This website uses cookies to ensure you have the best experience. Learn more

Comparison Of Reactors For Prediction Of Kinetics For A Reaction

3231 words - 13 pages

Comparison of reactors for prediction of kinetics for a reaction

In this report, a Matlab model for simulating simultaneous oxidation of carbon monoxide and propylene in a fixed bed reactor. The model takes into account temperature variation and pressure drop down the reactor. The catalyst pellets are assumed to be isothermal; only the concentration variation is considered inside the pellet. Both external and internal diffusion is taken into account in the model. The results are then analyzed and some problems are noted. Then a new model is simulated to eliminate those problems. Also, a simpler isothermal case is also simulated for relative study.
The reaction ...view middle of the document...

175cm. The length of the bed is 120m. These are represented by the following reactions:

1. CO + ½ O2 = CO2
2. C3H6 + 9/2 O2 = 3 CO2 + 3H2O

The rate equations for both the reactions are taken from Oh et al.:


The rate constants and adsorption constants are assumed to follow Arrhenius equation.

The assumptions considered in this model are as follows:
1. Particles are small compared to the length of reactor.
2. Plug flow in bed, no radial profiles.
3. Neglect axial diffusion in the bed.
4. Steady state.
5. Isothermal catalyst pellets
The various parameters and their values are given in the following table:

Parameter | Value |
Pressure | 2 atm |
Diameter of particle | 0.175 cm |
Tin | 550 K |
E1/R | 13108 |
E2/R | 15109 |
Eco/R | -409 |
Ec3h6 | 191 |
Ccof | 2% |
Co2f | 3% |
Cc3h6f | 0.05% |
k10 | 7.07E+19 |
kco | 8.10E+06 |
k20 | 1.47E+21 |
kc3h6 | 2.58E+08 |
Dco | 4.87E-02 |
Do2 | 4.69E-02 |
Dc3h6 | 4.87E-02 |
kmco | 3.90E+00 |
kmo2 | 4.07E+00 |
kmc3h6 | 3.90E+00 |

The mass transfer coefficients are taken from DeAcetis and Thodos.

Model equations:
All the modeling and simulation was done in Matlab.

The type of equations to describe a fixed bed reactor can be divided into 3 parts:
1. Equations for the reactor
2. Equations for the pellet
3. Coupling Equations
Mass balance:
dNjdV= Rj+AcUdCjdz

Heat Balance:
ρCpQdTdV= -∆HriRi+2RU0(Ta-T)

Pressure Drop across the reactor (Ergun’s equation):
dPdV=-1-ϵbDpϵb3QAc2 1501-ϵbμfDp+74ρQAc

For the reactor equations, we know the initial conditions (at the inlet of the reactor); hence those become boundary conditions.
Boundary conditions:
Nj=Nj,in at z=0
T=Tinat z=0
P=Pinat z=0

The pellet is supposed to be isothermal, since the size of pellet is too small to show any significant temperature variations. Therefore, the only equation required for simulating the inside of the pellet is the mass balance.
Mass balance:
Dj1r2ddrr2dCjdr= -ΩRj'
where , overall effectiveness factor, is defined as the ratio of actual rate of reaction and rate of reaction if the entire surface was exposed to the bulk conditions. The value of overall effectiveness factor is derived from internal effectiveness factor, which in turn is derived from thiele modulus.
For the pellet, we have 2 boundary conditions:
Boundary conditions:
dCjdr=0 at r=0
DjdCjdr=kjmCjs-Cj at r=R

The final equation equates the production rate seen by the fluid phase Rj, to the rate of production inside the particles, which is where the reaction actually takes place.
Rj= -1-ϵb SpVp DjdCjdr at r=R

Global collocation method was used to integrate the differential equations. The value of all the required constants were obtained from credible sources on the internet and are given in Table 1.

Apart from the above...

Other Essays Like Comparison of Reactors for Prediction of Kinetics for a Reaction

Stages of Grief Lament for a Son

1094 words - 5 pages Running head: STAGES OF GRIEF Stages of Grief Delores Clayton Grand Canyon University Religious in Health Care HLT-310V Gary Shields August 22, 2015 In this essay I will be completing my report from the book “Lament for a Son” not only written but also lived by Nicholas WolterstorffIn. In this book the author/character talks about his painful recollection and how his life has changed since his son that was 25 year old has pass away

Summary of "A Rose for Emily"

746 words - 3 pages Barbara N. Weeks Human Literary Heritage ENGL205-ADCP April 14, 2012 Critical Analysis of “A Rose for Emily” William Faulkner begins the story by telling of the death of Miss Emily Grierson. The people in the town went to Emily’s funeral not because they admired her or had love and affection for her, but mainly out of curiosity. The women could not wait to see the inside of the house, everyone knew that when her father died he only left

Comparison Of Financial Statements For The Sony Corporation And The Google Corporation

1038 words - 5 pages statements, and statement of cash flows for each. I will give my opinion about each of them in reference to the usefulness of their net income vs. cash from operating activities. Finally I intend to make a prediction about each company after reviewing their financial statements and reach one additional conclusion about each company from the additional information provided in their annual reports.According to the background material provided for module

