry reactor integrated mixing and separation

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Chinese Journal of Chemical Engineering 2020年第6期28卷 1514-1521页

作者： Hongyan Liu Zhuo Li shujun geng Fei Gao Taobo He Qingshan Huang School of Chemical Engineering and Technology Hebei University of TechnologyTianjin 300130China Key Laboratory of Biofuels Qingdao Institute of Bioenergy and Bioprocess Technology(QIBEBT)Chinese Academy of Sciences(CAS)Qingdao 266101China Dalian National Laboratory for Clean Energy(DNL) Dalian 116023China Petrochemical Research Institute China National Petroleum Corporation(CNPC)Beijing 100083China

A new developed external loop airlift slurry reactor, which was integrated with gas–liquid–solid three-phase mixing, mass transfer, and liquid–solid separation simultaneously, was deemed to be a promising slurry reactor due to its prominent advantages such as achieving continuous separation of clear liquid from slurry and cyclic utilization of solid particles without any extra energy, energy-saving, and intrinsic safety design. The principal operating parameters, including gas separator volume, handling capacity, and superficial gas velocity, are systematically investigated here to promote the capabilities of mixing, mass transfer, and yield in the pilot external loop airlift slurry reactor. The influences of top clearance and throughput of the clear liquid on flow regime and gas holdup in the riser, liquid circulating velocity, and volumetric mass transfer coefficient with a typical high solid holdup and free of particles are examined experimentally. It was found that increasing the gas separator volume could promote the liquid circulating velocity by about 14.0% at most. Increasing the handling capacity of the clear liquid from 0.9 m3·h-1 to 3.0 m3·h-1 not only could increase the output without any adverse consequences, but also could enhance the liquid circulating velocity as much as 97.3%. Typical operating conditions investigated here can provide some necessary data and guidelines for this new external loop airlift slurry reactor to upgrade its performances.

关键词： External loop airlift reactor Mixing Separation Hydrocyclone Hydrodynamics Mass transfer

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Two-fluid modeling of Geldart A particles in gas-solid micro-fluidized beds

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Particuology 2015年第4期13卷 118-127页

作者： Xiaoxing Liu Chuanqiang Zhu shujun geng Meiqin Yao Jinhui Zhan Guangwen Xu State Key Laboratory of Multi-phase Complex System Institute of Process Engineering Chinese Academy of Science Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China

The fiuidization behavior of Geldart A particles in a gas-solid micro-fluidized bed was investigated by Eulerian-Eulerian numerical simulation. The commonly used Gidaspow drag model was tested first. The simulation showed that the predicted minimum bubbling velocities were significantly lower than the experimental data even when an extremely fine grid size （of approximately one particle diameter） was used. The modified Gibilaro drag model was therefore tested next. The predicted minimum bubbling velocity and bed voidage were in reasonable agreement with the experimental data available in literature. The experimentally observed regime transition phenomena from bubbling to slugging were also reproduced successfully in the simulations. Parametric studies indicated that the solid-wall boundary conditions had a significant impact on the predicted gas and solid flow behavior.

关键词： Micro-fluidized bed Geldart A particle Two-fluid model Boundary condition Drag model

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Discrete and continuum modeling of granular flow in silo discharge

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Particuology 2018年第1期16卷 127-138页

作者： Tian Tian Jinglin Su Jinhui Zhan shujun geng Guangwen Xu Xiaoxing Liu State Key Laboratory of Multi-Phase Complex System Institute of Process Engineering Chinese Academy of Science Beijing 100190 China University of Chinese Academy ofSdences Beijing 100049 China Sino-Danish Center for Education and Research Beijing 100190 China

Granular material discharge from a flat-bottomed silo has been simulated by using continuum modeling and a three-dimensional discrete-element method （DEM）. The predictive abilities of three commonly used frictional viscosity models （Schaeffer, S-S, and μ（I）） were evaluated by comparing them with the DEM data. The funnel-flow pattern （type C） and the semi-mass-flow pattern （type B） that was predicted by DEM simulations can be represented when the Schaeffer orμ（I） model is used, whereas the S-S model gives a consistent type-B flow pattern. All three models over-estimate the discharge rate compared with the DEM. The profiles of the solids volume fraction and the vertical velocity above the outlet show that the larger discharge rates given by the Schaeffer and μ（I） model result from an over-estimation of volume fraction, whereas the deviation in the S-S model stems from the failure to predict a solid vertical velocity and a volume fraction.

关键词： Silo Flow pattern Discharge rate Discrete-element model Frictional viscosity model

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锂离子电池负极材料ZnSnO_(3)/C复合物的制备与性能

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工程科学学报 2024年第1期46卷 81-88页

作者：岳红伟邢若冰耿壮壮铁伟伟朱聪旭谢文合陈淑君许昌学院化工与材料学院许昌461000 信阳师范学院物理电子工程学院信阳464000

锡基双金属氧化物作为锂离子电池负极材料因具有高的理论比容量、嵌脱锂电位适中、储量丰富、价格低廉、安全性高以及环保等优点,已经受到了广泛的关注.本研究采用一步原位水热法制备了碳包覆的ZnSnO_(3)复合材料(ZnSnO_(3)/C).利用扫... 详细信息

