Questions and Answers of Chemical Reaction Engineering

The irreversible elementary reaction 2A → B takes place in the gas phase in an isothermal tubular (plug-flow) reactor. Reactant A and a diluent C are fed in equimolar ratio, and conversion of A is
1. Describe how CA and CB change when you experiment with varying the volumetric flow rate, υ0, and the specific reaction rate, k, and then write a conclusion bout your experiments.2. Click on the
Repeat Example 24.6 with the following two changesExample 24.6Figure E24.6 = We wish to lower the concentration of B in the liquid (V, 1.62 m, Cu = 55555.6 mol/m) of an agitated tank reactor by
A first-order reaction with k = 0.1 min–1 is to be carried out in the reactor whose RTD is shown in Figure 18-19B.A graph shows a Reactor E-curve, with t ( in minutes) marked on the horizontal axis
Use the data in Example 16-2 to make the following determinations.a. Calculate the Péclet numbers for both open and closed systems.b. For an open system, determine the space time τ and then
a. Example 18-1. Concentration and Conversion Profiles for Dispersion and Reaction in a Tubular ReactorWolfram and Python1. Vary Péclet number, Per from its largest to smallest value. Describe how
Can you use Figure 18-2 to find the dispersion coefficient for a liquid with a Schmidt number, Sc = 0.35 and a gas porosity ϕ = 0.5, a particle diameter dp = l cm, a gas velocity U = 10 cm/s, and a
The reactions described in Example 12-7 are to be carried out isothermally at 1000°C in the reactor whose RTD is described in Example 17-4 with CA0 = CB0 = 0.05 mol/dm3.a. Determine the exit
The reaction and corresponding rate data discussed in Example 12-3 are to be carried out isothermally at 613°R in a nonideal reactor where RTD is given by the data (i.e., E(t) and F(t)) in Example
A step tracer input was used on a real reactor with the following results:For t ≤ 10 min, then CT = 0.For 10 ≤ t ≤ 30 min, then CT = 10 g/dm3.For t ≥ 30 min, then CT = 40 g/dm3.The
a. Example 17-2: Mean Conversion, Xseg, Calculations in a Real ReactorWolfram and Python1. How do CA0, n and k affect the trajectories in X for the segregation model and the LFR?2. Write a set of
Go to the LearnChemE screencast link for Chapter 17 (http://www.learncheme.com/screencasts/kinetics-reactor-design). View one of the screencast 5- to 6-minute video tutorials and list two of the most
Read over the problems of this chapter. Make up an original problem that uses the concepts presented in this chapter. The guidelines are given in Problem P5- 1B. RTDs from real reactors can be found
Living Example 16-3 Wolfram and Python1. Vary and find the combination of parameters for which the exit conversion is virtually the same for both early mixing and late mixing.2. Find the combination
Read over the problems of this chapter. Discuss with a classmate ideas for making up an original problem that uses the concepts presented in this chapter. The guidelines are given in Question Q5-3A,
Derive the concentration profile and effectiveness factor for cylindrical pellets 0.2 cm in diameter and 1.5 cm in length. Neglect diffusion through the ends of the pellet.a. Assume that the reaction
The irreversible reaction A → B is taking place in the same porous catalyst slab shown in Figure P15-9A.The reaction is zero order in A.a. Show that the concentration profile using the symmetry
a. Example 15-1: Finding the Effective Diffusivity of DeWolfram1. Can you think up a question about the sliders that would be somewhat interesting? I am not sure I can, that’s why there is no
Capt. Apollo is piloting a shuttlecraft on his way to space station Klingon. Just as he is about to maneuver to dock his craft using the hydrazine system discussed in Example 14-2, the shuttle
As the final edits to the Sixth Edition were being made, the coronavirus pandemic struck and it was decided to expand Problem P9-7 and apply it to the pandemic. (Mayur Tikmani, Devosmita Sen, Manjeet
Synthron Explosion LEP. Read the Synthron example in Chapter 13 Additional Materials on the CRE Web Site (http://www.umich.edu/~elements/6e/13chap/obj.html#/additional-materials/)Wolfram and Python1.
