Questions tagged [chemical-engineering]

For questions about processes in commercial chemical manufacturing.

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Specific temperature ranges of kinetic combustion mechanisms

Do kinetic combustion mechanisms typically operate within specific temperature ranges? I tested some mechanisms from the scientific literature, and apparently they were only working at temperatures ...
Somestudent01's user avatar
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1 answer
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Calculating Fractional Yield as a function of temperature for a parallel reaction in a plug flow model

(This question comes from a Chemical Engineering background, I hope it still falls in the scope of engineering.stackexchange.com If not, please move.) I am trying to calculate and plot fractional ...
Hsauce13's user avatar
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1 answer
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Closed pressurized water vessel

Suppose we have a closed container not isolated from the external environment so that heat exchanges can occur on the lateral wall (mainly for convection). The water inside is pressurized by a gas (...
Enrico's user avatar
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How do polyurethane varnishes cure after only the solvent evaporates

How do polyurethane varnishes cure after only the solvent evaporates? I believe that polyurethane varnishes have as components isocyanates & polyols that react to form the polyurethane portion of ...
Tempus Nomen's user avatar
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Silver Nitrate Test for Acetylene gas qualification; looking for an appropriate instruction

Phosphine and Hydrogen sulfide along with some other hazardous gases are of impurities of acetylene plants witch are based on the reaction between water and calcium carbide. One of the simple and fast ...
Reza Koohpaee's user avatar
-4 votes
1 answer
134 views

how I can separate nickel and chrome in single [closed]

How I can separate chrome and nickel from a nickel sulphate,nickel chloride and chrome salt separately??when these mixed up in a single solution.Please tell me how to do it using simple house hold ...
Naveed AA's user avatar
4 votes
1 answer
117 views

Chemical species equations in a kinetic mechanism of combustion

In combustion, for a kinetic mechanism involving $m$ reactions and $n$ chemical species, of the form \begin{align} \begin{cases} \nu_{11}' \mathcal{S}_1 + \nu_{12}' \mathcal{S}_2 + \dots + ...
Somestudent01's user avatar
1 vote
1 answer
72 views

Effectivness factor for a cylinder

I would like to demonstrate the effectiveness factor of a porous cylinder, for diffusion-reaction (only radial diffusion, 1st order reaction, isothermal, diffusion coeff. is constant, steady-state), ...
Oquai's user avatar
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Heat transfer calculation in open tank equalization

Thanks for your replies guys, sorry for unclear and undefined question. Let me try to reparaphrase my question. Updated info: This is the way i try to solve this problem. I calculate the pipe length ...
Fee's user avatar
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1 answer
110 views

Process of Arecoline Extraction

What would be the proper procedure to extract and isolate arecoline, an alkaloid ester, from the seed of the Areca nut, and is it possible to mass produce arecoline using that method?
Josh Wohwie's user avatar
2 votes
1 answer
431 views

What is the difference between differential yield and selectivity?

I have a hard time understanding the difference between the differential yield and overall selectivity of a reaction. Levenspiel, Chemical Reaction Engineering writes: For convenience in evaluating ...
frgoe003's user avatar
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2 answers
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Solvay process and its relationship with sodium chloride and calcium carbonate

I’m studying some chemical engineering process and my teacher made a question in class that nobody knew how to answer it and then she asked to made a search after class. However, I don’t even found ...
ksa's user avatar
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Multi compartmental ODE's in chemical engineering

I am alien to the field of chemical engineering. And I am confused about equations, written by chemical engineers, including several variables belonging to different compartments. Assume that, $[X]$ ...
confused's user avatar
5 votes
2 answers
1k views

Suitable solvents to dissolve Aluminum Chloride (anhydrous) without generating Hydrochloric Acid (aqueous or gas)

Hypothetically, I have a chemical tank that was brought out of service and the solid deposits at the bottom of the tank primarily contain aluminum chloride. The whole system never sees water, and the ...
Sam's user avatar
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-1 votes
2 answers
503 views

How long can dimethyl sulfoxide be safely stored in a HDPE "barrier bottle"?

How long can dimethyl sulfoxide be contained in a HDPE barrier bottle without any reaction between the plastic and the solvent? I have read that DMSO is not reactive with HDPE, but I would like to ...
WishyQ's user avatar
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Calculating pourbaix diagram of Fe-H2O system at different temperatures

I have been trying to calculate the pourbaix diagram for Fe-H2O at different temperature for my high school research but I am facing a lot of problems. I have several question regarding the ...
Rajshibhu Pandey 's user avatar
1 vote
1 answer
98 views

What chemical reactions takes place in purifying acetylene?

Acetylene produced by water on calcium carbide method contain several impurity compound, that are harmful for welding or other purposes of acetylene and needs to be absorbed from the gas mixture ...
Reza Koohpaee's user avatar
1 vote
1 answer
287 views

What scientific and technical challenges prohibit the industrial use of the Sabatier reaction?

