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Questions tagged [chemical-engineering]

Use this tag for questions within the problem domain of chemical engineering.

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24 views

How to calculate flow rate and direction in system with multiple blowers

I have an odour control system where foul air is being extracted from multiple sources and then pushed into a scrubber vessel. Normally, all my designs look something like this: https://ibb.co/...
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1answer
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How to control precisely the wall temperature of a tubular reactor?

I have modelled a multi-tubular reactor performing a Fischer-Tropsch synthesis of alkanes and I was wondering about the stability of such a reactor. Even a very tiny deviation of the wall temperature ...
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29 views

COP of vortex tube Refrigeration

Recently, in an experiment of Vortex Tube Refrigeration System. We recorded an observation that was Temperature of cold side = 35 C at that time R.T. was recorded as 34 C. Using these observations COP ...
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When teaching separation processes, which one should be introduced first? Distillation or absorption?

I am preparing a basic course on Separation Processes (5th semester, BSc Chemical Engineering). I can see that many well-known textbooks (e.g. Seader & Henley, Wankat) start by teaching in detail ...
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1answer
22 views

Doubt in proof of condition dG<=0

I tried proving the condition dG<=0 where G is Gibb's free energy and instead ended up proving dB<=0 where B is exergy. Can someone please explain what went wrong with my derivation. I have ...
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1answer
23 views

the volume in hydraulic retention time is of reactor/container or liquid

I have a tiny reactor, and the volume I need is 425ml. If there is no/few other reactants, then the volume in hydraulic retention time is clear: reactor/container's ...
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1answer
35 views

Magnetic treatment of hard water to prevent scale and corrosion? How does this work?

I ran across this company at their booth at a Tradeshow (2018). They claim to have a chemical free (and as far as I can tell - a power free) treatment method for hard water to minimize scale and ...
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2answers
45 views

Systems In “Thermodynamic Equilibrium”

I'm trying to find an answer to a question in one of my thermodynamics textbooks. (Undergraduate chemical engineering is the context). It is a conceptual question, asking, "Do all systems in ...
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3answers
37 views

Flaring System in Industries

Why is Flaring done in industries? Why can't the same gases be used for production of energy (Thermal energy)? Or why can't the excess gas be recycled in the previous stream from which it came?
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1answer
36 views

equivalent deduction of Non-mechanical thermodynamic work

"Work (as in Thermodynamics) is said to be done by a system if sole effect on the surroundings could be the raising of a weight." So, how is non mechanical work like : Chemical work, Magnetization ...
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27 views

performances of a continuous flow reactor

How can we know the evolution of the oulet concentration of a perfectly well-mixed continuous flow reactor taking into account the residence time distribution function called $E(t)$? I have heard ...
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0answers
27 views

Eulerian description of fluid flow

In Eulerian description of fluid flow, we observe how the properties of the fluid are changing at a point. Since a point has zero dimension hence a zero area, how can we make sense of the 'finite ...
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0answers
38 views

Enthalpy vs Heat

If we have a closed cylinder filled with a gas and we heat it, by $1^{st}$ law we have: $\Delta q=\Delta U$ (?) since $\Delta V$ = 0. But $\Delta H= \Delta U+ V. \Delta P$. What does that difference ...
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Entrainers to distill MTBE from Methanol? - Chemical Engineering Question

What have you found to be some effective entrainers to distill MTBE from Methanol, given the azeotropic conditions at 67%. I have tried to simulate 1-butanol, as well as ethanol, and numerous other ...
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0answers
13 views

calculating amount of oxygen in feed when there is excess oxygen

problem: In the Deacon process for the manufacture of chlorine, hydrochloric acid, $\text{HCl}$, and oxygen, $\text{O}_2$, react to form chlorine, $\text{Cl}_2$, and water, $\text{H}_2\text{O}$. ...
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48 views

Solid-liquid separation of a crystal slurry

Let me preface my question by saying I am a recent chemical engineering graduate and apologize if my inexperience shows. I have designed a batch process which results in a water slurry stream ...
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1answer
27 views

head coefficient and volume coefficient for centrifugal pump

If I need to calculate the head coefficient using $c_h=\dfrac{gH}{N^2D^2}$ and the volume coefficient using $c_q= \dfrac{v}{ND^3}$ while keeping $N$ (impeller rotational speed in rpm), how can I make ...
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1answer
63 views

