Questions tagged [chemical-engineering]
Use this tag for questions within the problem domain of chemical engineering.
346
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How do I calculate magnitude of shear force per unit of length when all I'm given is the diameter?
I had a chemical engineering homework problem where I had to come up with a velocity profile for methanol flowing through a cylindrical tube, where viscosity and average velocity were given, but the ...
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What materials where used in this study or ones that would make the most sense please!
I understand that they used two different materials and combined them through fiber drawing process but I don’t truly understand which materials were used. Here is where it is mentioned in the article....
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Gas leak rate from a pipe
I am trying to find out how to calculate the leak rate of gas (composed of mostly methane at around 30degC and 150psi) from a pinhole leak (~5mm) to the atmosphere in a pipe where you do not have the ...
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How to safely experiment with wood pyrolysis?
I have been thinking about how to make a carbon negative BBQ.
The idea would be, use sustainably grown wood (so you start nearly carbon neutral) and pyrolyse some of it, and bury the resulting carbon....
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Calculate surface area of batch reactor
I have calculated the volume of reactor for 30000 tpa product also its diameter and height and its volume is 86 kL.
How to calculate the surface area of the same reactor to check requirement of heat?
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How would nanobots disassemble something on a molecular level?
I've been studying this topic for use in a story I'm working on and I've come across various videos and interviews on the topic, but they all seem mostly concerned with assembly of larger objects.
I ...
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Working of an eductor
Am currently learning P&ID diagrams. I came across the term ‘eductor’ and I’m trying to understand its working. Apparently, it’s different from an ejector in the sense that it draws the fluid in. ...
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How is the electrolyte stored in an Alkaline Fuel Cell?
Every type of fuel cell has a catalyst and an electrolyte to carry electrons between the cathode and anode. What I don't understand is how the electrolyte is stored in a Alkaline Fuel Cell. In essence,...
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Turbulent flow, fluctuating part of velocity
Let's say we have a fully developed turbulent flow on x axis (simple shear flow). Time-averaged components of velocity on y and z axis are 0. If a lump of particles is moving upwards, then the ...
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what is effect of temperature on dew point?
I read that relative humidity changes with change in temperature though there can be constant humidity. So, if RH is changing then dew point should get increase with increase in temperature?
https://...
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How to calculate the flow rate and kinetic energy of gas flowing in a pipe given its density, the pipes diameter and its velocity
I've been given a question which asks to calculate the kinetic energy of gas flowing through a pipe given the density(kg/m^3), pipe diameter(m) and velocity(m/s).
I'm first required to find the flow ...
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Calculating the mass flow of water vapour in a boiling pot. A little help with mass and energy balances needed
Suppose that I'm boiling water in an open pot. As the pot is heated by the stove, it loses mass in the form of vapour.
The pot is my control volume. That system could be modeled by the following ...
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Tanker exhaust sequence blows sulfuric acid everywhere and I need to rig up something to slow the exhaust without impeding flow rate
I am not an engineer myself and I'm hoping you guys can help me with a project I am working on.
So we receive rail car tankers full of sulfuric acid that we pressurize like a beer keg to offload the ...
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How the choice of etchant can affect the severity of hydrogen embrittlement during pickling and passivation?
Following this question, I am trying to understand how/if the choice of acid we might use during the pickling and passivation of certain metals, can influence the severity of hydrogen embrittlement. ...
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What will be the destiny of the oxygen gas created in the future hydrogen economy?
When I was recently studying biomass-to-electricity (gasification methods, Drax power station...), I was wondering whether the efficiencies of these systems would not benefit from a source of pure ...
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Orange spots at hot dip galvanized surface
I like to ask you about orange spots after galvanizing of Steel Purlins. I attached some of the pictures. Please advice the solution with your expertise.
Thank youenter image description here
enter ...
