Aqueous solutions of ionic liquids in the
extraction and purification of
compounds from biomass
João A. P. Coutinho
CICECO, Department of Chemistry,
University of Aveiro, 3810-193 Aveiro, Portugal.
http://path.web.ua.pt http://www.facebook.com/PATh.group
University of Coimbra
University of Aveiro
CICECO - AVEIRO INSTITUTE OF MATERIALS
university of aveiro
ciceco aveiro institute of materials
G1 – Inorganic Functional Nanomaterials & Organic-Inorganic Hybrids (J. R. Gomes) G2 – Multifunctional Ferroic Ceramics & Nanostructures (V. Amaral) G3 – Materials for Energy and Functional Surfaces (M. Zheludkevich) G4 – Biorefineries, Biobased Materials and Recycling (Armando J.D. Silvestre) G5 - Biomedical and Biomimetic Materials (A. Gil).
Research Groups
university of aveiro
ciceco aveiro institute of materials
Biorefinery: CICECO – VTT – Aalto
BoostBiorefine SEP-210273988 H2020 – TWINN - 2015
Biorefinery
Chemicals, Intermediates
The Biorefinery Concept
Energy
Polymers
Paper, Materials, Fibres
Food CO2
ILs and Water
The magic of aqueous solutions of ionic liquids -Greener
-Cheaper
-Lower viscosity
-Enhanced performance
ILs and Water
Caffeine extraction
from guaraná seeds
using aqueous
solutions of ionic
liquids
Ana Filipa Cláudio, Ana MC Ferreira, Mara G. Freire and Joao A.P. Coutinho Green Chemistry 15 (2013) 2002-2010
Guaraná
A climbing plant especially common in Brazil and its
seeds contain about twice the caffeine found in coffee
beans
Used in pharmaceutical, dietetic, food and beverage
industry
Extraction of caffein with IL solutions
Ana Filipa Cláudio, Ana MC Ferreira, Mara G. Freire and Joao A.P. Coutinho Green Chemistry 15 (2013) 2002-2010
Ana Filipa Cláudio, Ana MC Ferreira, Mara G. Freire and Joao A.P. Coutinho Green Chemistry 15 (2013) 2002-2010
Extraction of caffein with IL solutions
3.86
5.17
6.116.88
7.407.87
8.18
3.123.75
0
2
4
6
8
10
% w
t caf
H20 0.5 M 1.0 M 1.5 M 2.0 M 2.5 M 3.0 M 1.0 M 1.5 M
H20
[C4mim]Cl
NaCl
Caffeine extracted from guaraná seeds using particle diameters of guaraná seeds between 0.4 and 1 mm (T = 70 ºC, R=1:10, t= 30 min).
Ana Filipa Cláudio, Ana MC Ferreira, Mara G. Freire and Joao A.P. Coutinho Green Chemistry 15 (2013) 2002-2010
Extraction of caffein with IL solutions
Ana Filipa Cláudio, Ana MC Ferreira, Mara G. Freire and Joao A.P. Coutinho Green Chemistry 15 (2013) 2002-2010
T = [65 , 85] ˚C;
Re
su
lts
R;
Response surface methodology:
Factorial planning 23 (T, R, C )
Constants
parameters
t = 30 min
d < 0.4 mm
C ( ≥ 1.5 M ).
Response
surface plots
and contour on
the extraction of
caffeine.
T vs R C vs R C vs T
Caffeine
extraction
Extraction of caffein with IL solutions
Ana Filipa Cláudio, Ana MC Ferreira, Mara G. Freire and Joao A.P. Coutinho Green Chemistry 15 (2013) 2002-2010
Extraction of caffein with IL solutions
Solubility of caffein in IL solutions
0
50
100
150
200
250
300
350
0 20 40 60 80 100
[Bio
mo
lecu
le]
/ g.
L-1
[IL]/ wt%
Influence of concentration of IL at 303 K in solubility in aqueous solutions of:
[C4C1im][N(CN)2]; [C4C1im]Cl; [C2C1im][N(CN)2].
