Questions tagged [chemical-engineering]

For questions about processes in commercial chemical manufacturing.

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3
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0answers
27 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 ...
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19 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 ...
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21 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 ...
2
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1answer
84 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 ...
3
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30 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 ...
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92 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 ...
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17 views

Preventing Precipitation/Undilution: Shall I Try Another Solvent?

Thank you for your time in advance. Our facility is about $\pu{4000 ft}$ in terms of elevation. One of the main chemicals we manufacture is RAD140 or $\ce{C20H16ClN5O2}$. We use DMSO ($\ce{(CH3)2SO}$),...
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15 views

Electroplating: What exactly does an additive/ brightener do in the electrolyte?

A carrier or supressor is generally a poly-oxyalkyl compound that is instrumental in suppressing the electrolytic current. This is achieved by the formation of a diffusion layer when the additives ...
4
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1answer
82 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 ...
0
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1answer
123 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 ...
3
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1answer
171 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.)
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19 views

Doubt's regarding inputting surface reaction for Chemkin Pro

I want to simulate the reaction of a mixture of ethanol and Hydrogen Peroxide on $\ce{Pt}$ using Chemkin Pro. I want to create a surface input files which will include surface reaction mechanism of ...
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249 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 ...
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0answers
38 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'...
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2answers
50 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%....
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12 views

Measurement of Energy Density

I'd like to ask how researchers measure/calculate the energy density for chemical fuels? Do they just measure the enthalpy change of combustion (△H combustion) in a calorimeter and then divide it by ...
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1answer
155 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 ...
1
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1answer
57 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 ...
3
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1answer
266 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.
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2answers
69 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.
4
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3answers
137 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{...
0
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1answer
27 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 ...
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1answer
29 views

VOC conversion question

I'm trying to find out if a particular paint is considered low VOC. The only piece of data I have available is that the VOC content is $\pu{10 \mu mol / m^3}$. What does that equal in $\pu{g/L}$ of ...
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58 views

X-ray bombardment of CaCl2 and its resultant chemical changes

If one were to take $\pu{1 mol}$ of pure liquid Calcium Chloride (at $\pu{600 ^\circ C}$) and bombard it with $\pu{7.65 \times 10^{14} Ci}$ ($\pu{2.83 \times 10^25 particles}$) of x-rays ($\pu{75 keV}$...
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1answer
261 views

What is the difference between ideal stages and transfer units in a packed bed gas absorber?

I am having a hard time grasping what these two concepts are supposed to mean and how they differ. What I know so far is: In a counter-current gas absorber, if we set the inlet and outlet ...
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0answers
53 views

Is it possible to create an arbitrary, stable, unique chemical fingerprint? [closed]

Context: I want to be able to hash real-world objects Is it possible to create a substance containing a combination of elements (or isotopes?) in a random and difficult to reproduce (but simple to ...
0
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1answer
88 views

Is it possible to make micelles to pick up Microplastics from water?

I'd like to know if I could get micelles to pick up microplastics in water. I read that microplastics are sometimes charged, so can we make the lyophobic end to pick up microplastics, so that they can ...
2
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0answers
84 views

How to charge titanium dioxide particles for a DIY e-paper capsule? [closed]

I'm trying to make a single e-paper capsule (1 cm × 1 cm) at home. At first, I tried to charge the $\ce{TiO2}$ particles by putting them in $\ce{H2O}$ with $\ce{NaOH}$ and then putting that whole ...
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38 views

Chloride Process TiO2 recovery

In the chloride process (the process used to create titanium oxide from titanium ore), how is TiO2 collected? What prevents the TiO2 from building up on the walls of the reactor chamber? It's my ...
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34 views

Reaction between chlorine gas and oxygen at 600 degrees Centigrade

Chlorine gas will not normally react with oxygen gas directly at STP. However, would the two react at standard pressure and 600 degrees Centigrade?
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1answer
51 views

Numerical simulation and calculations of pH

a. Reaction of $\ce{CO2}$ addition in water is as follows: $\ce{CO2}$ + $\ce{H2O}$ $\ce{->}$ $\ce{H2CO3}$ b. Then, pH of $\ce{H2CO3}$ solution is increased to 12 by addition of 1M $\ce{NaOH}$. ...
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66 views

Why will A atoms diffuse from β phase to α phase and B atoms from α phase to β phase?

At the initial compositions 1 and 2 of $α$ and $β$ respectively the chemical potentials of A and B atoms in each phase can be found by extrapolation of the tangents to the free energy curves at 1 and ...
2
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1answer
267 views

Why do we use Ḡ (“G bar”) as a notation for partial molar free energy?

For partial molar entropy there is a bar that is positioned above the $G$ with a subscript I that is sometimes added to the $G~(\bar{G}).$ The bar I read sometimes denote the "partial nature of the $G$...
2
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1answer
481 views

What are glues/adhesives for cardboard boxes/crates made of?

