Modeling and analysis of air combustion and steam regeneration in methanol to olefins processes

Light olefins is the incredibly important materials in chemical industry.Methanol to olefins(MTO),which provides a non-oil route for light olefins production,received considerable attention in the past decades.However,the catalyst deactivation is an inevitable feature in MTO processes,and regeneration,therefore,is one of the key steps in industrial MTO processes.Traditionally the MTO catalyst is regenerated by removing the deposited coke via air combustion,which unavoidably transforms coke into carbon dioxide and reduces the carbon utilization efficiency.Recent study shows that the coke species over MTO catalyst can be regenerated via steam,which can promote the light olefins yield as the deactivated coke species can be essentially transferred to industrially useful synthesis gas,is a promising pathway for further MTO processes development.In this work,we modelled and analyzed these two MTO regeneration methods in terms of carbon utilization efficiency and technology economics.As shown,the steam regeneration could achieve a carbon utilization efficiency of 84.31%,compared to 74.74%for air combustion regeneration.The MTO processes using steam regeneration can essentially achieve the near-zero carbon emission.In addition,light olefins production of the MTO processes using steam regeneration is 12.81%higher than that using air combustion regeneration.In this regard,steam regeneration could be considered as a potential yet promising regeneration method for further MTO processes,showing not only great environmental benefits but also competitive economic performance.

Process Simulate在综合实训系统设计中的应用

为解决传统自动化产线编程调试需根据现场实际规划反复调试的问题,借助数字孪生技术,将Process Simulate软件强大的虚实联调技术应用于自动化产线设计、安装、编程、调试、故障解决中。在现实的智能工厂中,往往都是多工作站之间配合进而实现自动化产线的连续运行。多工作站之间的配合就会涉及到通讯,以西门子1500 PLC为例详细讲解如何借助Process Simulate软件实现多站之间的PUT/GET通讯,进而完成各站的PLC程序信号交互,最终完成自动化产线的程序调试。采用Process Simulate软件实现多站之间的通讯,优势体现在:虚拟的PLC即可实现多站之间的通讯,解决无真实设备状态下的编程和通讯,进而验证Process Simulate在智能装备多工作站中的应用高效性。

基于Teamcenter Process Simulate印章定制的生产线仿真设计

基于Teamcenter Process Simulate进行了印章定制生产线仿真设计。本设计是完成印章的组装和包装工作,模拟实际生产过程。整个生产过程是由仓储供料站提供原料,运输站将其送至加工站加工,送至装配站进行组装,组装完后经过机器进行检测,然后送至包装台进行产品包装,最后由AGV小车运输至仓储放料台进行产品入库。设计以出料、运送物料、产品加工、组装、检测、包装、运送、入库等执行单元作为自动生产线的整体设计,组成了自动生产线的生产平台。系统的总控是由一台PLC承担其控制任务。结合工作中的经验,通过机电一体化设计将生产流水线设计方案嵌入到具体的Process Simulate虚拟仿真中,通过PLCSIM Advanced软件创建虚拟PLC,同时构建PLC与Process Simulate通信的桥梁,进而通过编程控制实现印章定制化生产实训系统自动化产线的仿真调试。通过仿真测试,能大大提高实际生产效率。

基于ABB机器人与Process Simulate间的虚实联调研究

无论高等院校的师生还是智能工厂的数字化工程师,在利用软件Process Simulate完成机器人工作站的虚实联调时往往会消耗大量的时间,结果还不理想,因为其用到的方法是传统的创建多个机器人子程序,或是创建一个机器人程序在程序中用到大量的等待信号去完成物理属性的机器人工作站与软件内机器人工作站的数字孪生同步运行,此方法能够实现物理属性的机器人工作站与软件内机器人工作站的同步运行即虚实联调,但是效率低同时对项目实施者要求也非常高,因此利用传统的方法完成机器人工作站的虚实联调会困难重重,效果还不理想。为了节省数字孪生项目中机器人工作站与软件间的虚实联调的完成时间和降低项目完成难度,作者通过在数字孪生实验室的大量实验研究,最终通过在真实机器人控制器中编写机器人程序读取机器人各轴位置数据,借助Profinet通讯完成机器人与PS软件间的实时位置数据交互,进而较快地完成虚实联调项目。通过与传统的方法做对比测试,作者创建的方法使项目完成的效率得到显著提高,同时降低了项目完成难度。基于以上对比测试,作者研究的方法在以后数字孪生项目中会得到很好地推广,并慢慢会取代传统的方法。