It seems that the Sabatier reaction solves the biggest problem of climate change — it does create clean gas and hydrogen fuel from the captured carbon dioxide and water (from melting ice). $$\ce{CO2 + ...
TomR's user avatar
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how to make a PEM (proton exchange membrane) out of Nafion Dispersions?

I would like to use a Nafion membrane for a fuel cell project, but the Nafion sheets are hard to integrate. Therefore, I would like a gel type of Nafion that can take the shape of the container I put ...
Anwer Ak's user avatar
1 vote
2 answers
1k views

Evaporation Rate of Hydrochloric acid

I'm currently working in a Chemical Plant as an intern, and I was given a task to improve the efficiency of the blower, which is already in place right now, by designing a new blower for the ...
Ashutosh Purohit's user avatar
2 votes
4 answers
872 views

What non-toxic non-corrosive liquids are used for heat transfer?

I have a steel vessel placed concentrically within a larger steel vessel, resulting in air-filled annulus (air gap) between the two vessel walls (figure below). Due to the existing vessel construction,...
Armadillo's user avatar
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Rate of polymerization for copolymers with two monomers

I've found in textbooks that for a chain growth homopolymerization the rate of polymerization $r_\mathrm{p}$ is $$r_\mathrm{p} = k_\mathrm{p}\sqrt{\frac{f_\mathrm{kd}}{k_\mathrm{t}}}c_\ce{A}^ac_\ce{B}^...
Nebula's user avatar
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3 votes
1 answer
153 views

How can the reaction heat be ignored in an energy balance?

I have received from my professor the following (summarized) problem: A first-order exothermic reaction $\ce{A->B}$ took place in a typical tubular plug flow reactor (PFR). The tube was cooled to a ...
J Faller's user avatar
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24 views

Literature recommendation - non-stationary heat transfer in porous solids

I am trying to calculate a non-stationary heat transfer to a porous spheres by conduction. These spheres are placed in a thin metal tubes with a known heat capacity. Hot/cold air (or similar gaseous ...
Josh E.'s user avatar
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1 answer
899 views

How to relate equilibrium constant and equilibrium conversion?

For the following gas phase reaction: $$ A\leftrightarrow B $$ The concentration equilibrium constant ($K_c$) can be expressed as: $$ K_c = \frac{c_B}{c_A} = \frac{\frac{F_B}{\vartheta}}{\frac{F_A}{\...
HWIK's user avatar
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-2 votes
1 answer
104 views

Non-RSPO MB glycerin vs RSPO-MB glycerin

Does non-RSPO-MB glycerin function differently than RSPO-MB glycerin? For example in a cosmetic serum /lotion?
Johnna's user avatar
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1 vote
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59 views

Recycling flow if the chemical process of acetylene and hydrocyanic acid

I'm having some issues trying to solve this problem, because the concentration of inert in the recycling flow that I calculated is bigger that the concentration of the inert that is enterying to the ...
Camilo Vargas's user avatar
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0 answers
48 views

Which reaction is happening in the preparation of sulfuric acid through contact process?

I've read that in the preparation of $\ce{H2SO4}$ through the Contact process, on the absortion tower, the gas $\ce{SO3}$ is getting in contact with $\ce{H2SO4} (l)$ , because adding $\ce{SO3}$ to $\...
user117647's user avatar
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0 answers
128 views

Vapor - Liquid Equilibrium (VLE)

Most fundamental equation for VLE is $$ \mu_i^L = \mu_i^V $$ It states that for every component chemical potential must be equal in both liquid and vapor phase at equilibrium. However, in my thermo ...
Dario Mirić's user avatar
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1 answer
566 views

Is stoichiometric imbalance in polymerization important if the process has an evaporation step?

Polymerization texts stress the importance of stoichiometric balance of the monomers. For example here: https://www.e-education.psu.edu/matse202/node/606 I can understand how stoichiometric imbalance ...
Arthur's user avatar
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188 views

Ideal CSTR mixing assumption

Sorry if this seems like a silly question but it has me confused a lot. So I have just started taking Chemical Reaction Engineering, and was studying about continuous-stirred tank reactor (CSTR). So ...
obiwan's user avatar
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3 votes
0 answers
415 views

Why do we want to operate at dew point or bubble point when doing flash calculations?

I'm trying to dimension a flash drum for a separation between water and isobutane. I now the total inlet flow (F), the composition of the inlet flow ($z_1$ for isobutane and $z_2$ for water) and the ...
Erik Sahlin's user avatar
2 votes
0 answers
58 views

Process parameters of typical chemical processes [closed]

I am researching to opportunity of heat recuperation in the chemical industry be means of high temperature heat pumps. However, I am having some trouble with finding suitable applications. I would ...
Elias4's user avatar
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75 views

How much energy is required to liquify oxygen?

