All Matches
Solution Library
Expert Answer
Textbooks
Search Textbook questions, tutors and Books
Oops, something went wrong!
Change your search query and then try again
Toggle navigation
FREE Trial
S
Books
FREE
Tutors
Study Help
Expert Questions
Accounting
General Management
Mathematics
Finance
Organizational Behaviour
Law
Physics
Operating System
Management Leadership
Sociology
Programming
Marketing
Database
Computer Network
Economics
Textbooks Solutions
Accounting
Managerial Accounting
Management Leadership
Cost Accounting
Statistics
Business Law
Corporate Finance
Finance
Economics
Auditing
Ask a Question
Search
Search
Sign In
Register
study help
engineering
chemical engineering
Questions and Answers of
Chemical Engineering
Without looking at the text, define the following:a. Isothermal distillationb. The four flow regimes in a staged distillation columnc. Reflux and reflux ratiod. Boilup and boilup ratioe. Rectifying
Explain the reasons a constant pressure distillation column is preferable toa. An isothermal distillation system.b. A cascade of flash separators at constant temperature.c. A cascade of flash
In a countercurrent distillation column at constant pressure, where is the temperature highest? Where is it lowest?
Develop your own key relations chart for this chapter. In one page or less, draw sketches, write equations, and include all key words useful for solving problems.
For a binary separation, is \(\mathrm{K}_{\mathrm{MVC}} \mathrm{V} / \mathrm{L}\) usually less than, equal to, or greater than 1.0? For a binary separation, is \(\mathrm{K}_{\mathrm{LVC}} \mathrm{V}
Specifications for a distillation column similar to Figure 3-8 cannot include all three flow rates F, D, and B. Why not? H. y. Vin -+-1 Qc F2 hp(TF) 1 V2L1 Vj+4 f Lo xo Vkk kk-1 VN+1 N B(Xehe D. XD D
Is column pressure approximately constant \({ }^{*}\) for the following problems:a. Column operating at nominal pressure \(\mathrm{p}=1.0 \mathrm{~atm}\) with 10 traysb. Column operating at nominal
In an abstract sense, is boilup a type of reflux?
Why is the assumption of constant column pressure often reasonable for columns at atmospheric pressure and above, but often not reasonable for vacuum columns?
A common misconception of new graduates is that reflux is usually a saturated liquid. In practice, if the reflux needs to be pumped, the reflux is always subcooled. Explain why. (Note: We will see in
In the paragraph immediately before Example 3-1, the following sentence occurs: " \(\mathrm{Q}_{\mathrm{c}}\) is proportional to \((1+\mathrm{L} / \mathrm{D}) \mathrm{F}\), and
There are ways in which columns can be specified other than those listed in Tables 3-1 to 3-3.a. Develop alternative specifications for design problems.b. Develop alternative specifications for
We flash distill a mixture that is \(5.0 \mathrm{~mol} \%\) methane, \(12.3 \mathrm{~mol} \%\) ethane, 11.5 \(\mathrm{mol} \%\) n-butane, \(22.2 \mathrm{~mol} \%\) n-pentane, \(25.4 \mathrm{~mol}
We flash distill a mixture that is \(24.1 \mathrm{~mol} \%\) ethane, \(39.7 \mathrm{~mol} \% \mathrm{n}\)-hexane, and \(36.2 \mathrm{~mol} \% \mathrm{n}\)-heptane. If \(\mathrm{p}_{\text {drum
We flash distill a mixture that is \(28.1 \mathrm{~mol} \%\) n-butane, \(42.8 \mathrm{~mol} \% \mathrm{n}\)-pentane, and \(29.1 \mathrm{~mol} \% \mathrm{n}\)-heptane. \(\mathrm{T}_{\text {drum
Develop a spreadsheet to solve problem 2.D13, parts b and c. Use Eq. (2-28). (Note: The easiest approach to solving this problem is to develop a spreadsheet similar to Figures 2-B2 and run the
To explore what happens if a nonvolatile component is in the feed to a flash distillation, modify Figure 2-B2 to add \(37.5 \mathrm{kmol} / \mathrm{h}\) of a nonvolatile component to the feed.a. Keep
Benzene-toluene equilibrium is often approximated as \(\alpha_{\mathrm{BT}}=2.34\). Generate the \(\mathrm{y}-\mathrm{x}\) diagram for this relative volatility. Compare your results with data in the
Ethylene glycol and water are flash distilled in a cascade of three drums connected as shown in the figure. All drums operate at 228 mm Hg. Feed is 40 mol% water. One-third of the feed is vaporized
Pure water at a flow rate of \(1500 \mathrm{~kg} /\) minute at \(\mathrm{p}=5000 \mathrm{kPa}\) and \(\mathrm{T}=500 \mathrm{~K}\) is sent to an adiabatic flash system operating at \(\mathrm{p}=100
Use the Peng-Robinson VLE correlation in Aspen Plus to solve Problem 2.D13, part \(\mathrm{b}\), except feed is a saturated liquid at 10.0 bar. Pressure is dropped to 6.0 bar in the flash drum.