Simulation Research on the Effect of Spreading Process Parameters on the Quality of Lunar Regolith Powder Bed in Additive Manufacturing

Lunar surface additive manufacturing with lunar regolith is a key step in in-situ resource utilization.The powder spreading process is the key process,which has a major impact on the quality of the powder bed and the precision of molded parts.In this study,the discrete element method(DEM)was adopted to simulate the powder spreading process with a roller.The three powder bed quality indicators,including the molding layer offset,voidage fraction,and surface roughness,were established.Besides,the influence of the three process parameters,which are roller’s translational speed,rotational speed,and powder spreading layer thickness on the powder bed quality indicators was also analyzed.The results show that with the reduction of the powder spreading layer thickness and the increase of the rotational speed,the offset increased significantly;when the translational speed increased,the offset first increased and then decreased,which resulted in an extreme value;with the increase of the layer thickness and the decrease of the translational speed,the values for voidage fraction and surface roughness significantly reduced.The powder bed quality indicators were adopted as the optimization objective,and the multi-objective parameter optimization was carried out.The predicted optimal powder spreading parameters and powder bed quality indicators were then obtained.Moreover,the optimal values were then verified.This study can provide informative guidance for in-situ manufacturing at the moon in future deep space exploration missions.

Operation optimization of the steel manufacturing process: A brief review

Against the realistic background of excess production capacity, product structure imbalance, and high material and energy consumption in steel enterprises, the implementation of operation optimization for the steel manufacturing process is essential to reduce the production cost, increase the production or energy efficiency, and improve production management. In this study, the operation optimization problem of the steel manufacturing process, which needed to go through a complex production organization from customers' orders to workshop production, was analyzed. The existing research on the operation optimization techniques, including process simulation, production planning, production scheduling, interface scheduling, and scheduling of auxiliary equipment, was reviewed. The literature review reveals that, although considerable research has been conducted to optimize the operation of steel production, these techniques are usually independent and unsystematic.Therefore, the future work related to operation optimization of the steel manufacturing process based on the integration of multi technologies and the intersection of multi disciplines were summarized.

A continuous and high-efficiency process to separate coal bed methane with porous ZIF-8 slurry:Experimental study and mathematical modelling

Coal bed methane has been considered as an important energy resource.One major difficulty of purifying coal bed methane comes from the similar physical properties of CH_4 and N_2.The ZIF-8/water-glycol slurry was used as a medium to separate coal bed methane by fluidifying the solid adsorbent material.The sorption equilibrium experiment of binary mixture(CH_4/N_2)and slurry was conducted.The selectivity of CH_4 to N_2 is within the range of 2-6,which proved the feasibility of the slurry separation method.The modified Langmuir equation was used to describe the gas-slurry phase equilibrium behavior,and the calculated results were in good agreement with the experimental data.A continuous absorption-adsorption and desorption process on the separation of CH_4/N_2 in slurry is proposed and its mathematical model is also developed.Sensitivity analysis is conducted to determine the operation conditions and the energy performance of the proposed process was also evaluated.Feed gas contains 30 mol%of methane and the methane concentration in product gas is 95.46 mol%with the methane recovery ratio of 90.74%.The total energy consumption for per unit volume of product gas is determined as 1.846 kWh Nm^(-3).Experimental results and process simulation provide basic data for the design and operation of pilot and industrial plant.

