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Control structure comparison for three-product Petlyuk column

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Chinese Journal of Chemical Engineering 2018年第8期26卷 1621-1630页

作者： Shengkun Jia xing qian Xigang Yuan Sigurd Skogestad School of Chemical Engineering and Technology Chemical Engineering Research Center Collaborative Innovation Center of Chemical Science and Engineering (Tianjin)State Key Laboratory of Chemical Engineering Tianjin University Department of Chemical Engineering Norwegian University of Science and Technology (NTNU)

The focus of this paper is to investigate different control structures(single-loop PI control) for a dividing wall(Petlyuk) column for separating ethanol, n-propanol and n-butanol. Four control structures are studied. All the results are simulations based on Aspen Plus. Control structure 1(CS1) is stabilizing control structure with only temperature controllers. CS2, CS3 and CS4, containing also composition controllers, are introduced to reduce the steady state composition deviations. CS2 adds a distillate composition controller(CCDB) on top of CS1. CS3 is much more complicated with three temperature-composition cascade controllers and in addition a selector to the reboiler duty to control the maximum controller output of light impurity composition control in side stream and bottom impurity control in the prefractionator. CS4 adds another high selector to control the light impurity in the sidestream. Surprisingly, when considering the dynamic and even steady state performance of the proposed control structures, CS1 proves to be the best control structure to handle feed disturbances inserted into the three-product Petlyuk column.

关键词： Distillation columns Automatic process control Computer-aided control system design Petlyuk columns

Separation of methyl linolenate and its analogues by functional mixture of imidazolium based ionic liquid-organic solvent-cuprous salt

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Chinese Journal of Chemical Engineering 2019年第4期27卷 811-817页

作者： Xianghong Lu Jiajian Zhu xing qian Jianbing Ji Zhejiang Provincial Key Laboratory of Biofuel College of Chemical EngineeringZhejiang University of Technology

Methyl linolenate was separated from its analogues by a new extraction system constructed by solvent,imidazolium based ionic liquids and cuprous salt. Firstly, the effect of ionic liquid on the dissolution of CuCl in acetonitrile, N,N-dimethylformamide(DMF), methanol and water was evaluated by visual observation.[C4Mim][Cl]can improve the dissolution of CuCl in acetonitrile. Then, for the new system as acetonitrile-ILs-CuCl, extraction equilibrium, distribution ratio and selectivity of methyl linolenate and its analogues were determined by gas chromatography analysis and the mass balance. The extraction time, IL structures and CuCl concentrations were investigated. Distribution ratio decreased slightly, but selectivity increased significantly with the addition of CuCl,[C4Mim][Cl] or [C4Vim][NTF2] into acetonitrile.[C4Vim][NTF2] had higher selectivity than [C4Mim][Cl].But the selectivity of the system combining CuCl with [C4Vim][NTF2] was much lower than with [C4 Mim][Cl].For the CuCl-[C4Mim][Cl]-acetonitrile, the extraction efficiency was better than CuCl-acetonitrile, increasing Cu^+ concentration effectively improved the separation selectivity when ratio of CuCl/[C4Mim][Cl] was less than 1. Compared with previous aqueous AgNO3 extractions, the method of using CuCl is a much cheaper and practical way to enrich unsaturated fatty acid.

关键词： Methyl linolenate Cuprous salt Ionic liquid Cosolvent Extraction

Theoretical studies on alloying of germanene supported on Al (111) substrate

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Chinese Physics B 2020年第10期29卷 521-534页

作者： qian-xing Chen Hao Yang Gang Chen Laboratory of Advanced Materials Physics and Nanodevices School of Physics and TechnologyUniversity of JinanJinan 250022China School of Physics and Electronics Shandong Normal UniversityJinan 250358China