Two feeds containing methanol and water are sent to the same flash drum. Feed 1 is \(20 \mathrm{~mol} \%\) methanol, \(F_{1}=150 \mathrm{kmol} / \mathrm{h}\), and \((V / F)_{1}=0.4\). Feed 2 is \(30
Use a process simulator to solve Problem 2.D16. Do "what if?" simulations to see what happens to V/F and product compositions as temperature and/or pressure vary.Problem 2.D16. A feed that is 50.0
One \(\mathrm{kmol} / \mathrm{s}\) of a feed containing \(20 \mathrm{~mol} \%\) furfural, \(75 \mathrm{~mol} \%\) water, and \(5 \mathrm{~mol} \%\) ethanol at \(105^{\circ} \mathrm{C}\) and 3.0 bar
Use a process simulator to solve the following flash distillation problem. Feed is \(2 \mathrm{~mol} \%\) methane, \(30 \mathrm{~mol} \%\) n-butane, \(47 \mathrm{~mol} \% \mathrm{n}\)-pentane, and
A vertical flash drum will be used to separate \(1000 \mathrm{kmol} / \mathrm{h}\) of a feed that is 10.0 \(\mathrm{mol} \%\) isopropanol and \(90.0 \mathrm{~mol} \%\) water. Feed is at 9.0 bar and
A flash drum is to flash \(10,000 \mathrm{lbmol} / \mathrm{h}\) of a feed that is \(65 \mathrm{~mol} \% \mathrm{n}\)-hexane and \(35 \mathrm{~mol} \% \mathrm{n}-o c t a n e\) at \(1.0 \mathrm{~atm}\)
A flash drum at \(1.0 \mathrm{~atm}\) is separating a feed consisting of methanol and water. If the feed rate is \(2000 \mathrm{~kg} / \mathrm{h}\) and the feed is \(45 \mathrm{wt} \%\) methanol,
We are separating a mixture of methanol and water in a flash drum at 1 atm pressure. Equilibrium data are listed in Table 2-8.a. Feed is 60.0 mol% methanol, and 40.0% of the feed is vaporized. What
Two flash distillation chambers are hooked together as shown in the diagram. Both are at 1 atm pressure. The feed to the first drum is a binary mixture of methanol and water that is 55.0 mol%
Data for the equilibrium of water and n-butanol at 1.0 atmosphere are given in Table 8-5. Plot yw vs. xw. A feed of 100.0 kmol/h that is 20.0 mol% water is fed to flash chamber A, which is the first
A mixture of methanol and water is sent to a flash distillation drum operating at 1.0 atm. Feed rate is 10.0 kmol/h. The feed before the valve in Figure 2-1 is at 102.0C and a pressure of 5.0 bar.
