Questions and Answers of Chemical Reaction Engineering

It is believed, although never proven, that Bonnie murdered her first husband, Lefty, by poisoning the tepid brandy they drank together on their first anniversary. Lefty was unaware she had coated
Corrosion of high-nickel stainless steel plates was found to occur in a distillation column used at DuPont to separate HCN and water. Sulfuric acid is always added at the top of the column to prevent
The frequency of fireflies flashing and the frequency of crickets chirping as a function of temperature follow. Source: Keith J. Laidler, “Unconventional applications of the Arrhenius law.” J.
The following figures show the energy distribution function at 300 K for the reaction A + B → C.A graph of f (E, T) versus T is shown. The horizontal axis representing the energy (kilocalorie) per
Use Equation (3-20) to make a plot of f(E,T) as a function of E for T = 300, 500, 800, and 1200 K.a. What is the fraction of molecules that have sufficient energy to pass over a energy barrier of 25
a. Use Figure 3-1(b) to sketch the trajectory over the saddle point when the BC and AB molecules vibrate with the minimum separation distance being 0.20Angstroms and the maximum separation being 0.4
Molecular collision energies—refer to Figure 3-4 and to the Wolfram and Python LEP 3-1. cdf Variation of Energy Distribution withTemperature.1. What fraction of molecular collisions have energies
Exploring the Example Problems.1. Example 3-1. Activation Energy. In the Excel spreadsheet, replace the value of k at 312.5 K with k = 0.0009–1s and determine the new values of E and k.2. Example
(a) LEP: Variation of Energy Distribution with Temperature. Wolfram and Python1. Vary temperature, T, and activation energy, E, to learn their effects on energy distribution curve. Specifically, vary
The experiments on reaction A → B were carried out and the conversion-rate data is given in Table P2-11.a. What are the batch reactor times to achieve 10%, 50%, and 80% for the reactor A → B when
The curve shown in Figure 2-1 is typical of a reaction carried out isothermally, and the curve shown in Figure P2-10C is typical of a gas–solid catalytic exothermic reaction carried out
Estimate the reactor volumes of the two CSTRs and the PFR shown in the photo in Figure 2-9.Figure 2-9
The adiabatic exothermic irreversible gas-phase reaction 2A + B → 2C is to be carried out in a flow reactor for an equimolar feed of A and B. A Levenspiel plot for this reaction is shown in Figure
Read the Web Module “Chemical Reaction Engineering of Hippopotamus Stomach” on the CRE Web site (http://www.umich.edu/~elements/6e/web_mod/hippo/index.htm).a. Work problems (1) and (2) in the
The financially important reaction to produce the valuable product B (not the real name) was carried out in Jesse Pinkman’s garage (see Breaking Bad Season 3, Episode 7). This Breaking Bad,
The exothermic reaction of stillbene (A) to form the economically important trospophene (B) and methane(C), that is, A → B+ C was carried out adiabatically and the following data recorded:The
You have two CSTRs and two PFRs, each with a volume of 1.6 m3. Use Figure 2-2(b) to calculate the conversion for each of the reactors in the following arrangements.1. Two CSTRs in series.2. Two
1.Revisit the data in Table 2-1 Raw Data and calculate the batch reactor (BR) times to achieve 10%, 50%, and 80% conversion when 100 moles of A are charged to a 400 dm3 reactor.Table 2-12.Revisit
Download the Interactive Computer Game (ICG) from the CRE Web site, http://www.umich.edu/~elements/6e/icm/staging.html. Play this game and then record your performance number, which indicates your
What if... the PFR in Example 1-2 were replaced by a CSTR, what would be its volume?Example 1-2 Let's consider the liquid phase cis-trans isomerization of 2-butene H H H CH3 CH CH3 CH3 cis-2-hutene
QBR Questions Before Reading. Research has shown (J. Exp. Psychol. Learn. Mem. Cogn., 40, 106–114 (2014)) that if you ask a question of the material before reading the material you will have
The elementary reversible liquid-phase reaction takes place in a CSTR with a heat exchanger. Pure A enters the reactor.(a) Derive an expression (or set of expressions) to calculate G(T) as a function
Use the data in Problem P11-4A for the following reaction. The elementary, irreversible, organic liquid-phase reactionA + B → C is carried out in a flow reactor. An equal molar feed in A and B
Use the data and reaction in Problems P11-4A and P12-7B for the following reaction: A+B → C+D(a) Plot and then analyze the conversion, Qr, Qg, and temperature profiles up to a PFR reactor volume of
Circle the correct answer.(a) The elementary reversible isomerization of A to B was carried out in a packed-bed reactor. The following profiles were obtained:Two trend graph are shown. The horizontal
