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Chemical Processes - Science topic

Chemical Processes are the reactions and interactions of atoms and molecules, the changes in their structure and composition, and associated energy changes.
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I want to estimate freezing point of a mixture made from Ehhanol (H₃CCH₂OH, MW: 46.07 g/mol) , mono propylene glycol (CH₃CH(OH)CH₂OH, MW: 76.1 g/mol) and water. And the ratio of the mixure will vary for example I can start with 1:1:1 and so on. I spent couple of week to google it but not able to figure out how to do that. If someone here have some experience with it or have some suggestion / literature then please help to solve for this problem.
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Dear Dol Lamsal,
The best and simplest choice for the phase-equilibrium calculations and studying such systems (Including Water+Alcohols+Hydrocarbons) is the CPA (Cubic Plus Association) equation of state. I suggest you verify the following references:
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To estimate the production costs of the chemical process plant, these are the preliminary estimated data. This helps the process engineer to make a decision among the alternatives. 
What do you think?
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Its really serves as a good first estimate
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Nowadays, chemical process simulation is applied in almost all sectors of Chemical Process Engineering. In general, it is used in almost all engineering fields. It is the inevitable part of disciplines from process design, research & development, production planning, optimization, training & education to decision-making which makes it one of the most important disciplines of engineering. A wide palette of simulation solutions is mentioned below.
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Process Systems Engineering (PSE) cover these aspects. PSE is a new discipline at the interface of chemical/process engineering, computer sciences, and mathematics.
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The chemical process industries (CPI) and the chemical engineering profession are not always viewed by the general public as being very innovative fields. This perception may have some validity if we compare the CPI with the so-called technology sector.
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You can recent report published by The National Academic Press.
Please see attached.
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This is the flue gas composition from the Ammonia fired furnace which I have modeled in Aspen Plus. Does anyone have any idea about NOx emissions? Is this emission amount of emission accepted by the EPA?
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Generally for the cement industry it is a stack emission at 10% O2 dry for 500 mg/NM3 of NOx as NO2. The Power Industry at least in Europe is 200
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in my opinion, directly no because the shape of the resin after performing mechanical stirring will be mixed up and maybe it gets a circular shape but then we can modify the shape ( by some chemical processes) to obtain a honeycomb structure. I would like to know what do you think.
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Thank you!
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Atorvastatine with the commercial name lipitor is a statin based drug used to treat abnormal lipid levels for prevention of cardiovascular diseases. As far as I know, it is produced over several steps over a chemoenzymatic route.
My question would be, what is the reason there is no single-step fermentation based route to such drugs? In my understanding, it could be more efficient since atorvastatine for example contains chirality centers and enzymes in a isolated form therefore are used anyways in the current chemoenzymatic synthesis because of their advandageous enantioselectivity.
I also read a paper about a single-step fermentative procedure to a similar statin, the cholesterol-lowering drug Pravastatin.
However, since industry is not using fermentation to derive those statin drugs, there must be a reason the chemoenzymatic synthesis is favored or the only feasible route. Therefore, to improve my understanding, I wanted to ask what you think what are those reasons? Are cells currently not able to synthesize such a molecule like Atorvastatine, are the titers to low, is the purity with the enantiomeric excess not good enough, something like this.
I appreciate every answer very much.
Kind regards,
Thomas
(a biotechnology student)
In the appendix there is the structural formula of Atorvastatine
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In order to produce a drug by fermentation, there must be an organism that has the necessary metabolic pathway, which would require a set of enzymes, one for each step in the biosynthesis. Synthetic small-molecule drugs that are not natural products are usually produced by chemical synthesis because there is no existing enzymatic pathway for their synthesis in vivo. However, one or more of the starting materials for the chemical synthesis may have a natural origin. Some drugs are chemically modified versions of natural products. In addition, individual steps in the chemical synthesis may be catalyzed by purified enzymes in vitro.
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Hi,
I'm working on a project that required me to customize the particle size through a chemical process. Currently, we are implementing the process of slurrying the material in a selected solvent and water to improve the hardness of the solid so that we can sieve and get the desired particle size. The problem is, I did not get the consistency on the hardness as sometimes it became brittle and porous. Is any suggestion that I can use to improve this issue?
Thank you!
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Heat in an inert atmosphere to 100C below the melting point.
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Hi, I am a chemical engineer graduate working as process engineer. Now a days, there is increased buzz about process plant automation, industry 4.0 and a greater push towards IoT, Cloud DBMS. As a process engineer how should we equip ourselves for this? What are the skills to develop in software aspect in this regard?
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A lot of companies now require software skills along with chemical engineering knowledge. The most prominent one in them is Python. I have a lot of friends working on Python in process modeling & simulation etc.
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What are the main physical/chemistry properties of such materials?
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Highly recommend reading "Molecular Fluorescence - Principles and Applications 2nd Ed. (2012)" written by Bernard Valeur and Mario N. Berberan-Santos. Chapters 1-3 give an excellent overview.
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I need to prepare yttrium nitrate by dissolving its oxide into 6M nitric acid.
I would like to know any experimental considerations in this process to get best results.
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Dear Mohammad Jazirehpour many thanks for posting this interesting technical question. The preparation of Y(NO3)3􏰀x6H2O powder has been reported in the article cited below. It was obtained by dissolving yttrium oxide in 6 M nitric acid:
Size dependence of the upconverted luminescence of NaYF4:Er,Yb microspheres for use in ratiometric thermometry
From our own experinence I would suggest the following procedure: Place the nitric acid in a beaker and heat it to ca. 50-80 °C. With stirring, add a little more than the calculated amount of Y2O3 and let the mixture stir until most of the oxide has dissolved. A small excess of oxide is useful to completely consume the acid. Then filter the mixture and evaporate the clear filtrate until crystals begin to form. Pour the hot solution into a crystallization dish and let it stand at room temperature over night so that the remaining water evaporates. Then collect the product.