Use the reaction and corresponding parameter values in Problem P12-16B to describe the startup of a CSTR with Ti = 25°C and CAi = 0.0. Problem P12-16BThe elementary reversible liquid-phase reaction
The irreversible reaction liquid phase in Problems P11-4A and P12-7A A+2B→C is to be carried out in a 10 dm3 batch reactor. Plot and analyze the temperature and the concentrations of A, B, and C as
The liquid-phase reaction in Problems P11-4A and P12-7A is to be carried out in a semibatch reactor. There are 500 mol of A initially in the reactor at 25°C. Species B is fed to the reactor at 50°C
a. Example 13-1: Batch Reactor with an Exothermic ReactionWolfram1. Adiabatic Case: Use Wolfram to see whether you can find a trajectory that is ready “to ignite” and whose trajectory looks like
Derive the energy balance for a packed-bed membrane reactor. Apply the balance to the reaction in Problem P11-5A A ⇄ B + Cfor the case when it is reversible with KC = 1.0 mol/dm3 at 300 K. Species
Use the reaction data in Problems P11-4A and P12-7B for the case when heat is removed by a heat exchanger jacketing the reactor. The flow rate of coolant through the jacket is sufficiently high that
The elementary gas-phase reaction A + B ⇄ 2C in Problem P11-8B is now continued and carried out in packed-bed reactor. The entering molar flow rates are FA0 = 5 mol/s, FB0 = 2FA0, and FI = 2FA0
The gas-phase reversible reaction as discussed in Problem P11-7B A ⇄ B is now carried out under high pressure in a packed-bed reactor with pressure drop. The feed consists of both inerts I and
Taken from California Professional Engineer’s Exam. The endothermic liquid-phase elementary reaction A + B → 2C proceeds, substantially, to completion in a single steam-jacketed,
The following is an excerpt from The Morning News, Wilmington, Delaware (August 3, 1977): “Investigators sift through the debris from blast in quest for the cause [that destroyed the new nitrous
Download the Interactive Computer Games (ICG) from the CRE Web site. Play the game, and then record your performance number for the module, which indicates your mastery of the material. Note: For
Computer Experiments on a PFR for Reaction in Table 12-2.2. In order to develop a greater understanding of the temperatureeffects in PBRs, download the Living Example Problem Table 12-2, LEP T12-2,
Case 1 Adiabatic(i) Vary inlet flow rate of inert and observe the conversion and temperature profiles. Describe what you find.(ii) Find inlet temperature, T0, for which the reaction rate at V = 0.001
(a) LEP Table 12-2: Exothermic Reaction with Heat Exchange Download the Polymath, MATLAB, Python, or Wolfram codes for the algorithm and data given in Table T12-2 for the exothermic gas phase
What did the section And Now… A Word From Our Sponsor point out or emphasize that was not done in the other AWFOS sections? What were the top two takeaway points in Chapter 12’s AWFOS?
Read over the problems at the end of this chapter. Make up an original problem that uses the concepts presented in this chapter. To obtain a solution:(a) Make up your data and reaction.(b) Use a real
Before reading this chapter, identify the differences in applying the energy balance for co-current heat exchange and counter current heat exchange.
Shows the temperature–conversion trajectory for a train of reactors with interstage heating. Now consider replacing the interstage heating with injection of the feed stream in three equal portions,
The reaction A + B ⇄ C + D is carried out adiabatically in a series of staged packed-bed reactors with interstage cooling. The lowest temperature to which the reactant stream may be cooled is
The elementary gas-phase reaction A + B ⇄ 2C is carried out in a packed-bed reactor. The entering molar flow rates are FA0 = 5 mol/s, FB0 = 2FA0, and FI = 2FA0 with CT0 = a. Write the mole
The gas-phase reversible reaction A ⇄ B is carried out under high pressure in a packed-bed reactor with pressure drop. The feed consists of both inerts I and Species A with the ratio of inerts to
The irreversible endothermic vapor-phase reaction follows an elementary rate lawCH3COCH3 → CH2CO + CH4A → B + C and is carried out adiabatically in a 500-dm3 PFR. Species A is fed to the reactor
Download the following programs from the CRE Web site where appropriate:a. Example Table 11.2: Algorithm for Gas-Phase ReactionWolfram and Python1. What happens to X and Xe profiles as you vary T0?
Go to the LearnChemE screencasts link for Chapter 11 (http://www.umich.edu/~elements/6e/11chap/learn-cheme-videos.html). View one of the screencast 5-to 6-minute video tutorials and list two of the
Read over the problems at the end of this chapter. Make up an original problem that uses the concepts presented in this chapter.
Example 11-3: Adiabatic Liquid-Phase Isomerization of Normal Butane. Can you explain why the CSTR volume is smaller than the PFR volume?Example 11-3Normal butane, C4H10, is to be isomerized to
Example 11-1: What Additional Information Is Required? How would this example change if a CSTR were used instead of a PFR?Example 11-1The first-order liquid-phase reaction A → B is carried out in a
What if you were asked to give an everyday example that demonstrates the principles discussed in this chapter? (Would sipping a teaspoon of Tabasco or other hot sauce be one?)