The irreversible reaction A+B → C+D is carried out adiabatically in a CSTR. The “heat generated” G(T) and the “heat removed” R(T) curves are shown in Figure P12-14A.The graph represents the
The first-order, irreversible, exothermic liquid-phase reaction A → B is to be carried out in a jacketed CSTR. Species A and an inert I are fed to the reactor in equimolar amounts. The molar feed
The reversible liquid-phase reaction A ⇄ B is carried out in a 12-dm3 CSTR with heat exchange. Both the entering temperature, T0, and the heat exchange fluid, Ta, are at 330 K. An equal molar
The elementary gas-phase reaction 2A ⇄ C is carried out in a packed-bed reactor. Pure A enters the reactor at a 450-K flow rate of 10 mol/s, and a concentration of 0.25 mol/dm3. The PBR contains 90
A reaction is to be carried out in the packed-bed reactor shown in Figure P12-19C.PFR with heat exchange. The reactants enter the annular space between an outer insulated tube and an inner tube
The reaction A+B←→2C is carried out in a packed-bed reactor. Match the following temperature and conversion profiles for the four different heat-exchange cases: adiabatic, constant Ta, cocurrent
Also Hall of Fame Problem. The irreversible liquid-phase reactions Reaction(1)A + B → 2Cr1C = k1CCACBReaction(2)2B+C→Dr2D=k2DCBCC are carried out in a PFR with heat exchange. The temperature
The following elementary reactions are to be carried out in a PFR with a heat exchange with constant Ta:2A+B→CΔHRx1B=−10kJmol BA→DΔHRx2A=+10kJmol AB+2C→EΔHRx3C=−20kJmol C The reactants
The complex gas-phase reactions are elementaryand carried out in a PFR with a heat exchanger. Pure A enters at a rate of 5 mol/min, a concentration of 0.2 mol/dm3, and temperature 300 K. The entering
The elementary liquid-phase reactions(1) A+ 2B → 2C(2) A+C→ 2Dare carried out adiabatically in a 10 dm3 PFR. After streams A and B mix, species A enters the reactor at a concentration of CA0 = 2
Xylene has three major isomers, m-xylene (A), o-xylene (B), and p-xylene (C). When m-xylene (A) is passed over a Cryotite catalyst, the following elementary reactions are observed. The reaction to
Styrene can be produced from ethylbenzene by the following reaction: ethylbenzene↔styrene+H2(1)However, several irreversible side reactions also occur:ethylbenzene → benzene + ethylene (2)
The liquid-phase, dimer-quadmer series addition reaction 4 A → 2A2 → A4 can be written as2A→A2−r1A=k1ACA2ΔHRx1A=−32.5kcalmol A2A2→A4−r2A2=k2A2CA22ΔHRx2A2=−27.5kcalmol A2and is
Pure oxygen is being absorbed by xylene in a catalyzed reaction in the experimental apparatus sketched in Figure P14-3B. Under constant conditions of temperature and liquid composition, the following
Derive an equation for the time necessary to completely burn a 100 μm carbon particle as a function of D0. Also calculate the burning rate constant. Use the KS values of the parameter values, for
The decomposition of cyclohexane to benzene and hydrogen is mass transfer-limited at high temperatures. The reaction is carried out in a 5-cm-ID pipe 20 m in length packed with cylindrical pellets
Curves A, B, and C in Figure P15-4A show the variations in reaction rate for three different reactions catalyzed by solid catalyst pellets. What can you say about each reaction?Temperature dependence
Consider a real tubular reactor in which dispersion is occurring.a. For small deviations from plug flow, show that the conversion for a first-order reaction is given approximately as
The elementary liquid-phase reaction A→B,k1k1=1.0 min−1 is carried out in a packed-bed reactor in which dispersion is present. What is the conversion?Additional information: Porosity =
Sophia and Nic are operating a batch reactor at their grandfather’s plant in Kärläs, Jofostan. The reaction is first-order, irreversible, liquid-phase, and exothermic. An inert coolant is added
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
The reaction A+B→C is carried out adiabatically in a constant-volume batch reactor. The rate law is -rA=k1CA1/2CB1/2-k2CC Plot and analyze the conversion, temperature, and concentrations of the
The elementary irreversible liquid-phase reaction A+2B→C is to be carried out in a semi batch reactor in which B is fed to A. The volume of A in the reactor is 10 dm3, the initial concentration of
The following reactions are taking place in a 2000-dm3 liquid-phase batch reactor under a pressure of 400 psig:The initial temperature is 450 K and the initial concentrations of A, B, and C are 1.0,
a. Example 14-1: Mass Transfer of Oxygen to a Burning Carbon Particle Wolfram and Python1. Vary each slider to find the parameter to which the flux WAr is most sensitive.2. What happens when the
