Terry A. Ring Chemical Engineering University of Utah Batch Bio Reactor Design Ch 6 & 10 Bioprocess Engineering-Basic Concepts Terry A. Ring Chemical Engineering University of Utah

Bio Processing Examples See https://www.aiche.or g/community/studen ts/student-design- competition/past- problems Competition Teams of 4 students Start to form Teams Individual

Overview of Biopharmaceutical Plant 10 pg/cell/day 1 mL = 106 cells 1,000 kg/yr

Cell Growth Cycle ~100x Days For this process the doubling time is 36 hrs after lag time

Seed Train Demands For Each Cell entering the process ~2.7x108 cells must be generated to go into the production reactor More than 4 seed reactors generating 100x cell multiplication Seed Train 1st reactor is 100 mL 2nd reactor is 10 L 3rd reactor is 1000 L Production reactor

Seed Train Demands For Each Cell entering the process ~2.7x10^14 cells must be generated to go into the production reactor Seed reactors generating 100x cell multiplication in each One reactor is ~7 doubling times ~7*36 hr=10.5 days in each reactor

Cell Kinetics Nutrient utilization Net specific grow rate = growth – death X can be cell mass or cell number

Cell Kinetics and Doubling Time

Cell Death Rate Combining Forms μnet = μg-kd

Cell Growth Cycle Days

Utilization of Substrate (glucose) and Product Production Growth-associated Product Generation dS/dt=dX/dt * (YX/S)-1 dP/dt=dX/dt*(YX/S)-1*YP/S= YP/Sμg dO2/dt=μgX/YX/O2 = kLa(C*-CL) or

Growth Kinetics Substrate limited growth

Product Inhibited Growth P = Product Concentration, Kp= is product binding constant

Inhibition by Toxic Compound Inhibitor binds with KI binding constant

Combining Substrate and Cell Growth Kinetics Solve for X vs time (t)

Reactors Aspects of CSTR Aspects of Fed Batch Control pH Dissolved O2 Liquid Level Reactor Volume

CHEMOSTAT Material Balance on the cell concentration, X Dilution rate, D=F/VR =1/τ, τ = residence time At steady state when little death In – out + cell growth – cell death = accumulation Optimal Dilution Rate for max. P and X

Cell Growth Cycle Days

Production Reactor 2.7x108 cells must be generated to go into the production reactor 10 pg/cell/day Gives 1,000 kg/yr at 24/7 365 days/yr What is the total size of the production reactors Max cell density w/o death = 109cells/mL VR=274 L minimum (no down time all year) But you can be more accurate than this!! VR=

Combining Substrate and Cell Growth Kinetics Solve for X vs time (t)

CHEMOSTAT Material Balance on the cell concentration, X Dilution rate, D=F/VR =1/τ, τ = residence time At steady state when little death In – out + cell growth – cell death = accumulation Optimal Dilution Rate for max. P and X