Good luck and best wishes, Frank Edelmann
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What are the chemical processes in phosphorus fractions measurement?
What reactions occur when different solutions are added to the sediment? And how does it release phosphorus at different stages of fractionation?
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Hello Jalali,
Kindly look at this paper
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Hi guys and gals,
I am looking for a sample that is Raman active, with a shift of 1200-1600 wavenumbers, and high optical transmission in the NIR (700-900nm) range.
I prefer a sample that is common and won't require chemical processing on my side.
Does anyone have any suggestions?
Thanks,
Yoad
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Polystyrene should be quite transparent in the NIR and has strong Raman peaks at ~1004 cm-1 and ~1585 cm-1. Plastic Petri dishes are made of Polystyrene.
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I am researching UKF, and I would like to know where can I find performance measures of this. The system is a Chemical Process Plant.
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Maybe you can consider the recursive least squares algorithm (RLS). RLS is the recursive application of the well-known least squares (LS) regression algorithm, so that each new data point is taken in account to modify (correct) a previous estimate of the parameters from some linear (or linearized) correlation thought to model the observed system. The method allows for the dynamical application of LS to time series acquired in real-time. As with LS, there may be several correlation equations with the corresponding set of dependent (observed) variables. For the recursive least squares algorithm with forgetting factor (RLS-FF), adquired data is weighted according to its age, with increased weight given to the most recent data.
Years ago, while investigating adaptive control and energetic optimization of aerobic fermenters, I have applied the RLS-FF algorithm to estimate the parameters from the KLa correlation, used to predict the O2 gas-liquid mass-transfer, hence giving increased weight to most recent data. Estimates were improved by imposing sinusoidal disturbance to air flow and agitation speed (manipulated variables). Simulations assessed the effect of numerically generated white Gaussian noise (2-sigma truncated) and of first order delay. This investigation was reported at (MSc Thesis):
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Dear All,
I am working on a problem based on numerical evaluation of heat transfer in a steelmaking process. It involves heat generation and heat absorption via various chemical processes. Let me simplify my question. Hot metal @ 1350C charged into the steelmaking furnace has C,Si, Mn,P along with Fe. These element in liquid form get oxidized to respective oxides and gets heated up to 1600C.
I am interested in calculating the heat of dissolution during this process. For eg in case of Si, it reacts with O2 to form SiO2 that is in solid state at 298K . Now this silicon oxide needs to be dissolved before heating to high temperature (1600C), so an equivalent heat of dissolution is required. How can i calculate this value or is thr any tables that can provide me the value for the same.
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In my recent article on Heat balance in the oxygen steelmaking process, I have mentioned the values. Kindly find the attachment of the link.
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Dear all,
I was wondering if there are unsupervised method that can identify different areas in a given data set. For instance, in some engineering applications regarding to combustion, there are thin areas where chemical processes take place , so high accuracy will be needed in those areas. So I would like to know which methods area suitable for these purpose. I know that autoencoders (AE) are used for dimensionality reduction, but also for visualization, is it a good idea to use AE for this purpose? Like visualize high dimensional data in 2D using an autoencoder and after that use a clustering techniques such as k-means to partition the domain.
I hope you can help me.
Best regards,
Cristopher
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Yes, K-Means OR Bayesian Classification framework of Maximum Likelihood Estimation.
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Dear all,
I have simulated a chemical process and I would like to run a sensitivity analysis on the impact of its parameters. Could you provide me with a tutorial on Monte Carlo method?
Thanks in advance,
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following
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I am going to do some chemical processing to a wafer coated with graphene. But I am not sure whether my solution (i.e. PGMEA) would damage the graphene or not? How to I analysize the interaction between the solution and graphene? Thanks.
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Dear Dr. Zhong Chuyu ,
I agree with what Dr. Jhonatan Rodriguez-Pereira said.
For simplicity I would act by comparison and focus more on the morphological surface part (Optical Microscopy, Scanning Microscopy, Profilometry, etc.) acting on an unexposed sample and subsequently, trying to evaluate a well-defined area, I would evaluate different attack times in the liquid, compatibly with your needs.
My best regards, Pierluigi Traverso.
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When Collagen is treated with acids or/and bases in water as a part of it's hydrolysis to gelatin. As I know we lose the tertiary structure and weak interactions involved in collagen. This results in separated triple helicates. my question : Do we have hydrolysis of amide linkages which are covalent bonds in this process leading to different gelatin chains ? or it is only a denaturation process (physical transformation) ? Please, I need a specific answer with references (paper, review, book...) if you can ?
Thank you in advance,
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For those still interested. In addition to the suggestions given by Nicolas Tardiota some more references with related (background) info:
De Wolf, F. A. (2003). Chapter V Collagen and gelatin. In Progress in biotechnology (Vol. 23, pp. 133-218). Elsevier. (see enclosed file)
De Wolf, F. A., & Keller, R. C. A. (1996). Characterization of helical structures in gelatin networks and model polypeptides by circular dichroism. In Gels (pp. 9-14). Steinkopff.
Keller, R. C. A., & de Wolf, F. A. (1998). Characterization of helical junction zones in gelatin networks-A spectroscopic approach.
Best regards.
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Preparation of activated carbon
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Dear Ammar Hamdoon,
Chemical process is prefered over the thermal. 60% of activated carbon is processed chemically.
In chemical activation processes, the precursor is first treated with a chemical activation agent, often phosphoric acid, and then heated to a temperature of 450 – 700 °C in an activation kiln. The char is then washed with water to remove the acid from the carbon. It’s an easy going process. Granular activated carbon is made from raw organic materials (such as coconut shells or coal) that are high in carbon. The activated carbon removes certain chemicals that are dissolved in water passing through a filter containing GAC by trapping (adsorbing) the chemical in the GAC.
