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Process Simulation - Science topic

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I just made a process simulation of bio-based products from biomass. the process involved pretreatment, hydrolysis, fermentation, separation, biogas production, and CHP (electricity generation). The CHP produced excess electricity where I would like to make a credit simulation of it in Simapro. Anyway, all required electricity has been covered by this excess.
my questions are:
1. should I select the electricity consumption from CHP process in the column of energy?
for example: I make an inventory of pretreatment where it needs the electricity for the pump. So, I select the CHP process in the column of electricity. am I correct?
I face the problem of iteration by doing this
2. how about the excess electricity I have? it must reduce the number of environmental impact
how could I simulate it in simapro to show the credit of having this excess?
Please kindly your advice
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Hi Gustavo and Rendra.
The answer will depend of the borders of your system.
If you consider all the process (pretreatment, hydrolysis, fermentation, separation, biogas production, and CHP (electricity generation) as your system, then:
According this approach, the Inventory won´t reflect a Power Input inside your limits, but it will reflect an output (for instance, 3 GJ/functional unit to cover the electricity demand and 1 GJ/functional unit of surplus electricity). The output will be 1 GJ/functional unit of electricity.
1) If you generate the enough electricity to satisfy all power demand of your process, you don´t need to select "Energy inputs to technosphere", because actually no one electricity is crossing the limits of your system (as an Input), because you are creating this energy inside of the process (3 GJ/functional unit).
2) On the other hand, if you have a surplus of power (after covering all power demand of the process, 3 GJ/functional unit), this surplus can be accounted as "Avoided Product" and will be crossing the borders of the system, for instance towards power grid in Italy (1 GJ/functional unit). So, it will be a credit, as Gustavo said: only if you assume that the generated power in excess replaces electricity generation in the grid upon which you inject it.
Regards!
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Does anybody need to discuss steady state and/or dynamic process simulation using ASPEN HYSYS for research and/or industrial purposes?
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Benidir Abdelaali this HYSYS material resource would educate you more on the approach of deploying dynamic simulation in your power plant simulation using Aspen HYSYS: https://instruct.uwo.ca/engin-sc/cbe497/Doc/HYSYS/Dynamics.pdf
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I have a plug flow reactor with two parallel equations taking place simultaneously inside it. I am not able to see any conversion in the stream summary table. It is despite the fact that I have input proper kinetic data and proper inlet/outlet conditions. Does anyone have a clue about it?
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hey, did you solve the problem? im in the same situation Seyed Soheil Mansouri
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I want to simulate the Methanation of CO2 in a PFR. In the set of reaction equations the water gas shift reaction appears: CO + H2O <-> CO2 + H2. I am using a reaction rate expression published in: https://doi.org/10.1002/ceat.201500327 📷. In the rate the expression the partial pressure of CH4 is a variable, even though it's not included in the reaction equation. How can I implement this in the input form of heterogeneous catalytic reaction? How can I declare the variable name of the CH4 partial pressure?
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I could find a solution to this Problem: In the stoichiometric input tick CH4 but assign 0 as stoichiometric coefficient. CH4 will appear as "(N: CH4)" in the reaction equation. When using the option "Advanced" for kinetic input one can use N1 as variable name for the CH4 partial pressure.
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I am doing some process simulation of lignocellulosic biomass.
Does someone have the INHSPCD databank, an ASPEN PLUS Physical Property Database for Biofuels Components?
Thank you in advance.
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I nanaged to import the databank but the component's properties did not import. Only the names of the components Aikaterini Mountraki Can you please help me? I have Aspen Plus V10
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An permanent magnet machine needs a thermal guarantee from its software analysis, since overheating may destroy its magnetic field. There are videos showing the temperature animations but nowhere could I find a detailed process to compute it from the Maxwell 2-D file.
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Aditya Raj Hi. You may find the following work helpful (it discusses the thermal modeling of a thin-film CZTSSe solar cell in COMSOL and takes various heat sources into consideration including SRH nonradiative recombination, Joule heating and the conductive heat flux magnitude):
Best
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Petro-Sim and similar process simulation software may be an effective tool to be used in decision making. I need to know your experience in this field. Any examples or case studies will be useful and sharing them will be highly appreciated.
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Hi, Mr. Salaheldin
I used petrosim software for simulation of petroleum refinery units of iranian refineries such as Catalytic Naphtha refoming (CRU - CCR), Naphtha hydrotreating, Hydrocracking and .... units about 15 years from 2005 until now.
I have several papers from that simulations in scientific journals.
Thanks
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In Aspen Plus I have the following problem (see attached figure):
I have a RGibbs block which calculates a distribution for a predifined set of products. However, I would like to go beyond this conventional Gibbs Energy Minimization by additionally considering the calculated energy demand for the block as a problem constraint. The strategy, understood as a conditional statement would be something like:
IF Qprocess = Qliterature THEN ---> Go on with the simulation
Else ---> Constraint product's yields ---> Repeat until condition is met
My problem is I don't exactly know how to set those yield constraints for the declared RGibbs products. I thought of the "Inerts" declaration tab, but when you specify a mole flow, the software understands that should be the actual output flow rather than a boundary.
Any thoughts on the issue will be much appreciated.