Solubility of vanillin in IL solutions
Ana F Cláudio, M Neves, K Shimizu, JNC Lopes, Mara G Freire, Joao AP Coutinho Green Chem (2015) 10.1039/C5GC00712G
0
50
100
150
200
250
0 5 10 15 20 25
[Van
illin
] / g
.L-1
[IL] in water / wt %
11
Solubility
up to
18-fold
Only water
Recovery of vanilin: antisolvent
Ana F Cláudio, M Neves, K Shimizu, JNC Lopes, Mara G Freire, Joao AP Coutinho Green Chem (2015) 10.1039/C5GC00712G
0
100
200
300
400
500
300 305 310 315 320 325
[Van
illin
] /
g.L-1
T / K
Influence of temperature in the vanillin’s solubility in ▬ water1 and in aqueous
solutions of 10 wt % of sodium benzoate, 10 wt % of [C2C1im][N(CN)2],
20 wt % of sodium benzoate and 20 wt % of [C2C1im][N(CN)2].
Recovery of vanilin: antisolvent
Ana F Cláudio, M Neves, K Shimizu, JNC Lopes, Mara G Freire, Joao AP Coutinho Green Chem (2015) 10.1039/C5GC00712G
b) c) d) a)
Precipitation of vanillin
a) appearance of commercial vanillin; b) vanillin dissolved in 20 wt % [C4C1im]Cl;
c) precipitation of vanillin with addition of water; d) recovered vanillin.
Recovery of vanilin: antisolvent
Ana F Cláudio, M Neves, K Shimizu, JNC Lopes, Mara G Freire, Joao AP Coutinho Green Chem (2015) 10.1039/C5GC00712G
ABS
IL-rich phase
60 ⁰C
Filtration (0.45 μm) + water 84% dye recuperation
Sudan III
4 ⁰C
Filtration (0.45 μm)
Indigo Blue
76% dye recuperation
Dye recovery: antisolvent/ temperature
[P4441][CH3SO4] +
organic salt
A.M. Ferreira, João A.P. Coutinho, A.M. Fernandes, Mara G. Freire Sep Pur Tech 128 (2014) 58–66
0.0
1.0
2.0
3.0
4.0
% C
hlo
rop
hyll
Chl a Chl b
Process conditions:
R = 1:50 t = 30 min C = 10 wt.% of IL
The extraction efficiency of chlorophylls significantly increases with surface-active ionic
liquids, i.e., with ILs that are able to form aggregates in aqueous solution.
Extraction of clorophyll with IL solutions
0.0
1.0
2.0
3.0
4.0
% C
hlo
rop
hyll
Higher extraction efficiency with the
increase of the IL concentration;
0.5 wt.% [P44414]Cl
H2O 1 wt.% [P44414]Cl
5 wt.% [P44414]Cl
10 wt.% [P44414]Cl
7.5 wt.% [P44414]Cl
Chl a Chl b
At higher concentrations, the
extractions efficiencies are less
dependent on the IL amount in
aqueous solution;
The amount of extracted chlorophyll
b is similar for all IL concentrations.
Selective extraction of chlorophylls
Extraction of clorophyll with IL solutions
Process conditions:
R = 1:50 t = 30 min
Aqueous Biphasic Systems
• Polymer-Salt • Polymer-Polymer
Liquid-liquid extraction with ABS
Phase Diagrams of IL-based ABS
Aqueous Biphasic Systems
ABS of IL + Salt
[CF3CO2]-
ABS ILs + Water + K3PO4
Evaluation of IL Cation Influence
Evaluation of IL Anion Influence
[C2-6mim]+ [C1mim]+ [C2im]+ [C1im]+ [im]+
[C7H7mim]+ [amim]+ [OHC2mim]+
[HSO4]- [Cl]- [Br]- [MeSO4]
- [EtSO4]-
[CF3SO3]- [N(CN)2]
- [CH3SO3]- [CH3CO2]
-
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
0.0 0.5 1.0 1.5 2.0 2.5 3.0
IL /
(m
ol.
