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Experimental measurement and thermodynamic modeling of binary and ternary solid–liquid phase equilibrium for the systems formed by L-arabinose,D-xylose and water

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Chinese Journal of Chemical Engineering 2017年第10期25卷 1467-1472页

作者： Lei Guo Lianying Wu Weitao Zhang Chen Liang yangdong hu College of Chemistry and Chemical Engineering Ocean University of China Qingdao 266100 China

Solid–liquid phase equilibrium data for binary(L-arabinose–water) and(D-xylose–water) systems at temperatures from(269.85–298.05) K and ternary(L-arabinose–D-xylose–water) system at temperatures of 273.85 K,278.85 K and 284.45 K were measured at atmospheric *** ternary phase diagrams of the systems were constructed on the base of the measured *** pure solid phases were formed at given temperatures,including pure L-arabinose and pure D-xylose,which were con firmed and determined by the method of Schreinemakers' wet *** the same temperature,the crystallization region of L-arabinose was larger than D-xylose'*** acquired solubility data were then correlated using the NRTL model,Wilson model and Xu *** calculated solubility with the three models agreed well with the experimental values.

关键词： D-Xylose L-Arabinose Solid–liquid equilibrium Solubility Thermodynamics Model

Testing and validation of a self-diffusion coefficient model based on molecular dynamics simulations

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Chinese Journal of Chemical Engineering 2021年第8期34卷 138-145页

作者： Xia Chen Yan Wang Lianying Wu Weitao Zhang yangdong hu College of Chemistry and Chemical Engineering Ocean University of ChinaQingdao 266100China College of Chemistry and Chemical Engineering Qingdao UniversityQingdao 266071China

In our previous work,we endowed a new physical meaning of self-diffusion coefficient in Fick’s law,which proposed that the diffusion coefficient can be described as the product of the characteristic length and the diffusion *** testify this simple theory,in this work,we further investigated the underlying mechanism of the characteristic length and the diffusion velocity at the molecular *** a complete dynamic run,the statistical average diffusion velocity and the characteristic length of molecules can be obtained by scripts,and subsequently the diffusion coefficient was determined by our proposed *** diffusion processes in 35 systems with a wide range of pressure and concentration variations were simulated using this *** the simulated results,diffusion coefficients from our new model matched well with the experimental results from *** total average relative deviation of predicted values with respect to the experimental results is 8.18%,indicating that the novel model is objective and *** with the traditional MSD-t model,this novel diffusion coefficient model provides more reliable results,and the theory is simple and straightforward in ***,the effect of gas pressure and liquid concentration on the diffusion behavior were discussed,and the microscopic diffusion mechanism was elucidated through the distribution of diffusion velocity and the characteristic length ***,we suggested new distribution functions,providing more reliable data theoretical foundations for the future research about the diffusion coefficient.

关键词： Diffusion Molecular simulation Parameter identification Characteristic length Diffusion velocity

A novel model for multi-plant mixed heavy crude oils refinery planning

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Chinese Journal of Chemical Engineering 2017年第2期25卷 202-210页

作者： Xiaoqiao huang yangdong hu Lijuan Song Yuzhen Zhang Dongkui Chen College of Chemical Engineering China University of Petroleum (East China) Qingdao 266100 China College of Chemistry and Chemical Engineering Ocean University of China Qingdao 266100 China Liaoning Key Laboratory of Petrochemical Engineering. Liaoning Shihua University Fushun 113001 China PetroChina Qinhuangdao Fuel Oil Asphalt Co. Lrd Qinhuangdao 066000 China

In this paper, multi-refinery using the same heavy crude oils as raw materials is studied, while a new nonlinear model for mixed heavy crude distillation is proposed. In practical crude distillation operation, the distillate yield and product distribution of distillation units are different due to their various equipment and operating parameters, even the same ratio of raw materials is provided, so different process models for multi-refinery planning is therefore required. For process modeling, the relationships between total yields and mixing ratio of different refineries were determined, which is combined with process simulation using production data. Then,the yields and properties of crude distillation unit(CDU) fractions were calculated with the use of true boiling point(TBP) curves and property curves respectively when the initial cutting temperatures were given. Finally,in order to maximize the economic benefit of distillation, the optimal product distribution and the best mixing ratio of crude oil were calculated under the constraints of different properties of fractions. Comparing to previous models, the proposed model takes the influence of different refinery parameters on production process into account, while avoiding the complex process for determining the cutting points, which is considered more efficient and more accurate with respect to heavy crude refinery. Model was successfully verified by a case study,allowing a significant improvement of the refinery profit to be achieved.