Does anyone know where I can find some documentation of a real-world liquification process, and the energy costs? I can calculate the heat that must be removed from O2 gas to get to liquid, but how ...
dlight's user avatar
  • 337
3 votes
1 answer
333 views

Make pyridine from furfural

Furfural $(\ce{C5H4O2})$ has been used as a feedstock for synthesis. Furfurylamine $(\ce{C5H7NO})$ is made from furfural. Given that industrial manufacturing ammonia is matured, how about combining ...
Kav's user avatar
  • 232
4 votes
0 answers
163 views

How much energy is required to operate a Sabatier reactor?

I am trying to model some industrial processes and having a hard time finding information about the Sabatier reaction. The Sabatier reaction combines $\ce{CO2}$ (and possibly $\ce{CO}$) with $\ce{H2}$ ...
dlight's user avatar
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3 votes
0 answers
226 views

Calculating temperature of partial condenser, flash calculations

The iterative method I have learned to make flash calculations for a binary system where I know the inlet feed (F [mol/s]), total composition of the two components ($z_1$ and $z_2$), the amount of the ...
Erik Sahlin's user avatar
2 votes
0 answers
185 views

The Use of AI and Machine Learning in Organic Chemistry

I am trying to do a bit of research into the current use of machine learning in chemical industry. I've been told my original question was too general so I'll try to be more specific about what I'm ...
Allod's user avatar
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4 votes
1 answer
103 views

Modelling pH as function of time and position

I already posted this on the Engineering Stack Exchange under Chemical Engineering as I don't know where it's a better fit. I have a system whose initial state consists of three different sections ...
Iridium's user avatar
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0 votes
1 answer
178 views

Using the right equipment for successful detection of Novichok [closed]

Apparently, Navalny’s biomaterials were flown to Moscow's Nii Sklif lab which didn't find any traces of the poison. But they used an American Agilent Technologies GC-MS [1], while Bundeswehr ...
rych's user avatar
  • 117
3 votes
1 answer
1k views

How or Why does diesel/kerosene have a much higher 'flash point' but lower auto/self-ignition point than gasoline/petrol?

This is a very common question, but I have yet to find a good theoretical answer to both questions (diesel has higher flash point BUT lower spontaneous ignition temp.)
Kurt Hikes's user avatar
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0 answers
1k views

Thermodynamic and Transport properties input files for Chemkin

I am using Chemkin pro 2009 version. I want to model a decomposition+combustion reaction on my catalyst in a plug flow reactor.So I'll need to create my own Thermodynamic and Transport Properties file ...
user86428's user avatar
1 vote
0 answers
55 views

Definition of throughput

I wonder what's the exact meaning of throughput in chemistry synthesis, eg. in organic synthesis or production of pharmaceutical products. For instance, what are their units? How are they measured? I'...
MFC_503's user avatar
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1 vote
2 answers
77 views

Why am I getting higher conversion values of isopropanol dehydration over a zeolite catalyst than n-propanol dehydration?

The two process are run separetly but under the same condition, same activation of the catalyst, same reaction temperature, same flow. The initial conversion of n-propanol is ~50% and isopropanol ~70%....
marietiara's user avatar
-4 votes
1 answer
399 views

molecular orbital theory explaining molecular orbitals [closed]

i am a high school student,,and i am confused in molecular orbital theory,,,my confusion is that how bonding and non bonding orbitals are formed at the same time my teacher taught me that the two wave ...
happy sharma's user avatar
1 vote
1 answer
151 views

Studying chemical engineering [closed]

My question is pretty simple. Does studying chemical engineering require memorizing manufacturing processes and other complex chemical mechanisms, or does it rely more on the practical side of things ...
808kalli's user avatar
3 votes
1 answer
2k views

Is silicon dioxide decomposition possible?

I was thinking about this, I made Gibbs free energy calculations and I can't figure out if $$\ce{SiO2(s) -> Si(s) + O2(g)}$$ is actually possible, even at a ridiculous high temperature.
Horacio Barrios's user avatar
-3 votes
2 answers
87 views

From diagram, assuming that the reaction is 40% complete in the vessel: a. The weight of the methanol added per day b. The amount of Hl recycled

Here is my solution on the problem and the diagram below is the actual given of the problem. I hope you could help me correct it.
maejoyfaith lee's user avatar
5 votes
3 answers
228 views

Recycle unreacted ethene

The question is this: You want to make oxirane from ethene and oxygen gas: $$\ce{2 C2H4 + O2 -> 2 C2H4O}$$ The flow into the reactor is constant at $\pu{200kmol/h}$ of $\ce{C2H4}$ and $\pu{...
Hans's user avatar
  • 51
0 votes
1 answer
69 views

Using the electrical potential created by the electron transport chain to power electrical systems

My friend and I were discussing the extremely low energy density of modern batteries and read that food has a much higher energy density. Thus, we were considering the possibility of using biological ...
p-adict's user avatar
  • 19