Thermal process is comparatively complicated. The preparation of activated carbons (ACs) generally comprises two steps, the first is the carbonization of a raw material or precursor and the second is the carbon activation. The carbonization consists of a thermal decomposition of raw materials, eliminating non-carbon species and producing a fixed carbon mass with a rudimentary pore structure (very small and closed pores are created during this step). On the other hand, the purpose of activation is to enlarge the diameters of the small pores and to create new pores and it can be carried out by chemical or physical means. In a physical or thermal activation process, the lignocellulosic precursor is carbonized under an inert atmosphere, and the resulting carbon is subjected to a partial and controlled gasification at high temperature with steam, carbon dioxide, air or a mixture of these. Steam and CO2 are the two activating gases more used in the physical activation of carbons.
Chemical activation is the most used method for the preparation of ACs (~60 %) from lignocellulosic precursors. Physical activation methods is used in 28% of the studies. However, when thermal process compared with chemical activation, this method is not corrosive and does not require a washing step.That is a advantage of thermal process activation.
Ashish
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Hello all
I used to synthesis substituted hydroxyapatite using wet chemical process (Co-precipetation), but it leads me always to a structure full of Impurities, beside the uncomplet precepitation of the substituted metal seeing that the filtered solution still a little bit colored.
So could you please suggest a more efficient method to use or just give some advices about the wet chemical process.
thank you
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Hello to all friends and researchers.
In the next few weeks I will have a webinar on "Adaptive Fuzzy Sliding mode Control for Nonlinear Dynamic Chemical Processes". But I have trouble presenting content.
If any of you know the information or article or any reference in this field, I will be happy to share it with me and use your comments. Thanks
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This may be unrelated to your problem, but... If by nonlinear and chemical you mean something other than ideal gases, there's a problem. If the fugacity coefficient (indicative of chemical activity) is less than unity, the Gibbs problem (free energy minimization - the driving force and direction of the reaction) is ill-conditioned. The solution is free if you're interested in this aspect of reactions.
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A bioreactor is a container or system that maintains a biologically active environment. In some cases, a bioreactor is a container in which a chemical process is carried out that involves organisms or biochemically active substances derived from said organisms. With this in mind, what is the best type of bioreactor for the production of fermented beverages such as beer?
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Beer fermentation is anaerobic process and the conventional method is submerged free yeast fermentation . You can try immobilized yeast processing in submerged system or on immobilized column.
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Hi,
I would like to know more about practice-oriented journals for control systems application in: HVAC, industry, process systems, chemical processes, oil&gas etc. Majority of the Control journals are theory oriented, the most practical one is CEP (Control engineering practice), of course as the name suggests.
I need more titles like this. And also if some non-control dedicated journals cover various experience with applied control systems in some particular industrial field, please share.
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You can check journals list and their ranking here https://www.scimagojr.com/journalrank.php?category=2606
Best regards, Amin.
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The inside of the quartz tubes are thoroughly rinsed with acetone and then heated in a high flame.After the flame is removed and the tubes cool down,the coating is seen to be non uniform and coming off mainly from the bottom. Is there any alternative chemical or method to coat the quartz tubes?
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Im wondering what role time plays in the caramelization process if any? Do the chemical processes that are occurring require a certain period of time at the given temperature?
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Thank you Erik Kouba Kouba
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Is it possible to patent a mathematical (with algorithm ) model used for variables calculation of a chemical process, knowing that there are different models patented for the same chemical process ?
and what if my model is based on another model but with major equations modifications and improvements, can I still patent it ? (of course, while citing the prevuous work).
Thank you.
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Hey all, in order to open the discussion, you'll need to be aware of a few basic principles: a) patentability conditions, b) freedom-to-operate & doctrine of equivalence and c) exceptions of patentability.
a) a patent can be granted when your 'technical' invention is 1° new, 2° inventive and 3° industrial applicable. This third condition is 'here' important here because when talking about algorithms and mathematical formulae, they should be implemented in a particular application, such as a device, an apparatus, a process, etc. More particularly it is not enough to explain only the theoretical background, then you can choose for a scientific publication.
b) be aware of these already patented models, and you'll have to determine their scope of protection. When they claimed broadly and you use these already claimed features (in valid patents, covering your geographical market), you can be attacked for infringement, when entering these markets! So, you'll have to check your freedom-to-operate (FTO) for vending your product, with or without your own patent. Moreover, you can also be accused based on the doctrine of equivalence, when not exactly the same features of the patented technologies of others, but applying the spirit of invention even with your own slight differences. When you solve the same problem in a small different way, applying the fundamentals of the patented technologies, you'll need their authorisation to commercialize, like a license. A profound patent study is required here.
c) some 'non-technical' issues are not patentable, or at least open for discussion. This is i.a. the case with computer implemented inventions (software). This is mentioned in art.52 EPC (European Patent Convention): https://www.epo.org/law-practice/legal-texts/html/epc/2016/e/ar52.html. More specifically, art. 52 (2) (a) en (c) are important here. In the US: https://www.uspto.gov/web/offices/pac/mpep/consolidated_laws.pdf, art. 35 U.S.C. 101 and 103 are important. However, it could give you the impression that patentability is easier, less exclusions, etc... Case law in US states that abstract ideas and just data can be patented. Here again, the condition of a specific applications is required.