Suppose the reaction in Table 11-2 were carried out in BR instead of PFR. What steps in Table 11-2 would be different?Table 11-2At equilibrium –rA ≡ 0, and we can solve Equation (T11-2.7) for the
The hydrogenation of ethylbenzene to ethylcyclohexane over a nickel–mordenite catalyst is zero order in both reactants up to an ethylbenzene conversion of 75% (Ind. Eng. Chem. Res., 28 (3), 260
The decomposition of spartanol to wulfrene and CO2 is often carried out at high temperatures (J. Theor. Exp., 15, 15 (2014)). Consequently, the denominator of the catalytic rate law is easily
When the impurity cumene hydroperoxide is present in trace amounts in a cumene feed stream, it can deactivate the silica-alumina catalyst over which cumene is being cracked to form benzene and
The vapor-phase cracking of gas-oil in Example 10-6 is carried out over a different catalyst, for which the rate law is−rA′=k′PA2with k′=5×10−5kmolkg-cat⋅s⋅atm2a. Assuming that you can
With the increasing demand for xylene in the petrochemical industry, the production of xylene from toluene disproportionation has gained attention in recent years (Ind. Eng. Chem. Res., 26, 1854
The elementary irreversible gas-phase catalytic reaction A+B→kC+Dis to be carried out in a moving-bed reactor at constant temperature. The reactor contains 5 kg of catalyst. The feed is
Sketch qualitatively the reactant, product, and activity profiles as a function of length at various times for a packed-bed reactor foreach of the following cases. In addition, sketch the effluent
The dehydrogenation of methylcyclohexane (M) to produce toluene (T) was carried out over a 0.3% Pt/ catalyst in a differential catalytic reactor. The reaction is carried out in the presence of
Titanium dioxide is a wide-bandgap semiconductor that is showing promise as an insulating dielectric in VLSI capacitors and for use in solar cells. Thin films of TiO2 are to be prepared by chemical
Vanadium oxides are of interest for various sensor applications, owing to the sharp metal–insulator transitions they undergo as a function of temperature, pressure, or stress. Vanadium
Hydrogen and O2 can be combined in fuel cells to generate electricity. Solar energy can be used to split water to generate the raw reactants H2 and O2 for fuel cells. One method of solar thermal
Experimental data for the gas-phase catalytic reaction A + B → C is shown below. The limiting step in the reaction is known to be irreversible, so that the overall reaction is irreversible. The
Cyclohexanol was passed over a catalyst to form water and cyclohexene:Cyclohexanol→catalystWater+Cyclohexence It is suspected that the reaction may involve a dual-site mechanism, but it is not
Methyl ethyl ketone (MEK) is an important industrial solvent that can be produced from the dehydrogenation of butan-2-ol (Bu)over a zinc oxide catalyst (Ind. Eng. Chem. Res., 27, 2050
In 1981, the U.S. government put forth the following plan for automobile manufacturers to reduce emissions from automobiles over the next few years.All values are in grams per mile. An automobile
The catalytic dehydration of methanol (ME) to form dimethyl ether (DME) and water was carried out over an ion exchange catalyst (K. Klusacek, Collection Czech. Chem. Commun., 49, 170 (1984)). The
The dehydration of n-butyl alcohol (butanol) over an alumina-silica catalyst was investigated by J. F. Maurer (Ph.D. thesis,University of Michigan). The feed consisted of pure butanol.a. Suggest a
The formation of propenol on a catalytic surface is believed to proceed by the following mechanism O2+2S→←cat2O⋅SC3H6+O⋅S → C3HOH⋅SC3HOH⋅S←→ C3HOH+S Suggest a rate-limiting step and
The rate law for the hydrogenation (H) of ethylene (E) to form ethane (A) over a cobalt-molybdenum catalyst (Collection Czech. Chem. Commun., 51, 2760(1988)) is−rE′=kPEPH1+KEPEa. Suggest a
Consider the catalytic reaction as a function of the initial partial pressures 2A←→B+C The rate of disappearance of species A was obtained in a differential reactor and is shown below.Three
t-Butyl alcohol (TBA) is an important octane enhancer that is used to replace lead additives in gasoline (Ind. Eng. Chem. Res., 27, 2224 (1988)). TBA was produced by the liquid-phase hydration (W) of
Download the Interactive Computer Games (ICG) from the CRE Web site (http://www.umich.edu/~elements/6e/icm/install.html). Play the game and then record your performance number for the game, which
a.1. Find the critical value of KB at which fraction of vacant sites starts to increase with conversion for the initial settings. Repeat for KT. Vary only one parameter at a time.2. Find the value KB
AWFOS–S10 View the CSB video (http://umich.edu/~safeche/assets/pdf/courses/Problems/CRE/344Reaction-EngrModule(3)PS-Exxon.pdf). After watching the Chemical Safety Board video, what points do you
Go to the LearnChemE screencast link for Chapter 10 (http://www.umich.edu/~elements/6e/10chap/learn-cheme-videos.html). View one or more of the screencast 5- to 6-minute videos.1. List two items you