Polyvinylamine-Based Facilitated Transport Membranes for Post-Combustion CO_(2) Capture:Challenges and Perspectives from Materials to Processes

Carbon dioxide(CO_(2))capture by gas-separation membranes has become increasingly attractive due to its high energy efficiency,relatively low cost,and environmental impact.Polyvinylamine(PVAm)-based facilitated transport(FT)membranes were developed in the last decade for CO_(2) capture.This work discusses the challenges of applying PVAm-based FT membranes from materials to processes for postcombustion CO_(2) capture in power plants and cement factories.Experiences learned from a pilot demonstration system can be used to guide the design of other membranes for CO_(2) capture.The importance of module and process design is emphasized in the achievement of a high-performance membrane system.Moreover,the results from process simulation and cost estimation indicate that a three-stage membrane system is feasible for achieving a high CO_(2) purity of 95 vol%.The specific CO_(2) capture cost was found to significantly depend on the required CO_(2) capture ratio,and a moderate CO_(2) capture ratio of 50%presented a cost of 63.7USD per tonne CO_(2) captured.Thus,FT membrane systems were found to be more competitive for partial CO_(2) capture.

A techno-economic and life cycle assessment for the production of green methanol from CO_(2): catalyst and process bottlenecks

The success of catalytic schemes for the large-scale valorization of CO_(2) does not only depend on the development of active,selective and stable catalytic materials but also on the overall process design.Here we present a multidisciplinary study(from catalyst to plant and techno-economic/lifecycle analysis)for the production of green methanol from renewable H2 and CO_(2).We combine an in-depth kinetic analysis of one of the most promising recently reported methanol-synthesis catalysts(InCo)with a thorough process simulation and techno-economic assessment.We then perform a life cycle assessment of the simulated process to gauge the real environmental impact of green methanol production from CO_(2).Our results indicate that up to 1.75 ton of CO_(2) can be abated per ton of produced methanol only if renewable energy is used to run the process,while the sensitivity analysis suggest that either rock-bottom H2 prices(1.5$kg1)or severe CO_(2) taxation(300$per ton)are needed for a profitable methanol plant.Besides,we herein highlight and analyze some critical bottlenecks of the process.Especial attention has been paid to the contribution of H2 to the overall plant costs,CH4 trace formation,and purity and costs of raw gases.In addition to providing important information for policy makers and industrialists,directions for catalyst(and therefore process)improvements are outlined.

Progress in Numerical Simulation of Solidification Process of Shaped Casting

Solidification simulation of manufacturing shaped casting which plays an important role in asSuring the soundness and quality of castings, in minimizing the trial production time and in reducing the manufacturing cost becomes one of the hottest topics of the new research frontiers of foundry technology at home and abroad. Practical three dimensional computer numerical simulation system for temperature distribution during solidification as well as shrinkage cavity and porosity prediction has already been put into application all over the world. Further fundamental researche5 on fluid flow, thermal stress and micro-modeling as well as practical approaches of numerical simulation of solidification process of shaped castings for routine analysis of foundry industry are still underway.

基于Process Simulate的工业机器人信息物理融合系统

工业机器人在进行新工艺开发时一般存在周期长、调试复杂等常见问题。以ABB的IRB120型工业机器人作为研究对象,基于Process Simulate工业仿真平台,采用了工业机器人信息物理融合的方法,实现了工业机器人实体与虚拟模型深度融合的功能,通过数据的通信、采集与传输实现了二者的同步运动功能,进一步分析了虚拟模型相对于实体工业机器人的时间延迟误差。分析结果表明,二者的时间延迟误差在工业允许范围内,说明该技术可为智能制造提供有效的解决方案,可大幅缩短工艺开发周期、降低工艺开发成本,同时该技术也是数字孪生概念下的具体工程应用,技术本身具有较高的工程推广价值。