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Dear Reald Tashi and Enrique
I think the problem is how to add a new constraint to the GEM problem in Aspen, and RGibbs seems not suit for the job, even with a loop outside the block (through a DS or optimization). Have you considered solving the GEM problem using code (eg in MATLAB) and imposing the solution to the simulation model through RYield? That would also allow solving the problem calculating excess free energies of key components that satisfy your extra constraint.
I have spoken.
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Hello,
I am currently using ASPEN Plus for simulating biochemical processes, which consist of waste as feedstock. I find it hard and not accurate enough when it comes to introducing living organisms into the system (e.g.algae, bacteria). Does anyone know if there is any other simulation softwares that can deal better with bio-processes, or general batch processes?
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Yes, SuperPro Designer is more suitable for that.
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Assuming the multi-input single output data, the process simulation is to be implemented using the Adaptive-Neuro Fuzzy Model in MATLAB script. The data is to be presented in the numerical values stored as arrays.
The difficulty is experienced in the model, when the error says there is inconsistency in the output and input. The arguments in the input and output cannot match as there are five variables in the input and only variable in the output.
Please sort any remedy for this.
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Dear Dr.Sharma,
In ANFIS function, the training data includes inputs of the model that can be several columns and the last column should represent the output of the system as follows.
fuzex1trnData = [input1, input2, input3,....inputN, output1,output2,..., outputN]
fis = anfis(fuzex1trnData);
I think that would be great if you could follow the below example and please let me know if you had any issue to implement the model.
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Hi Everyone!
Could anyone please help me how Aspen Plus can be linked with Intel Visual Fortran. 
Thank You
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Dear researchers, I could successfully link Aspen with Fortran, and customized Aspen with user kinetics Fortran subroutine. Following file may help you to learn Fortran syntax for Aspen. Thanks
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My goal is get the undercut pattern after isotropic wet etching. my design has only 2 layers, top layer have designed pattern as a mask, bottom need some undercut as a sacrifice layer.
I tried to simulate it with COMSOL, but the simulation result largely rely on the mesh(size and variation), and can’t get the right finally shape. see picture1
Is there any simple script that can calculate the undercut in isotropic wet etching? Basiclly, calculate the biased contour of a given pattern.
Thanks
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Well, it might similar to the scale or bias function in Matlab, but the difference is how to plot the round corner.
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Several works available in the literature have addressed regression models for the prediction of mass yields and elemental composition of the bio-oil/biocrude produced from biomass thermochemical liquefaction (i.e. pyrolysis and HTL), based on its biochemical composition. However, I haven't been able to find any work going further and predicting the relative amount of representative families of compounds (e.g. alcohols, carboxylic acids, phenols, etc.) in the bio-oil/biocrude.
A couple of works (, ) have proposed computational algorithms for the chemical characterization of bio-oils/biocrudes by using a reduced number of compunds but, in the end, they rely on experimental data such as biocrude GC-MS/Simulated Distillation.
My idea, obviously, is not to get a detailed composition profile, but at least to be able to describe how biomass composition and process operating conditions affect the relative amount of maybe 10 to 15 representative compunds.
I would appreciate any ideas on the topic.
Best regards
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Its quite important to get the BMP test done and after particular days we can also start testing the effluent or the slurry on daily basis to get the actual data too
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MOSFET and similar other devices can be simulated using device simulator and process simulator, such as, MEDICI, TSUPREM, SILVACO etc. But these are very expensive for any university in Bangladesh to buy. But students want to learn these. So, I am searching for any free version of such type of software for teaching and learning and/or academic purposes only.
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Dear Muhibul Haque Bhuyan,
Please check out the following open-source TCAD tools
3. Charon Device Simulator https://charon.sandia.gov
4. Device Simulation Laboratory–Yuh-Renn Wu http://yrwu-wk.ee.ntu.edu.tw/
5. DEVSIM Open Source TCAD Software https://www.devsim.org
7. NanoTCAD ViDES http://vides.nanotcad.com
Further Reading
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Selection of right fluid package is always a challenge in process simulation.
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Fluid packages are designed to accommodate specific applications. Which applications are you interested in?
Usually cubic equations of state EOS are the de facto standard and there are some rudimentary rules to estimate the BIPs.
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In a situation, process simulation fails to converge for a particular set of decision variables, What would be the sequence of the line of code to close an unconverged simulation, and reopen the saved file before calling the simulation file for a new set of decision variables.
Also, in the case of an error message appearing during the simulation and the remaining VBA code cannot be executed. How do I use a "GoTo" statement to skip the remaining VBA code and continue the optimization by calling the simulation file for a new set of decision variables?
Can anyone help me with a similar VBA script that I can adapt to my code?
Attached here is the code for the interaction between excel and Aspen plus. Any idea/comment about the code to address this issue above would be highly appreciated.
Thanks
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In general, if your simulation process is preceded by the generation of a population of feseable solutions, starting from an adequate to your task optimization (mono or multiple objective) model, then you will be able to simulate only feasible solutions, so your simulation model will not fail
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During AM process, progressively activation of elements can predict the temperature/crystallinity history, including surroundings heat losses and than this data could be used to determine the deformation as well as the residual stresses within Abaqus AM plugin as one can do from user subroutines like UMATHT -> UMAT ? Are there any differences in term of results or convergence one have analyzed?