Boundary conditions in a heat transfer problem

One end of a small insulated rod is attached to a support which is maintained at a constant temperature of 473 K,and once the rod has reached a uniform temperature in its entire length the insulation ...
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0answers
32 views

Petroleum/Reservoir Engineering: Estimating Cumulative GOR (Gas Oil Ratio) & Cumulative Oil Production

I have a data set from producing oil/gas wells from multiple (separate) drilling locations. Note that a given well can either be conventional or unconventional. Overall, the data set retains info ...
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0answers
16 views

Why can we extend the derivation of delta(S mix) to ideal solution from ideal gas behavior?

The formula for change in enthalpy for ideal gas is derived using ideal-gas law which cannot be extended to ideal solutions (my intuition). Then why can we extend the formula of delta S mix to ideal ...
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1answer
34 views

How to derive phase equillibrium criteria for more than 2 phases mathematically?

I know the derivation of phase equilibrium criteria derivation for 2 phases. I am not getting how to extend the derivation to more than 2 phases. Please help me out on that. Thank you
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0answers
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Deriving Enthalpy in terms of (T,V) and (T,P)

We are being asked to develop thermodynamic expressions for the enthalpy of a system in terms of (T,V) and (T,P). I understand that the Legendre Transform can be used to find H=H(S,P), but I'm getting ...
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1answer
33 views

Issues creating a high pressure chamber for corrosive solution

I'm trying to do an experiment on high pressure's effect on the electrical impedance of a really corrosive solution. I'm aiming for at least 2,000 psi with a pressure chamber but the only material I ...
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1answer
43 views

pH calculations for boiler water

For water steam cycle in a "combined cycle power plant" containing 3 boiler drums and dosing of 5% ammonia solution in the condenser. How can I calculate the pH of the boiler water in each of the ...
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1answer
71 views

CSTR properties - What happens to conversion of products if I change the reactor size?

For example, initially this reactor is having a 2nd order reaction of $-ra=kaCa^2$ and it has a fractional conversion of 50% in a CSTR. I replace it with something 1/6 as large. What happens to the ...
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1answer
32 views

Minor loss due to splitting of pipe

I am solving pipe flow problems and it came to my mind how does one find out the minor loss associated with the splitting of pipe. Here how does one find the minor loss associated when the flow is in ...
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0answers
56 views

How can pitot tubes give us local velocity in a flow

I am studying about static pressure,dynamic pressure and the principle behind pitot tube. However in pitot tubes we apply Bernoulli equation between two points which are not on the same streamline. ...
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1answer
56 views

Calculate the specific surface area of a mesoporous sample

I'm a nanoengineering student who's been stuck on the following problem for a few days. I've gone back over my professors slides, watched podcasts from an old professor, etc. etc., but don't ...
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0answers
27 views

CSTR exit conditions [closed]

Will there be other factors such that it will affect the exit conditions of the CSTR to change ? For example, the temperature of the reactants that will be lost to the surroundings
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0answers
57 views

What are the raw materials for water filter housing production? [closed]

I want produce water filter housing (like below images) who can tell me what are need raw material for these? Best Regards
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1answer
61 views

Contradictory result for mass balance

I solved this problem by doing a mass balance for the mixing chamber and an energy balance for the water heater and the mixing chamber as follows: $\dot{m}_{\text{mix}}=\dot{m}_{\text{Tank}}+\dot{m}_{...
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0answers
37 views

Polyurethane with microbial resistance properties

I'm looking for a polyurethane with microbial resistance. Doing some research I found two commercial types: DESMOPAN 9392A and DESMOPAN 2792A. Both are manufactured under GMP conditions and limited ...
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1answer
691 views

Can current passing through a wire potentially ignite gasoline? If not, why?

I am doing some restauration on my old Vespa and since the fuel indicator doesn't work, I took the fuel gauge system out of the tank and tried to understand how it works to repair it. Apparently, 3 ...
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2answers
71 views

How can I vaporize metals?

