Questions tagged [chemical-engineering]
For questions about processes in commercial chemical manufacturing.
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9 views
Is there a luck situation in a chemical reaction?
I mean is there something like there are chances to get a product or something?
I am new to chemistry this so please explain simply.Edit tags as i dont know what to type
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0answers
18 views
Chemical bonding if an atom or molecules [on hold]
Describe the covalent bonding electron arrangement in the following by atomic molecules: 1, fluorine , 2,oxygen and 3, Nitrogen
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0answers
27 views
Chemical formula [duplicate]
My textbook says the chemical formula of Bleaching powder is $\ce{Ca(OCl)Cl}$.
But according to Wikipedia, the chemical formula is $\ce{Ca(OCl)2}$. Between these two formulas, there's an oxygen atom ...
2
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1answer
47 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
43 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 ...
1
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1answer
37 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 ...
1
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0answers
28 views
Creating a pressure vessel to make emeralds and rubies/sapphires
So I understand that this is going to be a very difficult thing to properly do but I am looking to create a vessel for growing crystals. I am not looking to build a Verneuil furnace bit rather a ...
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2answers
63 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
39 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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0answers
30 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, ...
1
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1answer
37 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
17 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 ...
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0answers
49 views
Which phase offers resistance when oxygen is being absorbed in strong alkaline pyrogallate solution?
While solving a few questions from interphase mass transfer I came across this question. The question stated that when oxygen is being absorbed from air to water it is a liquid phase resistance ...
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0answers
37 views
Extraparticle transport limitations in het. catalysis: Varying Damköhler without affecting the external prater number (and vice versa)
Solving a question for exam preparation; In the lecture script it is asked:
1. When both external MT and HT limitations exist, derive a solution from the general mass and energy balances in terms ...
2
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1answer
47 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 ...
2
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1answer
47 views
Dependence of mass transfer coefficient on solubility
Does solubility of the solute affect the value of the mass transfer coefficient?
The book I am following mentions that the mass transfer coefficient is a characteristic of the constituent and its ...
3
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0answers
40 views
Do theoretical plates required to obtain a pure product decrease under vacuum distillation?
For this question I am using Ethanol as an example. The following is the vapor-liquid equilibrium diagram for Ethanol under atmospheric pressures.
Under reduced pressures do the number of theoretical ...
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0answers
22 views
Can diamond be grown on copper wires using chemical vapor deposition techniques?
I am asking this as a follow-up to another question I asked earlier. It is regarding how to make higher voltage transformers. Diamond is a good dielectric material and would be good for using as a ...
1
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0answers
56 views
PTFE-to-PTFE or PTFE-to-Copper pressure seal
I am currently working on an engineering project with a friend. Without giving too much away, I have two parallel strips of Zirconium-Copper alloy sandwiched between an upper and lower piece of smooth ...
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1answer
39 views
How does cullet reduce the production temperature in glass production?
In my book, I read that broken glass pieces are reused in the production of glass, known to be cullet. This on one hand saves the production cost and also reduces the production temperature.
My ...
0
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1answer
168 views
Electromagnetic energy to Chemical energy [closed]
How can electromagnetic energy (photons) be efficiently converted to chemical energy? For instance, can water be efficiently split to hydrogen and oxygen using solar energy? As we are running out of ...
1
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1answer
283 views
How to use a modified Peng-Robinson equation to calculate a density?
I'm trying to use the Peng-Robinson-Stryjek-Vera 2 (PRSV2) Equation of State to calculate the density of a compound, in this example: methanol. At ambient temperature and pressure, shouldn't I be able ...
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1answer
80 views
Stoichiometry of incomplete combustion
Methane is burned with air in a continuous steady-state combustion reactor to yield a mixture of carbon monoxide, carbon dioxide and water.
The feed to the reactor contains: $\pu{7.8 mole \% }\ce{...
3
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1answer
124 views
Mixing Supplements - Will the Distributions Remain?
I am combining various vitamins and minerals into a food supplement for my dog and I currently measure each powder individually for each batch of food each week. The supplements are in powder form ...
2
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2answers
59 views
Separation of solvent from residue of material. [closed]
I have a residue of 2kl in which 1.8kl is solvent (EDC) and rest material is residue. First i was thinking to go with normal distillation to recover our solvent. But i heared somewhere that there is ...
1
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1answer
49 views
What is the reason behind the 2% increase in silver metal composition just after melting the raw silver alloy (55% silver)? [closed]
I determined the silver composition from an alloy obtained from a jeweler to be 55% and wanted to extract silver out of it. However, upon melting around 5 kgs of alloy, the silver composition went up ...
3
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0answers
29 views
Determine whether the tank will overflow with mass flowrate
Hydrocarbon mixture ($\pu{20 mol\%}$ $\ce{CH4}$ and the balance is $\ce{C2H6}$) enters a tank at a velocity of $\pu{1 m/s}$ and is withdrawn at a rate of $\pu{2 kg/s}$. The tank is initially one ...
6
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1answer
279 views
A chamber to control concentration of a vapor: Is there a name for this equipment?
Mechanical engineer here so please excuse me if my question seems dumb to you!
I want to have a chamber $(\approx 40 \times 30 \times \pu{30 cm})$ to control concentration $(\pu{ppm})$ of a flammable ...
3
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0answers
280 views
What is the relation between pressure and chemical potential?
I know that in a two-component gas-liquid system (for simplicity) the chemical potential $\mu_i$ ($i=1,2$) and total pressure $p$ can be defined by
$$\mu_i=\left(\frac{\partial U}{\partial N_i}\right)...
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1answer
258 views
Energy balance for a system [closed]
A hydropower plant uses a river to generate electrical energy. It has a drop of $\pu{107 m}$ and the flow rate of water is $\pu{275 m3 s-1}$. The flow rate of the water is the same in and out of the ...
7
votes
1answer
241 views
What are introductory level books on chemical engineering?
I'm currently enrolled in a chemical engineering course in my college, and in my first year, I'd like to get a nice introductory book on that field of study.
I'd prefer that the book covers several ...
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0answers
77 views
What is the process for chemical engineering? [closed]
I will be upfront -- I am not a Chemist, nor do I have much experience beyond high school Chemistry.
I have always had a vested interest in chemistry, but my engineers brain has always left me ...
2
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1answer
66 views
Conservation rule in closed systems
In a closed system the reacting species interconvert but do not leave the system. Therefore the amounts of different species in the system would be bound by a conservation rule.
A simple example:
...
2
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0answers
89 views
Is there a chemical reaction between tungsten carbide and acrylic?
My company machines acrylic (Poly(methyl methacrylate) $\ce{(C5O2H8)_n}$), and notices that tungsten carbide tools break down quickly compared to high-speed steel, even though carbide is harder and ...
8
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2answers
5k views
Selective etchant for Al2O3 (Does not etch Al, Cu, Zn, Sn)
I'm looking for a wet-etchant to remove aluminum oxide created by anodizing, but not etch the unoxidized metal (with greater than 10:1 selectivity)
I know about chromium(IV) oxide and fluorine-based ...
