Questions tagged [process-chemistry]
The process-chemistry tag has no usage guidance.
30 questions
0
votes
2
answers
289
views
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 ...
- 11
2
votes
1
answer
569
views
Do dessicants work inside of a freezer?
I learned that water sublimates when frozen, which prompts me to ask:
Do dessicants work inside a freezer?
While dessication inside of a freezer is unlikely to remove large quantities of water fast, ...
- 1,107
2
votes
1
answer
252
views
Is Silica Gel fit for Ultra-High Dessication?
I had the (perhaps wrong) notion that silica gel wasn't that strong of a dessicant, especially compared to CaO, MgO, CaSO4, H2SO4, KOH, Mg(ClO4)2), but I've been exposed to information* that might ...
- 1,107
0
votes
1
answer
388
views
PFR reactor: -1/r vs conversion plot
A generic reagent A is considered. The behavior equations of a CSTR reactor is the following:
$$
\tau = c_\mathrm{A,0} \intop_0^{X_\mathrm{A,final}}
\dfrac{1}{-r_\mathrm{A}} dX_\mathrm{A}
$$
where $\...
- 265
0
votes
0
answers
108
views
Calculation of the Seperation factor of Ethanol / Water rectification based on two saturated vapor temperatures
I want to calculate the efficacy of a Water / Ethanol rectification based on two temperatures with help of a vapor-liquid equilibration diagram.
The first temperature is measured right above the ...
- 1
4
votes
1
answer
185
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 ...
- 41
2
votes
2
answers
4k
views
Percentage yield of Haber process
The yield of a single pass of the Haber process is around $\pu{10\%}$ to $\pu{15\%}$ of ammonia when operating at $\pu{200 °C}$ and $\pu{450 atm}.$ However, most graphs show that at this condition ...
- 169
1
vote
0
answers
63
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 ...
7
votes
2
answers
889
views
Is there a simple way to distinguish grades of purity for copper metal?
Is there a simple way to distinguish different grades of fine copper purity (on a trace metal basis) that can be carried out in a small lab?
Specifically, I would like to be able to differentiate 4N, ...
- 1,107
1
vote
1
answer
773
views
Why are the rare Earth elements divided into light and heavy categories?
Rare Earth's up to z=62 (Samarium) are often called 'light' rare Earths, while z=63 (Europium) and beyond are sometimes referred to as 'heavy' ones. Why such distinction? I didn't have come across (or ...
- 1,833
43
votes
10
answers
9k
views
Why is chemistry unpredictable?
Disclaimer: I am not a chemist by any means, and I only have knowledge limited to what I learned in my university's Chemistry III course. Basic understanding of everything up to valence electron ...
- 533
0
votes
1
answer
279
views
Monosodium Diphosphate (NaH3P2O7) Preparation
I looked on wikipedia for an answer but I couldn't even find a page for this salt, a subsequent google search didn't further enlighten me.
Does any one know how monosodium diphosphate can be prepared?
- 1,107
1
vote
1
answer
144
views
Why does the titanium go to the tungsten filament in the crystal bar process?
I've tried to read a report by the US atomic energy commission [1], but couldn't really find the answer, or maybe I missed it.
Why is the gaseous titanium deposited on the tungsten wire/filament ...
- 748
3
votes
1
answer
2k
views
Laboratory setup for the distillation of sulfuric acid
Purification of Laboratory Chemicals, 5th Edition, by Armarego, reads (p. 53):
Reagents such as water, ammonia, hydrochloric acid, nitric acid, perchloric acid, and sulfuric acid can be purified via ...
- 1,107
3
votes
0
answers
527
views
The most convenient process to purify Oxalic Acid up to a high level of purity
I am set out to purify a batch of commercial oxalic acid with the aim in mind to end up with a highly pure product (starting from $\pu{4,000 ppm}$ total impurities and doing so with basic lab ...
- 1,107
0
votes
0
answers
34
views
Little to no reaction in my hot process soap
I tried to make hot process soap and it was a failure. I carefully weighed the ingredients, but when I added the KOH to the melted oil, nothing happened. When I watch videos on hot process soap making,...