What are some common ways that I can vaporize Metals into a vacuum chamber? How can I keep these Metals in a gaseous state?
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1answer
35 views

Can chemical vapor deposition chambers be used to lay down thick layers of metal?

Can CVD Chambers be used to lay down thick (~1 mm) layers of metal?
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1answer
23 views

How can I convert volume as a function of time to mass or mole as a function of time for a dissolving drug particle?

I have been given a spherical drug particle that dissolves by surface erosion into the bloodstream. The rate of dissolution is proportional to the exposed surface area of the particle. I have to model ...
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1answer
237 views

Entropy change in a throttling process

In an adiabatic throttling process of ideal gas: I understand that mathematically lost work is given by Tsurr * entropy generated. But intuitively I can't understand if there is not heat exchange ...
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1answer
61 views

Modelling gas desorption from a still solution (e.g. a beer)

The common way to model or estimate gas (e.g. CO2) desorption rate from a liquid solution is by using an equation similar to this one $J_{CO_2} = -k_L a(H·C^G_{CO_2} - C^L_{CO_2})$ where $J_{CO_2}$ ...
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2answers
51 views

what classes should I take so that I can perform research into finding catalysts to split water into oxygen and hydrogen? [closed]

I am a freshman student and I am very interested in using solar energy to break water into hydrogen and oxygen. So, I want to know which areas are important in this regard..
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1answer
25 views

How To Find Reheat Parameters In an ideal rankine system

So I was trying To Solve a problem on reheat Rankine cycle . I can Solve for everything Aside The part of The Reheat That has Entropy constant With the Main boiler entropy.. I don't know if when ...
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1answer
32 views

If I replace a flow orifice with a Coriolis flow meter of the same size do I need to worry about pressure drop with the new Coriolis meter?

I have a 3 inch line with a 1.5 inch flow orifice. If I take out the flow orifice and put in a 1.5 inch coriolis meter will the pressure drop be the same or better with the new coriolis meter than ...
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0answers
18 views

How widely used are ethylene receptor inhibitors in fruit packaging & shipping?

Ethylene works as a gaseous "aging" hormone for many fruits. There are lots of papers on ethylene receptor inhibitors (e.g. 1-MCP) to delay this process. I also found out that 1-MCP has been EPA-...
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2answers
259 views

Can Fortran 90 be used with Aspen Plus, or only Fortran 77?

I am attempting to write a user model in Fortran that can be connected to the Aspen Plus process simulator. Can Fortran 90 be used, or does Aspen only work with the older Fortran 77? I have checked ...
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1answer
55 views

Designing a horizontal pressure vessel

The question reads Design a horizontal pressure vessel with hemispherical head supported by saddle support and fitted with 2 nozzles welded to the head. It's used for storing and delivering fuel ...
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0answers
8 views

Distribution of turbulent energy dissipation in a stirred tank

Is detailed experimental information on the distribution of energy dissipation in a stirred tank(45o Pitch blade) available? I require this variation in all directions in a standard stirred tank ...
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0answers
21 views

How to quantify adulteration of urea and hydrogen per oxide in cow milk? [closed]

I am very much new in this field and trying to get some information on adulteration of cow milk. I have searched and saw that mostly urea and hydrogen per oxide are mixed with cow milk. I found that ...
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1answer
39 views

How to identify the time delay of manipulated variables which are important to the final quality of polymer product

In a polymer production process, there are a lot of manipulated variables(MV) such as temperature ,pressure , or level of reactor that affect the quality of my polymer product. However, it usually ...
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1answer
53 views

What about the natural convection heat transfer coefficient (*h*) at low Delta-T?

In a system I am modeling for personal research, I have a sphere (S) submerged in air (A), initially at the same temperature Ts = Ta. Then the temperature of air is slowly increased (or decreased), ...
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1answer
67 views

Thai Cave Rescue-Using trace gas detection to locate chimney entrances [closed]

One of the potential ideas that was suggested for rescuing the Thai soccer team trapped in the cave is to locate a "chimney" or secondary entrance to the chamber where the team is trapped. However, ...
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0answers
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Phase Change Materials Charge and Discharge [closed]

Is there a way to approximate the charge and discharge time of a PCM. I understand that this is a transient process as a material melts from the outside in, but I was wondering it there a means of ...