Comparison of Science Based and Spiritual Based Reasons for Saving Environment

634 words - 3 pages helping all of God's children along the path. Kimball's focus is on the eternal perspective of things, and has somewhat of a higher understanding of what is eternally important than Raven does. Raven does a good job in what he wrote, but tends to focus on the temporal things of this world. Both advocate for taking better care of the environment, they just differ when it comes to applications of their philosophies, Kimball on individual behavior

A Comparison of Ethical Theories

681 words - 3 pages A Comparison of Ethical Theories Ethics are codes of behavior, adopted by a group; a family, community or nations, setting the boarders for behavior. Some examples of ethics theories include: virtue ethics, utilitarianism, and deontology.  The virtue theory of ethics can be summed up with the statement, that if a person’s character is good, they will make good choices. The choices they make are strictly based on their internal thoughts and

A Comparison Of Love Poems

2691 words - 11 pages only twelve books. Each of the things in the list seem to be metaphors of what normally occurs within a relationship. For instance 'built a wall´ would be; perhaps, they had bought their own home. 'Planted a golden tree´ would be to signify life; perhaps they had children and prospered.In the third stanza, it is obvious that Clarke is writing as an older matured person, because it tackles death. 'On an open shelf I keep my box. Its key

Literary Comparison Of A Clock

1841 words - 8 pages A Literary Comparison Of A Clockwork Orange and The Crucible      The existence of evil in the world is a universal question that is often contemplated. Anthony Burgess and Arthur Miller in their novels A Clockwork Orange and The Crucible address this question of evil. One of these stories is set in the future, and the other in the past confirming the belief that the human struggle between good and evil is timeless

The Concept of a Hero for Each of Everyone

571 words - 3 pages HERO The concept of a hero can be defined in many ways. Many individuals believe to call someone a hero is to give them tremendous power. Certainly that power may be used for good, but it may also be used to destroy individuals. Some of society’s concept of a hero goes back to their childhood figure that they looked up to. The hero could be there mom, dad, a dog or maybe even the guy on the television who wore tights and a cape and spent

Sodium Thiosulphate Rates of Reaction

1883 words - 8 pages concentration of Sodium Thiosulphate the reaction will occur much faster then when I use a lower concentration. I predict that there may be a pattern to the results because the concentration is decreasing in equal amounts and therefore the rate of reaction may do too. This is because for a reaction to take place particles have to "collide" with another but only a small percentage of these "collisions" result in a reaction. If I

Experiment on Rates of Reaction

780 words - 4 pages . Results: We had to record our results in a table as shown; Concentration of Sodium Thiosulphate (g/h) Time (Secs) 1st 2nd 10 g/h 98.02 97.06 20 g/h 65.22 63.16 30 g/h 45.56 44.62 40 g/h 34.43 32.39 Conclusion: From my prediction, when you increase the concentration of an acid, the rate of the reaction will increase. A reason for this is that the chemicals in the concentration make the rate of the

Chemistry Rates of Reaction Coursework

5365 words - 22 pages precipitate of sure sulphur being produced at a faster rate due to more collisions happening. As the concentration of sodium thiosulfate is lowered due to the addition of water, I predict that the reaction rate will be lowered. I will be able to test my prediction by measuring the volume of sodium thiosulfate and also the water added to the sodium thiosulfate to bring the volume of the solution up to 50cm3 against the time taken for the precipitate to

Related Papers

A Comparison Of Peace, Anthem For Doomed Youth And Dulce Et Decorum Est

966 words - 4 pages A Comparison of Peace, Anthem for Doomed Youth and Dulce et Decorum Est Works Cited Missing All three poems are about the First World War but Peace has a highly patriotic view and displays a positive feeling about war whereas Anthem and Dulce concentrate more on the fact that people were killed for no particular reason and they also

Comparison And Contrast Of 'the Yellow Wallpaper" And "A Rose For Emily"

2137 words - 9 pages Introduction"A Rose for Emily", is a story written by William Faulkner, who wrote many stories which include Sartoris, The Sound and the Fury, and As I Lay Dying (DLB, 1991). In "A Rose for Emily", the reader sees a woman, Emily Grierson, who lives a life of loneliness, and how her attitude changes with this loneliness. Emily Grierson's loneliness can be attributed to three main factors: her father, her secluded lifestyle, and Homer Barron's

For This Pieces Of Coursework I Had To Visit Two Places Of Worship And Write A Comparison On Them

4704 words - 19 pages buildings and the furnishings.B) Explain the significance of these features and furnishings for the worshipper and how they reflect and assist beliefC) 'You do not need to go to a place of public worship to be a Christian.' Do you agree? Give reasons to support your answer and show that you have thought about different points of view.A) Visit two local Christian places of worship. Using pictures and/or diagrams, describe the main features of the

For The Price Of A Burrito

1011 words - 5 pages Summer of 1983, we lived in Standish California. It was such a small town that if you blinked while you drove through, you’d defiantly miss it. Mostly full of dust and sagebrush, but people had their ranches out there. If you ventured into the town you would see chickens, horses, cattle and maybe goats. For a mere dollar you could buy fresh from the cow’s tit milk in a gallon mayonnaise jar. When my parents bought their property it came