Modeling ofN2 Separation From Natural Gas Using Alumina Membrane
Purification of natural gas is very crucial step for upgrading the current value of natural gas, which contain about 5-20% of nitrogen. Petroleum refineries currently employ cryogemcs, pressure swing adsorption (PSA), and membrane systems for hydrogen recovery. Each of these technologies has limi...
Saved in:
Main Author: | |
---|---|
Format: | Final Year Project |
Language: | English |
Published: |
Universiti Teknologi Petronas
2004
|
Subjects: | |
Online Access: | http://utpedia.utp.edu.my/8623/1/2004%20-%20Modeling%20of%20Manufacturing%20Assembly%20Line%20for%203%20Pin%20Power%20Plug.pdf http://utpedia.utp.edu.my/8623/ |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
id |
my-utp-utpedia.8623 |
---|---|
record_format |
eprints |
spelling |
my-utp-utpedia.86232017-01-25T09:47:10Z http://utpedia.utp.edu.my/8623/ Modeling ofN2 Separation From Natural Gas Using Alumina Membrane Abdul Karim, Marcella TP Chemical technology Purification of natural gas is very crucial step for upgrading the current value of natural gas, which contain about 5-20% of nitrogen. Petroleum refineries currently employ cryogemcs, pressure swing adsorption (PSA), and membrane systems for hydrogen recovery. Each of these technologies has limitations: cryogenics is generally used only in large-scale facilities with liquid hydrocarbon recovery, because of its high capital cost; and PSA typically recovers less of the feedstream and is limited to modest temperatures. Due to this reasons, alternative approach using membrane technology is to be explore. The purpose of this study is to develop a mathematical model for predicting the permeability and separation of nitrogen from natural gas. The parameters of concerns are operating pressure and temperature, feed composition and membrane pore size. Simulated results shows that increase in temperature gives rise to a strong increase in membrane segmental motions, causing the pore diameter to become larger resulting the selectivity will be lower. The effective diffusivity is either determined experimentally without knowledge of the porosity or tortuosity or use of predictive method for ordinary molecular diffusivity. It considers the normal molecular diffusivity and the Knudsen diffusivity. Operating conditions can be very important; an excellent membrane will achieve a poor performance if the operating conditions have not been properly selected. Selectivity is controlled by the properties of the active layer, and the porous supporting layer improves mechanical properties of the membrane only. The membrane used in this study is alumina. The equation used to calculate the permeability for pure gases consider the effect of viscous, Knudsen and surface diffusion. The total permeability of gases will increase as the membrane pore size increased. At 323.25 K, and pressure 60 bar, the permeability of methane at rp =0.2nm is 4.8313xl0"11 molls and the value increase to 1.76xl0.10 molls at rp=2nm.The effect of pressure and temperature were also studied, where increase in feed pressure will in result increase the total permeability. The effect of temperature shows the opposite trend where the total permeability decreased as the temperature increased.The permeability of the binary mixture of methane and nitrogen is very close to permeability of pure methane. Pure methane attained the highest permeability. As the membrane pore size increase, more gas molecules can diffuse through the membrane and as a result, the total permeability of gases increased. Due to increase value in permeability of both methane and nitrogen, the separation process will be less selective and thus it decrease with increase in pore size. As the flow rate at the retentate side is higher, the percentage removal will decrease. Thus in order to achieve high nitrogen removal, the stage cut must be low. Universiti Teknologi Petronas 2004-01 Final Year Project NonPeerReviewed application/pdf en http://utpedia.utp.edu.my/8623/1/2004%20-%20Modeling%20of%20Manufacturing%20Assembly%20Line%20for%203%20Pin%20Power%20Plug.pdf Abdul Karim, Marcella (2004) Modeling ofN2 Separation From Natural Gas Using Alumina Membrane. Universiti Teknologi Petronas. (Unpublished) |
institution |
Universiti Teknologi Petronas |
building |
UTP Resource Centre |
collection |
Institutional Repository |
continent |
Asia |
country |
Malaysia |
content_provider |
Universiti Teknologi Petronas |
content_source |
UTP Electronic and Digitized Intellectual Asset |
url_provider |
http://utpedia.utp.edu.my/ |
language |
English |
topic |
TP Chemical technology |
spellingShingle |
TP Chemical technology Abdul Karim, Marcella Modeling ofN2 Separation From Natural Gas Using Alumina Membrane |
description |
Purification of natural gas is very crucial step for upgrading the current value of natural
gas, which contain about 5-20% of nitrogen. Petroleum refineries currently employ
cryogemcs, pressure swing adsorption (PSA), and membrane systems for hydrogen
recovery. Each of these technologies has limitations: cryogenics is generally used only in
large-scale facilities with liquid hydrocarbon recovery, because of its high capital cost;
and PSA typically recovers less of the feedstream and is limited to modest temperatures.