Read over the problems at the end of this chapter. Make up an original problem that uses the concepts presented in this chapter. See Problem P5-1A for the guidelines. To obtain a solution:1. Make up
Assume the minimum respiration rate of a chipmunk is 1.5 micromoles of O2/min. The corresponding volumetric rate of gas intake is 0.05 dm3/min at STP.a. What is the deepest a chipmunk can burrow a
In a diving-chamber experiment, a human subject breathed a mixture of O2 and He while small areas of his skin were exposed to nitrogen gas. After some time, the exposed areas became blotchy, with
Lead titanate, PbTiO3, is a material having remarkable ferroelectric, pyroelectric, and piezoelectric properties [ J. Elec. Chem. Soc., 135, 3137 (1988)]. A thin film of PbTiO3 was deposited in a CVD
A plant is removing a trace of Cl2 from a waste-gas stream by passing it over a solid granulm absorbent in a tubular packed bed (Figure P14-8B). At present, 63.2% removal is being acomplished, but it
In a certain chemical plant, a reversible fluid-phase isomerization A→←B is carried out over a solid catalyst in a tubular packed-bed reactor. If the reaction is so rapid that mass transfer
The irreversible gas-phase reaction A→cat B is carried out adiabatically over a packed bed of solid catalyst particles. The reaction is first order in the concentration of A on the catalyst
The following oxygen-18 data were obtained from soil samples taken at different depths in Ontario, Canada. Assuming that all the 18O was laid down during the last glacial age and that the transport
Transdermal Drug Delivery. See photo on page 781. The principles of steady-state diffusion have been used in a number of drug-delivery systems. Specifically, medicated patches are commonly attached
A spherical particle is dissolving in a liquid. The rate of dissolution is first order in the solvent concentration, C. Assuming that the solvent is in excess, show that the following conversion-time
Derive the diffusion and reaction equation in spherical coordinates to describe the dissolution of a drug in the form of a spherical pellet. Plot the drug concentration as a function distance r and
A powder is to be completely dissolved in an aqueous solution in a large, well-mixed tank. An acid must be added to the solution to render the spherical particle soluble. The particles are
An antibiotic drug is contained in a solid inner core and is surrounded by an outer coating that makes it palatable. The outer coating and the drug are dissolved at different rates in the stomach,
If disposal of industrial liquid wastes by incineration is to be a feasible process, it is important that the toxic chemicals be completely decomposed into harmless substances. One study carried out
The catalytic reaction A → B takes place within a fixed bed containing spherical porous catalyst X22. Figure P15-2B shows the overall rates of reaction at a point in the reactor as a function of
The reaction A → B is carried out in a differential packed-bed reactor at different temperatures, flow rates, and particle sizes. The results shown in Figure P15-3B were obtained.Reaction rates in
The swimming rate of a small organism (J. Theoret. Biol., 26, 11 (1970)) is related to the energy released by the hydrolysis of adenosine triphosphate (ATP) to adenosine diphosphate (ADP). The rate
A first-order heterogeneous irreversible reaction is taking place within a spherical catalyst pellet that is plated with platinum throughout the pellet. The reactant concentration halfway between the
A first-order, heterogeneous, irreversible reaction is taking place within a catalyst pore that is plated with platinum entirely along the length of the pore (Figure P15-7B). The reactant
Six Types of Critical Thinking Questions1. Write a Critical Thinking Question for each type of CTQ for the Monsanto Incident, Example 13-2.2. Write another question for each CTQ for the case history
The elementary isomerization reaction A → B is taking place on the walls of a cylindrical catalyst pore (see Figure P15-7B.) In one run, a catalyst poison P entered the reactor together with the
A first-order reaction is taking place inside a porous catalyst. Assume dilute concentrations and neglect any variations in the axial (x) direction.a. Derive an equation for both the internal and
The second-order decomposition reaction A → B + 2C is carried out in a tubular reactor packed with catalyst pellets 0.4 cm in diameter. The reaction is internal-diffusion-limited. Pure A enters the
The irreversible gas-phase dimerization 2A → A2 is carried out at 8.2 atm in a stirred contained-solids reactor to which only pure A is fed. There are 40 g of catalyst in each of the four spinning
Derive Equation. d2ydλ2−ϕn2yn=0 by 2dy/dλ, rearrange to get ddλ(dydλ)2=ϕn2yn2dydλ and solve using the boundary conditions dy/dλ = 0 at λ = 0.