kg
-1)
K3PO4 / (mol. kg-1)
[C2mim][CH3SO3]
[C2mim][Cl]
[C2mim][CH3CO2]
[C2mim][Br]
[C2mim][MeSO4]
[C2mim][EtSO4]
[C2mim][CF3SO3]
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
0.0 0.5 1.0 1.5 2.0 2.5
IL /
(m
ol.
kg
-1)
K3PO4 / (mol. kg-1)
[C4mim][CH3CO2]
[C4mim][Cl]
[C4mim][CH3SO3]
[C4mim][Br]
[C4mim][TFA]
[C4mim][N(CN)2]
[C4mim][HSO4]
[C4mim][CF3SO3]
[CF3SO3] > [EtSO4] > [MeSO4] > [Br] > [CH3CO2] > [Cl] > [CH3SO3]
[CF3SO3] > [HSO4] > [N(CN)2] > [TFA] > [Br] > [CH3SO3] > [Cl] > [CH3CO2]
Anion Influence
Ventura, S. P.; Neves, C. M. S. S.; Freire, M. G.; Marrucho, I. M.; Coutinho, J. A. P. J. Phys. Chem. B 113 (2009) 9304-9310
ABS ILs + Water + K3PO4
Descending order of ATPS formation
Descending order of ATPS formation
0.0
1.0
2.0
3.0
4.0
5.0
6.0
0.0 0.5 1.0 1.5 2.0 2.5
IL /
(m
ol.
kg
-1)
K3PO4 / (mol. kg-1)
[OHC2mim][Cl]
[C1mim][Cl]
[C2mim][Cl]
[amim][Cl]
[C4mim][Cl]
[C7H7mim][Cl]
[C6mim][Cl]
Cation Influence
[C6mim] > [C7H7mim] > [C4mim] > [C2mim] ≈ [amim] > [C1mim] > [OHC2mim]
Neves, C. M. S. S.; Ventura, S. P.; Freire, M. G.; Marrucho, I. M.; Coutinho, J. A. P. J. Phys. Chem. B 113 (2009) 5194-5199.
ABS ILs + Water + K3PO4
Descending order of ATPS formation
Evaluation of the salt effect: anion
PO43->C6H5O7
3->HPO42-≈CO3
2->SO42-≈SO3
2->C4H4O62->H2PO4
->OH->CH3COO-≈HSO4-≈HCO3
->Cl-
Evaluation of the salt effect: cation
Mg2+ ≈ Ni2+ ≈ Sr2+ > Ca2+ > > Na+ > K+ > Cs+
IL-based ABS
Salt cation
10
Salt anion
20
IL cation
10
IL anion
20
IL chain funct
20
Total
800,000 x x x x
Each tie line is a different extraction system, with different partition coefficients and selectivities
The tuneability of ionic liquids allows them to form ABSs with various compounds
IL-based ABS
Over one million of ABS can be prepared with the ILs available
ATPS ILs + Water + aminoacids
M. Domínguez-Pérez, L.I.N. Tomé, M.G. Freire, I. M. Marrucho, O. Cabeza, J.A.P. Coutinho Sep Pur Tech 72 (2010) 85-91
ATPS ILs + Water + Sugar
D-Glucose
D-Mannose
D-Galactose
D-(+)-Xylose
D -(-)-arabinose
L-(+)-Arabinose
Sucrose
Lactose
D-Sorbitol
Xylitol
D-Maltitol
Mara G. Freire, Cláudia L. S. Louros, Luís Paulo N. Rebelo and João A. P. Coutinho Green Chemistry (2011) 13: 1536-1545
ATPS ILs + Water + Sugar
Mara G. Freire, Cláudia L. S. Louros, Luís Paulo N. Rebelo and João A. P. Coutinho Green Chemistry (2011) 13: 1536-1545
ATPS ILs + Water + Sugar
Mara G. Freire, Cláudia L. S. Louros, Luís Paulo N. Rebelo and João A. P. Coutinho Green Chemistry (2011) 13: 1536-1545