We have a feed that is a binary mixture of methanol and water (55.0 mol% methanol) that is sent to a system of two flash drums hooked together. The vapor from the first drum is cooled, which
Antoine constants for 1-octanol and 1-propanol are listed in Table 2- 3.a. At 1.50 atm and 100.0C, what is vapor pressure of 1-octanol in mm Hg?b. Assuming Raoult's law is valid, what is the K value
Your plant feeds 100.0 kmol/h of a mixture that is 46.0 mol% ethanol and 54.0 mol% water to a flash drum. Your boss thinks that results will be better with two flash drums (same configuration as in
A flash drum at 700.0 kPa is separating binary mixtures of ethane and n-butane.a. The following equilibrium results were generated using correct units in Eq. (2-28) and then converting temperature to
We wish to flash distill an ethanol-water mixture that is \(30.0 \mathrm{wt} \%\) ethanol and has a feed flow of \(1000 \mathrm{~kg} / \mathrm{h}\). Feed is at \(200.0^{\circ} \mathrm{C}\). The flash
We have a mixture that is \(35.0 \mathrm{~mol} \% \mathrm{n}\)-butane with unknown amounts of propane and n-hexane. We are able to operate a flash drum at \(400.0 \mathrm{kPa}\) and \(70.0^{\circ}
An equilibrium mixture of ethylene and propylene is at \(2500 \mathrm{kPa}\) and \(25.0^{\circ} \mathrm{C}\). Find the vapor and liquid mole fractions of ethylene. Use DePriester charts or Eq.
Find the diameter and length of a horizontal flash drum for Problem 2.D1c if a hold-up time of 1.0 hours is specified.Problem 2.D1cc. If the feed is \(30.0 \mathrm{~mol} \%\) methanol and we desire a
We flash distill a mixture of methane and n-butane at \(\mathrm{p}_{\text {drum }}=6.0\) bar.a. Use the DePriester charts or Eq. (2-28). For several temperatures from \(\mathrm{T}=\) \(-60^{\circ}
A ternary mixture of methanol, n-propanol, and n-butanol is flash distilled at a pressure of \(0.74 \mathrm{~atm}\). The feed is \(36 \mathrm{~mol} \%\) methanol, \(42 \mathrm{~mol} \%
We have a flash drum separating \(50.0 \mathrm{kmol} / \mathrm{h}\) of a mixture of ethane, isobutane, = and n-butane. The ratio of isobutane to n-butane is held constant at 0.80 (that is, Zic4/ZnC4
A feed that is \(50.0 \mathrm{~mol} \%\) methane, \(10.0 \mathrm{~mol} \% \mathrm{n}\)-butane, \(15.0 \mathrm{~mol} \% \mathrm{n}\)-pentane, and \(25.0 \mathrm{~mol} \% \mathrm{n}\)-hexane is flash
Two feeds containing ethanol and water at \(1.0 \mathrm{~atm}\) are fed simultaneously to the same flash drum. Feed 1 is \(10.0 \mathrm{~mol} \%\) ethanol, \(\mathrm{F}_{1}=150.0 \mathrm{kmol} /
\(10 \mathrm{kmol} / \mathrm{h}\) of a feed that is \(10.0 \mathrm{~mol} \%\) propane, \(30.0 \mathrm{~mol} \% \mathrm{n}\)-butane, and 60.0 \(\mathrm{mol} \% \mathrm{n}\)-hexane is flash distilled
A flash drum operating at \(300 \mathrm{kPa}\) is separating \(1000.0 \mathrm{kmol} / \mathrm{h}\) of a mixture that is \(40.0 \mathrm{~mol} \%\) isobutane, \(25.0 \% \mathrm{n}\)-pentane, and \(35.0
\(200 \mathrm{kmol} / \mathrm{h}\) of a feed that is \(10.0 \mathrm{~mol} \%\) ethanol and \(90.0 \mathrm{~mol} \%\) water is separated in a pair of flash drums. The vapor from drum 1 is partially
We wish to flash distill a feed that is \(55.0 \mathrm{~mol} \%\) ethane and \(45.0 \mathrm{~mol} \% \mathrm{n}-\) pentane. \(\mathrm{p}_{\text {drum }}=700 \mathrm{kPa}\) and \(\mathrm{T}_{\text
\(50 \mathrm{kmol} / \mathrm{h}\) of a vapor feed that is \(70 \mathrm{~mol} \%\) methanol and \(30 \mathrm{~mol} \%\) water is partially condensed in a heat exchanger and then fed to a flash drum
You specified a 5.5 -foot diameter, 22.0 -foot long drum with a mesh demister for Example 2-4. This drum was built. Later, your boss informed you that a minor [the boss' word] mistake had been made
