CHE 304 (Spring 2010) ______
LAST NAME, FIRST
Problem set #4
(1) Run Kinetic Challenge II (
Click on the CHE 304 distribution folder, then copy theKinetic2 folder to your flash drive or H:\ drive. Open this folder and click on the appropriate program name (Kinetic Challenge II.exe). Turn in the last page of the program with performance number.
(2)[1]
(a)Taking H2 as your basis of calculation, construct a complete stoichiometric table for the following reaction
0.5N2 + 1.5H2 NH3
The reaction is isobaric, isothermal flow system with equimolar feeds of N2 and H2.
(b)If the entering total pressure is 16.4 atm and the entering temperature is 1727oC, calculate the concentrations of ammonia and hydrogen when the conversion of H2 is 60%.
(c) If you took N2 as your basis of calculation, could 60% conversion of N2 be achieved?
(3)1The gas-phase reaction 2A + 4B 2C is first-order in A and first-order in B is to be carried out isothermally in a plug-flow reactor. The entering volumetric flow rate is 2.5 L/min, and the feed is equimolar in A and B. The entering temperature and pressure are 727oC and 10 atm, respectively. The specific reaction rate at this temperature is 4 L/molmin and the activation energy is 15,000 cal/mol.
(a)What is the volumetric flow rate when the conversion of A is 25%?
(b)What is the rate of reaction at the entrance to the reactor.
(c)What is the rate of reaction when the conversion of A is 40%?
(d)What is the concentration of A at the entrance to the reactor?
(e)What is the concentration of A at 40% conversion of A?
(f)What is the value of the specific reaction rate at 1227oC.
(4)1 Calculate the equilibrium conversion and concentrations for each of the following reactions.
(a)The liquid-phase reaction
A + B C
with CA0 = CB0 = 2 mol/L and Keq = = 10 L/mol.
(b)The gas-phase reaction
A 3C
carried out in a flow reactor with no pressure drop. Pure A enters at a temperature of 400oK and 10 atm. At this temperature Keq = 0.25 mol2/L2.
(c)The gas phase reaction in part (b) carried out in a constant-volume batch reactor.
(d)The gas phase reaction in part (b) carried out in a constant-pressure batch reactor.
(5) (P5-31) The irreversible isomerization
A B
was carried out in a batch reactor and the following concentration-time data were obtained:
t(min) / 0 / 3 / 5 / 8 / 10 / 12 / 15 / 17.5CA(mol/L) / 4.0 / 2.89 / 2.25 / 1.45 / 1.0 / 0.65 / 0.25 / 0.07
a) Determine the reaction order, , and the specific reaction rate, k using differential method of rate analysis. Fit your data by a fourth order polynomial.
b) Assume a rate law of the form
rA = kCA
Integrate the equation for the combined mole balance and rate law and then use Matlab function fminsearch to determine and k.
(6) Instead of expanding T cells in a batch reactor, you decide to expand them in a CSTR. The fastest you can expand cells in a CSTR is when the growth rate of the cells (k) is exactly equal to one over the residence time of the reactor (1/). Assume that you are growing cells in a 1 L CSTR, with a volumetric flow rate of feed and exit at 0.0294L/h, and that cell growth, rT= kCT, where k=0.0294 h-1. The steady state concentration of T cells is 109 cells/L. If, at some point in time, a bacterial contaminant gets introduced in the feed stream at a concentration of 10 cells/L, and the bacteria grows at a rate of 0.46 h-1, how long will it be before the concentration of bacteria in the reactor (and in the outlet stream with the T cells) is 106 cells/L. At a certain concentration, the bacteria not only would pose a health risk to the patient to whom the T cells could be returned, but they might also secrete toxins and compete for nutrients, thus killing off the healthy T cell population.
(7)[2] We have a process that reacts 67% CH4 in O2 at 10 atm to form syngas (HRx = 8.5 kcal/mol CH4). Note: syngas is CO and H2.
(a)Estimate the adiabatic reactor temperature at completion if we produce 100% syngas with a feed temperature of 400oC. Assume Cp = 7 cal/moloK.
(b)Estimate the adiabatic reactor temperature if we suddenly begin producing 100% total combustion products (HRx = 192 kcal/mol).
(c)What do we have to be concerned with regarding reactor construction materials and pressure relief capabilities to design for this possibility.
(8)[2]You have a summer job with a company that is interested in building a plant to manufacture the painkiller ibuprofen [2-(p-isobutylphenyl) propionic acid, C13H18O2] using a new reaction scheme. Your assignment is to collect some data on one of the reactions, as a first step in designing a full-scale reactor. In one experiment, you mix 134 g isobutylbenzene (IBB, C10H14) with 134 g acetic anhydride (AAn, C4H6O3) in a laboratory-scale batch reactor, adjust the temperature, and wait 1 hour. At the end of the hour you stop the reaction, collect all the material in the pot, and send it for chemical analysis. The report come back that the pot contains IBB, acetic anhydride, isobutylacetophenone (IBA, C12H16O) and acetic acid (AAc, CH3COOH). Unfortunately, someone spilled coffee on the report and all you can read is the amount of isobutylbenxene: 1.6 g. Your boss is upset-he needs the data right away. Can you determine the amounts of IBB, AAn, and IBA from the available information for your boss?
[1] Fogler, H. S., Elements of Chemical Reaction Engineering, Prentice Hall, 1999
[2] Schmidt, L.D., The Engineering of Chemical Reactions, Oxford, 2004, pg. 83 (p. 2.11)
[2] Murphy, R. M., “Introduction to Chemical Processes Principles, Analysis, Synthesis”, McGraw Hill, 2007, p. 96