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There are very few people working with AM Plugin. Perhaps, in my opinion, results would be more reliable than the traditional method. However, I don't have sufficient data to support this claim.
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Hello. My name is Rand and I'm an Industrial Engineering student. I'm currently working on my bachelor's thesis where I will be using a simulation-based DVSM. However, I got stuck on the logic behind the storage part and order picking for a warehousing 4.0. I came across your thesis which happens to be for a warehouse as well. Could you please help out with the logic? Thank you!
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Rand
I write essay's about what I think is logical. I became aware that my logic is like a fish in water where no other fish is interested in me. So I try to study the logic of somebody else hoping to keep in contact and to interchange the logic of one another and to find out some common logic.
quote
"the logic and limitations behind the storage part and order picking for a warehousing 4.0. I"
Can you tell me what is particular for the warehousing system 4.0.1. may be I can give you my view about it.
Ad
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I typically use Silvaco Athena to simulate a process flow... is there any other software better than that ? Thanks in advance.
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Dear Towhidur,
welcome,
The best software is the software that is capable to model and simulate all fabrication steps in advanced integrated circuits.It must be an easy to use and gives a correct solution under the practical operating conditions.
Yes Silvaco Athena may be the the most commonly used process simulation software. We also use it.
But i think there may be equally god process simulation software from Synopsys
which is PROCESS SIMULATION TOOLS. They are four tools: Synopsys has four process simulation tools: Sentaurus Process; Taurus TSUPREM-4; Sentaurus Lithography; and Sentaurus Topography.
My opinion is that your question needs investigations to answer it precisely.
Best wishes
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Dear all,
I would like to create this space for sharing process simulation examples, good practices, common pitfalls, tips, and much more. If you are struggling with "that flowsheet", let others help you. No language restrictions, sharing is the most important. So let's get started!!!
Best,
J.L
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I have had 40 years experience building refinery/chemical plant simulations. Most set up problems seem to occur in distillation columns often because trays "dry up" during intermediate calculations when the program tries to converge the column to get a a solution.
Starting with large amounts of reflux or artificial liquid feed at the top of the tower to get initial convergence and then slowly backing out the artificial liquid feed in the converged case is often a good route to avoid this "dry tray during intermediate convergence calculation problem" and get to a converged case quickly. Once you get a converged case most simulators are usually very robust.
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I have completed a simulation in ASPEN 8.4 with almost 36 blocks. The simulation did run and provided results, the next I tried running the simulation it gives this error and I am not able to get any results for further analysis. This error came while I was trying to incorporate calculator and design spec. I have got the same error with other simulations too where i was not using calculator or design spec too. I tried reset, it is not working. 
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Hello, I am trying to do a simulation all my stream appeared correct but when I run the simulation a message shows:
Main Process Flowsheet:
Section GLOBAL:
BLOCK not complete: BLKID = ABSORB
Required outlet port: P(OUT) does not have stream connected
BLOCK not complete: BLKID = PUMP
Required outlet port: P(OUT) does not have stream connected
could any one help le to solve the prob
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I have used appropriate references for all the values and inputs that I have used for simulation. Please kindly help me out. I have been working through this for quite sometime.
I used unisim for carrying out this. File is attatched below if anyone is free to debug.
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Arjun Sankar S Defined Spec. for tower is incorrect so check these paramete in order to make the converging of the tower.
re-Check the parameters again and tell me what happened??
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Dear all, Can anybody please explain this Abaqus error and how can i rectify it. The simulation ran for some time and gave this error, there were no warnings. "Process terminated by external request (SIGTERM or SIGINT received)." I am unable to find the reason behind this error. Thank you
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Tufail Mabood, I also got the same trouble. But, when I checked, VPN was the trouble maker. Somehow, it got disconnected automatically, and the solver was exited, as suggested by Pedro José Silva Campos. I think the ABAQUS sends and receives packet information for a licence every now and then. Thus, for me, when the VPN is connected, it's working.
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I am modeling a humidication device in AspenPlus to control the relative humidity of a room. The device (please see the attached diagram for clarification) is intended to operate by introducing or retiring H2O from the inlet air stream in order to meet the required humidity set point. A DesigSpec is utilized to vary the amount of introduced/retired water. However, I need it to be able to change the manipulated variable depending on the specific case. For example:
IF Real Humidity< Humidity set point THEN Increase H2OIN & do not manipulate H2OOUT
IF Real Humidity>Humidity set point THEN Increase H2OOUT & do not manipulate H2OIN
I appreciate any contribution to overcome the problem.
Best regards
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Thanks for your answer Markus H Bauer
I will try it
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I am trying to simulate the deposition of Silicon over SiO2. In reality, when we try to deposit a crystalline Silicon over SiO2 (amorphous), we get rather a polycrystalline Silicon. In ATHENA though, when simulating the same process, the final deposited Silicon layer is not Polycrystalline Silicon but Crystalline silicon.
So, If someone can help me know how to capture this effect in Silicon and how to measure the quality of the deposited film in the Silvaco ATHENA TCAD tool, it would be really helpful.
If the proper simulation is not possible in ATHENA, please let me know which tool can capture these effects properly.
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I think your test can not bring a decisive judgement about the crystallinity of the structure. It is the dislocation distribution in the deposited material that can give the grain nature of the deposit. It is so that at the grain boundary you will find a high density of dislocations. In the grain bulk you will have less dislocations.