To finish my small intervention , a practical approach in a patent database. One of the patent classes that be used to search for models is: https://worldwide.espacenet.com/classification#!/CPC=G05B17/00. An example of a granted patent in this field is https://worldwide.espacenet.com/publicationDetails/originalDocument?FT=D&date=20190925&DB=EPODOC&locale=en_EP&CC=EP&NR=2556414B1&KC=B1&ND=4#. In order to select the granted patents (or thus those that are patentable by the EPO) you'll have to choose EPB in the field of the publication number and combining this with the CPC field: G05B17/low. Another very important Class is https://worldwide.espacenet.com/classification#!/CPC=G16C
Another example: https://worldwide.espacenet.com/publicationDetails/originalDocument?FT=D&date=19990811&DB=EPODOC&locale=&CC=EP&NR=0494110B1&KC=B1&ND=4#. When looking at the claims: claim 1 describes a process for the estimation of the physical parameters....using a computer. The classifications G06F17/50: https://worldwide.espacenet.com/classification#!/CPC=G06F17/50 (which is broader for multiple applications) and G06F19 can also be very useful to search. https://worldwide.espacenet.com/classification#!/CPC=G16B are related to ICT applications (bioinformatics).
So, to conclude: 1° try to find similar granted patents and have a look at the claims what they exactly claim, 2° detect patents that you can infringe and check their legal status (preferably with professional assistance) in the framework of your FTO. If you don't have FTO, your are blocked for your future steps, if FTO think about step 3, 3° ask for a patent professional to analyze your model in order to evaluate the novelty and inventive step, and the techncial application. When you solve the problem with a feature that is not obvious for a skilled person and you don't use the fundamentals of earlier valid patents, unless you can agree a cross-license or an agreement of use, patentability is on the floor. The best.
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What are the trends of research in chemical engineering in general and process engineering in particular? And what are the skills needed to master (modeling , data analytics , softwares ... ) in order to not be left behind in the future.
Thanks in advance
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Thank you Wilson, good addition.
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I added the equation about it here.
I'm stopped since I failed to calculate wave impedence.
Especially, relative permittivity and relative permeability are big obstacles for me to solve.
What I'd like you to do for me is not let me know how to calculate easily(of course, I'd thank you for it),
it would be even very thankful to you if you share me with books addressing this, with book names together.
Thank you for reading my question. I hope you help me.
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Wave impedance: At a point in an electromagnetic wave, the ratio of the electric field strength to the magnetic field strength. (188) Note 1: If the electric field strength is expressed in volts per meter and the magnetic field strength is expressed in ampere-turns per meter, the wave impedance will have the units of ohms. The wave impedance, Z , of an electromagnetic wave is given by
📷
where is the magnetic permeability and is the electric permitivity. For free space, these values are 4 × 10-7 H/m (henries per meter) and (1/36) F/m (farads per meter), from which 120, i.e., 377, ohms is obtained. In dielectric materials, the wave impedance is 377/n, where n is the refractive index. Note 2: Although the ratio is called the wave impedance, it is also the impedance of the free space or the material medium.
In the following website you find and example and solution to calculate wave impedance.
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In engineering design, it is very important to calculate the energy required for thermal remediation. Therefore, it is necessary to simulate the thermal remediation process, and the reliability of the simulation is closely related to the actual physical and chemical processes.
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Thermal remediation is very complex process depending on many factors (pollutants type, matrix quality, water content, chemical characteristics of pollutants to mention some of them), General information you can find in any textbook and on the EPA web site as mentioned @ Rick Manner above.
Regards
Vit
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Dear all,
I am performing a Techno-Economic assessment of the scalin-up Nano particles production, and I am looking for a free access and updated database for bulk chemical prices other than alibaba or molbase.
Many thanks in advance
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Dear Mouad Hachhach,
Bulk chemical prices database.
  1. https://www.sigmaaldrich.com/india.html
  2. https://www.zauba.com/
  3. https://www.chembid.com/en/
  4. https://www.made-in-china.com/
I hope the information will help you.
With Best Wishes,
Samir G. Pandya
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There are several different definitions of the rate of a chemical reaction in the scintific literature. However, in the case of a quantitative description of the chemical process in the reactor, mass balance equations are used. The definition of reaction rate is unnecessary there. Defining the reaction rate is necessary in determining the form of the kinetic equation (rate law) using differential method. But is it only this case?
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From chemical reaction engineering kinetics the order of the reaction is dependent on volume of reactor and the reaction is to be considered as constant
volume or constant pressure . There are different types of reactors depending upon the type of reaction used ie liquid / Gas phase and accordingly reactor will
be classified as Batch , CSTR / PFR type of reactors .
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I could not find an accurate value in the literature, would you know it?
I would need the polar and dispersive parts as well.
Thanks in advance.
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dear Antoine and Yuri, we just completed this year an extensive comparative study of the surface energies of as received Si(100) wafers native oxides with different dopants, using 3LCAA and the vOCG theory, and published it in MRS Advances. You may find the results useful to answer your question. We have two more manuscripts in preparation.
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Hello all,
I am looking for applications or systems where two phases, wherein one is Newtonian while other is non-Newtonian of both are non-Newtonian are involved.
Some initial search do gives some broad fields like bio-medical, chemical process but I am looking for more precise examples.
It would be kind to seek some answers.
Thanks
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You can use star ccm+, in this software you can define most fluids such an
Newtonian and non-Newtonian and chemical process and multiphase of them.
Best Regards
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Green products are environmentally benign, sustainable products consider social perspective along with environmental responsibility whereas organic products are made of herbs, plants and natural elements without any chemical process.
What are the similarities and difference among these types of products?
Do customers really think about green, sustainable and organic?
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A green product means that it is biodegradable, that in general it does not pollute the environment, a sustainable product means that when we produce it or sell it, the future generations will still have the same possibility of producing it for their benefit, and an organic product means that they not used hormones or pesticides in their production, it is produced in the old way.