Due to this reasons, alternative approach using membrane technology is to be explore.
The purpose of this study is to develop a mathematical model for predicting the
permeability and separation of nitrogen from natural gas. The parameters of concerns are
operating pressure and temperature, feed composition and membrane pore size.
Simulated results shows that increase in temperature gives rise to a strong increase in
membrane segmental motions, causing the pore diameter to become larger resulting the
selectivity will be lower. The effective diffusivity is either determined experimentally
without knowledge of the porosity or tortuosity or use of predictive method for ordinary
molecular diffusivity. It considers the normal molecular diffusivity and the Knudsen
diffusivity. Operating conditions can be very important; an excellent membrane will
achieve a poor performance if the operating conditions have not been properly selected.
Selectivity is controlled by the properties of the active layer, and the porous supporting
layer improves mechanical properties of the membrane only. The membrane used in this
study is alumina. The equation used to calculate the permeability for pure gases consider
the effect of viscous, Knudsen and surface diffusion. The total permeability of gases will
increase as the membrane pore size increased. At 323.25 K, and pressure 60 bar, the
permeability of methane at rp =0.2nm is 4.8313xl0"11 molls and the value increase to
1.76xl0.10 molls at rp=2nm.The effect of pressure and temperature were also studied,
where increase in feed pressure will in result increase the total permeability. The effect of
temperature shows the opposite trend where the total permeability decreased as the
temperature increased.The permeability of the binary mixture of methane and nitrogen is very close to
permeability of pure methane. Pure methane attained the highest permeability. As the
membrane pore size increase, more gas molecules can diffuse through the membrane and
as a result, the total permeability of gases increased. Due to increase value in
permeability of both methane and nitrogen, the separation process will be less selective
and thus it decrease with increase in pore size. As the flow rate at the retentate side is
higher, the percentage removal will decrease. Thus in order to achieve high nitrogen
removal, the stage cut must be low. |
format |
Final Year Project |
author |
Abdul Karim, Marcella |
author_facet |
Abdul Karim, Marcella |
author_sort |
Abdul Karim, Marcella |
title |
Modeling ofN2 Separation From Natural Gas Using Alumina Membrane |
title_short |
Modeling ofN2 Separation From Natural Gas Using Alumina Membrane |
title_full |
Modeling ofN2 Separation From Natural Gas Using Alumina Membrane |
title_fullStr |
Modeling ofN2 Separation From Natural Gas Using Alumina Membrane |
title_full_unstemmed |
Modeling ofN2 Separation From Natural Gas Using Alumina Membrane |
title_sort |
modeling ofn2 separation from natural gas using alumina membrane |
publisher |
Universiti Teknologi Petronas |
publishDate |
2004 |
url |
http://utpedia.utp.edu.my/8623/1/2004%20-%20Modeling%20of%20Manufacturing%20Assembly%20Line%20for%203%20Pin%20Power%20Plug.pdf http://utpedia.utp.edu.my/8623/ |
_version_ |
1739831592517369856 |
score |
13.154949 |