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Modeling of propane dehydrogenation combined with chemical looping combustion of hydrogen in a fixed bed reactor

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Chinese Journal of Chemical Engineering 2022年第7期35卷 165-173页

作者： Junru Liu Rui Hu Xinlei Liu Qunfeng Zhang guanghua ye Zhijun Sui Xinggui Zhou State Key Laboratory of Chemical Engineering School of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237China

A redox process combining propane dehydrogenation(PDH)with selective hydrogen combustion(SHC)is proposed,modeled,simulated,and optimized.In this process,PDH and SHC catalysts are physically mixed in a fixed-bed reactor,so that the two reactions proceed simultaneously.The redox process can be up to 177.0%higher in propylene yield than the conventional process where only PDH catalysts are packed in the reactor.The reason is twofold:firstly,SHC reaction consumes hydrogen and then shifts PDH reaction equilibrium towards propylene;secondly,SHC reaction provides much heat to drive the highly endothermic PDH reaction.Considering propylene yield,operating time,and other factors,the preferable operating conditions for the redox process are a feed temperature of 973 K,a feed pressure of 0.1 MPa,and a mole ratio of H_(2) to C_(3)H_(8) of 0.15,and the optimal mass fraction of PDH catalyst is 0.5.This work should provide some useful guidance for the development of redox processes for propane dehydrogenation.

关键词： Propane dehydrogenation Selective hydrogen combustion Simulation Optimization Redox process

Understanding the effects of electrode meso-macropore structure and solvent polarity on electric double layer capacitors based on a continuum model

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Chinese Journal of Chemical Engineering 2022年第10期50卷 423-434页

作者： Haotian Lu Jinghong Zhou Yueqiang Cao Tongxin Shang guanghua ye Quan-Hong Yang Xinggui Zhou State-Key Laboratory of Chemical Engineering East China University of Science of TechnologyShanghai 200237China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityBinhai New CityFuzhou 350207China Nanoyang Group State Key Laboratory of Chemical EngineeringSchool of Chemical Engineering and TechnologyTianjin UniversityTianjin 300350China

The structures of electrode meso-macropore and the solvent polarity are the crucial factors dominating the performance of the electric double layer capacitors(EDLCs),but their impacts are usually tangled and difficult to decouple and quantitate.Here the effects of electrode meso-macropore structure and solvent polarity on the specific capacitance of an EDLC are quantitatively investigated using a steady-state continuum model.The simulation results indicate the specific capacitances are significantly affected by the meso-macropore surface structure.The specific capacitances significantly decrease for both convex surface structures but obviously increase for both concave surface structures,with the increase of curvature radius from 1 to 20 nm.As for solvents,the polar solvent with high saturated dielectric permittivity improves the capacitance performance.Moreover,the electrode meso-macropore structure is of more concern compared with solvent polarity when aiming at enhancing the specific capacitance.These results provide fundamentals for the rational design of porous electrodes and polar electrolytes for EDLCs.

关键词： Electric doublelayercapacitors Numerical simulation Meso-macropore Electrolytes Saturated dielectricpermittivity

Effects of particle shape and packing style on ethylene oxidation reaction using particle-resolved CFD simulation

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Particuology 2023年第11期82卷 87-97页

作者： Yao Shi Hao Chen Wenyao Chen guanghua ye Jin Qu Jinbing Li Xinggui Zhou Xuezhi Duan State Key Laboratory of Chemical Engineering School of Chemical EngineeringEast China University of Science and TechnologyShanghai200237China Yanshan Branch of Beijing Research Institute of Chemical Industry China Petroleum&Chemical Company(Sinopec Corp.)Beijing102500China

Gaining in-depth insights into the effects of particle shapes and packing style on ethylene oxidation reaction is of paramount industrial importance.In this work,reactor models of five packing structures with different particle shapes and three packing structures with different packing styles are established by employing software Blender and COMSOL Multiphysics to explore how the reaction-diffusion behaviors affect ethylene oxidation process.The reliabilities of rigid body dynamics model and particle-resolved reactor model are verified by comparing simulated and experimental pressure drops and ethylene conversions.In all the five packing structures with laminar flow conditions,the high bed porosity and low total particle surface area for the trilobe packing structure give rise to the lowest pressure drop of 27.8 Pa/m,while the internal voids cutting mode provides the excellent heat transfer capacity for the Raschig ring packing structure and the highest ethylene conversion and thereby the highest bed temperature rise of 25.1 K for the four-hole cylinder packing structure.Based on these analyses,changing the packing style to the bottom-up Raschig ring-four hole cylinder packing structure would be a good strategy for the effectively lowered reactor temperature rise by 4.8 K together with the slightly reduced ethylene conversion.