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MEE Feed : 3300 kg/hr in fisrt VLS-01, Feed temp 75 deg C and vapor temp @ 68 Deg C, Steam is 1250  kg/hr, with 2.7 kg/cm2g steam, First effect chest pressure 0.66 kg/cm2g
Second VLS- liqid temp: 60 deg C, and vapor temp., 64 deg C
Third VLS-liquid temp: 61.6 Deg C, vapor temp : 47.5 Deg C, Vacuum 670 mmHG
Circulation Pump in Effect 1-2-3: 800- 400- 400
HTA:
Effect 1: 200 m2 : Dia : 1 inch
Effect2: 78 m2: Dia : 1 inch
Effecr-3: 78 m2: Dia : 1 inch
Condenser: 426 m2
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I want to make PbO nanoparticle through chemical process. Can anyone provide me the protocol.
Thanks in advance
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You can see the paper DOI:10.1016/j.matchemphys.2007.09.045
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I need time series data of any chemical reactors or separation columns for making a ARX or ARMAX models , can anyone please direct me towards a reliable sources'
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I will suggest you search for the information on science direct.
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For example, for natural gas sweetening, several processes such as Rectisol process, Selexol process, Amine-based processes, etc. are available. I want to screen the processes to select the best/optimum process for my plant considering all types of feasibility parameters (Technical, financial, etc.). Is there any step-wise methodology, technique available for process selection? Usually, people go with Checklist method. But I am looking for something advanced, something more rigorous and detailed.
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Yes there are. They are called Plackett-Burman Experimental Designs.Please see the attached paper as well as the book in this link:
Best wishes, David Booth
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Hello, I'd like to study metal poweder coating recently.
In some paper, they do chemical process with metal powder such as copper.
So, I want to know how i can rinse metal powder properly.
Is there good tools for cleaning and rinsing metal powder?
How can I drain water without throwing away the metal powders?
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To rinse a powder you need a sieve with the mesh size smaller than the particle size of the powder. For example, such a
laboratory sieve:
For small amounts of powder, it goes without a sieve. You rinse the powder in a large beaker and leave suspension for a while: metal powder sediments on the floor and you can carefully drain off water. Then you dry the powder with the remaining water in a drying oven.
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We have a requirement to dissolve solid graphite by chemical process with or without electrolytic process.
Note: This is not related to graphene production process in any way and responses related to graphene are not required.
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Solid Graphite is not soluble in polar and non-polar solvents, but it may soluble in molten Nickel and warm chlorosulphuric acid.
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Are there any papers that discuss the formation of iron precipitates in wastewater?
Does it only happen in RBC plants or does it also happen in activated sludge, etc.?
Is it a chemical process or a biological process?
Under what conditions does this occur? Influent parameters? pH range? Temperature influence?
Is there a way to inhibit it?
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Hello Djigui, please see the attached paper which may be of assistance.
Good luck in your research.
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I carried out an experiment, where COOH functionalized CNTs were dispersed in an aqueous solution along with polycarboxylate based superplasticizer. In addition, nano-silica oxide was added to the mix and left on the desk.
After 5 days, the solution has completely solidified. I'm looking for some suggestions on this chemical process?
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By saying "nano-silica oxide", do you mean Aerosil from Degussa or its equivalent? Nanoparticulate (or fumed) SiO2 easily forms silica gel, and can be used, for example, for thickening electrolytes in batteries:
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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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I have the pre exponential factor, activation energy and the Keq values (A and B values) for the reactions involved. How do I specify driving expression coefficients using partial pressure basis and the corresponding power law concentration exponents? All reactions in naphtha reforming are pseudo first order reactions.
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Dear all,
I am trying to co-simulate a chemical process in two-different environment. One is Aspen Plus and another is an CFD based simulator.
The process has different units to be simulated in above two environments. In order to do so, I need to connect the two.
Questions:
1. is there any tools available , which is open-source and connects the two / or inbuilt in the two?
2. How to download and use CAPE-OPEN for the same?
thank you.
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DWSIM is an open-source CAPE-OPEN compliant chemical process simulator for Windows, Linux and macOS. DWSIM is built on top of the Microsoft .NET and Mono Platforms and features a Graphical User Interface (GUI), advanced thermodynamics calculations, reactions support and petroleum characterization / hypothetical component generation tools.
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I want to enlist all the metabolites found in a particular plant. I have a very limited knowledge on chemical processes like chromatography. I wanted to know whether an HPLC can isolate particular secondary metabolite molecules from a mixture. And if it can I want to know the principle behind it. Any material on the basics of HPLC is welcomed. Thanks in advance.
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HPLC is probably not suitable and first you need to define what kind of component you want to purify.
Looking for the theory of preparative HPLC, just Google and you will find for example
Looking for examples ?
Good luck
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Hello Guys,
Suppose that we have a data from a chemical process. There are some inputs and one output, the output depends on those inputs and also the time. I am gonna identify this process. So what is the difference between using simple MLP with Lagged output as an input (lagging the output as an input to the model, like 5 step before) and using recurrent neural network such as ELMAN or JORDAN without lagging the output, because i know JORDAN is just feeding back one step before as an input.
Thanks
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Thank you all guys for nice information.
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I am looking for the chemical process to strip 2H+ from free base Phthalocyanine and replace them with Cu2+ to form CuPc. Copper salt in alkaline medium... or..?
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Boiling the mixture of H2Pc and copper(II) acetate in 1-chloronaphthalene or quinoline should probably work. However, I agree with Tomas Tempesti that making CuPc from scratch would be easier. If you have access to the vacuum sublimation apparatus, then heating bulk mixture of phthalonitrile and copper(II) acetate with with the two subsequent sublimations should yield reasonable amounts of very pure CuPc crystals.