Also the distribution of the crystallographic orientation in the layer.
You can also judge the crystallographic structure by measuring the resistivity of the material. It is so that the resistivity of the polycrystalline si is much greater than the single crystal.
Best wishes
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I need to simulate a distribution gas network, in particular I need to perform steady-state analysis on this network.
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Dear Anirbid Sircar Anirbid Sircar
Can we use CFD Fluent tool to simulate gaseous fluid under steady state condition.
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I'm looking for an open-source process simulation software for biomass power plant exergy analysis.
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Maybe also try DWSIM http://dwsim.inforside.com.br/ (sequential modular)
or ASCEND http://ascend4.org/Main_Page (equation-based)
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I need a software to simulate a electrolysis process in a molten salt I need to know regards flow simulation and reaction inside crucible and usual flowsheet, because we have to add to this system others elements in the plant which could be in aspen hysys.
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I hope this paper can be useful in your research:
• Numerical Simulation of Temperature Field in Electrolytic Bath for Preparing Rare Earth Cerium by Molten Salt Electrolysis.
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Dears,
I have a planned idea to govern a software for image processing , simulation and (maybe) coding or decoding of mechanical properties analysis through an appropriate software.
1- you recommend MATLAB, ANSYS or both altogether?
2- do you prefer other software rather than these aforementioned ones?
Thank you very much for any valuable idea added to enrich these projects, especially I am looking for their publication in HIGH IMPACT FACTOR JOURNALS.
Yours sincerely,
Zhwan
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Hi Zhwan Sktani,
You can use the MATLAB for developing the image processing programs, analyzing the images and for decoding the material properties. ANSYS is suitable for the numerical simulation, provided you already have the material properties data. The custom FEM codes can also be developed in MATLAB for the analysis. You may read more about the digital image correlation (DIC) techniques to know more about the measurement of mechanical properties using image based techniques.
Thanks
Sajith
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I want to dilute 48% (by wt) caustic solution to 18% (by wt). This process will release the heat. One way of calculating heat of dilution is to use the conventional charts. Is it possible to workout this heat by Aspen Plus or some other process simulator?
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I propose to draw the release curve of this challeur, work at three levels, initial temperature 48%, 38%, 28%, 18%, and make the mathematical model with startgraphics.
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We are tackling exploiting a process simulator that receives some initial input data and outputs time series transition in parameters, and we are comparing these results and real data (using as answer).
However I have trouble in how to evaluate this. Some results show the good correspondence to the real data at the end of simulation but in the interim progress deviate from the read data. While other results show good correspondence at first, but gradually and slightly deviates from the read data, and in the end it results in lager error.
I have no idea about whether the former or the latter is good and want to know how to evaluate it in terms of mathematics.
I would appreciate it if you tell me a hint.
Best regards.,
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In purely mathematical sense, what you want to know/evaluate is the distance between two sets, namely a set of observed vs. predicted values. Unfortunately the distance may be defined in many ways, producing different numerical values for the same case. One of the most popular is rms deviation (\sqrt{\sum (pi - oi)2} / n, where n is the number of pairs prediction--observation. It is popular because there are many books dealing with this problem as well as computer programs to adjust unknown parameters in order to get possibly small rms deviation. But for calibration purposes one prefers another distance: maxi |pi - oi|.
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Hello, I am working on scaling up of nanoparticles(MoS2) from lab to industrial scale. I would to know the methodology of doing so in general , and in particular in the case where we don't know the kinetics and thermodynamics of the process at lab scale .
Thanks in advance
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Dear Elhalimi,
I cam late.
However,I think this question is very interesting.
It is so that you want to increases the productivity of the material. You can make the scaling up in step by step basis such that you ramp up the rate of production of you material in steps rather than in one step. This is an engineering appraoch.
You have to keep the reaction parameters in all scales the same such that you increase only the size of the reactor to feed it with more materials. The reaction parameter are the temperature, the pressure the mixing ration and the process of mixing and homogenizing the mixer.
You can also use many small reactors similar to that used in the lab experiment. This may be a staight forward appraoch. It is used in epitaxial reactors where one uses many few wafer reactors at the same time.
So, you can increase the size of the reactor keeping the reaction parameters the same as in the laboratory phase or you can use multiple small reactors much similar to laboratory scale type.
Best wishes
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In ethanol steam reforming , how to calculate the heat of the different unit operation in aspen plus, provided with different NIO/ethanol molar ratios and the carbon yield?
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Why would anyone want to turn ethanol - a valuable trasportation fuel in syngas - CO + H2 waiting t be turned into something more valueable - like ethanol.
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Currently, i am simulating a Ambient Air Vaporizer (AAV) for LNG Regasification terminal in HYSYS Dynamic. The UA (overall heat transfer coeff) of AAV dependent with time and position. so i wanted to simulate the change of UA in AAV that is function of time and position. i have completed the calculation and now have line equation with dependent variable is UA and the independent variable is time and position, i wanted to use spreasdsheet to use this formula, but i dont know how to import the time data (in integrator) to make my formula works, does anybody know how to do that? i really appreciate your answer thank you
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David Limb yes, i wanted to know the reduced rate of heat transfer as the frost builds up
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Am in the process of simulation of SOFC with Indirect Internal Reforming set up. What % of produced power is consumed by reformer as heat required for reforming Natural gas in case of Indirect Internal Reforming? Should I consider 20% or 30% something like that?
