Questions tagged [chemical-engineering]
For questions about processes in commercial chemical manufacturing.
49
questions
-1
votes
0answers
5 views
Where can I find flux formulation for different solder composition? [on hold]
I am looking to make my own soldering flux and want to understand where do I get started?
-2
votes
0answers
18 views
Can liquefied fluorine gas react with warm water? [on hold]
Is it possible for a liquefied fluorine gas at a temperature of -186°c to react with warm water?.
0
votes
1answer
51 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
votes
0answers
47 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 ...
0
votes
0answers
36 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 ...
0
votes
0answers
25 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?
0
votes
1answer
35 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 $\ce{NaOH}$.
...
0
votes
0answers
47 views
Purifying Potassium-40
What method is commonly used for separating out potassium-40 from natural potassium with a purity grade around 95% or more? How much would one kilogram of potassium-40 cost if this method is used?
2
votes
0answers
50 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
votes
1answer
44 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
votes
1answer
56 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
votes
2answers
59 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
votes
1answer
106 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 ...
1
vote
0answers
17 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
votes
2answers
84 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 ...
1
vote
0answers
28 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 ...
1
vote
1answer
30 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
votes
2answers
53 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 $\Delta_r G^\circ_\text{AB} = \pu{400 J/mol}$, $\...
0
votes
0answers
29 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
votes
1answer
57 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
votes
1answer
57 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
vote
1answer
61 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
vote
0answers
37 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 ...
0
votes
2answers
81 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
vote
1answer
55 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 ...
1
vote
0answers
41 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
vote
1answer
38 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
votes
1answer
22 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
votes
1answer
57 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
votes
1answer
80 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
votes
0answers
56 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 ...
1
vote
0answers
23 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
vote
0answers
57 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 ...
0
votes
1answer
49 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
votes
1answer
331 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
vote
1answer
471 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 ...
0
votes
1answer
170 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: $\pu{7.8 mole \% }\ce{...
3
votes
1answer
133 views
Mixing Supplements - Will the Distributions Remain?
I am combining various vitamins and minerals into a food supplement for my dog and I currently measure each powder individually for each batch of food each week. The supplements are in powder form ...
2
votes
2answers
69 views
Separation of solvent from residue of material. [closed]
I have a residue of 2kl in which 1.8kl is solvent (EDC) and rest material is residue. First i was thinking to go with normal distillation to recover our solvent. But i heared somewhere that there is ...
1
vote
1answer
52 views
What is the reason behind the 2% increase in silver metal composition just after melting the raw silver alloy (55% silver)? [closed]
I determined the silver composition from an alloy obtained from a jeweler to be 55% and wanted to extract silver out of it. However, upon melting around 5 kgs of alloy, the silver composition went up ...
3
votes
0answers
30 views
Determine whether the tank will overflow with mass flowrate
Hydrocarbon mixture ($\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 ...
5
votes
1answer
284 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
votes
0answers
429 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)...
-1
votes
1answer
315 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 ...
8
votes
1answer
282 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 ...
1
vote
0answers
96 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
votes
1answer
67 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
votes
0answers
102 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 ...
7
votes
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 ...