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I am working on the immobilization of enzymes for textile chemical processing applications, I wish to ascertain the covalent immobilization of Glucose-oxidase enzyme over the chitosan beads using glutararldehyde as a cross-linking agent. Which peaks characterize the imine bond (Schiff's base) formation.
I had refereed many papers, they give different explanations regarding peaks.
Can anyone help me in this context?
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The stretching vibration of imine group in IR
appear around 1630__1590
Also you can check it by HNMR where the signal of azomethaine proton appear at
8.5__9 ppm
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I know cery little about soot or the chemical processes involved in its oxidation.
I know that dangerous compouns such as carbon monoxide are produced when the available oxygen is low.
Introducing biofuels would introduce more oxygen or redesigning the engine but other than that i'm stuck already.
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Can you tell us more about the application?
In ethylene plant pyrolysis furnaces, a hydrocarbon feed (ethane, propane, etc) is heated to about 1500°F-ish in the tubes of the furnace. The hydrocarbon "cracks" making ethylene, propylene and 50 some other components. In the process, coke is also formed and deposits on the inner walls of the tubes. At some point, the tubes will have to be "decoked". The decoking starts with steam and it followed by allowing air into the tubes at temperatures around 1200°F. The oxygen in the air reacts with the coke converting it to water and carbon dioxide. The decoking could last at to one day, a period after which the tubes are presumed to be clean enough to switch the furnace operation back to cracking.
I hope this helps.
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While Monte Carlo simulation of a chemical process ''catalyst, monomer and agent'', is there any 'routine' to track runs so that in future runs for same or similar process, the probability can be increased for an earlier exact to actual output?
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Run 5 or more times and evaluate the averages and standard deviations.
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Can you please tell which wet chemical process is good to clean Si, Ge, SiGe wafers to remove metals, native oxides and organic impurities?
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It is my understanding that Tregs can influence development of autoimmunity through complex signaling pathways. Since they are often at high levels in progression of breast, ovarian and pancreatic cancers, I was wondering whether this is due to what's going on inside these tumors or their environment as a chemical process that may increase Treg production or differentiation, or whether the high levels of Tregs result from a patient's depleted immune system?
Can strategies be targeted selectively on reducing Tregs if they are interfering with a patient's response to therapy?
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Different strategies including the use of depleting/blocking antibodies (CD25, CTLA-4, CCL2), IL-2/immunotoxin conjugates, cyclophosphamide, or COX2 inhibitors have been tested in mouse models of cancer and pre-clinical trials, but these did not always result in decreased numbers of Tregs or good anti-tumour response (see: Beyer & Schultze. 2006. Blood 108(3)804-11. https://www.ncbi.nlm.nih.gov/pubmed/16861339).
Frederick Arce, in Sergio Quezada’s group (University College London Cancer Institute), has recently published a paper in which they report on the importance of the anti-CD25-depleting antibody isotype in mouse models of transplantable tumour cell lines. They found that using engineered anti-CD25 antibodies with increased binding to Fc receptors results in enhanced depletion of intra-tumoral Tregs. This antibody, used in combination with immune check-point therapy led to complete tumour rejection in mice. Their observation that CD25 expression is restricted to CD4+Foxp3+ in human peripheral and tumour-infiltrating lymphocytes led them to propose that this validates the use of CD25 as a target for therapeutic Treg depletion in humans.
Very interesting paper (https://www.ncbi.nlm.nih.gov/pubmed/28410988) to read and see where the field of combined immunotherapy for cancer is moving. Their results suggest that efficient depletion of Tregs would be possible in clinical trials in order to improve the response to other therapies.
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I am used to using Aspen Plus in courses at Uni.
However, I no longer have access to such a software.
I am looking for comparable software that is Open Source, and preferably operational on a Mac OS Sierra (I do have bootcamp, however).
I need it primarily for wastewater reactions, or something that can analyze biological matrices in reactors. 
Any sources/suggestions welcome.
Thank you.
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Try DWSIM
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Hi I am trying a process and the process is like this
1. disperse some transition metal into 20mL IPA (or ethanol)
2. add 0.35mL of H2O2
3. Once it reacts fully, dry the solution.
in the third step, if I want to dry the solution and have no redundant H2O2 left in the solution, can I heat the solution? If so what is the best temperature to do? Most importantly, Will it exposes any danger.
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Without knowing the details of your process, you should be aware that ethanol and IPA form azeotropes with water. That ultimately means that such mixtures cannot be separated completely via the application of heat alone. For example, in the production of pure ethanol from a mixture of water and ethanol, the distillate (the azeotropic mixture) is further processed - using  temperature swing adsorption, for example - to "break" the azeotrope.
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There are hundreds of very harmful chemicals at this process i have to know which are most harmful.
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Dear Akin,
The document proposed by messaoud is very interesting, but it is in French. This is one of the few documents that reveal the type of chemicals used in hydraulic fracturing.. Here is an excerpt in English.
At the last meeting of the Congress, the Committee on Energy and Commerce (USA) launched an investigation to examine the practice of hydraulic fracturing in the United States. As part of this investigation, the Committee asked 14 major oil and gas companies to disclose the types and volumes of hydraulic fracturing products used in their fluids between 2005 and 2009 and the chemical content of these products.
