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