锡基双金属氧化物作为锂离子电池负极材料因具有高的理论比容量、嵌脱锂电位适中、储量丰富、价格低廉、安全性高以及环保等优点,已经受到了广泛的关注.本研究采用一步原位水热法制备了碳包覆的ZnSnO_(3)复合材料(ZnSnO_(3)/C).利用扫描电子显微镜、透射电子显微镜、X射线衍射、拉曼光谱、X射线光电子能谱分析和恒流充放电测试等一系列表征测试方法对材料的微观形貌、物相组成、结构和电化学性能进行分析.电化学测试结果表明:当作为锂离子电池负极材料时,ZnSnO_(3)/C复合电极的储锂性能优于纯ZnSnO_(3)电极.在200 mA·g^(-1)电流密度下,ZnSnO_(3)/C复合电极经200次循环后可逆容量可达1274.9 mA·h·g^(-1),即使在大电流5000 mA·g^(-1)下经500次循环仍然提供663.2 mA·h·g^(-1)的放电比容量,同时也表现出卓越的倍率性能.优异的储量性能归因于ZnSnO_(3)/C复合材料中具有高电导率的C不仅提高了整个电极的导电性,有利于电子的传输,而且增大了电解液与活性材料之间的接触面积,缩短了锂离子的扩散距离;同时碳包覆层可有效缓冲ZnSnO_(3)在嵌脱锂过程中由于体积变化产生的应力,也能在一定程度上抑制ZnSnO_(3)在循环过程中的团聚.

关键词：锡酸锌碳复合材料负极锂离子电池

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升阳除湿防风汤联合化疗治疗晚期胃癌疗效及对患者血清CA72-4、sICAM-1的影响

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陕西中医 2024年第6期45卷 775-779页

作者：慈书俊梁惠吴宁波耿亚迪六安市中医院安徽六安237006

目的:观察升阳除湿防风汤联合化疗治疗晚期胃癌患者的临床疗效及血清糖类抗原72-4(CA72-4)、可溶性细胞间黏附分子-1(sICAM-1)变化。方法:选择86例晚期胃癌患者,根据治疗方法将其分为两组,各43例,化疗组给予常规化疗治疗,观察组在化疗... 详细信息

目的:观察升阳除湿防风汤联合化疗治疗晚期胃癌患者的临床疗效及血清糖类抗原72-4(CA72-4)、可溶性细胞间黏附分子-1(sICAM-1)变化。方法:选择86例晚期胃癌患者,根据治疗方法将其分为两组,各43例,化疗组给予常规化疗治疗,观察组在化疗组基础上给予升阳除湿防风汤治疗,比较两组客观缓解率(ORR)、疾病控制率(DCR)、中医症状积分、血清CA72-4、sICAM-1水平、T淋巴细胞亚群指标(CD3^(+)、CD4^(+)、CD8^(+)、CD4^(+)/CD8^(+))、不良反应总发生率。结果:观察组ORR、DCR均较化疗组更高(P0.05)。结论:升阳除湿防风汤联合化疗可有效提高晚期胃癌客观缓解率、疾病控制率,缓解脘腹胀满等症状,改善免疫功能,纠正免疫失衡,降低血清CA72-4、sICAM-1表达量,且未增加不良反应发生率。

关键词：胃癌升阳除湿防风汤多西他赛顺铂 5-氟尿嘧啶糖类抗原72-4 可溶性细胞间黏附分子-1

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CYFRA21-1、CEA和Ki67在非小细胞肺癌中的表达及预后因素分析

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中国胸心血管外科临床杂志 2024年第5期31卷 682-688页

作者：潘剑云黄贻恩洪淑君方韶韩刘经纬陈伟强潘高涧姜杰耿国军厦门大学附属第一医院胸外科厦门大学医学院福建厦门361003 厦门大学附属第一医院胸外科福建厦门361003 福建医科大学第三临床医学院福州350122

目的探讨术前细胞角蛋白19的可溶性片段(CYFRA21-1)、癌胚抗原(CEA)联合术后细胞核增殖相关抗原Ki67检测对非小细胞肺癌患者预后评估的价值。方法收集2017年于厦门大学附属第一医院胸外科就诊的非小细胞肺癌患者的临床资料。CYFRA21-1>3... 详细信息

目的探讨术前细胞角蛋白19的可溶性片段(CYFRA21-1)、癌胚抗原(CEA)联合术后细胞核增殖相关抗原Ki67检测对非小细胞肺癌患者预后评估的价值。方法收集2017年于厦门大学附属第一医院胸外科就诊的非小细胞肺癌患者的临床资料。CYFRA21-1>3.39 ng/mL或CEA>5 ng/mL定义为阳性。绘制Ki67表达水平的受试者工作特征(ROC)曲线,曲线下面积(AUC)最大时为Ki67表达水平的截断值,Ki67表达水平大于其截断值定义为阳性。利用Cox回归分析确定非小细胞肺癌患者不良预后的独立危险因素。结果纳入患者248例,其中男125例、女123例,手术时中位年龄61(30~81)岁。单因素分析表明,CYFRA21-1阳性、Ki67高表达、CEA阳性、患者手术时年龄≥60岁、有淋巴结转移、肿瘤最大直径>3 cm、TNM分期Ⅲ期与非小细胞肺癌患者不良预后相关(P均<0.05)。联合检测术前肿瘤标志物与术后Ki67时,全阴性时患者预后均最好,全阳性时患者预后均最差。Cox回归多因素分析显示,CEA阳性+CYFRA21-1阳性+Ki67高表达是非小细胞肺癌患者不良预后的独立危险因素(P<0.05)。结论联合检测术前血清CYFRA21-1、CEA与术后Ki67对评估非小细胞肺癌患者预后有重要价值。

关键词：非小细胞肺癌肿瘤标志物 Ki67 预后

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