Chemical Reaction Engineering (CRE) is the field that studies the rates and mechanisms of chemical reactions and the design of the reactors in which they take place. Lecture 16

Today’s lecture Enzyme Kinetics Noncompetitive Inhibition Bioreactors Monod Equation Yield Coefficients Washout 2

Last lecture A given enzyme can only catalyze only one reaction. Urea is decomposed by the enzyme urease, as shown below. Michaelis Menten Equation The corresponding mechanism is: 3

Lecture 16 - Bioreactors Nutrient ++ Products Nutrient ++ Products cells more cells 4

Bioreactors 5

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inoculum t=0 time  8 Cells + Substrate  More Cells + Product

Bioreactors 9 Exponential Growth Phase Death Phase Stationar y Phase Lag Phase 0 time lnC c a)Phases of Bacteria growth: I. Lag II. Exponential III. StationaryIV. Death b) Monod growth rate law:

10 Mass Balances: Accumulation = In - Out + Growth - Death Bioreactors

Rate Laws: C p *= Product Concentration at which all metabolism ceases 11 Bioreactors

Stoichiometry: A.) Yield Coefficients B.) Maintenance 12 Bioreactors

v 0 C S0 V=V 0 vCCCSvCCCSC Volume=V 13 1) Mass balance:

Bioreactors 14

2) Rates: 3) Parameters: 15 Bioreactors

Polymath Setup 1.) d(C C )/d(t)=-D*C C +(r g -r d ) 2.) d(C S )/d(t)=-D*(C S0 -C S )-Y sg *r g -m*C C 3.) d(C P )/d(t)=-D*C P +Y PC *r g 4.) rg=(((1-(C P /C pstar ))**0.52)*mumax*(C S /(K S +C S ))*C C 5.) D=0.2 6.) k d = ) r d =k d *C C 8.) C S0 =250 9.) Y PC = ) m= ) mumax= ) Y SC = ) K S =1.7 16

Bioreactors – Chemostats - CSTRs 1. Steady State - Neglect Death Rate and Cell Maintenance 2. Cell 17

Bioreactors – Chemostats - CSTRs 3. Substrate 18

Bioreactors CSTR Washout C DWDW DC 19 Washout dilution rate

How does this figure relate to drinking a lot of fluids when you have an infection or cold? DC C DWDW D D maxprod 20 Maximum Product Flow Rate

End of Lecture 16 21