Between 2005 and 2009, 14 major oil and gas companies (USA) used more than 2,500 hydraulic fracturing products containing 750 chemicals and other components. Overall, these companies used 780 million gallons of hydraulic fracturing products - not including water added to the well site - between 2005 and 2009. Some of the components used in hydraulic fracturing products were used frequently and generally harmless, such as salt and citric acid. Some were unexpected, such as instant coffee and nut shells. And some are extremely toxic, such as benzene and lead. The most widely used product in hydraulic fracturing during this period, as measured by the number of compounds containing the chemical, was methanol. Methanol, which has been used in 342 hydraulic fracturing products, is a hazardous air pollutant and is on the list of potential "candidates" for regulation under the Safe Drinking Water Act. Some of the most widely used chemicals are isopropyl alcohol (used in 274 products), 2-butoxyethanol (used in 126 products), and ethylene glycol (used in 119 products). BTEX - benzene, toluene, ethylbenzene and xylene - occur in 60 of the hydraulic fracturing products used between 2005 and 2009. Each compound is a BTEX contaminant regulated under the Safe Drinking Water and and a hazardous air pollutant under the Clean Air Act. Benzene is also a carcinogen. Hydraulic fracturing companies injected 11.4 million gallons of products containing at least one BTEX chemical over the five-year period. Between 2005 and 2009, hydraulic fracturing companies used 95 products containing 13 different carcinogens. They include naphthalene (a possible carcinogen for humans), benzene (a carcinogen), and acrylamide (a probable carcinogen for the man). Overall, these companies injected 10.2 million gallons of fracturing products containing at least one carcinogen. Many of the chemical components of hydraulic fracturing fluids used by companies were listed on MSDSs as "proprietary" or "industrial secret". Hydraulic fracking companies used 93.6 million gallons of 279 products containing at least one exclusive element between 2005 and 2009. Here are some of the most widely used toxic chemicals :
Methanol (Methyl alcohol), Isopropanol (Isopropyl alcohol, Propan-2-ol), Ethylene glycol monobutyl ether (2-butoxyethanol), Ethylene glycol (1,2-ethanediol), Hydrotreated light petroleum distillates,
With my best regards
Prof. Bachir ACHOUR
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Room temperature is preferable......
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Ozone is best choice. Also permanganate is possible. You may add static electricity if these are not successful. Normally nickel forms a thin durable oxide layer in air, indicated by the loss of reflectivity.
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We have Graphene nano palates. We want to produce Graphene oxide nano particles to be used for water treatment. What would be the chemical process to convert these Graphene nano palates into Graphene oxide? Plz help.
Thanx in advance
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Simply try the reflux with HNO3.
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Hi,
I have a chemical process that I will evaporate ammonium molybdate tetrahydrate. So there will be ammonia NH3 gas coming out. What should I do for the risk control. I am thinking to do this process in the fume hood that evacuate the ammonia immediately.
To make it more clear, the amount of ammonium molybdate tetrahydrate diluted in DI water would be no greater than 0.25g, which is saying that amount of NH3 could coming out from the solution should be no greater than 0.01g. Is this amount of NH3 would be dangerous? 
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Chemical Fume hood with good ventilation is best option in a lab
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Hi everyone
i need to remove the water formed during the reaction and i've seen articles mentioning removing it by distillation. i have never performed distillation Simultaneous with my reaction,  can i just connect a distillation setup to my reaction flask? i'm afraid some of my solvent will be removed too, although it has a high boiling point ( ≥ 200) 
also is it possible to remove the water using a dean-stark apparatus?
some articles also mention using vacuum to remove the water. Which way is better?
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removal of water using Dean-stark is only possible when you heat the solvent to boiling point, and generally the solvent should be imiscible with water.
since your solvent has such a high bp, Dean-stark does not seem to be the way to go. Removal by distillation is possible but depends on the solvent which may trap the water and raise the temperature required to drive off the water. You didn't mention the temperature you run your reaction, so you may not need to heat your reaction for it to proceed.
Another way is to use molecular sieves to remove the water, or chemical drying agents like orthoformates (although this may have other side reactions).
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We had used solvothermal method to synthesize copper oxide NPs using copper chloride precursor, but chlorine couldn't be removed entirely from the product (evident  from EDX analyses result). Large amounts of water and ethanol have been used to wash the product after preparation and to no avail.
Appreciate your suggestions/tips
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Chloride is an excellent ligand to Cu. Thus, there is only one way to obtain Cl-free CuO samples. Avoid any halide in the precursor! Washing will not help to remove coordinated Cl on the CoO surface.
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I'm  working in chemical industry. i want learn energy and mass balance.? please provide related genrals.
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You can read the book of chemical process industries, process calculations (Himmelblau). It will be useful. Its a vast topic, you need to know and understand the unit operation you are interested in, details of reactant, product and the time and temperature at which the reaction proceed forward or backward or may be irreversible, composition of the feed, composition of the product and reaction pattern that can say some details about the intermediate products (if any). Once you know everything you can make an energy balance and mass balance. Mass balance is super simple and straight forward, to calculate the energy balance, you need to know the chemistry involved and information on the system, like the free energy and how it change and the internal energy, so on. Its very difficult to answer here as you need previous knowledge on this topic and you have to read the above said text book.
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While using GC methods for predicting any chemical properties, how one will represent the chemical structure and find the number of occurrences of each group? Is there any publicly available codes for predicting any chemical properties using GC methods?
Thanks in advance,
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Methods used in ASPEN Plus are also available in public. There are many methods. A popular book is Reid and Sherwood,  Properties of Liquids and Gases, where group contribution is the main content.
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Since surface color impact on  solar radiation absorption and it may affect other chemical process relating to energy possession. So UV prone region how dye synthesized solar cell will be affected by it.
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I very strongly suggest you keep ALL UV out of DSC as it will rapidly degrade most of the organics. Fortunately this is not difficult to do.
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Raman analysis  can indicate well dispersion of GO in membrane ?
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Dear Soheila Manshad,
As mentioned above by Dr/Prof Eldenglawey you can use optical techniques. I would not recommend Raman for the dispersion state as it is mainly a surface technique. However, XRD can give you a relative indication whether your GO is exfoliated in your membrane.
