CO2 Capture Using Ionic liquid
Prepared byAhmad T. MalkiAhmad K. AL-Askar
Supervised byProf. Emadadeen M. Ali Prof. Mohammad Asif
Global Worming
Fossil fuels (coal, oil, natural gas)
Carbon Dioxide (CO2)
Global Warming
Sources of CO2 emissions
World-wide statistical data of CO2
Objectives
1. Study the effectiveness of using Ionic Liquid (IL) (1- Butyl-3-methylimidazolium tetrafluoroborate) as an alternative solvent for CO2 capturing.
2. Compare the efficacy of IL with that of MEA in terms of Sorbent and energy requirements
CO2 separation processSeparation using Sorbent/Solvent
MEAAdvantage & Disadvantages
Advantages
Inexpensive material (1ton of MEA cost $1100)
DisadvantagesLow carbon dioxide loading capacity
Equipment corrosion
High-energy penalty during absorbent regeneration
MEA: Monoethanolamin is the most common material used in industry to absorb CO2
Ionic Liquids
A new class of compounds that have emerged in the last twenty years with several applications in chemical and physical separation.
ILs are salts with melting points below 100 degree C.
ILs are environmentally-friendly alternatives to organic solvent for liquid/liquid extraction, and separation.
Method of Solution
Peng Robinson Equation of State
Validated with experimental data Predict CO2 solubility in IL Predict VLE Temperature for stripping
Model Validation
1 3 5 7 90
0.02
0.04
0.06
0.08
0.1
0.12
Pressure (atm)
CO
2 Sol
ubil
ity
(m
ole/
mol
e so
lven
t)
T= 40oC
10 20 30 40 50 60 70 80 90 1000
0.005
0.01
0.015
0.02
Temperature (oC)
CO
2 Sol
ubil
ity
(m
ole/
mol
e so
lven
t)
P = 1 atm
Process Performance when xo=0.2, f = 85%, T=25 oC
0
1
2
L/G
(a)
0
0.1
0.2
0.3
CO
2 load
ing
(b)(b)
3 4 5 6 7 8 9 100
2
4
6
CO
2x100
0 (
kmol
e/hr
)
Absorber Pressure (atm)
(c)(c)
Rich sorbentLean sorbent
3 4 5 6 7 8 9 100
50
100
150
200
250
300
350
Absorber Pressure (atm)
Str
ippi
ng T
empe
ratu
re, (
K)
Pf=4 atm
Pf=3 atm
Pf=2 atm
Pf=1 atm
Process performance when L=CO2cap/m, f = 85%, T=25 oC
0
2
4
L/G
(a)
0
0.5
1
CO
2 load
ing
(b)
Rich sorbentLean sorbent
1 2 3 4 5 6 7 8 9 100
10
20
CO
2x100
0 (
kmol
e/hr
)
Absorber Pressure (atm)
(c)
1 2 3 4 5 6 7 8 9 100
50
100
150
200
250
300
350
400
Absorber Pressure (atm)
Str
ippi
ng T
empe
ratu
re, (
K)
P
f=4 atm
Pf=3 atm
Pf=2 atm
Pf=1 atm
Advantage & Disadvantages of IL
Advantages
Non-flammable and non- corrosive
Thermally and hydrolytically stable
Non-volatile
Minimize the environmental hazards
Disadvantages
Expensive materials(1kg of IL cost $100)
Conclusions
The IL is favored over MEA because of ease of regenerating the spent sorbent. This is attributed to the non-chemical reaction during the absorption process.
Although IL is environmentally safe, the economic analysis however reveals high operational cost due to high pressure demand.
Recommendations
Use of Hybrid Technology to increase the CO2 concentration (partial pressure) in the feed gas in order to decrease the power consumption in the absorber
Development of mixed solvent (IL+ low cost solvent) strategy, e.g. IL and MEA, IL and water etc. in order to reduce the cost