Using density functional theory,we study the alloying of the buckled hexagonal germanene superlattice supported on Al(111)-(3×3),the sheet composed of triangular,rhombic,and pentagonal motifs on Al(111)-(3×3),and the buckled geometry on Al(111)-(√7×√7)(19°),which are denoted,respectively,by BHS,TRP,and SRT7,to facilitate the discussion in this *** could be alloyed in the low doping concentration *** stable configurations BHS,TRP,and SRT7 of the pure and alloyed germanenes supported on both Al(111) and its Al2 Ge surface alloy,except the SRT7 pure germanene on Al2 Ge,could re-produce the experimental scanning tunneling microscopy *** relatively stable AlGe alloy species are the Al3 Ge5 BHS-2 T,Al3 Ge5 TRP-2 T,and Al3 Ge3 SRT7-1 T on Al(111) while they are the Al4 Ge4 BHS-1 T,Al3 Ge5 TRP-2 T,and A127 Ge27 SRT7-(3×3)-9 T on Al2 Ge(the n in the nT means that there are n Ge atoms per unit which sit at the top sites and protrude upward).In addition,the Al3 Ge5 BHS-2 T and Al4 Ge4 BHS-1 T are the most stable alloy sheets on Al(111) and Al2 Ge,*** with the experimental studies,there exists no structural transition among these alloyed configurations,which suggests that the experimental conditions play a crucial role in selectively growing the pure or the alloyed germanene sheets,which may also help grow the one-atomic thick honeycomb structure on idea Al(111).

关键词： first-principles calculation alloyed two-dimensional material substrate for two-dimensional material growth two-dimensional nanostructure

Tuning heterogeneous microstructures to enhance mechanical properties of nano-TiN particle reinforced Haynes 230 composites by laser powder bed fusion

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Rare Metals 2024年第9期43卷 4548-4565页

作者： Wen-Jie Liu Hui Li qian-xing Yin He-Jun Du School of Power and Mechanical Engineering Wuhan UniversityWuhan 430072China The Institute of Technological Sciences Wuhan UniversityWuhan 430072China School of Mechanical&Aerospace Engineering Nanyang Technological UniversitySingapore 639798Singapore

Laser powder bed fusion(LPBF)is considered to be one of the most promising additive manufacturing technologies for producing components with geometries and high geometrical precision that are unattainable by traditional *** superalloy exhibits exceptional mechanical and high-temperature performances,rendering it a prime candidate for advanced aero-engine *** the high demand for LPBF-manufactured superalloys,the superalloy is one of the materials manufactured difficultly by LPBF due to their large laser absorptivity fluctuation,poor molten pool stability and sharp temperature ***,superalloys are characterized by severe pores,undesirable coarse columnar grains and poor mechanical *** this work,the effect of nano-TiN particles on defects,molten pool characteristics and microstructure and performance of the composites were *** 4.5 wt%TiN/Haynes230 samples exhibited exceptional nanohardness and elastic modulus with maximum values reaching 5.53 GPa and 240.03 GPa,*** superior mechanical properties were attributed to the combined effects of spatter and gas pore inhibition,grain refinement and duplex nanophases ***,the stability of molten pool was enhanced,and spatter was effectively suppressed by adding nano-TiN particles,while grain refinement and columnar to equiaxed transitions were ***,the matrix exhibited a high dislocation density due to a significant hindrance of dislocation movement caused by massive nano-phases(e.g.,TiN and M_(23)C_(6)),resulting in the formation of extensive dislocation tangles and *** work offers novel insights into the role of nanoparticles reinforced superalloy composites by LPBF.

关键词： Composites Laser powder bed fusion Molten pool characteristics Microstructure Mechanical properties

Silver(I) Oxide Mediated Regioselective Monoacylation of 2,4-Dihydroxyls in L-Rhamnopyranosides

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Chinese Chemical Letters 2006年第8期17卷 1009-1012页

作者： qian YANG xing Mei ZHU Jin Song YANG Ministry of Education Key Laboratory of Drug Targeting School of Pharmacy Sichuan University Chengdu 610041

A series of acyls （Ac, Bz and Ts） were introduced regioselectively to the 2-hydroxyl in methyl and ally 3-O-benzyl-α-L-rhamnopyranosides mediated by silver（I） oxide in the presence of a catalytic amount of potass... 详细信息

关键词： Silver(Ⅰ) oxide acylation regioselectivity,α-L-rhamnopyranoside.