You will need to read about slurry reactions on the Web site’s Additional Material. The following table was obtained from the data taken in a slurry reactor for the hydrogenation of methyl
The catalytic hydrogenation of methyl linoleate to methyl oleate was carried out in a laboratory-scale slurry reactor in which hydrogen gas was bubbled up through the liquid containing spherical
The equations describing diffusion and reaction in porous catalysts also can be used to derive rates of tissue growth and have been studied by Professor Kristi Anseth and her students at the
Suggest a diagnosis (e.g., bypassing, dead volume, multiple mixing zones, internal circulation) for each of the following real reactors in Figure P16-2B (a) (1–10 curves) that had the following RTD
a. Example 16-1. What fraction of the fluid spends 9 minutes or longer in the reactor? What fraction spends 2 minutes or less?Example 16-1A sample of the tracer hytane at 320 K was injected as a
Consider the E(t) curve below.A graph is shown, with t (in minutes) on horizontal axis and E of t (minutes inverse) on vertical axis. A hemi (half) circular curve starts at the origin and ends at 2
A step tracer input was used on a real reactor with the following results:a. What is the mean residence time tm?b. What is the variance σ2? For t≤ 10 min, then C₁ = 0 For 10 st≤ 30 min, then
The following E(t) curves were obtained from a tracer test on two tubular reactors in which dispersion is believed to occur.(a) RTD Reactor A; (b) RTD Reactor B The graphs for RTD reactors A and B
Derive E(t), F(t), tm, and σ2 for a turbulent flow reactor with 1/7 the power law, that is,U=Umax(1−rR)1/7
Using a negative step tracer input, Cholette and Cloutier (Can. J. Chem. Eng., 37, 107 (1959)) studied the RTD in a tank for different stirring speeds. Their tank had a 30-in. diameter and a fluid
Pick two critical thinking questions and describe why they are the most important questions to ask.
Consider again the nonideal reactor characterized by the RTD data in Example 17-5, where E (t) and F(t) are given as polynomials. The irreversible gasphase nonelementary reaction A + B → C + D is
The second-order, elementary liquid-phase reaction 2A→k1AB is carried out in a nonideal CSTR. At 300 K, the specific reaction rate is k1A = 0.5 dm3 / mol · min. In a tracer test, the tracer
Using the data in Problem P16-11B,a. Plot the internal-age distribution I(t) as a function of time.b. What is the mean internal age αm?c. The activity of a “fluidized” CSTR is maintained
The relative tracer concentrations obtained from pulse tracer tests on a commercial packed-bed desulfurization reactor are shown in Figure P17-18B. After studying the RTD, what problems are occurring
Use the RTD data in Examples 16-1 and 16-2 to predict XPFR, XCSTR, XLFR, XT-I-S, Xseg and Xmm for the following elementary gas-phase reactionsa. A → B k = 0.1 min–1b. A → 2B k = 0.1 min–1c.
For the catalytic reaction A → cat C + D the rate law can be written as −rA′=kCA(1+KACA)2Which will predict the highest conversion, the maximum mixedness model or the segregation model? Specify
Consider an ideal PFR, CSTR, and LFR.a. Evaluate the first moment about the mean m1=∫0∞(t−τ) E(t)dt for a PFR, a CSTR, and an LFR.b. Calculate the conversion in each of these ideal reactors
The following E(t) curve was obtained from a tracer test on a reactor. E(t)=0.25t0
Go to the LearnChemE screencast link for Chapter 18 (http://umich.edu/~elements/6e/18chap/learn-cheme-videos.html). View one or more of the screencast 5- to 6-minute videos and write a two-sentence
An Algorithm for Management of Change (MoC). List three things that would not have occurred if the MoC algorithm had been followed.
A second-order reaction is to be carried out in a real reactor that gives the following outlet concentration for a step input:For 0 ≤ t < 10 min, then CT = 10 (1 –e.1t)For 10 min ≤ t, then CT =
Let’s continue Problem P16-11D. Where τ = 10 min and = 14 min21. What would be the conversion for a second-order reaction with kCA0 = 0.1 min–1 and CA0 = 1 mol/dm3 using the segregation
Suggest combinations of ideal reactors to model the real reactors given in Problem P16-2b(b) for either E(θ), E(t), F(θ), F(t), or (1 – F(θ)).
There is a 2-m3 reactor in storage that is to be used to carry out the liquid-phase second-order reaction A + B → C A and B are to be fed in equimolar amounts at a volumetric rate of 1 m3/min. The

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