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Integrating the Onsager formulated mass transport equation for a binary mixture
I want to develop a model for the Maxwell-Stefan mass Diffusion for a binary mixture for a nano porous membrane. I have permeation data and adsorption isotherms measured I just need to implement the ...
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Calculation of Pressure and Temperature inside the combustion chamber of a Compression Ignition engine just before the combustion process
For a small student project on Molecular Dynamics, I have calculated the values of pressure and temperature just before the combustion process in a 4-stroke Compression Ignition (CI) engine producing ...
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Heat transfer in open equalization tank
I have to cool waste water in equalization tank (open tank) from 60 C to 30 C.
Here is the information about the waste water:
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/...
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How to find the unknown compositions and flows?
$\require{\mhchem}$
I've been trying to solve this problem:
A stream consisting of $\ce{C10H14}$ (49.6%) and $\ce{C4H6O3}$ (50.4%) is brought into contact with a stream consisting of $\ce{CO}$ (41%) ...
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Enthalpy Of Water vapour at room temperature
I am wondering how to calculate the enthalpy of water vapour at room temperature with a reference state of 25 C 1 atm.
I understand that normally for water vapour above boiling point, one would ...
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Double Meniscus of Capillary Tube
I recently realized that if I turned my coffee cup downward, all the liquid spills out easily. This amazement prompted me to wonder about the impacts of surface tension for a situation in which the ...
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Aspen Plus - Sensitivity Analysis / Case Study - Need Assistance
Can someone please point me in the right direction, I've spent all day on this and have read through the support documentation / user manual.
I want to perform a sensitivity analysis. In this example ...
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After how many days can concrete framework be removed?
After how many days can concrete framework be removed? Do admixture chemicals like superplasticizer or accelerating admixtures allow early removal of concrete framework?
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How to couple an electrochemical model of a cell several times to get a battery?
I have an electrochemical simulation of a lithium ion cell, and I want to use this simulation to simulate a battery pack. I am interested in modeling phenomena in battery packs like the inequal ...
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Is there a filtration mechanism that allows nicotine molecules to pass and not particulate matter?
I was wondering if an equivalent of the vaporization of tobacco could be achieved by normal combustion but passing the smoke through a filtration mechanism that only allows pure nicotine vapor through ...
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Solar distillation of sump pump water and the issue of Radon gas
Lately I have been thinking about designing and building a solar-powered water distiller that would be placed close to my house in my backyard.
One thought that I have is installing a bypass valve on ...
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Is there a reason to connect tube reactors in series?
With CSTR (continuous stirred-tank reactor), it is in many cases benificial to connect multiple CSTR in series. I wonder if there is a purpose for tubular reactors to be connect in series as well?
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How much Energy is Radiated by a gray body?
How much energy is radiated by a gray body at an ambient temperature of T Degrees Kelvin, between the wavelengths of w1 and w2 micrometers , if the emissivity of this gray body is 0.6 ? (Note: ...
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Why do Nickel Manganese Cobalt batteries wear out before Lithium Iron Phosphate batteries?
Do NMC batteries lithium plate faster? Does the Solid Electrolyte Interface (SEI) grow faster on NMC batteries? Do they heat up more and therefore the SEI grows faster? Does the Iron stabilize the ...
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Why Sintered Tantalum Powder Forms a Sponge-Like Structure?
I read that to make a dipped tantalum capacitor, they make tantalum powdered stick together with a binder and then sinter, which makes it porous.
But why do the pores form? It seems that if they are ...
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How to use natural gas mostly sourced from ʟɴɢ on appliances designed only with propane burners?
Given identical pipes, and given in Europe propane from bottles is distributed at 34millibars (G31) and 20millibars for main gas (G20 standard).
Using the Wobbe index, how much natural gas should be ...
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Why Sodium Sulphate is used in Sponge making
I read that sodium sulphate crystals are used to make sponges. The crystals are mixed in with some other stuff, then put into a mold. The mold is heated, causing the sodium sulphate crystals to melt ...
