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Mohammad Reza Eghlimpour (Petroleum University of Technology)
Reza Mosayebi Behbahani
Makan Yousefi
Maede Zargar
Keywords: Amine-based, gas sweetening, Methyldiethanolamine (MDEA), Ionic Liquid,Bmim[Ac]
Results & Discussion
CO2 & CH4 solubility in aqueous mixtures of [Bmim][Ac] &MDEA (in mass fraction
(wt%)) at T=308.15 K and pressures up to 50 bar.
Solubility of CO2 & CH4 in mixture CH4/CO2 (75/25 % mole) in aqueous mixtures of
[Bmim][Ac] +MDEA (in mass fraction (wt%)) at T=308.15 K and pressures up to 50 bar.
Solubility of CO2&CH4 in mixture CH4/CO2 (50/50 % mole) in aqueous mixtures of[Bmim][Ac] +MDEA (in mass fraction (wt%)) at T=308.15 K and pressures up to 50 bar.
Solubility of CO2&CH4 in mixture CH4/CO2 (25/75 % mole) in aqueous mixtures of[Bmim][Ac] +MDEA (in mass fraction (wt%)) at T=308.15 K and pressures up to 50 bar.
References:[1]Afshin Ahmady, Mohd Ali Hashim, and Mohamed Kheireddine Aroua, Experimental
Investigation on the Solubility and Initial Rate of Absorption of CO2 in Aqueous Mixtures of
Methyldiethanolamine with the Ionic Liquid 1-Butyl-3-methylimidazolium Tetrafluoroborate
, Chemical Engineering Department, University of Malaya, 50603 Kuala Lumpur, Malaysia.
[2]Abolfazl Shojaeian, Ali Haghtalab. Solubility and density of carbon dioxide in different
aqueous alkanolamine solutions blended with 1-butyl-3-methylimidazolium acetate ionic
liquid at high pressure. Department of Chemical Engineering, Tarbiat Modares University,
P.O. Box: 14115-143, Tehran, Iran .
Abstract:Carbon dioxide has been identified as the main factor responsible for
global warming. Currently, the process applied for CO2 capture at a
large scale is the amine-based solvent absorption process. Amines,
considered as conventional solvents, are being used for gas sweetening
process. The main disadvantages of these conventional amines are
solvent degradation, high volatility, corrosion and high energy cost of
their regeneration causing low solvent recovery and high energy
consumption in the regeneration process because of the large enthalpy of
formation produced in reactions with CO2. Ionic liquids, known as
“green solvents”, are considerably given attention as promising
alternatives for amines to remove acid gases in gas sweetening process.
Ionic liquids have several remarkable advantages such as low vapor
pressure, low cost of regeneration, nonflammability, high thermal and
chemical stability. The main aim of this thesis was to experimental
investigation on the Solubility and Absorption of CO2 and CH4 in
Aqueous Mixtures of Methyldiethanolamine (MDEA) with the Ionic
Liquid 1-butyl-3-methylimidazolium acetate ([Bmim][Ac]. The
solubility of CO2, CH4, and CO2/CH4 mixtures (25/75 mol%, 50/50
mol% and 75/25 mol%) in Aqueous Mixtures of ionic liquids
[Bmim][Ac], and MDEA are measured at 308.15 K for pressures up to
50 bar.
Introduction:Absorption is one of the most effective methods to remove carbon
dioxide (CO2) and hydrogen sulfide (H2S), namely acid gases, from
natural gas. Amines, considered as conventional solvents, are being used
for gas sweetening. Alkanolamines including diethanolamine (DEA),
monoethanolamine (MEA), and methyl-diethanolamine (MDEA) are
being utilized for CO2 capture. In this research, a new aqueous solution
of ILs with Amins is examined for absorbing CO2 form CH4 by the
combination of physical and chemical absorption. The studied ILs were
1-butyl-3-methylimidazolium acetate ([Bmim][Ac]) and Amin is MDEA.
Volumetric diagram of the apparatus.
.
Conclusion:It had been found that adding amino acid IL greatly reinforced the
CO2 absorption of MDEA aqueous solution at high pressure. For feed
gas CO2/CH4=75/25 &50/50 mol% aqueous mixtures of 35 wt%
MDEA+ 5 wt% [Bmim][Ac] had higher capacity to absorbed CO2 and
For feed gas CO2/CH4= 25/75 mol% 30 wt% MDEA+ 10 wt%
[Bmim][Ac] led to higher values of CO2 solubility at medium and high
pressures. Aqueous mixture of [Bmim][Ac]+MDEA had higher capacity
to absorb CO2 at high pressure because of the physical absorption CO2
gas by ionic liquid ([Bmim][Ac])in liquid phase. On other hand at low
pressure MDEA led to chemical absorption of CO2 therefore had higher
capacity to absorb CO2. CH4 solubility in mixture has been decreased
approximately by adding [Bmim][Ac] to the aqueous mixture of MDEA.
0
5
10
15
20
25
30
35
40
45
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7
Pre
ssure
(b
ar)
Mole fraction CO2
CO2+40w%MDEA
CO2+35w%MDEA+5%[Bmim][Ac]
CO2+30w%MDEA+10w%[Bmim][Ac]
0
5
10
15
20
25
30
35
0 0.005 0.01 0.015 0.02
Pre
ssure
(b
ar)
Mole fraction CH4
CH4+40w%MDEA
CH4+35w%MDEA+5w%[Bmim][Ac]
CH4+30w%MDEA+10w%[Bmim][Ac]