关键词： Heavy crudeMixing ratioMulti-plantOptimizationPlanning

Optimized Design of Spacer in Electrodialyzer Using CFD Simulation Method

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Journal of Ocean University of China 2018年第3期17卷 603-608页

作者： JIA Yuxiang YAN Chunsheng CHEN Lijun hu yangdong Key Laboratory of Marine Chemistry Theory and Technology Ministry of Education College of Chemistry and Chemical Engineering Ocean University of China

In this study, the effects of length-width ratio and diversion trench of the spacer on the fluid flow behavior in an electrodialyzer have been investigated through CFD simulation method. The relevant information, including the pressure drop, velocity vector distribution and shear stress distribution, demonstrates the importance of optimized design of the spacer in an electrodialysis process. The results show width of the diversion trench has a great effect on the fluid flow compared with length. Increase of the diversion trench width could strength the fluid flow, but also increase the pressure drop. Secondly, the dead zone of the fluid flow decreases with increase of length-width ratio of the spacer, but the pressure drop increases with the increase of length-width ratio of the spacer. So the appropriate length-width ratio of the space should be moderate.

关键词： computational fluid dynamics electrodialysis fluid flow spacer

The green hydrolysis technology of hemicellulose in corncob by the repeated use of hydrolysate

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Chinese Journal of Chemical Engineering 2018年第1期26卷 191-195页

作者： Lei Guo yangdong hu Lianying Wu Chen Liang Weitao Zhang College of Chemistry and Chemical Engineering Ocean University of China

To achieve green hydrolysis technology of hemicellulose through repeated using hydrolysate, the hydrolysis of hemicellulose in corncob was studied. The influence of repeated use of corncob hydrolysate on concentrations of D-xylose and L-arabinose was investigated. The loss rates of D-xylose in the prepared D-xylose solutions both with and without corncob, and repeated using corncob hydrolysate under identical acidity condition were discussed. The result shows that D-XyIOSe concentration and L-arabinose concentration are all gradually increas- ing with the growing time of repeated use of corncob hydrolysate. After the fifth repetition, the concentrations of D-xylose and L-arabinose are 196.7 g. L-1 and 22.0 g.L-1, respectively. Substance inhibiting the degradation of D-xylose is generated during repeated use of corncob hydrolysate, and the production is further proved by the change of D-xylose concentration and the loss rate of D-xylose over heating time.

关键词： D-xylose Repeatedly-using hydrolysate Acidolysis Water-saving Acid-saving

Application of the Clustering Method in Molecular Dynamics Simulation of the Diffusion Coefficient

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Journal of Ocean University of China 2008年第1期7卷 43-47页

作者： LIU Qingzhi hu yangdong College of Chemistry and Chemical Engineering Ocean University of China Qingdao 266100 P. R. China

Using molecular dynamics (MD) simulation, the diffusion of oxygen, methane, ammonia and carbon dioxide in water was simulated in the canonical NVT ensemble, and the diffusion coefficient was analyzed by the clustering method. By comparing to the conventional method (using the Einstein model) and the differentiation-interval variation method, we found that the results ob- tained by the clustering method used in this study are more close to the experimental values. This method proved to be more reason- able than the other two methods.