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AGM battery float voltage
It is a fact that AGM batteries are typically charged with higher voltages, compared to the other lead-acid batteries (flooded and GEL).
I don't understand the reason for this, is it related to the ...
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What is the gain of a purely integrating process?
Consider a system where: $ \frac{Y(s)}{U(s)}=\frac{k}{s} $. Is the gain k, or infinity? Given that to a step response, steady state is never reached, but it increases linearly with no end. Thanks!
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How to determine which variables are state or input variables in dynamic modeling?
When given a P&ID and a process flow diagram, and asked to determine which of the relevant variables to a process input variables, and which are state variables (eg.: mass flow, temperature, ...
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What is the difference between mathematical and process/control degrees of freedom?
Taking mathematical DOF as:
$$ DOF= N_{vars}-N_{eqs} $$
How would process, or control degrees of freedom be defined as?
Thanks!
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Suitable solvents to dissolve Aluminum Chloride (anhydrous) without generating Hydrochloric Acid (aqueous or gas),
Hypothetically, I have a chemical tank that was brought out of service and the solid deposits at the bottom of the tank primarily contain aluminum chloride. The whole system never sees water, and the ...
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How to calculate the Knudsen number?
when calculating the Knudsen number:
$$ Kn=\frac{\lambda_{mf}}{L} $$
Where $\lambda_{mf}$ is the mean free path of a molecule, and $L$ is the characteristic length. How is the characteristic length ...
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Am I a chemist or a chemical engineer?
I apologise if this is the wrong place to ask. I tried asking on reddit but so far I didn't get a lot of answers/
It seems that in America these two degrees are considered separate. Not so much here ...
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Calculating the mass of CO2 from stack emissions
I am working on calculations for an LCA of an operation. The plant operator has provided me a report from an engineering firm who has measured the emissions from their stack. I am trying to estimate ...
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Is it possible to do hot gas filtration through fluidized bed reactors
I am working on flue gas filtration and HCl gas is to be removed from the gas. I am wondering if a fluidized bed reactor could be used to filter the gas. The problem is, a furnace is used to provide ...
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Reactor tube material at moderately high temps (600-1000 C) with water vapor as primary constituent of flow
I work with a type of spectrometer (made by Picarro) that uses near-infrared lasers to measure the stable isotopic composition of water vapor. The samples measured are typically liquid water samples ...
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What does it mean when an oil is labeled with an ISO range rather than a single ISO value
I am a layperson, not an engineer. After reading some articles on what ISO viscosity grades mean, I do not understand what it means for an oil to be labeled with an ISO viscosity range, e.g. "ISO ...
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Continuous stirred-tank reactor (CSTR) in parallel problem
I am having a difficult time solving the following problem. The only thing we learned in class was parallel continuous stirred-tank reactor (CSTR) with equal-sized reactors and equal flow rates for ...
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Is half of depletion region a part of N region or P region?
Is it correct to say that if the P-N junction is in the middle of the depletion region, half of the depletion region is for the P region and the other half is for the N region?
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Why heat transfer happens only via conduction in this case?
Why heat transfer between a heated flat plate and a fluid happens via conduction only and not convection, when the fluid is present below it?
Consider a plate under which a fluid is present and it ...
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Fastest possible mean (peak?) piston speed on a Diesel engine
On a Diesel engine running distillate fuel (the kind you run in cars, SUV's, trucks, trains, boats, and smaller ships), what are the theoretical and practical limits to maximum mean piston speed you ...
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Mean temperature of a fluid in a pipe
Consider a pipe in which a fluid flows such that the pipe is at a higher temperature than the fluid. At any cross section of the pipe we get a varying temperature profile. We can define a mean ...
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Size characterization
Which technique can I use to characterize the size of my particles? They would be in the range of 50 μm to 300 μm. I have verified using a microscope, but I need a technique to analyse the size ...