关键词： Ethylene oxidation Particle shape Packing style Heat transfer

Optimization of catalyst pellet structures and operation conditions for CO methanation

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Chinese Journal of Chemical Engineering 2021年第12期34卷 106-113页

作者： Yiquan Zhao Yao Shi guanghua ye Jing Zhang Xuezhi Duan Gang Qian Xinggui Zhou State Key Laboratory of Chemical Engineering School of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237China

A fundamental understanding of the effects of catalyst pellet structures and operation conditions on catalytic performance is crucial for the reactions limited by diffusion mass transfer. In this work, a numerical investigation has been carried out to understand the effect of catalyst pellet shapes(sphere, cylinder, trilobe and tetralobe) on the reaction-diffusion behaviors of CO methanation. The results reveal that the poly-lobe pellets with larger external specific surface area have shorter diffusion path, and thus result in higher effectiveness factors and CO conversion rates in comparison with the spherical and cylindrical pellets. The effects of operating conditions and pore structures on the trilobular catalyst pellet with high performance are further probed. Though lower temperature can contribute to larger effectiveness factors of pellets, it also brings about lower reaction rates, and pressure has little impact on the effectiveness factors of the pellets. The increase in porosity can reduce the pellet internal diffusion limitations effectively and there exists an optimal porosity for the methanation reaction. Finally, the height of the trilobular pellet is optimized under the given geometric volume, and the results demonstrate that the higher the trilobular catalyst, the better the reaction performance within the allowable mechanical strength range.

关键词： CO methanation Numerical simulation Catalyst pellet Shape effects Reaction-diffusion behavior

Explosion limits estimation and process optimization of direct propylene epoxidation with H2 and O2

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Chinese Journal of Chemical Engineering 2019年第12期27卷 2968-2978页

作者： Mengke Lu Yanqiang Tang Wenyao Chen guanghua ye Gang Qian Xuezhi Duan Weikang Yuan Xinggui Zhou State Key Laboratory of Chemical Engineering East China University of Science and TechnologyShanghai 200237China

Direct propylene epoxidation with H2 and O2,an attractive process to produce propylene oxide(PO),has a potential explosion danger due to the coexistence of flammable gases(i.e.,C3 H6 and H2)and oxidizer(i.e.,O2).The unknown explosion limits of the multi-component feed gas mixture make it difficult to optimize the reaction process under safe operation conditions.In this work,a distribution method is proposed and verified to be effective by comparing estimated and experimental explosion limits of more than 200 kinds of flammable gas mixture.Then,it is employed to estimate the explosion limits of the feed gas mixture,some results of which are also validated by the classic Le Chatelier’s Rule and flammable resistance method.Based on the estimated explosion limits,process optimization is carried out using commercially high and inherently safe reactant concentrations to enhance reaction performance.The promising results are directly obtained through the interface called gOPT in gPROMS only by using a simple,easy-constructed and mature packed-bed reactor,such as the PO yield of 13.3%,PO selectivity of 85.1%and outlet PO fraction of 1.8%.These results can be rationalized by indepth analyses and discussion about the effects of the decision variables on the operation safety and reaction performance.The insights revealed here could shed new light on the process development of the PO production based on the estimation of the explosion limits of the multi-component feed gas mixture containing flammable gase s,inert gas and O2,followed by process optimization.

关键词： Direct propylene epoxidation with H2/O2 Propylene oxide Safe operation Explosion limits estimation Process optimization

新型欧姆加热式反应器强化甲烷蒸汽重整的过程分析和优化

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低碳化学与化工 2024年第1期49卷 76-84页

作者：高贤清宋楠叶光华周兴贵华东理工大学化工学院化学工程联合国家重点实验室上海200237

传统甲烷蒸汽重整(SMR)反应器(cSMR反应器)中容易出现较大的径向温度梯度,增加了催化剂积炭失活的风险。提出了一种新型的含内外管欧姆加热蒸汽重整固定床反应器(eSMR反应器),以欧姆加热替代了传统工业反应器的燃烧供热方式。通过二维... 详细信息

传统甲烷蒸汽重整(SMR)反应器(cSMR反应器)中容易出现较大的径向温度梯度,增加了催化剂积炭失活的风险。提出了一种新型的含内外管欧姆加热蒸汽重整固定床反应器(eSMR反应器),以欧姆加热替代了传统工业反应器的燃烧供热方式。通过二维拟均相固定床反应器模拟,比较了eSMR与cSMR反应器的性能差异,分析了eSMR反应器结构及操作条件对其性能的影响。结果表明,相比于cSMR,eSMR反应器出口的平均甲烷转化率和平均温度分别高出26.6%和121 K,且径向温度分布更加均匀;eSMR反应器的内外管直径之比为0.589时,其径向温度梯度最小;增加入口温度、加热电压和水碳比均会提高eSMR反应器出口的平均甲烷转化率和平均温度,增加入口压力的影响相反。本研究可为欧姆加热蒸汽重整反应器的开发提供一定的借鉴。

关键词：欧姆加热甲烷蒸汽重整固定床反应器数学模型优化设计

Soft-HGRNs:soft hierarchical graph recurrent networks for multi-agent partially observable environments

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Frontiers of Information Technology & Electronic Engineering 2023年第1期24卷 117-130页

作者： Yixiang REN Zhenhui ye Yining CHEN Xiaohong JIANG guanghua SONG School of Aeronautics and Astronautics Zhejiang UniversityHangzhou 310027China College of Computer Science and Technology Zhejiang UniversityHangzhou 310027China

