1. Kinetics
Patrick Cable, Dat Huynh, Greg Kalinyak, Ryan Leech, Wright Makambi, Ronak Ujla

2. Batch Reactor No inlet or outlet flow
Reactants are placed inside the reactor and allowed to react over a set period of time
Advantages
High Conversion can be achieved if allowed a long reaction time
Versatile, and can be quickly adapted for different products
Disadvantages
Difficult to use for large scale production
High cost of labor per unit of production

3. Batch Reactor Design Equations
Input - Output + Generation = Accumulation
Input = Output = 0

4. Semi-Batch Reactor In between a CSTR and a Batch reactor
No outlet flow, only an inlet flow
Reactants are fed in at a set rate in either a two phase reaction or to prevent unwanted side reactions
Advantages
Minimize side reactions
Good temperature control
Disadvantages
Not good for large scale production
High Cost
Reactor operation can be difficult to analyze

5. Semi-Batch Reactor Design Equations
Input - Output + Generation = Accumulation
Due to the change in both Volume over time and Concentration with time, solving the equations needs the use of a computer
Need to set up an equation for each component using the mass balance and another for the volume and solve simultaneously

6. Continuous Stir Tank Reactor (CSTR)
A constant inlet and outlet flow that is continuously mixed
The concentration inside the reactor is the same as the outlet
Advantages
Cheap to construct
Large amounts of product
Temperature Control is easy
Disadvantages
Conversion of reactor to product is small compared to other reactors
Deadzones can occur if mixing isn’t done well.

7. CSTR Design Equation Input - Output + Generation = Accumulation

8. Slurry Reactors
Multiphase reactor where gas is bubbled through a solvent containing catalyst particles
Can be operated in batch or continuously
Advantages
Good temperature control
Large heat capacity
Good catalyst control and extended life
Common Applications - Hydrogenation, Oxidation, Hydroformylation, Polymers
Elements of Chemical Reaction Engineering, 5th Edition

9. Steps in Slurry Reactor
Adsorption from gas phase to bubble surface
Diffusion from bubble surface to bulk
Diffusion from bulk to catalyst surface
Diffusion from catalyst surface into porous catalyst
Reaction with catalyst
Elements of Chemical Reaction Engineering, 5th Edition

10. Design Equation Derivation
Rearranging...
Elements of Chemical Reaction Engineering, 5th Edition

11. Fluidized Bed Reactors (FBR)
Similar flow pattern to slurry reactors
Bed of solid catalyst, liquid or gas pumped/forced up thru the bed, suspending catalyst particles
“Fluidized” catalyst particles
Useful for:
Catalytic cracking of petroleum naphthas for gasoline
Advantages:
Excellent mixing/contact of catalyst and reactants
Uniform temperature
Continuous regeneration of catalyst
Disadvantages:
Fluid mechanics not well known
Need to overcome gravity to suspend the catalyst/move the fluid
Increased size requirements due to expansion
Elements of Chemical Reaction Engineering, 5th Edition

12. FBR Considerations
Velocity/flow rate of fluid/gas must be great enough to suspend solid catalyst, but slow enough that the solid catalyst is not carried out of the reactor with the fluid/gas
Porosity of catalytic bed prior to (and post) fluidization
Mass transfer rates must be taken into account
Elements of Chemical Reaction Engineering, 5th Edition

13. Bubbling Bed Model by Kunii & Levenspiel
Reactant gas bubbles up through the reactor
MT of reactant occurs, through the wall of the bubble, onto the solid catalyst particles, which convert to product
MT of product occurs, back through the wall of the bubble, and the resultant reactant/product mixture is carried out of the reactor
Conversion depends on rate of MT in/out of bubbles, rate of reaction, as well as on the residence time of reactant in the reactor.
Elements of Chemical Reaction Engineering, 5th Edition

14. FBR Design Parameters Porosity of bed at minimum fluidization
Minimum fluidization velocity
Maximum fluidization velocity
Bubble size
Velocity of bubble rise
Fraction of total bed occupied by bubbles
Fraction of the bed consisting as wakes
Volume of catalyst in bubbles, clouds and emulsion
Mass of solid catalyst

15. Packed Bed Reactor (PBR)
Similar to the previous reactors.
Contains a compartment for the catalyst.
Heterogeneous reactions.
Considerations
Pressure drop
Catalyst size
Most common found in industry
Applications:
Methanol synthesis/oxidation
Styrene production
Wastewater treatment

16. PBR cont... Advantages High Conversion per weight of catalyst.
Easy to build.
More contact between reactant and catalyst.
More effective at high temperatures and pressures.
Disadvantages
No temperature control.
Difficulty in replacing catalyst.
Channeling of gas stream.

17. PBR Design equations
Unlike a PFR the volume of the reactor is no longer relevant.
Catalyst weight and density

18. Plug Flow Reactor (PFR)
Reactors that consist of a cylindrical pipe where reactants flow in and products flow out
Plug flow means no radial changes in velocity, temperature, or concentration
Good for various applications in gas and liquid systems
Gasoline Production
Ammonia Synthesis
Advantages
Mechanically simple and easy to maintain
High conversion rate per reactor volume
Disadvantages
Reactor temperature difficult to control
Undesirable thermal gradients
Sourced from:
Elements of Chemical Reaction Engineering, 5th Edition

19. PFR Design Equations
Elements of Chemical Reaction Engineering, 5th Edition

20. Laminar Flow Reactor (LFR)
Very similar to PFR except it is a tube with laminar flow which means radial changes in velocity
Generally been used in research for multiphase reactions
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21. Thank you! Q&A