- 2,354
-1
votes
1
answer
7k
views
Main industrial method for producing ethyl ethanoate (acetate)? [closed]
I am aware there are various methods, however, which is most prevalent in industry? Researching on Google has indicated Fischer esterification or Tishchenko reaction and other versions. Which is most ...
3
votes
0
answers
131
views
How to control pH in a fermenter based on the acid produced by mircoorganism
I have got a bioreactor with an aqueous medium which produces biomass (yeast; S.cerevisiae) after inoculation.
I am observing and collecting data over the whole process via probes/etc. on different ...
- 103
2
votes
1
answer
63
views
Are there still "prairie dog refineries"?
In the old days (meaning the 1940s) there still many small "prairie dog" oil refineries, that were little more than a bunch of hooch stills soldered together, but from what I understand these are all ...
- 2,354
3
votes
1
answer
13k
views
What is the difference between an industrial and a laboratory production method?
I'm not sure if this is the correct SE in order to ask this, if that is true just said me that in comments and I will delete my question, there is no need of downvote or ban.
I was answering a ...
- 170
0
votes
2
answers
112
views
Why is it so hard to turn plastics into something useful or decompose it? [closed]
Even after so many years, why haven't we yet come up with a solution to the plastic problem ?
Why are plastics so hard to decompose via chemical or physical processes into something harmless or ...
- 423
19
votes
3
answers
3k
views
What happens to the argon in the Haber-Bosch process?
The Haber–Bosch process is used to synthesis ammonia from atmospheric nitrogen and hydrogen derived from a hydrocarbon such as methane. The process requires high temperatures and pressures and also ...
- 439
1
vote
2
answers
116
views
Working with typical glass: What temperatures would I be dealing with?
I want to be able to melt down typical glass (the kind you usually find at home) and mold it into other shapes. What temperatures would achieve this?
For comparison; if I were to take some sand and ...
- 111
-1
votes
1
answer
3k
views
Heating a mixture of methanol and water?
I have a mixture methanol and water, at 25°C, and I want to take it to 250°C. I'll use two heat exchangers: one for taking the mixture from a liquid state (25°C) to a vapor state (X°C), and the second ...
- 1
3
votes
1
answer
75
views
Sudden pressure rising in a pipe of an old plant transporting 33% ammonia solution
We pump 33% ammonia solution along a single pipe line before we introduce it to the mix. We've had two occasions now where the ammonia pressure has rapidly risen in the pipe. It happens when the fluid ...
- 33
0
votes
1
answer
6k
views
How is the process of converting calcium carbonate (CaCO3) into calcium oxide (CaO)? [closed]
I need to provide accurate information in relation to the production process of calcium oxide from calcium carbonate.
$$\ce{CaCO3 -> CaO + CO2}$$
- 21
1
vote
0
answers
32
views
Calculating the effects in a fractionating column
Consider a fractionating column used to separate a mixture of acetone (A) and toluene (B) with a liquid molar composition of acetone called x. The feed is F, the distillate is D, the waste is W and ...
- 53
0
votes
1
answer
233
views
Mass transfert in process chemistry engineering, two film theory
I'm having troubles to understand a part of my lesson. I have no idea where to ask my question, but it is consider as chemistry so here we go.
Let me introduce some notations :
$x$ and $y$ are the ...
- 4,205
2
votes
2
answers
1k
views
Separation of sulfur dioxide and sulfur trioxide in the contact process
When gases leave the catalytic reactor in the contact process of sulfuric acid generation, both $\ce{SO2}$ and $\ce{SO3}$ will be present. According to descriptions I have read, the trioxide reacts ...
- 2,354
15
votes
3
answers
20k
views
Why is the Haber process carried out at such high temperatures?
On a large scale, ammonia is prepared via the Haber process:
$$\ce{N2(g) + 3H2(g)->2NH3(g)} \qquad \Delta _\mathrm{f}H^\circ = -46.1~\mathrm{kJ \cdot mol^{-1}}$$
The optimum conditions for the ...
- 1,091