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In SOFC it is important to have internal reforming. It is a way to valorize heat production in electrical power. Don't forget : in SOFC direct oxidation of CH4 and CO at electrodes is more difficult compare to H2 oxidation. So there is, first internal reforming and shift reaction, followed by H2 diffusion to layers and H2 oxidation. Even with internal steam reforming which is endothermal heat is produced in excess. To calculate the part of endothermal energy you calculate the enthalpy of the steam reforming reaction at the SOFC temperature. I think you are right with 20%. This energy is not lost. It permits to rise the electrical efficiency.
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I want to know how to give reaction in extraction column in aspen plus process simulator.
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Dillon Pillay- Thankyou for your valuable advice
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What are the values for 1. Maximum pressure at failure 2. Minimum principal strain at failure 3. Maximum effective strain at failure 4. Volumetric strain at failure 5. Number of failed integration points prior to element deletion 6. Number of failure conditions to satisfy before failure occurs 7.Minimum pressure at failure, and other constant present in MAT_ADD_EROSION card.
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hi.
Read papers that are similar to your work and fill those parameters.
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What kind of software for simulation of discrete processes (manufacturing processes) can you recommend? In fact I am looking for software both for research purposes and for didactics. For the time being I have been used Technomatix Plant Simulation and Enterprise Dynamics software. But maybe you will suggest me something better… ? What is your experience in this field?
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We use Promodel in our university, because there is a version for student, limited but free. If you want you can pay a proffesional version but theres is others softwares that can help you.
check this link:
My best regards
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I have been working with queueing systems with nonstationary (i.e., time-varying arrival rate) non-Poisson (NSNP) arrival processes.
To analyze the performance of this type system, I used to write a simulation code by myself since I thought there is definitely no currently available simulation software. The oldest paper about this has been published just in 2009: Gerhardt and Nelson, Transforming renewal processes for simulation of nonstationary arrival processes, INFORMS Journal on Computing.
Recently, somebody asked me if there is a commercial (or noncommercial) software that generates NSNP. As far as I know, there isn't but I cannot make it sure. Do anybody know about the fact?
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Review the distributions in Queueing Theory and maybe one these distributions can help you.
My best regards
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I'm need to select a property method for estimation physical property of above mentioned components that involved in a chemical process at high temperature and moderate pressure.
in the most parts of process, mixtures present in gas phase, but in the some separation units of the process, liquid phase is appeared.
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The parameters of the molecuels can be obtained with antechamber in AMBER (RESP for charges and gaff for other parameters).
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Hi everyone,
I am simulating welding process in ansys apdl.
I have applied EKILL and EALIVE commands in my simulation , but I can not write ls file. ansys says that, by using element birth and death I can not use LSWRITE command. it says, I should use solve command repeatedly.
I have a DO loop. I put /SOLVE command in it, but it does not work.
Could you help me?
Many thanks
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My guess is that you kill the element and bring it to live in same time step and for that reason your code doesn't work. If you want to kill the element and bring it to live or vise versa, you need at least two time steps in which you can define a few substeps under each of them. that should get you started.
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Hello! I want to estimate the payback period of IPA-water separation process. I have estimated the capital cost and operating cost. How can i calculate the pay back period? I have used Aspen plus for the process simulation.
I want to know if there is any general method to calculate payback period (or cash flow)?
Thank you
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I can give you a practical and easy way to do the calculation just using a spreadsheet like excel.
Write in a file a list of annual net flow (Negative: Investment, capital cost, raw materials, operational cost, etc and Positive: earnings of products and by products). Then start adding the flow from the first period so on till you find a positive result. The number of periods give you the answers
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I have tried to simulate pyrolysis process in both PRO/II and Hysys using a Gibbs reactor. I have tried two kinds of feedstock to simulate the polymer material (PET), as the process is about plastic wastes pyrolysis, in PRO/II I get some amount of carbon in the product stream, which is similar to real case as in real experiments we have also solid residue, however, in Hysys simulation I don't have any carbon in the product stream and it's all converted to gas and tar products. Is that because Hysys is not able to handle solid state compounds in the process simulation or there is something wrong with the Hysys simulation?
Thanks
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Hysys can handle solids in several ways, but not in all ways. The ways it can handle solids include:
1. As non-reactive stream components that affect heat and mass transfer but not phase equilibrium. This, for example, describes solids transport as slurries or entrained dust.
2. As an organic liquid using the OLI (organic liquid interface).
3. As an equilibrium component in a Gibbs reactor.
However, solids cannot form or be destroyed in a heat exchanger or other vessel other than a Gibbs reactor (except possibly in the case of the OLI approach - I do not have much experience with that). There is no robust SVLE computation in Hysys outside of a Gibbs reactor.
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I want know how to design the synthetic process for propylene from methanol and analyze by using chemical process simulating software Aspen HYSIS.
Thank you!
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attached info shoud help
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Please could anyone recommend a good paper on Business Process Simulation Problems/Challenges?