The recent progress in multi-agent deep reinforcement learning(MADRL)makes it more practical in real-world tasks,but its relatively poor scalability and the partially observable constraint raise more challenges for its performance and deployment.Based on our intuitive observation that human society could be regarded as a large-scale partially observable environment,where everyone has the functions of communicating with neighbors and remembering his/her own experience,we propose a novel network structure called the hierarchical graph recurrent network(HGRN)for multi-agent cooperation under partial observability.Specifically,we construct the multiagent system as a graph,use a novel graph convolution structure to achieve communication between heterogeneous neighboring agents,and adopt a recurrent unit to enable agents to record historical information.To encourage exploration and improve robustness,we design a maximum-entropy learning method that can learn stochastic policies of a configurable target action entropy.Based on the above technologies,we propose a value-based MADRL algorithm called Soft-HGRN and its actor-critic variant called SAC-HGRN.Experimental results based on three homogeneous tasks and one heterogeneous environment not only show that our approach achieves clear improvements compared with four MADRL baselines,but also demonstrate the interpretability,scalability,and transferability of the proposed model.

关键词： Deep reinforcement learning Graph-based communication Maximum-entropy learning Partial observability Heterogeneous settings

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中医院急诊科医疗安全现状的分析及改革建议

中国中西医结合急救杂志 2024年第1期31卷 82-85页

作者：曾瑞峰赖芳叶烨奚小土唐光华刘诗怡丁邦晗李俊广州中医药大学第二附属医院急诊科广东省中医院急诊科广东省中医急症研究重点实验室广东广州510120 广州中医药大学第一附属医院急诊科广东广州510405

急诊科作为医院的窗口单位,其医疗质量决定了整个医院的医疗质量,急诊医疗安全是医院建设的关键。但由于中医院急诊科人员配置及医疗技术等问题,医疗质量发展极不平衡。针对我国中医院急诊科的医疗安全问题,广州中医药大学第二附属医院... 详细信息

急诊科作为医院的窗口单位,其医疗质量决定了整个医院的医疗质量,急诊医疗安全是医院建设的关键。但由于中医院急诊科人员配置及医疗技术等问题,医疗质量发展极不平衡。针对我国中医院急诊科的医疗安全问题,广州中医药大学第二附属医院急诊科团队人员通过部析国内外现状、分析医疗差错原因,提出中医院急诊科医疗安全改革建议,希望通过硬件改造升级、规范标准流程、构建健全的沟通机制、营造安全文化氛围等一系列改革措施,能有效减少医疗差错的发生。

关键词：中医院急诊科医疗安全医疗差错高效团队安全文化

颈椎后纵韧带骨化症肥胖相关基因的筛选及鉴定

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中华骨与关节外科杂志 2024年第1期17卷 21-30页

作者：蒋安龙费希状董放王玉玞闫景龙陈光华姬烨哈尔滨医科大学附属第二医院脊柱外科哈尔滨150086

目的:探索颈椎后纵韧带骨化症(OPLL)肥胖相关基因及其功能特征。方法:从高通量基因表达(GEO)数据库中下载颈椎OPLL相关的转录组数据集GSE69787,与Gene数据库中肥胖相关基因进行筛选,获得颈椎OPLL肥胖相关差异表达基因(DEGs)。使用DAVID... 详细信息

目的:探索颈椎后纵韧带骨化症(OPLL)肥胖相关基因及其功能特征。方法:从高通量基因表达(GEO)数据库中下载颈椎OPLL相关的转录组数据集GSE69787,与Gene数据库中肥胖相关基因进行筛选,获得颈椎OPLL肥胖相关差异表达基因(DEGs)。使用DAVID软件和R软件对肥胖相关DEGs进行基因本体(GO)和京都基因与基因组百科全书(KEGG)富集分析,应用Cytoscape软件将数据可视化,并通过cytoHubba工具包计算得到中心基因。采用实时定量PCR(qRT-PCR)检测中心基因在颈椎后纵韧带组织中的表达水平。结果:通过GSE69787数据集与肥胖相关基因筛选得到24个颈椎OPLL肥胖相关DEGs,构建并计算这24个肥胖相关DEGs的蛋白质相互作用网络,最终筛选出10个中心基因。GO/KEGG富集分析结果显示这10个肥胖相关DEGs主要富集于蛋白激酶B信号通路及其调控、骨化、炎症反应调控、骨矿化及PI3K-Akt信号通路、MAPK信号通路等生物学过程和生物信号通路。最后通过qRT-PCR验证发现LEP、IGF2、IL18、BMP2和LOX在颈椎OPLL组韧带组织中高表达(P均<0.05),MMP9、PTGS2在颈椎OPLL组韧带组织中低表达。结论:LEP、IGF2、IL18、BMP2、LOX、MMP9、PTGS2是颈椎OPLL患者与肥胖相关的基因,其异常表达可能与颈椎OPLL的发生、发展相关,并可能为合并肥胖的颈椎OPLL患者的诊断和治疗提供新的思路。

关键词：颈椎后纵韧带骨化症肥胖基因