This is the powerpoint file of the reactor design that was assigned to me during my final year design project. I solved the rate equations in MATLAB to calculate the reactor volume.

1. Hashim Khan (DDP-SP13-BEC-53)
Supervisor
Dr. Maria Mustafa

2. Abstract
Reactor Volume
Impeller Selection
Impeller Type & Flow Pattern
Material Of Construction
Summary

3. • Abstract
• Core objective of this project is to design and develop a profitable biodiesel production
plant. Relying on the conventional mass and energy balances we can estimate the real life
construction of this plant.
• Most diesel engines can run on cooking oil once they are warm, but cooking oil is not
sufficiently volatile to start a cold diesel engine. A base catalyzed trans-esterification,
using methanol as the alcohol and NaOH as the catalyst, converts fats and oils to the
methyl esters of the three individual fatty acids. With molecular weights about a third of
the original triglyceride, these methyl esters are more volatile and work well in diesel
engines. The mixture of fatty acid methyl esters is called biodiesel.

5. • Equipment Design
• AFTER ALL the preliminary work has been completed, the detailed design work is
initiated.
1. Equipment can be designed in its final form and full specification sheets prepared for
each item.
2. Process flowsheet and equipment list can be checked and amended.
3. Cost estimates can also be revised to account for any significant changes from the
preliminary design specifications.

6. Abstract
Reactor Volume
Impeller Selection
Impeller Type & Flow Pattern
Material Of Construction
Summary

7. • Reactor Design
• The rectors we are using are CSTR jacketed vessels. We are using two of them in series.
Our total conversion is 99% while per reactor conversion is 90 %. We are to design
the two reactors.
• Reactor design mainly involves:
1. Volume calculation
2. Height/Diameter
3. Impeller Design & Type Selection
4. Thickness calculation
5. P&I Diagram
• We will use reaction kinetics to calculate the reactor volume…

8. • Why CSTR?
• Liquid phase reaction.
• Provides optimal mixing.
• The reactors can be operated at temperatures between -6.66 and 232°C and at pressures
up to 7 atm.
• Relatively cheap to construct. Also relatively easy to clean and maintain.
• Ease of control of temperature in each stage, since each operates in a stationary state;
heat transfer surface for this can be easily provided hence it is relatively easy to maintain
good temperature control with a CSTR.
• Can be readily adapted for automatic control in general, allowing fast response to changes
in operating conditions (e.g., feed rate and concentration).
• With efficient stirring and viscosity that is not too high, the model behavior can be closely
approached in practice to obtain predictable performance.

9. • Assumptions & Approximations:
1. Well mixed
2. All reactants enter at the same time
3. Steady State
4. No extra side reactions
5. Isothermal operation

10. Reactor Type CSTR Units
Temperature 60 / 333 °C/°K
Total Conversion 99 %
Residence Time 1 ℎ𝑜𝑢𝑟
Number Of Reactors 2 -----------
Configuration Series -----------
Molar Flow Of Oil (𝐹𝑎𝑜) 1.355 𝑘𝑚𝑜𝑙/ℎ𝑜𝑢𝑟
Volumetric Flow Rate Of
Oil (𝑣 𝑎𝑜)
1.35 𝑚3/ℎ𝑜𝑢𝑟
Cao 1.0 𝑘𝑚𝑜𝑙/𝑚3
Material of Construction SS Type 304 -----------
• Reactor Details
• Lets look at the provided information…

13. • Reactions
• According to the literature the transesterification reactions takes place in three steps.
That basically means that there are multiple reactions associated with this process.

17. Rate Constants (mole/dm^3*seconds) Values
k1 .049
k2 .102
k3 .218
k4 1.280
k5 .239
k6 .007
k7 7.84e-05
k8 1.58e-05
• Rate Constants
• Lets look at the provided information…

18. • Rate Law
𝑟𝑡𝑟𝑖𝑜𝑙𝑒𝑖𝑛 = − 𝑘 ∗ 𝐶𝑡𝑟𝑖𝑜𝑙𝑒𝑖𝑛
We Know
−𝑟𝑡𝑟𝑖𝑜𝑙𝑒𝑖𝑛= −
ⅆ𝐶𝑡𝑟𝑖𝑜𝑙𝑒𝑖𝑛
ⅆ𝑡
−
ⅆ𝐶𝑡𝑟𝑖𝑜𝑙𝑒𝑖𝑛
ⅆ𝑡
= 𝑘 𝐶𝑡𝑟𝑖𝑜𝑙𝑒𝑖𝑛
−𝑟𝑡𝑟𝑖𝑜𝑙𝑒𝑖𝑛= 𝑘 𝐶𝑡𝑟𝑖𝑜𝑙𝑒𝑖𝑛

19. • CSTR Volume Calculation
• The above mentioned differential equations were used to model the reaction rate through
which the volume of the CSTR was calculated… as we know…
𝑉 =
(𝐹𝑖 −𝐹𝑖𝑜)
−𝑟𝑖
Or
𝑉 =
𝐹𝑖 ∗ 𝑋
−𝑟𝑖

20. Newer Version

21. • Results
• After we solve the given ODEs for time t = 1 hour. We get volume of both the reactors. Now
keeping the height to diameter ratio as 1.5 we can calculate the diameter and the height of
the reactors.
Properties CSTR Units
Reactor 1 (V) 5.3 𝑚3
Reactor 2 (V) 1 𝑚3
Residence Time 1 ℎ𝑜𝑢𝑟