We plan to separate a mixture of propane and n-hexane at 300 kPa.a. Using the data in the DePriester charts, plot ypropane VS. Xp Xpropane for this mixture at 300 kPa. Xpropane and T vs.b. If the
Two feeds containing ethanol and water at \(1.0 \mathrm{~atm}\) are fed simultaneously to the same flash drum. Feed 1 is \(20.0 \mathrm{~mol} \%\) ethanol, \(\mathrm{F}_{1}=150.0 \mathrm{kmol} /
Use Eq. (2-11) to create a table comparing the y values for methanol for methanol-water VLE at \(1.0 \mathrm{~atm}\) versus y values from Table 2-8 (in problem 2.D1) for all the \(x\) values in Table
Antoine constants for vapor pressure for \(\mathrm{n}\)-pentane and \(\mathrm{n}\)-hexane are listed in Table 2-3.a. Predict the vapor pressure at \(0.0^{\circ} \mathrm{C}\) for pure
Repeat Example 2-4, but with \(\mathrm{F}=3000 \mathrm{lbmol} / \mathrm{h}\), and use a horizontal flash drum with holding time \(=55 \mathrm{~min}\) and surge time \(=85 \mathrm{~min}\). Calculate
Design a horizontal flash drum to separate \(15,000 \mathrm{~kg} / \mathrm{h}\) of a feed with the following mass fractions: methane 0.21 , propane 0.39 , n-butane 0.24 , i-butane 0.11 , and
A flash drum is separating \(n\)-butane and \(n\)-pentane with \(T_{\text {drum }}=20.0^{\circ} \mathrm{C}\) and \(p_{\text {drum }}\) \(=101.3 \mathrm{kPa}\). The feed is \(50.0 \mathrm{wt} \%
A feed of \(100.0 \mathrm{kmol} / \mathrm{h}\) that is \(60.0 \mathrm{~mol} \%\) methanol, and \(40.0 \mathrm{~mol} \%\) water is sent to a system of three flash drums operating at 1.0 atmosphere.
In Figure 2-9, the feed plots as a two-phase mixture, whereas it is a liquid before introduction to the flash chamber. Explain why. Why can’t the feed location be plotted directly from known values
Can weight units be used in the flash calculations instead of molar units?
Flash distillation is usually operated adiabatically. Where does the energy to vaporize part of the feed come from?
In the flash distillation of salt water, the salt is totally nonvolatile (this is the equilibrium statement). Show a McCabe-Thiele diagram for feed water containing 3.5 wt % salt. Be sure to plot
Develop your own key relations chart for this chapter. That is, on one page summarize everything you would want to know to solve problems in flash distillation. Include sketches, equations, and key
In a flash drum separating a multicomponent mixture, raising the pressure willa. increase the drum diameter and increase the relative volatilities.b. increase the drum diameter and cause no change to
a. What would Figure 2-2 look like if we plotted y2 vs. X2 (i.e., plot less volatile component mole fractions)?b. What would Figure 2-3 look like if we plotted T vs. X2 or y2 (less volatile
a. At 100.0°C and a pressure of 200.0 kPa, what is the K value of n-hexane?b. As the pressure increases, does the K value (a) increase, (b) decrease, or (c) stay constant?c. Within a homologous
Use the DePriester chart:What is the K value of propane at 240.0 kPa and 25.0°C?What is the normal boiling point of n-pentane?What is the boiling point of n-pentane at p = 600.0 kPa?
Use the vapor-liquid equilibrium data at 1.0 atm. for methanol-water (Table 2-8 in Problem 2.D1) for the following:If the methanol vapor mole fraction is 0.600, what is the methanol liquid mole
An open glass of an alcoholic beverage that is 15.0 mol% ethanol and 85.0 mol% water has been sitting on the table for a long time and is at 1.0 atm pressure and 25.0°C. The temperature and mole
Why is there a difference between degrees of freedom for equilibrium and degrees of freedom for complete design? Example: binary flash. Gibbs phase rule, F = C − P + 2 =2; entire design F = 6.