IL + Dextran + H2O at 298 K
0,0
0,4
0,8
1,2
1,6
2,0
2,4
2,8
3,2
3,6
0 0,001 0,002 0,003 0,004 0,005 0,006 0,007
[IL]/
(mo
l.k
g-1
)
[Dextran 100k]/(mol.kg-1)
, [C4mim][BF4] , [C4mim][CF3SO3] , [C2mim][CF3SO3] , [C4mim][C2SO4]
, [C4mim][N(CN)2]
, [C4mim][TOS]
, [C4mim][C1SO4]
Potential for forming ABS
[C4mim][BF4]≈[C4mim][CF3SO3]>[C4mim][C2SO4]≈ [C4mim] [N(CN)2]>[C4mim][TOS]>[C4mim][C1SO4]
ABS ILs + Water + Dextran
ABS composed of ILs + Polysaccharides:
IL + Dextran + H2O at 298 K
The higher the molecular weight of the dextran the more effective is the separation into two phases
0,0
0,4
0,8
1,2
1,6
2,0
0 0,02 0,04 0,06 0,08
[C4
mim
[]B
F4
]/(m
ol.k
g-1
)
[Dextran]/(mol.kg-1)
[C4mim][BF4] + Dextran 6k
[C4mim][BF4] + Dextran 40k
[C4mim][BF4] + Dextran 100k
ABS ILs + Water + Dextran
ABS composed of ILs + Polysaccharides:
Speciation curve of Chloranilic acid
PEG
dye
IL
dye
dyeC
CK
Neutral 1 negative charge
2 negative charge
PEG
salt
PEG
dextran
IL
PEG
PEG
IL
IL
PEG
IL
PEG
IL
PEG
PEG
IL
IL
PEG
IL
PEG
ABS ILs + Water + PEGs
J. F. B. Pereira, L. P. N. Rebelo, Robin D. Rogers, João A. P. Coutinho and Mara G. Freire PCCP 15 (2013) 19580-19583
Indigo Blue Partition
Indigo Carmine Partition
Na2SO4 [C4mim]Cl [C4mpirr]Cl [C4mpip]Cl
Salt
Salt
ABS ILs + Water + PEGs
ABS with Deep Eutectic Solvents
To verify the ability of DES to create an ABS;
To characterize DES-based ABS;
To demonstrate the potential of these systems in extractive processes
5
ABS with Deep Eutectic Solvents
ABS with Deep Eutectic Solvents
DES + H2O + PPG 400 ternary systems
0,00
2,00
4,00
6,00
0,00 0,50 1,00 1,50 2,00
[PP
G]
/ m
ol.
kg-1
[IL] / mol.kg-1
IL [Ch]Cl
[Ch][DHC]
l [Ch][Gly]
n [Ch][Lac]
[Ch][Ac]
0,00 0,50 1,00 1,50 2,00 2,50[DES] / mol.kg-1
DES [Ch]Cl
Citric acid + [Ch]Cl (1:1)
l Glycolic acid + [Ch]Cl (1:1)
n Lactic acid + [Ch]Cl (1:1)
Acetic acid + [Ch]Cl (1:1)
o Citric acid ≈ Glycolic acid < Lactic acid ≈ Acetic acid o [Ch][DHC] < [Ch][Gly] ≈ [Ch][Lac] ≈ [Ch][Ace]
ABS with Deep Eutectic Solvents
0,00
2,00
4,00
6,00
8,00
10,00
0,00 0,50 1,00 1,50 2,00 2,50
[PP
G]
/ m
ol.
kg-1
[DES] / mol.kg-1
Citric acid
0,00
2,00
4,00
6,00
0,00 0,50 1,00 1,50 2,00 2,50 3,00
[PP
G]
/ m
ol.
kg-1
[DES] / mol.kg-1
Lactic acid
IL [Ch]Cl n Acid + [Ch]Cl (1:2) l Acid + [Ch]Cl (1:1) Acid + [Ch]Cl (2:1)
ABS with Deep Eutectic Solvents
0,00
2,00
4,00
6,00
0,00 1,00 2,00 3,00
[PP
G]
/ m
ol.