23. • Diameter Of Reactor 1
• Calculation of diameter keeping the ratio as (h/d = 1.5)
𝑉 = 𝜋 ∗
ⅆ
4
2
∗ ℎ
5.3 ∗ 4
𝜋
= ⅆ2
∗ ℎ
5.3 ∗ 4
𝜋 ∗ 1.5
= ⅆ3
4.51 = ⅆ3
ⅆ ≈ 1. 8 𝑚

24. • Diameter Of Reactor 2
• Calculation of diameter keeping the ratio as (h/d = 1.5)
𝑉 = 𝜋 ∗
ⅆ
4
2
∗ ℎ
1 ∗ 4
𝜋
= ⅆ2
∗ ℎ
1 ∗ 4
𝜋 ∗ 1.5
= ⅆ3
7.41 = ⅆ3
ⅆ ≈ 1 𝑚

25. Abstract
Reactor Volume
Impeller Selection
Impeller Type & Flow Pattern
Material Of Construction
Summary

26. • Impeller Type
• Mixing vessels fitted with some form of agitator are the most commonly used type of
equipment for blending liquids and preparing solutions.
• Mixing occurs through the bulk flow of the liquid and, on a microscopic scale, by the
motion of the turbulent eddies created by the agitator.
• Bulk flow is the predominant mixing mechanism required for the blending of miscible
liquids and for solids suspension. Turbulent mixing is important in operations involving
mass and heat transfer; which can be considered as shear controlled processes.
• The most suitable agitator for a particular application will depend on the type of mixing
required, the capacity of the vessel, and the fluid properties, mainly the viscosity.

30. Properties CSTR Units
Reynold's Number 6200 Dimensionless
Capacity Of The Vessel 5.3 𝑚3
Residence Time 1 hour
Diameter 1.8 𝑚
Height 2.5 𝑚
rpm 1750 rpm
Fluid Viscosity 0.0161
𝑁. 𝑠
𝑚2
• Reactor 1

32. Properties CSTR Units
Reynold's Number 6200 Dimensionless
Capacity Of The Vessel 1 𝑚3
Residence Time 1 hour
Diameter 1 𝑚
Height 1.4 𝑚
rpm 1750 rpm
Fluid Viscosity 0.016
𝑁. 𝑠
𝑚2
• Reactor 2

33. • Impeller Type Reactor 1
• In the light of the data provided we use the turbine type impeller…
Properties CSTR Units
Reynolds Number 6200 Dimensionless
Capacity Of The Vessel 5.3 𝑚3
Residence Time 1 Hour
Fluid Viscosity 0.016 𝑁. 𝑠
𝑚2

34. • Impeller Type Reactor 2
• In the light of the data provided we use the turbine type impeller…
Properties CSTR Units
Reynolds Number 6200 Dimensionless
Capacity Of The Vessel 1 𝑚3
Residence Time 1 Hour
Fluid Viscosity 0.016 𝑁. 𝑠
𝑚2

35. • Impeller Diameter Reactor 1
• For turbine agitators, impeller to tank diameter ratios of up to about 0.6 are used, with
the depth of liquid equal to the tank diameter.
Properties CSTR Units
Impeller Diameter (ID) ? 𝑚
Vessel Diameter (VD) 1.8 𝑚
Ratio (ID/VD) .6 Dimensionless
𝐼𝐷
𝑉𝐷
= .6 = 1.08 𝑚
Impeller Diameter (D) .3 𝑚

36. • Impeller Diameter Reactor 2
• For turbine agitators, impeller to tank diameter ratios of up to about 0.6 are used, with
the depth of liquid equal to the tank diameter.
Properties CSTR Units
Impeller Diameter (ID) ? 𝑚
Vessel Diameter (VD) 1 𝑚
Ratio (ID/VD) .6 Dimensionless
𝐼𝐷
𝑉𝐷
= .6 = .6 𝑚
Impeller Diameter (D) .6 𝑚

37. Abstract
Reactor Volume
Impeller Selection
Impeller Type & Flow Pattern
Material Of Construction
Summary

40. Abstract
Reactor Volume
Impeller Selection
Impeller Type & Flow Pattern
Material Of Construction
Summary

43. • Material of Construction
• We are using carbon steel because it does not let the oil stick as well as is suitable for the
protecting against the corrosiveness of the caustic.
• Our process parameters are as such are not extreme. A mere 60 °C is required to
maintained in the reactor. While the steam were providing has a temperature of 141 °C
and is at 2.74 bar pressure.
• A very suitable option hence also recommended in our primary literature is Type
304 (the so-called 18/8 stainless steels). These are widely used and widely
available steels.
• A simple jacket can withstand pressures up to 10 bar therefore we can simply use a
simple jacket construction around our vessel.

44. Abstract
Reactor Volume
Impeller Selection
Impeller Type & Flow Pattern
Material Of Construction
Summary

45. • Material of Construction
•
Parameter Value Units
Temperature
60 / 333 (Vessel) °C / °K
141 / 414 (Jacket) °C / °K
Pressure
103 / 1 bar (Vessel) 𝑘𝑁/𝑚2
274 / 2.74 bar (Jacket) 𝑘𝑁/𝑚2

46. Abstract
Reactor Volume
Impeller Selection
Impeller Type & Flow Pattern
Material Of Construction
Summary

47. • Material of Construction
•
Parameter Value Units
R-1 Volume 5.3 𝑚3
R-2 Volume 1 𝑚3
R-1 Diameter 1.8 𝑚
R-1 Height 2.5 𝑚
R-2 Diameter 1 𝑚
R-2 Height 1.4 𝑚
Impeller Type For Both Turbine Dimensionless
R-1 Impeller Dia. 1.08 𝑚
R-2 Impeller Dia. .6 𝑚

57. • END