1、 Corresponding Solutions for Chemical Reaction EngineeringCHAPTER 1 OVERVIEW OF CHEMICAL REACTION ENGINEERING .1CHAPTER 2 KINETICS OF HOMOGENEOUS REACTIONS.3CHAPTER 3 INTERPRETATION OF BATCH REACTOR DATA.7CHAPTER 4 INTRODUCTION TO REACTOR DESIGN .19CHAPTER 5 IDEAL REACTOR FOR A SINGLE REACTOR .22CHA
2、PTER 6 DESIGN FOR SINGLE REACTIONS .26CHAPTER 10 CHOOSING THE RIGHT KIND OF REACTOR .32CHAPTER 11 BASICS OF NON-IDEAL FLOW .34CHAPTER 18 SOLID CATALYZED REACTIONS.431Chapter 1 Overview of Chemical Reaction Engineering1.1 Municipal waste water treatment plant. Consider a municipal water treatment pla
3、nt for a small community (Fig.P1.1). Waste water, 32000 m3/day, flows through the treatment plant with a mean residence time of 8 hr, air is bubbled through the tanks, and microbes in the tank attack and break down the organic material(organic waste) +O2 CO2 + H2O microbesA typical entering feed has
4、 a BOD (biological oxygen demand) of 200 mg O2/liter, while the effluent has a megligible BOD. Find the rate of reaction, or decrease in BOD in the treatment tanks.Waste water32,000 m3/dayWaste waterTreatment plant Clean water 32,000 m3/day200 mg O2needed/literMean residencetime =8 hr tZero O2 neede
5、dFigure P1.1Solution: )/(107.2)/(75.18 3132/10)02()(3131204smoldaymol daymolgLgLdayVdtNrA 1.2 Coal burning electrical power station. Large central power stations (about 1000 MW electrical) using fluiding bed combustors may be built some day (see Fig.P1.2). These giants would be fed 240 tons of coal/
6、hr (90% C, 10%H2), 50% of which would burn within the battery of primary fluidized beds, the other 50% elsewhere in the system. One suggested design would use a battery of 10 fluidized beds, each 20 m long, 4 m wide, and containing solids to a depth of 1 m. Find the rate of reaction within the beds,
7、 based on the oxygen used.2Solution: 3801)420(mV )/(99.501240 33 hrbedolchrkgckgcoalhrcoaltNc )/(25.18322 lOtVrccO )/(120490hrbedmoldt )/(17.48/5.1 322 smolltVrO 3Chapter 2 Kinetics of Homogeneous Reactions2.1 A reaction has the stoichiometric equation A + B =2R . What is the order of reaction?Solut
8、ion: Because we dont know whether it is an elementary reaction or not, we cant tell the index of the reaction.2.2 Given the reaction 2NO2 + 1/2 O2 = N2O5 , what is the relation between the rates of formation and disappearance of the three reaction components?Solution: 52224NONrr2.3 A reaction with s
9、toichiometric equation 0.5 A + B = R +0.5 S has the following rate expression-rA = 2 C0.5 ACBWhat is the rate expression for this reaction if the stoichiometric equation is written as A + 2B = 2R + SSolution: No change. The stoichiometric equation cant effect the rate equation, so it doesnt change.2
10、.4 For the enzyme-substrate reaction of Example 2, the rate of disappearance of substrate is given by-rA = , mol/m3sA0617CEWhat are the units of the two constants?Solution: 603AAksmolr 3/molCsllsok1)/)(/( 3332.5 For the complex reaction with stoichiometry A + 3B 2R + S and with second-order rate exp
11、ression -rA = k1AB4are the reaction rates related as follows: rA= rB= rR? If the rates are not so related, then how are they related? Please account for the sings , + or - .Solution: RBArr2132.6 A certain reaction has a rate given by -rA = 0.005 C2 A , mol/cm3min If the concentration is to be expres
12、sed in mol/liter and time in hours, what would be the value and units of the rate constant?Solution: min)()(3 colrhLmolrAA 22443 305.10610in AA CclolhLr AAACcmolLC33 10)()(2422 )(03)(r 413k2.7 For a gas reaction at 400 K the rate is reported as - = 3.66 p2 A, atm/hrdtpA(a) What are the units of the
13、rate constant?(b) What is the value of the rate constant for this reaction if the rate equation is expressed as-rA = - = k C2 A , mol/m3sdtNVA1Solution:(a) The unit of the rate constant is /1hratm(b) dtNVrAA1Because its a gas reaction occuring at the fined terperatuse, so V=constant, and T=constant,
14、 so the equation can be reduced to 522)(6.3.)(1RTCPRTdtTdtPVRr AAAAA 2)6.3(AkCSo we can get that the value of 1.204085.63. T2.9 The pyrolysis of ethane proceeds with an activation energy of about 300 kJ/mol. How much faster the decomposition at 650 than at 500?Solution: 586.7)92317()10/(34.8)1(32121