New process development and process evaluation for capturing CO2 in flue gas from power plants using ionic liquid[emim][Tf2N]

Using the ionic liquid[emim][Tf2N]as a physical solvent,it was found by Aspen Plus simulation that it was possible to attempt to capture CO2 from the flue gas discharged from the coal-fired unit of the power plant.Using the combination of model calculation and experimental determination,the density,isostatic heat capacity,viscosity,vapor pressure,thermal conductivity,surface tension and solubility of[emim][Tf2N]were obtained.Based on the NRTL model,the Henry coefficient and NRTL binary interaction parameters of CO2 dissolved in[emim][Tf2N]were obtained by correlating[emim][Tf2N]with the gas–liquid equilibrium data of CO2.Firstly,the calculated relevant data is imported into Aspen Plus,and the whole process model of the ionic liquid absorption process is established.Then the absorption process is optimized according to the temperature distribution in the absorption tower to obtain a new absorption process.Finally,the density,constant pressure heat capacity,surface tension,thermal conductivity,and viscosity of[emim][Tf2N]were changed to investigate the effect of ionic liquid properties on process energy consumption,solvent circulation and heat exchanger design.The results showed that based on the composition of the inlet gas stream to the absorbers,CO2 with a capture rate of 90%and a mass purity higher than 99.5%was captured.These results indicate that the[emim][Tf2N]could be used as a physical solvent for CO2 capture from coal-fired units.In addition,the results will provide a theoretical basis for the design of new ionic liquids for CO2 capture.

Machine learning-based ionic liquids design and process simulation for CO_(2) separation from flue gas

Rational design of ionic liquids(ILs),which is highly dependent on the accuracy of the model used,has always been crucial for CO_(2)separation from flue gas.In this study,a support vector machine(SVM)model which is a machine learning approach is established,so as to improve the prediction accuracy and range of IL melting points.Based on IL melting points data with 600 training data and 168 testing data,the estimated average absolute relative deviations(AARD)and squared correlation coefficients(R^(2))are 3.11%,0.8820 and 5.12%,0.8542 for the training set and testing set of the SVM model,respectively.Then,through the melting points model and other rational design processes including conductor-like screening model for real solvents(COSMO-RS)calculation and physical property constraints,cyano-based ILs are obtained,in which tetracyanoborate[TCB]-is often ruled out due to incorrect estimation of melting points model in the literature.Subsequently,by means of process simulation using Aspen Plus,optimal IL are compared with excellent IL reported in the literature.Finally,1-ethyl-3-methylimidazolium tricyanomethanide[EMIM][TCM]is selected as a most suitable solvent for CO_(2)separation from flue gas,the process of which leads to 12.9%savings on total annualized cost compared to that of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide[EMIM][Tf_(2)N].

Modeling and Optimization of Ethane Steam Cracking Process in An Industrial Tubular Reactor with Improved Reaction Scheme

Ethane steam cracking process in an industrial reactor was investigated.An one-demsional(1D)steady-state model was developed firstly by using an improved molecular reaction scheme and was then simulated in Aspen Plus.A comparison of model results with industrial data and previously reported results showed that the model can predict the process kinetics more accurately.In addition,the validated model was used to study the effects of different process variables,including coil outlet temperature(COT),steam-to-ethane ratio and residence time on ethane conversion,ethylene selectivity,products yields,and coking rate.Finally,steady-state optimization was conducted to the operation of industrial reactor.The COT and steam-to-ethane ratio were taken as decision variables to maximize the annual operational profit.

A Study on Numerical Simulation of Core-Shooting Process

In order to evaluate the main factors influencing the core-shooting process and to optimize the design of core boxes, the fluid-particle (air-sand) model has been built based on the two-phase flow theory. The fluid phase, air, and the particulate phase, sand granules, have been treated as a continuum. By using this model, it is possible to simulate the flow and compaction behavior of sand particles during the core-shooting process. To benchmark the calculated results, the shooting process has been recorded with a digital high speed camera, and the inlet condition of sand particles has also been achieved by using the camera. The preliminary results have showed that the calculation is in agreement with the testing results.

