Thermal cracking of ethane to ethylene by heterogeneous catalytic reaction

1. Simplest Formula Series in Chemistry
Thermal Cracking of Ethane in a Tubular Reactor
Stephen Joseph Boylan 2020
Learning Objective: Use the Arrhenius equation and linear regression analysis to calculate the
frequency factor and activation energy from temperatures and reaction rate constants. This
exercise will develope your habits and skills to analyse temperature and rate data using linear
regression.

2. Thermal Cracking of
Ethane in a Tubular
Reactor
Arrhenius Equation and
Linear Regression Analysis
Stephen Joseph Boylan October 2020

4. Index
1. Introduction
2. Regression Analysis
3. Verify Numbers
4. Charts
5. Send reports

5. Part 1 Introduction
This assignment combines the chemistry of thermal cracking
and the Arrhenius equation with the statistical method of
linear regression and with using a spread sheet on the
computer.

6. Introduction - Chemistry
Ethane is a molecule that is available in a chemical plant.
Ethane is converted to ethylene by the process of thermal
cracking in a chemical reactor. The ethylene produced goes to
make many different products including plastics. In the
process of thermal cracking the ethane flow is heated. The
high temperature causes the ethane molecules to break into
the smaller molecules of ethylene.

7. Introduction - Arrhenius Equation
The Arrhenius equation presents the relation of reaction rate
constant to temperature. The form of the Arrhenius
equation used in this assignment is:
ln k = ln A + (-Ea/R)*(1/T)

8. Introduction - Symbols for the Arrhenius Equation
ln k = ln A + (-Ea/R)*(1/T)
ln = natural logarithm base e
k = reaction rate constant
A = pre-exponential constant
Ea = activation energy
R = gas law constant
* = multiplication operation
T = temperature in Kelvin

9. Introduction - Linear Regression
Linear regression is an analysis method that provides an
equation in which a variable y is determined as a function of
varible x. The form of the equation is:
y = a + b * x
x and y are variables. a and b are parameters.

10. Assignment Objectives
In this assignment you have three objectives.

11. Objective One
Your first objective is to do a linear regression analysis by
making two tables on a spread sheet.
The spread sheet and tables are shown in the next slide.
The spread sheet is shown in small form to fit the page. Later
slides will be enlarged to show details.

12. 11. P

13. Objective Two
Your second objective is to make two charts showing the
relation of reaction rate constant to temperature.
The charts are shown on the next slide.
Charts are shown in small form to fit the page. Later charts
will be enlarged to show details.

14. 11. P

15. Objective Three
Your third objective is to use your sheet to estimate the
reaction rate constants at two different temperatures.
The next slide shows the estimated reaction rate constants in
the Summary of Analysis section.

16. 4. Check analysis summary
S

17. Part 2 Build the tables and Charts.
Follow the instructions on the next slides to build the
tables and charts.

18. Step 1. Start a new Sheet in Chromebook or other spread
sheet.
Use plus icon to start a new application.
Identify your new sheet as Thermal Cracking
xxxyyyymmdd
Substitute your initiates for xxx
Substitute the date for yyyymmdd

19. 2 Start a Sheet
.

20. Step 2. Enter title block at top of sheet
Title block shown on next sheet.
Type your name after Prepared by:

21. 1. Enter title block at top of sheet

22. Step 3. Enter summary of analysis
See next sheet for summary of analysis.
Enter the formulas as shown in column D and column H
Start your formulas with the = sign.

23. 1. Enter title block at top of sheet

24. Step 4. Enter Table 1 on sheet
Table 1 is shown on next page
Type the formulas as shown in columns C, D, E and F

25. 2. Enter Table 1 on sheet

26. Step 5. Enter Table 2 on sheet
Table 2 shown on next sheet.
Type formulas in column B
Do not change the column width..

27. 3. Enter Table 2 on sheet
V

28. Part 3. Check your numbers
Now that you have entered the formulas the spread sheet will
calculate numerical values.

29. Step 6. Check numerical values in the Summary of Analysis
The next sheet shows the numerical values calculated from
the data.

30. 4. Check analysis summary
S

31. Step 7. Check Table 1 for correct numbers.
Table 1 is shown on next sheet.
The next sheet shows the numerical values you should get
from the data.

32. 5. Check Table 1 for correct numbers.
Table 2 shown on next sheet.

33. Step 8. Check Table 2 for correct numbers.
Table 2 shown on next sheet.
The next sheet shows the values you should get in Table 2.

34. 2. Enter Table 1 on sheet

35. Part 4. Make two Charts
Chart 91-A shows the input data of reaction rate constant
versus temperature. This is a non-linear relation.
Chart 91-B shows the natural logarithm of the reaction rate
constant versus reciprocal temperature. This is a linear
relation and can be represented by an straight line.

36. Step 9. Make a Chart 91-A
See next sheet

37. 6. Make a Chart 91-A
See next sheet

38. Step 10. Make a Chart 91-B
See next sheet

39. 6. Make a Chart 91-B
See next sheet

40. Step 11. Your sheet will look like the following

41. 11. P

42. 11. P

43. Part 5. Place your report in your discussion board post

44. Step 12. Place your report in your discussion board post

45. Part Nine Nine Nine
.Fini.

46. Simplest Formula Series in Chemistry
Thermal Cracking of Ethane in a Tubular Reactor
Stephen Joseph Boylan 2020
Learning Objective: Use the Arrhenius equation and linear regression analysis to calculate the
frequency factor and activation energy from temperatures and reaction rate constants. This
exercise will develope your habits and skills to analyse temperature and rate data using linear
regression.

47. Simplest Formula Series in Chemistry
Thermal Cracking of Ethane in a Tubular Reactor
References
Froment, G. F., Bischoff, K. B., Chemical Reactor Analysis and Design Second Edition, John
Wiley& Sons, Inc., New York 1990
Walepole, R. E., Myers, R. H., Probability and Statistics for Engineers and Scientists 2ed.,
Macmillian Publishing Co., Inc., New York, 1978

49. … … … … …
Thank you for taking the time to
watch.
Stephen Joseph Boylan
2020

50. The End

51. The End
The End .