Part E of Example 2-3 determines the differences between Aspen Plus and Example 2-3 results. Explain how the % difference in V is about 4.5 times as the % difference in L yet the numerical
Figure 2-4 is at a pressure of 1.0 kg/cm2 (actually kgf/cm2), which was formerly a fairly common pressure unit. What is the pressure in bar and in atm? 100 400 O 05 100
Think of all the ways a binary flash distillation problem can be specified. For example, we have usually specified F, z, Tdrum, Pdrum in addition to T and p. If T and p are constant, what other
An existing flash drum is available. The vertical drum has a demister and is 4 ft in diameter and 12 ft tall. The feed is 30 mol% methanol and 70.0 mol% water. A vapor product that is 58 mol%
Determine the effect of pressure on the temperature, separation, and diameter of a flash drum.
Analytically solve the Rachford-Rice equation for V/F for a binary system.
Assume that vapor pressure can be calculated from the Antoine equation and that Raoult's law can be used to calculate K values. For a binary flash system, derive an analytical expression for the drum
Prove that the operating and y = x lines for binary flash distillation intersect at y = x = z.
Choosing to use V/F to develop the Rachford-Rice equation is conventional but arbitrary. We could also use L/F, the fraction remaining liquid, as the trial variable. Develop the Rachford-Rice
In flash distillation, a liquid mixture is partially vaporized. We could also take a vapor mixture and partially condense it. Draw a schematic diagram of partial condensation equipment. Derive the
Plot Eq. (2-39a) vs. V/F for Example 2-2 to illustrate that convergence is not as linear as the Rachford-Rice equation.Eq (2-39a)Example 2-2A flash chamber operating at 50°C and 200 kPa is
For a vapor-liquid-liquid flash distillation, derive Eqs. (2-56) and (2-57) and the equations that allow calculation of all the mole fractions once V/F and Lliquid-1/F are known.Eqs (2-56)Eqs (2-57)
Return to your successful solution of a fairly difficult problem in one of your previous chemical engineering courses. Look at this solution from the point of view of the process used to solve the
Without returning to the book, answer the following: a. Define a unit operation. Give a few examples. b. What is the equilibrium stage concept? c. What are the steps in the systematic
The equilibrium stage concept a. Is a hypothetical construct. b. Assumes that phases leaving the stage are in equilibrium. c. Is useful even when phases are not in equilibrium. d. All of the
If you have studied heat transfer, relate Eq. (1-4) to the similar basic definition of heat transfer by conduction and convection.Equation (1-4) Mass transfer rate = (area) x (mass transfer
Do you satisfy the prerequisites? If not, how can you remedy this situation?
Develop a key relations chart (one page or less) for this chapter. A key relations chart is a summary of everything you need to solve problems or answer questions from the chapter. In general, it
The results of Web searches can often give surprising results. Use a standard search engine to search for “separation processes,” and see what the results are.
In addition to units not being standard everywhere, symbols for different variables are often different. Explain why it is difficult to obtain uniform agreement on symbols.
List as many products and how they are purified or separated as you can.
Separation methods for water treatment are common in homes in the United States. List the separations that you are familiar with, and briefly describe how you think they work.
The body uses several membrane separation methods. List as many of these as you can, and describe how you think they work.
Separation operations are very common in chemistry laboratories. List the separations that you employed in various chemistry labs.
Write the mass and energy balances (in general form) for the separator shown in Figure 1-1. If necessary to complete this task, review mass and energy balances.Figure 1-1 Raw Materials By-products
Flow rate is 1200 kmol/h of a 30.0 mol% ethanol and 70.0 mol% water feed. What are the ethanol weight fraction and total flow rate in pounds per hour? Data: The locations in this textbook of
Flow rate of a 30.0 wt.% ethanol and 70.0 wt.% water feed is 1200 kmol/h. What are the ethanol mole fraction and the total flow rate in kg/h?
Pressure is 1900 mm Hg. What is the pressure in kPa? Unit conversions are in Appendix C.Appendix C Unit Conversions Density and Weight 1000.0 g = 1.0 kg 1.0 g/cm = 1000.0 kg/m = 62.43 lbm/ft 1.0
18.0 kJ/s are required. How many kW is this? Unit conversions are in Appendix C.Appendix C Unit Conversions Density and Weight 1000.0 g = 1.0 kg 1.0 g/cm = 1000.0 kg/m = 62.43 lbm/ft 1.0 lbm=0.45359
Showing 800 - 900
of 1798
First
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Last