Another technique you might consider is microfocus x-ray tomography which I've used in my own studies. It is non-destructive and gives you a decent 3d-image that you can reconstruct to differentiate between the polymer membrane and filler.
Kind regards
Louis van Rooyen
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n-butanol as a biofuel which is considered as a future energy source to substitute with gasoline. The heating value of n-butanol is higher than that of ethanol that for this reason, the first alcohol gives only carbon dioxide and water. While the second alcohol produces SOx, NOx, CO, and other harmful byproducts
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What are you burning alcohol with (or what is the 2nd reactant in the  reaction  with Alcohol)
Alcohol + O2  >  CO2, H2, CO, H2O, Heat
Alcohol + Air  >  CO2, H2, CO, H2O, NOx, SOx, Heat
N and S are  constituents of  Air
N and S may be a contamination in your alcohol.
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i want to convert dicarboxylic acid to acid chloride, i want practical procedure.
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Ajit:
Thionyl chloride is the most widely used reagent for the preparation of acid chlorides. The procedure normally involves heating the carboxylic acid or dicarboxylic acids with a slight to large excess of SOCl2 in an inert solvent or with SOCl2 itself as the solvent. Performing the conversion at the boiling point of the solvent speeds removal of the byproducts, HCl and SO2. The ease of removal of the byproducts is the chief advantage of SOCl2 over PCl5 and PCl3. This simple procedure gives good yields of the acid chlorides. The reactions are first order in each reactant and electron-withdrawing groups on the acid decrease the rate. This reaction should only be performed in a hood. !! 
The conversion is a pretty standard organic reaction and you could use either thionyl chloride SOCl2 or phosphorus chloride PCl3 or PCl5 avoid contact with zinc.
Good Luck
Steve
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Hi all,
can you help me to correctly interpret the protocol I reported as follows?
My protocol says "
Subsequently, 11.25 ml of 5% (w/v) Zwittergent Z 3-14® and 0.5 M CaCl2  in water were added and stirred for 1 h at room temperature (RT)".
I interpret it as a one solution with Zwittergent, Cacl2 and water..Is it right?
To calculate the volumes I did like this:
I calculated the mls of a 1 M solution of CaCl2  to have a CaCl2 solution 0.5 M in a final volume of 11.25. So:
11.25 ml X 0.5M/ 1M = 5.625 ml
For the Zwittergent I have just calculated the amount to weight to have a 5% solution  in a volume of 11.25 ml
So: 5g/100ml X 11.25ml = 0.5625 g..
So, I should weight 0.5625 g and dissolve it in the mix with the 5.625ml CaCl2 and bring up to volume with water...Does it make sense?
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Hi Silvia, correct! Actually the protocol is a bit ambiguous. You can find the correct phrasing of the protocol in this paper:
Polish Journal of Microbiology (2009) 58, 205.
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I added the equation about it here.
I'm stopped since I failed to calculate wave impedence.
Especially, relative permittivity and relative permeability are big obstacles for me to solve.
What I'd like you to do for me is not let me know how to calculate easily(of course, I'd thank you for it),
it would be even very thankful to you if you share me with books addressing this, with book names together.
Thank you for reading my question. I hope you help me.
Can you let me know how to calculate wave impedence?
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Sorry for my late response.
And thank you for your kindness.
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I read in one of the papers that at pH as low as 1.0, Cr(VI) anions are likely to get reduced to Cr(III) ions. Can anyone please give an explanation for the same?
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Thank you so much Carlos.
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I am using polyacrylamide gel electrophoresis. I want to analyse 700 kDa aggregates. I don't have gradient maker. I have tried different concentration of (stacking gel and resolving gel) as (3%,5%) and (3%,6%) but I have not observed any band. Can you help me with gel and concentration I can use ?
Thank You
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Maybe i think 5 position of phen was nitration by HNO3 and H2SO4 and Br- in NaBr reducted nitro group in phen. But, how can phendione be produced?
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Jae Jun Lee:
                         The electrophillic substitution reactions such as nitration on the aromatic hydrocarbons phenanthrene and1,10- phenanthroline are generally difficult/complicated. That is due to the higher reactivity of the functional unit (that may not be real part of aromatic system as shown in attached file) toward addition reactions. Due to its typical reactivity, this structural unit generally behaves like alkene in few reactions and is more prone to give addition reactions rather than substitutions. In your experiment, you have used two oxidizing agents such as nitric acid acid and sulphuric acid. There may be many complicated processes involving in the oxidation. The most reasonable is given in the attachment.
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I am simulating a CO2 capture unit with MEA amine. Everything in the simulation converged except the recycle stream that is coming from the stripper to the absorber. I tried different operation parameters to make the stream converged, but still the problem persists. So any hint in order to tackle this problem? 
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To converge such simulations I initialize the lean solvent stream already with some CO2 content. For MEA, you want to use something from 0.1-0.3 molCO2/molMEA. Then I use the design-spec tool in order to fix the conditions at the stripper's bottom to the same desired CO2 loading by manipulating the reboiler duty. Depending on your operating pressure, you should use a balance block to replace your water and MEA losses by adding a make-up stream. When your recycle stream is similar enough to your lean solvent stream (temperature, pressure, composition), you can use a transfer block to copy the recycle stream into the lean stream on every iteration, virtually closing the recycle. Try changing the tear converging method from Wegstein to Broyden as well. I've found this to be a quite robust approach. If you are interested, a detailed explanation is also given in my linked publication:
I hope that helps,
Best regards,
Alberto
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If I have a dithienyl-benzothiadiazole, and I intend to brominate only one out of two thiophene ring of the structure. Did anyone have any idea/pathway how to do it? Can it be done by controlling the ratio of bromine source?
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Thank you for your reply.