关键词： clustering molecular simulation diffusion coefficient oxygen methane ammonia carbon dioxide

Study of the Relationship Between New Ionic Interaction Parameters and Salt Solubility in Electrolyte Solutions Based on Molecular Dynamics Simulation

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Journal of Ocean University of China 2024年第2期23卷 467-476页

作者： SUN Wenting hu yangdong ZHENG Jiahuan SUN Qichao Chen Xia DING Jiakun ZHANG Weitao WU Lianying College of Chemistry and Chemical Engineering Ocean University of ChinaQingdao 266100China Institute of Chemical Engineering Guangdong Academy of Science Guangzhou 510665China

Studying the relationship between ionic interactions and salt solubility in seawater has implications for seawater desalination and mineral *** this paper,a new method of expressing ion-to-ion interaction is proposed by using molecular dynamics simulation,and the relationship between ion-to-ion interaction and salt solubility in a simulated seawater water-salt system is *** analyzing the variation of distance and contact time between ions in an electrolyte solution,from both spatial and temporal perspectives,new parameters were proposed to describe the interaction between ions:interaction distance(ID),and interaction time ratio(ITR).The best correlation between characteristic time ratio and solubility was found for a molar ratio of salt-to-water of 10:100 with a correlation coefficient of *** the same salt,a positive correlation was found between CTR and the molar ratio of salt and *** type 1-1,type 2-1,type 1-2,and type 2-2 salts,the correlation coefficients between CTR and solubility were 0.93,0.96,0.92,and 0.98 for a salt-to-water molar ratio of 10:100,*** solubility of multiple salts was predicted by simulations and compared with experimental values,yielding an average relative deviation of 12.4%.The new ion-interaction parameters offer significant advantages in describing strongly correlated and strongly hydrated electrolyte solutions.

关键词： molecular dynamics simulation interaction distance interaction time rate electrolyte aqueous solutions solubility

Simulation of Countercurrent Multi-Effect Drying System

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Advances in Materials Physics and Chemistry 2012年第4期2卷 206-211页

作者： Hong Li Lianying Wu Xianli Wu yangdong hu Department of Chemical Engineering Ocean University of China Qingdao 266000 China

The paper bulids a countercurrent multi-effect drying process model which can be expressed as a linear programming(LP) problem with the minimum total energy consumption as target function. Based on the model it can be conventient to solve the heat load , degree of drying and other drying parameters of each effect. And it realizes the mathematical simulation an analysis of multi-effect drying process. Such process not only reuses the secondary steam but also utilizes the high energy grade. Drying silica sand using 1-effect drying to 5-effect drying is presented as an example. The energy consumption and energy saving rate are compared by using co-current multi-effect drying and countercurrent multi-effect drying. As a summary, the countercurrent multi-effect drying is better than co-current drying. Considered the equipment investment and energy conservation, the study also concluded that the countercurrent 4-effect drying is the optimum selection, and it can save 57.6% energy compared to countercurrent 1-effect drying.

关键词： Countercurrent Drying Multi-Effect Drying Secondary Steam LP

考虑水需求的水电联产海水淡化系统的优化设计

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化工学报 2013年第8期64卷 2924-2929页

作者：伍联营胡仰栋高从堦中国海洋大学化学化工学院山东青岛266100

水电联产不仅能缓解淡水资源不足的问题,而且可有效降低能耗和淡化成本。建立了水电联产系统数学模型,将优化设计描述为一个混合整数非线性规划(MINLP)问题,并采用混合编码的遗传算法进行求解,结果表明,以水定电模式下水电联产系统最优... 详细信息

水电联产不仅能缓解淡水资源不足的问题,而且可有效降低能耗和淡化成本。建立了水电联产系统数学模型,将优化设计描述为一个混合整数非线性规划(MINLP)问题,并采用混合编码的遗传算法进行求解,结果表明,以水定电模式下水电联产系统最优操作模式为发电、多级闪蒸(MSF)和反渗透(RO)三者的集成,且MSF和RO的产水比存在最优值,发电采用背压式蒸汽轮机。随着淡水需求量的增加,联产系统的淡水成本逐渐降低,MSF与RO的产水比呈现出逐渐降低的趋势。

关键词：水电联产海水淡化遗传算法优化设计