基于Process Simulate在物料智能分拣系统中的应用

为解决传统自动化产线编程调试需根据现场实际规划反复调试的问题,可借助数字双胞胎技术,将Process Simulate软件强大的虚实联调技术应用于自动化产线设计、安装、编程、调试及故障解决中。通过Process Simulate软件加载物料智能分拣设备3D模型,在软件中创建三维模型的运动学、通讯信号,并以PLCSIM Advanced的通讯方式建立Process Simulate模型与虚拟PLC的连接,可实现虚拟PLC控制Process Simulate模型的运动。经实践运行测试发现,Process Simulate物料智能分拣系统工作效率高、运行可靠,有较强的实用性和较大的应用推广价值。

基于Process Simulate自动化离线编程的应用

为了解决中职、高职、本科院校在进行实践授课时设备短缺问题,借助数字孪生技术,通过Process Simulate软件加载设备的3D模型,在软件中创建设备模型的运动学、通讯信号,并以PLCSIM Advanced的通讯方式建立软件模型与虚拟PLC的连接,从而实现自动化设备的离线编程,进而实现PLC对设备的控制。经实际运行测试,用这种数字孪生技术同样能够实现教学目的和教学任务,并且更具高效性和安全性,有较强的实用性和较高的推广价值。

Three-Dimensional Rigid-Plastic FEM Simulation of Bulk Forming Processes with New Contact and Remeshing Techniques

Some techniques such as die surface description, contact judgement algorithm and remeshing are proposed to improve the robustness of the numerical solution. Based on these techniques, a three-dimensional rigid-plastic FEM code has been developed. Isothermal forging process of a cylindrical housing has been simulated. The simulation results show that the given techniques and the FEM code are reasonable and feasible for three-dimensional bulk forming processes.

基于Process Simulate的机器人运动程序开发及应用

针对目前汽车行业车身车间越来越高的自动化程度和日益复杂的车型更新,使用Tecnomatix软件进行虚拟调试,把前期设计数模导入Process Simulate模块,进行运动仿真和碰撞模拟测试,提前发现设计缺陷,并与机器人厂家联合开发运动和工艺模块,与上位PLC进行逻辑处理,与下位应用设备进行标准化模块处理及数据通信,提前在虚拟化环境中进行验证,最终输出机器人运动和安全程序,提高了机器人程序的质量并且能够大大减少现场调试时间。

Flue gas analysis for biomass and coal co‑fring in fuidized bed:process simulation and validation

Coal-conversion technologies,although used ubiquitously,are often discredited due to high pollutant emissions,thereby emphasizing a dire need to optimize the combustion process.The co-fring of coal/biomass in a fuidized bed reactor has been an efcient way to optimize the pollutants emission.Herein,a new model has been designed in Aspen Plus®to simultaneously include detailed reaction kinetics,volatile compositions,tar combustion,and hydrodynamics of the reactor.Validation of the process model was done with variations in the fuel including high-sulfur Spanish lignite,high-ash Ekibastuz coal,wood pellets,and locally collected municipal solid waste(MSW)and the temperature ranging from 1073 to 1223 K.The composition of the exhaust gases,namely,CO/CO_(2)/NO/SO_(2)were determined from the model to be within 2%of the experimental observations.Co-combustion of local MSW with Ekibastuz coal had fue gas composition ranging from 1000 to 5000 ppm of CO,16.2%–17.2%of CO_(2),200–550 ppm of NO,and 130–210 ppm of SO_(2).A sensitivity analysis on co-fring of local biomass and Ekibastuz coal demonstrated the optimal operating temperature for fuidized bed reactor at 1148 K with the recommended biomass-to-coal ratio is 1/4,leading to minimum emissions of CO,NO,and SO_(2).