Ethylene Oligomerization by (dppe)MCl_2 [M = Fe(II), Co(II),Ni(II)] Complexes/EAO

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Chinese Chemical Letters 2001年第12期12卷 1115-1118页

作者： Yu Liang ZHANG Ming xing qian Ren HE State Key Laboratory of Fine Chemicals Dalian University of TechnologyDalian 116012

The catalytic properties of a series of (dppe) MCl2 [M = Fe(II), Co(II), Ni(II)] in combination with EAO (ethylaluminoxane) for ethylene oligomerization have been investigated. Treatment of the bidentate phosphine metal complexes with EAO in toluene generated in situ active catalysts which catalyze oligomerizaton of ethylene to low-carbon olefins. The effects of reaction temperature, ratios of n(Al) : n(M) and reaction periods on catalytic activity and product distribution have been studied. The activity of cobalt complex with EAO at 200C was 4021 g/g(Co)h, and the selectivity of C4-10 olefins is 95.5%.

关键词： Ethylene oligomerization bidentate phosphine complexes EAO a-olefins.

Determination of sulfite in water samples by flow injection analysis with fluorescence detection

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Chinese Chemical Letters 2010年第12期21卷 1457-1461页

作者： Li qian Yin Dong xing Yuan Min Zhang State Key Laboratory of Marine Environmental Science Environmental Science Research Centre Xiamen University Xiamen 361005 China

A fast,sensitive,and reliable method for the determination of sulfite（SO3^2-） in fresh water and seawater samples was *** proposed method was based on the reaction of o-phthalaldehyde（OPA）-sulfite-NH_3 in alkaline solution,with flow injection analysis and fluorescence *** experimental parameters were investigated in pure water and seawater matrixes. The detection limits（S/N = 3） were 0.006μmol/L in pure water and 0.018μmol/L in seawater for SO3^2-.The method was successfully applied to analyze SO3^2- iin the samples of rain water and flue gas desulfurization seawater.

关键词： Sulfite Fluorophotometry FIA Flue gas desulfurization seawater Rainwater

Control of reactive dividing wall column for selective hydrogenation and separation of C3 stream

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Chinese Journal of Chemical Engineering 2016年第9期24卷 1213-1228页

作者： xing qian Shengkun Jia Yiqing Luo Xigang Yuan Kuo-Tsong Yu School of Chemical Engineering and Technology Chemical Engineering Research Center Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) State Key Laboratory of Chemical Engineering Tianjin University

In our previous work, the reactive dividing wall column(RDWC) was proposed and proved to be effective for selective hydrogenation and separation of C3 stream. In the present paper, the dynamics and control of the proposed RDWC are investigated. Four control structures including composition and temperature controls are proposed. The feed forward controllers are employed in the four control strategies to shorten the dynamic response time, reduce the maximum deviations and offer an immediate adjustment. The control structures are compared by applying them into the RDWC system with 20% disturbances in both the feed flow rate and the feed compositions, and the results are discussed.

关键词： Process control C3 stream selective hydrogenation Reactive dividing wall column

Cascade equilibrium stage relaxation method by introducing equilibrium efficiency parameter

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Chinese Journal of Chemical Engineering 2024年第2期66卷 145-156页

作者： Xuepu Cao Shengkun Jia xing qian Yiqing Luo Xigang Yuan College of Chemical and Pharmaceutical Hebei University of Science&TechnologyShijiazhuang 050018China School of Chemical Engineering and Technology State Key Laboratory of Chemical EngineeringTianjin UniversityTianjin 300072China College of Information Science and Technology Beijing University of Chemical TechnologyBeijing 100029China

Optimizing multistage processes,such as distillation or absorption,is a complex mixed-integer nonlinear programming(MINLP)*** integer into continuous variables and solving the easier nonlinear programming(NLP)problem is an optimization idea for the multistage *** this article,we propose a relaxation method based on the efficiency *** the efficiency parameter is 1or 0,the proposed model is equivalent to the complete existence or inexistence of the equilibrium *** non-integer efficiency represents partial existence.A multi-component absorption case shows a natural penalty for non-integer efficiency,which can assist the efficiency parameter converging to 0 or ***,its penalty is weaker than the existing relaxation models,such as the bypass efficiency *** a simple distillation case,we show that this property can weaken the nonconvexity of the optimization problem and increase the probability of obtaining better optimization results.

关键词： Mathematical modeling Absorption Distillation Optimization