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Speakin on oil production, there are several process simulation softwares (Pipesim, Olga, Eclipse), but in asset cost estimation Pemex work with Que$tor software, for offshore and onshore oil or gas well production installations.
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Aspen Plus for Oil Shale processes
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Why is Aspen Plus required for Oil Shale process? We have tried HTRI for designing Heat ex changers for Shale Gas exploitation.
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Hello everyone,
My project is the simulation and modelling of hybrid PSA/membrane fro Helium gas separation. A PSA process will be modelled and simulated in Aspen Adsorption package (He/N2 separation), and membrane process will be simulated and modelled in Aspen HYSYS (He/CH4 separation).
Now for getting full flow sheet (hybrid process) dynamic simulation results needed to integrate both processes results.
Can anyone advise me how to integrate?
Thanks in advanced!
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You could use the CUSTOM MODELER if you have that ASPEN license. In ASPEN PLUS you can make a user defined block with your PSA logic programmed in an EXCEL subroutine or in a FORTRAN subprogram. In your user module you can include two or more adsorption unit operations in different states of pressure swings.
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Some have used dynamo meter to measure the torque. and some used an unknown sensor and calculated the power using lab view interface software. I would be very glad if any one could give your valuable suggestions for my problem. Thanks.
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Having studied adaptive control and energetic optimization of aerobic fermenters, I used a torque meter inserted at the impeller shaft to access the power dissipated by agitation, as can be found reported at the following MSc Thesis:
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Hello how best would I electro-deposit ZnTe onto a metal Oxide with good adherence. Also the sulfuric acid used in dissolving the ZnTe seems to etch of the ITO glass substrate during deposition. How best can I do this deposition without etching the substrate as well
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Search for Benedict Ita, University of Calabar, Calabar · Department of Pure and Applied Chemistry. He is a professor of physical and electrochemistry.
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When components are in a database it is easy to make calculations by using the properties from the database, but often it is necessary to use UNIFAC and other prediction methods to estimate properties. But what if the UNIFAC does not predict for a structure because of missing groups? How to deal with groups which are not in the UNIFAC table in Aspen Plus? This is the case with some of my compounds: furfuryl alcohol, methylfuran, etc.
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best way to estimate binary coefficients is by searching references. the last priority goes to UNIFAC model. there is a good article about estimating and challenges of predicting binary coefficients. it will clear the way for you. especially check table 4 & 5 for most reliable references. 
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Hi, I was curious about the possibility of retrieving the "activity coefficient" of solute in a solution by using methods like UNIFAC or NRTL. In Aspen Plus it is possible to retrieve these parameters, including fugacities. How is it possible to do this in Aspen Hysys?
Thanks in advance for your kind help
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Greetings Gianfranco,
   I am more familiar with Aspen Plus, but my speculation is that it should be fairly similar to get the activity coefficients and fugacities.   From the aspen plus user interface you can generate x-y  VLE, curves for selected pairs of components which have binary parameters.  This feature also generates associated properties such as the activity coefficients for these pairs.  Fugacity Coefficients  (PHIL, PHILMX, and PHIV)  for liquid pure components, liquid mixtures, and vapor can also be obtained as a stream property.  As mentioned above, if you have the binary parameters, you can do flashes on the relevant streams to get xi and yi compositions and do the calculations manually to get Fugacity.   Because these are accessible from Aspen Plus its a certainty that they are also accessible in Hysys.  
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I am currently doing the simulation of this system on Aspen Plus, I would like to find some materials that can help to run the shortcut first, in order to get some initial estimations of the rigorous column.
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Hi
There are many papers published on this subject by Professor Anton Kiss and Costin Sorin Bildea on thissubject. They are on research gate. You can also get on Anton Kiss's site www.tonykiss.com and see his full list of publications and ask him via e-mail.
Regards
Binoy Shah 
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I am working on a project. So, i come across one problem is that,
if we have n No. of machines with their utilization as U1, U2 ,.....,Un . And Now if i have the overall plant utilization as, Up. So, can anyone please tell how should i relate Up, with the utilization of the machines?
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Ronald is correct if the machines are in series they must be treated as a single unit and both must operate for the unit to count as operating.  If there are 3 units  (2 operating/1spare) each with a probability of 90% of operating the expected utilization of the unit will be the probability that all 3 are available (.9*.9*.9 = .729) + the probability that 2 of the three are available (.9 *.9*.1*3)= .243 so the overall expected reliability of the unit will be .729+.243 =.972
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To design the plant.
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POX is a  good way to produce syngas/H2 from any hydrocarbon.  Usually low value  hydrocarbon  like vacuum resdue or natural gas are used as feed but any hydrocarbon will work.  
If you want to produce H2 from C6+ Hydrocarbon naphtha reforming is a good option that will increase the octane of the naphtha and make H2 as a byproduct 
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I want to Simulate Triple Effect Falling Film Evaporators (Forward Feed arrangement & Feed is Caustic Soda (NaOH)) to validate design steam economy, overall heat transfer coefficients, boiling point elevations and Heat transfer areas of each evaporator.
How can we use Aspen Plus or Aspen HYSYS to model & simulate the above process.
Any kind of input on this will be very much helpful,
Thanks!
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normally The evaporator is replaced by a flash drum and a heater. but there are different configurations for this system.
if you want I have solved Cases with Aspen-HYSYS
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I want to use electrolyte and nonelectrolyte fluid package for simulation of a plant at the same time. 
