Scale Up Issues

Question 1

What are the 8 scale up issues?

Answer 1

• Scale up is non linear
• Reaction kinetics affected
• Chemical equilibrium must be reached
• Suitable materials must be selected
• Fluid dynamics change non linearly
• Thermo analysis must take place
• Suitable equipment must be selected
• Correct amount of turbulence must be achieved

Question 2

Explain turbulence scale up issue

Answer 2

The correct amount of thrbulence is necessary for good reaction kinectics

Agitators and baffles can be used to increase turbulence as well as stirring

Stirring must be done carefully as it can damage cells

Question 3

Explain scale up issue in equipment selection

Answer 3

-Phyisical limitations such as size of equipment can seriously inpact chemcial reactions: control, thermo, fluid dynamics

Question 4

Explain thermo anaylsis as scale up issue

Answer 4

• chem reactions are very sensitive

- thermo anaylsis must take place to understand heat gain and loss

Question 5

Explain fluid dynamics scale up issue

Answer 5

• fluid dynamics change non linearly as system increases in size
• must try to maintain same flow/Re
• difficult to predict changes

Question 6

Expalin material selection scale up issue

Answer 6

• materials will be in contact with reaction

- can influence reaction, erode or drive costs up unecesarily

Question 7

Explain chem equilibrium as scale up issue

Answer 7

• time to reach chem equilibrium increases as quantity of chemicals increases
• reaction is not producitve until at chrm equi

Question 8

Explain reaction kinetics as scale up issue

Answer 8

• molecules must mix well to reach equilibrium asap

- cant just increase speed of mixing as will damage cells

Question 9

Why is non linear scaling up an issue?

Answer 9

• Cant just use the same process and equipment from lab and increase size
• SA to mass change, flow regimes, reaction kinetics, thermo and fluid mechanics all change non linearly