Open cardboard boxes/crates, often for foodstuffs, are often glued to hold their shape. What is the glue/adhesive made of? I ask to know if it is biodegradable, such that it is suitable for ...
0
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2answers
257 views

Does this reaction require catalyst/solvent?

Planning on synthesising 2-formylphenyl benzoate by reacting benzoyl chloride with salicylaldehyde. Since both Benzoyl chloride and salicylaldehyde is liquid, will it require a catalyst/ solvent? Or ...
6
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1answer
121 views

How can hydrogen and oxygen coexist in high temperature? Where did the oxygen come from?

A gasification worked with the combustion of bio pallets with production of syn gases. Pure oxygen and $\ce{H2O}$ were fed into the combustion reactor to combust the pallets with no opening of any syn ...
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0answers
66 views

Correct Generalization for Adair Equation?

I know how to derive the Adair Equation for n binding sites the long way, writing n+1 mini equations and linking them to relate all sub $K_b$ values to $K_{b-intrinsic}$. Tried to find a general ...
3
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2answers
182 views

Can a reactor be operated at both reflux and above atmospheric pressure?

I'm not a chemist by trade so my experience in the lab has probably not been as in-depth as most of you. I've been tasked with investigating a proposed reaction in which an organic mixture (mostly ...
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0answers
290 views

Impact of pH? Change in Binding Affinity of protein-ligand complex based on pH and Kd?

When the $\mathrm{pH}$ was $5.0$, the temperature was $\pu{25 °C}$,the $K_\mathrm{D}$ was $\pu{5 μM}$, and [L] was equal to $K_D$, the protein(s) were half bound. Question considers half bound ...
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1answer
41 views

Chemical Equilibria - Fraction Bound equation based on Kd, [R], [L], [RL], is actually an average?

Let's say 150 stem cells express exactly 150 copies of the same mebrane antigen X. While all differentiated cells express exactly 15 copies of X. To the cell mixture you add a large amount of 0.2 μM ...
2
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2answers
68 views

Thermodynamics - Series Reaction - Estimating mols of reactants based on Free Energy of Rxn

Question Three reactions occur simulteneously (assume ideal) at $\pu{T = 0^\circ C}$. $$\ce{A<=>B<=>C<=>D}$$ a) With $\Delta_r G^\circ_\text{AB} = \pu{400 J/mol}$, $\...
2
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1answer
80 views

Simple alternative to UNIFAC to prove that a mixture containing 1ml of x and 5 litres of propylene glycol is not flammable?

Section 2.6.1 of the REGULATION (EC) No 1272/2008 (CLP) defines a flammable liquid as: Flammable liquid means a liquid having a flash point of not more than $60 ^{\circ}$C. So data on flash ...
3
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1answer
101 views

Equation for overall heat transfer coefficient

The heat flow (in $[\pu{J/s}]$) through the wall of a tube of length $L$ and inner radius $R_0$ is $$Q = (2πR_0L)U(T_{1\infty} - T_{2\infty}),$$ where $T_{1\infty}$ is the bulk temperature in the ...
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1answer
63 views

What would be a stable way to hold lithium hydride powder?

I currently have 100 grams of lithium hydride powder that needs to be held in a solid form. Initially, I was considering using cement, however, the moisture require converts the lithium hydride to ...
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2answers
130 views

Flow rate of the fuel consisting of ethanol and water burning in air of a given flow rate

I hope that someone could give me some hints or tips on how to approach this question, even though these types of questions are usually closed off as homework. A burner is run by a fuel mixture of $\...
1
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1answer
213 views

Heat of formation method

For enthalpy calculations why is it that in some cases the "heat of formation method" is used? I know that $ΔH_f$ represents the heat required to form the compound at standard temperature and pressure ...
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55 views

Reference conditions for balances on nonreactive processes

In one of the examples in my book (Elementary Priniciples of Chemical Processes) where I am asked to calculate the rate of heat input required to heat a stream of methane and air from 20°C to 300°C, ...
2
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1answer
54 views

How do you figure out fuel specific impulse non-experimentally?

Simple question, probably very complicated answer: Without building a test engine/rocket and finding out experimentally, that is to say, based on chemical characteristics alone, how can one compute ...
2
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1answer
28 views

What are standard controllers for automatic pH control?

My background in control theory comes from electrical engineering (robots, motors, etc.) and I want to build a control system for automatic pH control. Can I directly apply my knowledge from ...
2
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1answer
80 views

Double surface in the pressure temperature concentration curve for a binary mixture

In the 3 dimensional diagram given, when a constant pressure plane intersects with the double surface, it produces a looped curve without a maxima or minima. What is the double surface and how is the ...