Learning about the process: Gas phase balances Sef Heijnen, - - PowerPoint PPT Presentation

▶
learning about the process gas phase balances
SMART_READER_LITE
LIVE PREVIEW

Learning about the process: Gas phase balances Sef Heijnen, - - PowerPoint PPT Presentation

Oct 16, 2023 754 likes •895 views

Learning about the process: Gas phase balances Sef Heijnen, Department of Biotechnology, Faculty of Applied Sciences Completing the picture Broth-Balances Substrate [mol s/h]: d(V L c s )/dt = R s +F in c s,in F out c s,out F in c s,in

slide-1
SLIDE 1

Sef Heijnen, Department of Biotechnology, Faculty of Applied Sciences

Learning about the process: Gas phase balances

slide-2
SLIDE 2

Broth-Balances Substrate [mol s/h]: Product [mol p/h]: Biomass [mol x/h]:

Completing the picture

Fin cs,in cp,in cx,in Fout cs,out cp,out cx,out O2

d(VLcs)/dt = Rs+Fincs,in – Fout cs,out d(VLcp)/dt = Rp+Fincp,in – Fout cp,out d(VLcx)/dt = Rx+Fincx,in– Fout cx,out

VL cs cp cX

slide-3
SLIDE 3

cO,in [mol/m3] Fin [m3/h]

(Transport term)

cO,out [mol/m3] Fout [m3/h]

(Transport term)

The oxygen balance for the broth (mol O2/h)

cO [mol/m3]·VL [m3] = NO [mol]

Broth

Broth oxygen balance: (mol O2/h) d(VLcO)/dt = RO + FincO,in - FoutcO,out + TN,O

System boundary Gas

TN,O [mol/h]

(Transfer term)

RO [mol/h]

slide-4
SLIDE 4

d(NGyO)/dt = 0 + FN,inyO,in – FN,outyO,out - TN,O

yO,in [mol/mol] FN,in [mol air/h]

(Transport term)

yO,out [mol/mol] FN,out [mol gas/h]

(Transport term)

The oxygen balance for the gas phase (mol O2/h)

yO [mol O2 /mol gas]·NG [mol gas] = NO [mol O2]

Broth System boundary Gas

TN,O [mol O2/h]

(Transfer term)

Gas phase oxygen balance:

slide-5
SLIDE 5

Combined broth/gas O2-balances (mol O2/h)

Broth balance: Gas phase balance: Combined balance: 0 = 0 + FN,inyO,in – FN,outyO,out – TN,O 0 = RO + FincO,in - FoutcO,out + TN,O

  • RO = FincO,in - FoutcO,out + FN,inyO,in – FN,outyO,out

Measurements needed to calculate RO: Fin, cO,in, Fout, cO,out, FN,in, YO,in, YO,out, FN,out

slide-6
SLIDE 6

Fout cC,out TN,C Fin cC,in FN,in yC,in FN,out yC,out NG yC Combined broth/ gas balances CO2: VL cC RC = - FincC,in + FoutcC,out - FN,inyC,in + FN,outyC,out

slide-7
SLIDE 7

Combined broth/gas balances O2:

How to determine FN,out

Combined broth/gas balances CO2: N2 gas balance:

  • RO = Fin cO,in – Fout cO,out + FN,in yO,in – FN,out yO,out

RC = -Fin cC,in + Fout cC,out - FN,in yC,in + FN,out yC,out FN,in (1 - yO,in - yC,in) = FN,out (1 - yO,out - yC,out)

slide-8
SLIDE 8

Understanding and improving the fermentation process

C6H12O6 C1H1.8O0.5N0.2 (Biomass) C3H8O2 (PDO)

6Rs = 3Rp + 1Rx+ 1RC

C-conservation

CO2 Rs Rp Rx RC

slide-9
SLIDE 9

Understanding and improving the fermentation process

C6H12O6

6Rs > 3Rp + 1Rx+ 1RC

C-conservation

CO2 Rs Rp Rx RC C1H1.8O0.5N0.2 (Biomass) C3H8O2 (PDO)

slide-10
SLIDE 10

Understanding and improving the fermentation process

  • Unknown by product
  • Volatile product/substrate
  • Product is degraded

CO2 Rs Rp Rx RC C6H12O6 C1H1.8O0.5N0.2 (Biomass) C3H8O2 (PDO)

slide-11
SLIDE 11

Understanding and improving the fermentation process

C6H12O6

6Rs < 3Rp + 1Rx+ 1RC

C-conservation

CO2 Rs Rp Rx RC

Measurements Are Wrong

C1H1.8O0.5N0.2 (Biomass) C3H8O2 (PDO)

slide-12
SLIDE 12

Wrap up:

Learning about the process: Broth and Gas phase balances

Rates

  • Cannot be measured, but are calculated from proper

compound balances and measurements Compound Balances

  • System boundaries (gas, broth,..)
  • Tells you what to measure
  • Broth and Gas balances

Learning about the process

  • Conservation of element
  • Unknown mechanisms working on product/substrate
  • Faulty measurements
  • Easy opportunities to improve process economy
slide-13
SLIDE 13

See you in the next unit!