CHE142 Q2 8/18/17 SCHOOL OF CHEMICAL ENGINEERING AND CHEMISTRY. MAPAU UNIVERSIT Y Instructions:
Problem Solving. Write the necessary comments for each step of the solution in the problem solving. solving. Indicate all the units. i. Write neatly and clearly by proving enough space in between each line of your solution. If the solution is more than one page, continue on the next nex t page, clearly indicating that you have done so. ii. Clearly indicate the answer you are submitting, (e.g., b y circling). This exam is worth 100 points. Time limit: 1.5 hours
1. The enzyme, urease, is immobilized in Ca-alginate C a-alginate beads 4 mm in diameter. When the urea concentration in the bulk liquid is 0.5 m M the rate of urea hydrolysis is v = 9 mM/h diffusivity of urea in Ca-alginate beads is De = 3.5x10 – 4 cm2/sec, and the Michaelis constant for the enzyme is Km = 0.35 m M. By neglecting the liquid film resistance on the beads (i.e., [So] = [S s]) determine the following: h ydrolysis Vm, Thiele modulus ( (), and effectiveness factor ( ( ). ). a. Maximum rate of hydrolysis b. What would be the Vm, , and values for a particle size of Dp = 6 mm? 3/ for large values of ( ( > 2). Hint: Assume = 3/ The Michaelis-Menten kinetic parameters for a soluble enzyme for a certain substrate are found to be 2.
= 0.05 mol/L r max max=10 mol/L min .
Km
After immobilizing this enzyme on the surface of insoluble matrix by physical adsorption, it was
found that the value was increased to 0.08 mol/L whereas the value stayed the same as vmax. What is the effectiveness factor of the immobilized enzyme when the substrate concentration is 1 mol/L?
1. Problem 3. Growth Growth Stoichiometry and yield yield coefficient 30 pts Aerobic degradation of an organic compound by a mixed mix ed culture of organisms in waste water can be represented by the following reaction
C3H6O3 + a O2 + b NH3 → c C5H7 NO2 + d H2O + e CO2 a) Determine a, b, c, d, and e, if
YX/S =0.38 gX/gS
b) Determine the yield coefficients YX/O2 and Yx/NH3 c) Determine the degree of reductions for the substrate, bacteria, and RQ for the organisms. Problem 3.
BIOCHEMICAL ENGINEERING| ENGINEERING| EXAM 11
CHE142 Q2 8/18/17 SCHOOL OF CHEMICAL ENGINEERING AND CHEMISTRY. MAPAU UNIVERSIT Y
In a batch reactor of volume 5,000 liters, the final desired yeast concentration is 50 gdw/l. Using the above reaction stoichiometry a. Determine the concentration and total amount of glucose and (NH4)2SO4 in the nutrient medium. b. Determine the yield coefficients Y O2 (biomass/oxygen). X /S (biomass/glucose) and Y X/ O2 c. Determine the total amount of oxygen required. d. If the rate of growth at exponential phase is rx 0.7 gdw/l-h, determine the rate of oxygen consumption (g O2/l-h). e. Calculate the heat-removal requirements for the reactor.
BIOCHEMICAL ENGINEERING| ENGINEERING| EXAM 11
CHE142 Q2 8/18/17 SCHOOL OF CHEMICAL ENGINEERING AND CHEMISTRY. MAPAU UNIVERSIT Y
BIOCHEMICAL ENGINEERING| ENGINEERING| EXAM 11
CHE142 Q2 8/18/17 SCHOOL OF CHEMICAL ENGINEERING AND CHEMISTRY. MAPAU UNIVERSIT Y