Choose five Chapter 10 i>clicker questions, pick the one that was the most challenging, and explain why.Chapter 5 Questions1.How do the steps in the design of a CSTR differ from those of a CSTR or a
For the decomposition of cumene discussed in this chapter, if an adsorbing inert is present, how would you compare the initial rate as a function of total pressure when desorption is the RLS, as
Read over the problems at the end of this chapter. Make up an original problem that uses the concepts presented in this chapter. To obtain a solution:1. Create your data and reaction.2. Use a real
Short calculations on the algae ponds.a. If the pond is initially seeded with 0.5 mg/dm3 of algae, how long will it take the algae to reach a cell density (i.e., concentration) of 200 mg/dm3? Sketch
In the summer of 2009, ExxonMobil decided to invest 600 million dollars on developing algae as an alternative fuel and their TVcommercials on this initiative were recently shown (e.g., December
Diabetes is a global epidemic affecting more than 240 million people worldwide. The vast majority of the cases are Type 2. Recently a drug, Januvia (J), was discovered to treat Type 2 diabetes. When
A CSTR is being operated at steady state. The cell growth follows the Monod growth law without inhibition. The exiting substrate and cell concentrations are measured as a function of the volumetric
The bacteria X-II can be described by a simple Monod equation with μmax = 0.8 h–1 and KS = 4 g/dm3, Yp/c = 0.2 g/g, and Ys/c = 2 g/g. The process is carried out in a CSTR in which the feed rate is
Redo Problem P9-17B (a), (c), and (d) using the Tessier equationrg = μmax[1 – e–Cs/k]Ccwith μmax = 1.0 h–1 and k = 8 g/dm3.Data from problem P9-17B (a), (c), and (d)a. The reaction is to be
The production of a product P from a particular gram-negative bacteria follows the Monod growth lawrg=μmaxCsCcKS+Cswith μmax = 1 h–1, KS = 0.25 g/dm3, and Yc/s = 0.5 g/g.a. The reaction is to be
The biomass reactionSubstrate S+Cells→More cells +Producttakes place in a 12-dm3 CSTR (chemostat) where the entering concentration of substrate is 200 g/dm3. The rate law follows the Monod equation
An enzymatic reaction that follows, Michaels-Menten kinetics rate law with initial enzyme concentration CE0 is−rA=k2CE0(S)1+KM(S)The rate constant, k2, was measured as a function of inhibitor
An Eadie–Hofstee Plot is shown in Figure P9-14B for different types of enzyme inhibition.Figure P9-14Ba. Match the line with the type of inhibition.1. Line A Inhibition Mechanism. Ans: ________2.
The hydrogen ion, H+, binds with the enzyme (E–) to activate it in the form EH. The hydrogen ion, H+, also binds with EH to deactivate it by forming
The enzymatic hydrolysis of starch was carried out with and without maltose and α-dextrin added. (Adapted from S. Aiba, A. E.Humphrey, and N.F. Mills, Biochemical Engineering, New York: Academic
The following data on baker’s yeast in a particular medium at 23.4°C were obtained in the presence and in the absence of an inhibitor, sulfanilamide. The reaction rate (–rS) was measured in
It has been observed that substrate inhibition occurs in the following enzymatic reaction:E + S → P + Ea. Show that the rate law for substrate inhibition is consistent with the plot in Figure
Beef catalase has been used to accelerate the decomposition of hydrogen peroxide to yield water and oxygen (Chem. Eng. Educ.,5, 141). The concentration of hydrogen peroxide is given as a function of
Derive the rate laws for the following enzymatic reactions and sketch and compare, where possible.a. E + S ⇄ E · S ⇄ P + Eb. E + S ⇄ E · S ⇄ → P + Ec. E + S1 ⇄ E · S1E · S1 + S2 ⇄ E
Consider the application of the PSSH to epidemiology. We shall treat each of the following steps as elementary, in that the rate will be proportional to the number of people in a particular state of
One of the major reasons for engine–oil degradation is the oxidation of the motor oil. To retard the degradation process, most oils contain an antioxidant. Without an inhibitor to oxidation
a. For each of the reactions in parts (a), (b), and (c), suggest a mechanism and apply the PSSH to learn if the mechanism is consistent with the rate law.b. The gas-phase homogeneous oxidation of
The pyrolysis of acetaldehyde is believed to take place according to the following sequence:CH3CHO→k1CH3⋅+CHOCH3⋅+CH3CHO→k2CH3⋅+CO+CH4CHO⋅+CH3CHO→k3CH3+2CO+H22CH3⋅→k4C2H6a. Derive
Hydrogen radicals are important to sustaining combustion reactions. Consequently, if chemical compounds that can scavenge the hydrogenradicals are introduced, the flames can be extinguished. While
a. Load the ICG on your computer and carry out the exercise. Performance number =________________________.(http://www.umich.edu/~elements/6e/icm/enzyme.html)b. Rederive Equation (9-9) assuming the

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