kg-1
[DES] / mol.kg-1
0,00
2,00
4,00
6,00
0,00 1,00 2,00 3,00
[PP
G]
/ m
ol.
kg-1
[DES] / mol.kg-1
Glycolic acid Acetic acid
IL [Ch]Cl n Acid + [Ch]Cl (1:2) l Acid + [Ch]Cl (1:1) Acid + [Ch]Cl (2:1)
[Acid] ability for ABS formation
ABS with Deep Eutectic Solvents
• High Extraction efficiencies
• DES > [Ch]Cl
Selective separation of dyes (sudan III and PB29 respectly)
PB29 Sudan III
-100
-75
-50
-25
0
25
50
75
100
EED
ye %
PB 29 Sudan III
PPG-rich phase
DES-rich phase
2:1 1:1 1:2 [Ch]Cl
ABS with Deep Eutectic Solvents
DES showed an
intermediate toxicity
when compared
with the respective
starting materials.
These DES are
included in the
“moderately toxic”
compounds against
Vibrio fischeri
AA << LA < CA < GA
Toxicities of Deep Eutectic Solvents
Their toxicity against
the marine bacteria is
dependent of the
concentration of the
acid.
The effect of the acid
is controlling the
toxicity of the DES
Toxicities of Deep Eutectic Solvents
DES seem to be much more toxic than the corresponding ILs
Toxicities of Deep Eutectic Solvents
Reversible IL-based ABS
Recently, a large interest has been devoted to the study of reversible biphasic systems constituted by ILs: temperature-driven phenomenon CO2/N2 flushing
Reversible Systems
Saita et al., Chem. Commun., 2012, 48, 7119 Saita et al., Chem. Commun., 2013, 49, 8988 Xiong et al., Green Chem., 2013, 15, 1941 Xiong et al., ChemSusChem, 2012, 5, 2255 Jessop et al., Energy Environ. Sci., 2012, 5, 7240
0
20
40
60
80
0 20 40 60
IL /
( w
t %
)
[Salt] / (wt %)
Biphasic region
Monophasic region
pH-reversible IL-ABS
Phase diagrams (at different pH values) for ABS composed of:
+ K3C6H5O7 + C6H8O7 + KOH [C4mim]Br [C4mim]Cl
[C4mpy]Cl [C4C1mim]Cl
[C4mpip]Cl [P4444]Cl
The relative amount of the citrate-based species has a crucial impact on the phase diagrams and on their ability to form ABS
pH-reversible IL-ABS
IL-s
alt
A
TP
S
IL+ Potassium Citrate + Water
Citric acid
KOH
Biphasic region
Monophasic region
Biphasic region
Reversibility behaviour:
speciation of the salt anion.
Reversibility behaviour:
speciation of the IL anion.
