Post combustion CO2 absorption using Ionic Liquid

1. Noakhali Science and Technology University
Dept.of Applied Chemistry and Chemical Engineering
Project Title: Post combustion CO2 absorption using ionic liquid
Presented By:
ASH1204047M
Session: 2012-13
Year: 04 , Term: 01
Submitted To:
Department of ACCE

2. Outline
 Introduction
 Objectives of my project
 Definition and properties of Ionic Liquid
 CO2 Capture Systems
 Post Combustion CO2 capture methods
 Solubility of CO2 in ionic liquid
 CO2 capture in ionic liquid
 Conclusion
 Reference
 Acknowledgement

3. Introduction
 The general increase in the earth’s near surface and ocean
temperatures – A pressing issue in the world.
 The Intergovernmental Panel on Climate Change predicts a 1.9°C rise in
temperature by the year 2100.
 CO2 is one of the green house gases and is responsible for global
warming.
 Carbon capture and storage (CCS) is a major strategy that can be used
to reduce GHGs emission.
 Economical and environmental aspects are the main motivation for
research on energy efficient processes and the search for environment
friendly materials for CO2 capture.
 Ionic liquids are alternative to the conventional volatile solvents9m,
because of their interesting properties.

4. Objectives of the Project
The objectives of this project involves with the CO2
absorption using ionic liquid. Specially the aims are:
Literature review on application of ionic liquid more specially
post combustion CO2 absorption using ionic liquid as a solvent
focusing on the followings:
a. Definition and properties of ionic liquid
b. Solubility of CO2 in different ionic liquid
c. Energy consumption for CO2 capture and recovery of ionic
liquids using temperature-swing technique and compare it with
MEA-based CO2 capture technology.

5. Ionic Liquid
Definition: Ionic liquids are molten salts entirely composed of ions (+ve,
-vely charged) that are liquid at or below room temperature,i.e
M.P< 1000C .
Example: 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide,
([emim][Tf2N]),M.P= 17 0C .
Properties of Ionic Liquid:
 Non-flammable
 Very low vapor pressure
 High thermal stability
 High ion conductivity
 Green solvents
 viscisity= 10 to above 1000cP
 Density=0.8-3.3 g/cc
 Wide electro-chemical window

6. Typical Cations and Anions of Ionic Liquid

7. Structure of Ionic LIquid

8. CO2 Capture Systems
There are three basic systems for capturing CO2 from
use of fossil fuels and/or biomass.
 Post-combustion capture
 Pre-combustion capture
 Oxy-fuel combustion capture

9. CO2 Capture Systems
These systems are shown in simplified form in
below-

10. Drawbacks of CO2 Capture Systems
 The main issue with post combustion capture system is the
low concentration of CO2 in the flue gases (3-10%) that
makes the process very costly
 In pre combustion capture system, cost of equipment and
the availability are the drawbacks
 With oxyfuel combustion capture system, large cryogenic
oxygen production requirement may be cost prohibitive.

11. Post Combustion CO2 Capture Methods
Different technologies are available for post-combustion CO2 capture. These
different currently available and emerging technologies are:
Current Technologies
 Amine based technology
Emerging Technologies
 Cryogenic Separation
 Soluble Carbonate based systems
 Ammonia based systems
 Membrane systems
 Enzyme-based systems
 Solid sorbent based systems (Adsorption)
 CO2 absorption using ionic liquid instead of Mono Ethanol Amine (MEA)

12. Solubility of CO2 in Ionic Liquid
CO2 is remarkably soluble in ILs. According to the solubility of CO2
structural features and absorption mechanisms, the ILs can be
classified into two categories. These are-
 Conventional ILs (second generation ILs)-absorb less
amount of CO2 due to physical interactions between CO2 and
ILs.
 Task-specific ILs (third generation ILs)-Task-specific ILs with
alkaline groups could sequester larger amount of CO2 due to
chemical interactions or reactivities between CO2 and alkaline
groups of ILs.

13. Factors affecting CO2 solubility
Effects of various factors on CO2 solubility in Ionic Liquid
Temperature- solubility decreases with increase in temperature
Pressure–solubility increases with increase in pressure. CO2 is more soluble
at a low pressure in ionic liquid than C2H4, C2H6, CH4, Ar, O2.
Anion effect –CO2 solubility mainly depends on choice of anion
due to strong interactions of CO2 with anion.
Fluorination Effect of Anion -CO2 is least soluble in the ILs with
nonfluorinated anions, [NO3] and [DCA]. It has the highest
solubility in ILs with anions containing fluoroalkyl groups [TfO], [Tf2N],
and [methide]
Cation effect- The CO2 solubility slightly increases with an increase in
the alkyl chain length in cation at low pressures and this increase becomes
more apparent at higher pressures.

14. Reaction Between CO2 and ILs

15. Capturing Process of CO2 in Ionic Liquid

16. Comparison Between ILs and MEA
Ionic Liquid Based System MEA Based System
Avoid solvent evaporation , low VP Solvent evaporation ,High VP
Low volatility High volatility
High thermal stability Low thermal stability
Lower energy and cost for regeneration High cost of solvent scrubbing
Less degradation and lower corrosivity It is corrosive in nature

17. Conclusion
As compare to the present earlier CO2 capture
strategies,
Ionic Liquid has been emerged as a novel media for co2
capture in chemical absorption technique.

18. Acknowledgement
I would like to express my heartfelt gratitude, profound appreciation to my honorable
teacher and Supervisor Nahid sultana for his untiring inspiration, scholastic supervision,
constructive criticism, affectionate feeling and generous help for completion of the research
work and writingup this project report.
I feel proud to express my sincere appreciation and indebtedness to Prof Dr.Md. Yusuf Miah,
chairman, Dr. Newaz Mohammed Bahadur, Associate professor, Dr. Md. Ashraful Alam,
Associate professor, Zakarul Islam, Associate professor, Department of ACCE; Mohammed
Saiful Alam, Assistant professor, Department ofACCE; Md. Azizul Haque, Assistant
professor, Department of ACCE; Md. Shafiul Islam, Assistant professor, Department of
ACCE; Shovon Bhattacharjee, Assistant professor, Department of ACCE; Shukanta
Bhowmik, Assistant professor, Department of ACCE; Rajib Chandra Das, Lecturer,
Department of ACCE; ShujitChandra Paul, Lecturer, Department of ACCE, Noakhali Science
and Technology University, Noakhali, for their valuable suggestions and generous help in
need for the Project work and preparation of the report.

19. References
 Anthony, J. L.; Aki, S. N. V. K.; Maginn E. J.; Brennecke, J. F. (2004).
Feasibility of using Ionic Liquids for Carbon dioxide capture. Int. J.
Environmental Tech. and Management, Vol. 4, Nos. 1/2, 105-115.
 Seddon, K. R.; Stark, A.; Torres, M. J. (2000). Influence of chloride,
water, and organic solvents on the physical properti es of ionic solids.
Pure Appl. Chem.,72, 2275-2287.
 Hurley, F.N.; Wier, T. P. (1951). The electrodeposition of aluminum from
nonaqueous solutions at room temperature. Journal of the
Electrochemical Society, 98, 207-212.
 . Cadena, C.; Anthony, J. L.; Shah, J. K.; Morrow, T. I.; Brennecke, J. F.
Maginn E. J. (2004). Why is CO2 so soluble in Imidazolium-based Ionic
Liquids? J. American Chem. Society., 126, 5300-5308