15、2 KmolkJTREkLnr .9712r2.11 In the mid-nineteenth century the entomologist Henri Fabre noted that French ants (garden variety) busily bustled about their business on hot days but were rather sluggish on cool days. Checking his results with Oregon ants, I find Running speed, m/hr 150 160 230 295 370Te
16、mperature, 13 16 22 24 28What activation energy represents this change in bustliness?Solution: RTETRTE ekatconsiconetraflticonetrafekr 00 )()(LA1Suppose , TxnryA,so interceptREslopeLnk6)/(1hmrA150 160 230 295 370Ln-3.1780 -3.1135-2.7506 -2.5017 -2.2752CTo/13 16 22 24 283103.4947 3.4584 3.3881 3.3653
17、 3.3206-y = 5417.9x - 15.686R2 = 0.97012340.0033 0.00335 0.0034 0.00345 0.00351/T-Lnr-y = -5147.9 x + 15.686Also , intercept = 15.686 ,KREslope9.7LnkmolJmolJ/80.42)/(31458.57Chapter 3 Interpretation of Batch Reactor Data3.1 If -rA = - (dCA/dt) =0.2 mol/litersec when CA = 1 mol/liter, what is the rat
18、e of reaction when CA = 10 mol/liter?Note: the order of reaction is not known.Solution: Information is not enough, so we cant answer this kind of question.3.2 Liquid a sedomposes by first-order kinetics, and in a batch reactor 50% of A is converted in a 5-minute run. How much longer would it take to
19、 reach 75% conversion?Solution: Because the decomposition of A is a 1st-order reaction, so we can express the rate equation as: AkCrWe know that for 1st-order reaction, ,tLnAo, 1ktCAo2ktnAo, o5.01 oC5.02So equ(1)21)4()(1212 LnkLnknLktAAo equ(2)mi5)(11CntAoSo mi512tt3.3 Repeat the previous problem fo
20、r second-order kinetics.Solution: We know that for 2nd-order reaction, ,ktCA01So we have two equations as follow:, equ(1)min5110 ktCAoAoA8, equ(2)212 3)(141ktCCAooAoA So , min1532t in01t3.4 A 10-minute experimental run shows that 75% of liquid reactant is converted to product by a -order rate. What
21、would be the fraction converted in a half-hour run?2Solution:In a order reaction: ,15.0AAkCdtrAfter integration, we can get: ,5.01.2oSo we have two equations as follow:, equ(1)min)10(.)4(5.05.05.0.15.0 ktCCAoAooAo , equ(2)min32. ktCombining these two equations, we can get: , but this means , which i
22、s 25.01ktAo 05.2ACimpossible, so we can conclude that less than half hours, all the reactant is consumed up. So the fraction converted .1AX3.5 In a hmogeneous isothermal liquid polymerization, 20% of the monomer disappears in 34 minutes for initial monomer concentration of 0.04 and also for 0.8 mol/
23、liter. What rate equation represents the disappearance of the monomer?Solution: The rate of reactant is independent of the initial concentration of monomers, so we know the order of reaction is first-order, monermonerkCAnd Loi)34(8.01in657.kmoermoner C)(93.6 After 8 minutes in a batch reactor, react
24、ant (CA0 = 1 mol/liter) is 80% converted; after 18 minutes, conversion is 90%. Find a rate equation to represent this reaction.Solution:In 1st order reaction, , dissatisfied.43.151212 LnXnktAIn 2nd order reaction, , satisfied.49/12.0.)(1212 AoAoAo CCktAccording to the information, the reaction is a
25、2nd-order reaction.3.7 nake-Eyes Magoo is a man of habit. For instance, his Friday evenings are all alikeinto the joint with his weeks salary of 180, steady gambling at “2-up” for two hours, then home to his family leaving 45 behind. Snake Eyess betting pattern is predictable. He always bets in amou
26、nts proportional to his cash at hand, and his losses are also predictableat a rate proportional to his cash at hand. This week Snake-Eyes received a raise in salary, so he played for three hours, but as usual went home with 135. How much was his raise?Solution: , , ,180Aon3Aht2, , 5 t; AknrSo we obt
27、ain , ktnLAo)()(tLtAoAo, 315280Ao28n3.9 The first-order reversible liquid reaction A R , CA0 = 0.5 mol/liter, CR0=0takes place in a batch reactor. After 8 minutes, conversion of A is 33.3% while equilibrium conversion is 66.7%. Find the equation for the this reaction.Solution: Liquid reaction, which belongs to constant volume system,1st order reversible reaction, according to page56 eq. 53b, we obtain