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For example ethane to ethene. In this process the electrolyte and non electrolyte systems are used. The electrolyte is used for the caustic washing column.
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I want to model the supercritical separation process in aspen plus. This involves phase behavior modeling of supercritical CO2-Solid and supercritical CO2-Liquid systems. I know how to use Aspen Plus. But, never, performed such type of modeling at high pressure.
Please suggest to me some guide resource where step-by-step instructions are provided for doing this job. I made initial attempts by regressing experimental VLE data for getting optimized binary interaction parameter but no luck. I don't know what else I am missing. Thanks for your help.
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such simulations are previously conducted in 
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Hello Everyone,
I want to solve some power plants  problem with the sequential modular approach and the simultaneous solution approach in "System Flow-sheeting". Can somebody suggest me any good books or articles for "System Flow-sheeting"? Thanks in advance...
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This is note by Dr. Hong-ming Ku about "Flowsheet Flowsheet – Tear Streams"
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Nitric acid absorber tower have cooling coils at every stage. How can i add cooling coils in the aspen model for 59 stages ? The degree of cooling will determine the acid strength.
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you can take out a side outlet liquid stream from a plate and  circulate the liquid with a fairly high circulation rate compared to the through flow around a heat exchanger coil with specified area, overall heat transfer coefficient  and  coolant flow rate and inlet temperature and feed back the liquid stream to the same plate
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I am working on Arc welding process simulation. I am trying to make a heat source model based on goldak's double ellipsoidal volumetric heat ditribution.
initially i applied heat source on point(node), then i tried on volume(Cube), then Cylinder form, then ellipse form. but i dont know how to define second ellipse at a time. I dont know how to apply different load on different ellipses at same time.
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In APDL, you can firstly select some nodes inside your ellipsoid and use the command CM to define them as a node group. Then you can apply the specific heat source to this node group. For different ellipsoids you just need to do the process separately. For example in my case I use: bf,nodef,hgen,%front%.
You may check the attached paper, particularly in Fig.10 and the corresponding descriptions. Hope it can be helpful.
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Hi everyone
please suggest me TCAD code for below 45nm
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Dear Yogesh,
The following URL provides an insight on a 32nm MOSFET
You can try to use the figures to estimate necessary implants.
Best,
Dao
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HI!
I am using petrofrac model in Aspen Plus to simulate crude tower operation. As indicated in the file attached here, I would like to split pumparond inlet stream into two streams and connect it to main crude tower.
Does anyone know how to solve this problem?
Regards,
Bhautesh
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Aspen have pump around option for simulation of tower using PETROFAC model
You can try this option.
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I am currently modeling processes like Reactor Control or Crystallizer Control. Which Process Simulator I can use for processes like these ?
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Here you can find a collection of 45 Tools für process simulation. The website is in German but if you use the links to the tools there will also be an English version available.
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Process fab expert
Athena user world wide
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deposit material=material_name thick=value divisions=set_by_user
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I am working on ASPEN simulation for an OSN membrane which requires pressure to be set at 30bars but my exit stream from the pump is giving a very high temperature at the same pressure and low discharge flow rate
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As suggested by Luo, you may try to cool and condense the stream before pumping, so the temperature of liquid streams practically have no rise.
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I know that FlexSim software is used for simulation and optimization of manufacturing systems. However, I would like to know whether it can be used for process simulation like molding processes and turning processes?
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You can use DELMIA software also for better simulation of the NC machining process as it gives the simulation in real time too. In addition to this you can also analyse the results obtained and fine tune the process as you desire.
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In a recent talk with a colleague, he mentioned that in Chemical Processes it is not worthy to perform frequency analyses at values higher that 100 Hz, is this true? if so, why? is there any reference for that? 
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For the most part I would agree with this statement, however, I would add that there is no clear cut rule on what frequencies should be considered and where the cut-off is for stopping the analysis. The reason for this is that the relevant frequencies depend upon the time constants of the process and the accuracy of the model.
Let me briefly explain: if you are dealing with a distillation column and the input-output behavior under in investigation has a time constant of 30 minnutes, then you likely do not include some faster phenomena, such as opening/closing of valves, etc, in your model. As such, your model will not be accurate at higher frequencies due to information that is commonly (and for all practical purposes correctly) ignored. However, opening and closing a value may have a time constant of a few seconds to a few minutes. As such, your model will not be accurate at those frequencies or frequencies that are even higher. 100Hz is a lot faster than the dynamics that got ignored in what I outlined. Your analysis should likely stop at even lower frequencies.
Now all of that being said, if you are dealing with very fast processes (not very common in industrial scale chemical processes, but some exist) then you may want to consider carrying out your analysis to higher frequencies. In short: your analysis should be appropriate for the time scale of the process and the model that you use to describe the process.
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I want to simulate something like a combustion with ration of air/fuel=2 at aspen hysys
how can I do that?
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In HYSYS, this can be easily done by introducing a "set point" block which would maintain a constant ratio between two streams which can be connected to a "mixer" block to produce a mixed stream. I'm certain that a similar operation should be available in ASPEN as well.
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It is an established fact that activity coefficient models are best for modeling solid-liquid equilibrium, while equation-of-state models are best for solid-supercritical fluid equilibrium. Most times when a thermodynamic model has been selected and validated for specific processes, it becomes difficult to modify or switch such a model. There is therefore the need to have a selection format for thermodynamic models that can be flexible even if it is validated.
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May I suggest a correction in your point of view: activity coefficients are best for polar mixtures (S-L, L-L, L-V). Equations of state are best for supercritical condition due effect of pressure. There is no universal model. If you use a process simulator your first responsibility is the choice of the thermodynamic model. If you calculate on spreadsheet also you need to choose the thermodynamic model. There is an article that help the selection of the thermodynamic model: see the article of E. C. CARLSON: Don't gamble with physico-chemical properties for simulation Chem. Eng. Prog. (oct. 1996) p. 35-46.
Good luck! 
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I have groundwater level data for 10 years (2000-2010), and want to analyze the impact of land use type change on groundwater level fluctuation. However, I can only get 3 years land use classification data (2000, 2005, and 2010). I can calculate the constituent ratios of different categories in the fixed neighborhood of each groundwater well. Because I have a long time series of groundwater level data, I plan to use time series analysis. But I don’t know how to process or simulate the land use date to represent its continuous change year by year, in which case it could be suitable for time series analysis. Or is there any better methods for this analysis? Thanks
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Hi
Having land use maps from three dates, you can estimate matrices of land use transition probabilities between 2005-2005 and 2005-2010. Then, with Markov Chain Analysis and those transition matrices, you can estimate annual land cover maps, for your region of interest. From each of these annual maps you'll be able to derive your annual vectors of proportional land cover composition.
This link to a Google Scholar search gives you access to many papers that have used this approach: http://scholar.google.com/scholar?q=Markov+chain+analysis+land+cover+transitions&hl=en&as_sdt=0%2C5&as_vis=1&as_ylo=2000&as_yhi=
The commercial GIS package Idrisi implements this approach, and some of its more sophisticated variants as well.
Good luck with your work
JP
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I have learned gPROMS and it was very useful when I wanted to run a model (differential) equation. To update myself, I just want to know any similar software packages are available in the market?
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You can try Aspen Custom Modeller; it has the capability for developing codes for ODEs.
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Business process simulation captures and models discrete aspects of systems' behavior while System Dynamics captures the continuous aspect. It is desirable in many systems that these aspects are combined into a feedback relationship. How can we accomplish this?
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Hi Veerendra,
Any control theory basically applies to sets of differential equations, known as State-Space equations/model/method, derived by applying theoretical equations, curve fitting, interpolation, stochastic or some other methods from any empirical n-dimensional lookup table. Consequently, making these lookup table models out of your system is crucial. The variables could be as physical as time and temperature, to financial or process related, as long as ones depend/are related to the others. Then, you can apply software, such as Matlab/Simulink (trial versions are available) or dBASE, and some control theory knowledge for your non-linear MIMO (multi-input multi-output) system feedback control design.
References:
Brogan's "Modern Control Theory" (ISBN-13: 978-0135897638 ISBN-10: 0135897637 Edition: 3rd) is a good, basic feedback control design textbook reference for such systems.
Maybe, Anderson's "Business Economics and Finance with MATLAB, GIS, and Simulation Models" (ISBN: 1-58488-348-0 http://www.mathworks.com/support/books/book48464.html) will be more suitable for your problem.
However, a shortcut could be found in most of control design software "help" manuals or recorded Webinars, such as Mathworks' Matlab/Simulink library references (by the way, I am not associated with Mathworks' other than being longtime user of Matlab and Simulink for my electronic control designs, so that I am more familiar with this than other similar software):
Good luck with your design.
Best regards,
Zoran Mihailovic
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I would like to know whether any software packages are available for simulation and optimization of cement process that incorporates Raw meal preparation, Clinkerization, Cement grinding, and gas flow engieering.
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you can use the CCD method in the design of experiments.
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I want to remove the condenser of a distillation tower and add a heat exchanger and a separator, but I don't know how to transfer the streams between flow sheets in Hysys 8.0.
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Yasser,
I am more familiar with Aspen Plus so what I am suggesting here may or may not work. Within Aspen plus there is a way to create something called a Pseudo Stream. This is something you can also do with the distillation column, so the stream entering the condenser is the vapor leaving stage 1. You can define that stream as a pseudo-stream, and aspen should allow you to create a stream tag for that new stream which will be shown on the graphic as a stream exiting the column. Once the stream is defined you can then use a transfer block to transfer the compositon and T, P and flow to another stream or you can just copy from the aspen stream report to your new stream. That may be one approach you can try, if the pseudo stream or something equivalent is available in Hysys.
Regards,
Dave
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I am interested in using REMD for a protein folding related problem.
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This is the current target list
So far they post 488 residues, maybe the next days will appear larger
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I may want to modify an existing FORTRAN code that someone else has made, however, I would like to modify the code and see where should I fix when encountering an error after modifications. To put it simple, I want to know where does the calculation stop.
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Seyed,
Even if the environment doesn't offer any particular tools, the old 'tried and tested' method of liberally sprinkling the code with reporting WRITE statements (indexes of loops, simple line reports to see where the code has got to, etc.) isn't a bad first attempt.
How big is the code and what sort of problems are you encountering?