j
j
pH-reversible IL-ABS
pH ≈6 pH ≈7
-100
-80
-60
-40
-20
0
20
40
60
80
100
1 2 3 4
EED
ye %
Sudan III PB27
IL- rich phase
Salt -rich phase
[C4mim]Cl [C4C1mim]Cl [C4mpip]Cl [C4mpy]Cl
[C4mim]Cl
[C4C1mim]Cl
[C4mpip]Cl
[C4mpy]Cl
Complete separation of the two
dyes for opposite phases
↑ EE %
Mixture of dyes in the
monophasic region
Sudan III
PB27
Separation of the
two dyes
pH-reversible IL-ABS
Phase diagrams (at different pH values) for ABS composed of:
[Ch]Cl [Ch][Ac] [Ch][Pro]
[Ch][Gly] [Ch][But]
[Ch][Lac] PPG
+ PPG 400 + Acid corresponding to the IL anion + [Ch]OH
pH-reversible IL-ABS
Phase diagrams for the systems composed of ILs + water + PPG 400 at 298 K
[Ch][Hex]
[Ch][But]
[Ch]Cl
[Ch][Pro]
[Ch][Lac]
[Ch][Ac]
[Ch][Gly]
Hydration capacity
Anions with alkyl side chains
Anions with ↑ alkyl side chains
Addition of extra –OH groups
Form ABS
Don’t form ABS
Enhanced capacity to form ABS
×
○
▲
l
+
0
20
40
60
80
0 5 10 15 20 25
[PP
G 4
00
] /
(wt
%)
[IL] / (wt %)
Monophasic region
Biphasic region
10
15
20
10 15 20
pH-reversible IL-ABS
Phase diagrams for the systems composed of PPG 400 + Water + ILs/Respective Acid (pH ≈ 4-9) at 298 K
Higher pH values are favorable for ABS formation
♦ pH ≈ 9 ■ pH ≈ 8 pH 7 ● pH 6 ▲pH 5
[IL] / wt%
Higher pH
pH-reversible IL-ABS
pH
not favorable for the formation of
ABS
pH 9 8 7 6 5 4 3 2 1 0
[Ch]Cl
[Ch][Ac]
[Ch][Gly]
[Ch][Lac]
[Ch]Prop]
[Ch][But]
Ability to form ABS is related with the pKa of the acid corresponding
to the IL anion
Acid pKa1 pKa2
hydrochloric acid --- ---
acetic acid 4.54 ---
propanoic acid 4.75 ---
butanoic acid 4.91 ---
lactic acid 14.59 3.78
glycolic acid 14.78 3.53
Identification of the systems able to form ABS at different pH values
pH-reversible IL-ABS
PB27 PB29
Selective separation of dyes with reversible ABS
Sudan III PB27 PB29
pH-reversible IL-ABS
Saita et al., Chem. Commun., 2013, 49, 8988. Nockemann et al., J. Phys. Chem. B, 2006, 110, 20978.
Temperature-driven phenomenon
Thermoreversible systems
PIL+
PPG400
+H2O PIL
aqueousrich phase
PPG400
aqueousrich phase
25 °C 35 °C0
10
20
30
40
50
60
70
80
90
100
0
10
20
30
40
50
60
70
80
90
100
Thermoreversible IL-ABS
[N1120][C1CO2] [N1220][C1SO3]
[N11[2(N110)]0][C1CO2] [N11[2(N110)]0]Cl
[N11[2(N110)]0][C7CO2] [N1220][C7H7CO2]
Thermoreversible IL-ABS
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6
[PP
G-4
00
] / (
mo
l∙k
g-1
)
[PIL] / (mol·kg-1)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0.0 0.5 1.0 1.5 2.0 2.5 3.0
[PP
G-4
00
] /
(mo
l∙k
g-1
)
[PIL] / (mol·kg-1)
25 ºC 35 ºC
Monophasic region
Biphasic region
Monophasic region
Biphasic region
Phase diagrams for the ternary systems composed of PPG-400 + PIL + water at 25 ºC and
35 ºC: [N1120][C1CO2] (); [N1220][C1SO3] (); [N11[2(N110)]0]Cl (n); [N11[2(N110)]0][C1CO2] (●).
Thermoreversible IL-ABS
45ºC
Azocasein Citocrome C
EE%
[N11[2(N110)]0]Cl
[N11[2(N110)]0] [C1CO2]
95.3% 99.8% 100%
[N11[2(N110)]0][C1CO2] [N11[2(N110)]0][C1CO2]
25ºC
pH ≈ 8 pH ≈ 8 pH ≈ 4
Thermoreversible IL-ABS
0.0
0.5
1.0
1.5
2.0
2.5
0.0 0.5 1.0 1.5 2.0 2.5 3.0
[PPG
-400
] / (m
ol·k
g-1)
[PIL] / (mol·kg-1)Evaluation of temperature effect in the ternary phase diagram composed of [N11[2(N110)]0]Cl + PPG-
400 + water at 25 ºC (), 35 ºC (n) and 45 ºC (), and selective separation of dyes by a thermoreversible behavior.
25 ºC
35 ºC
45 ºC
25 ºC
35 ºC PPG-aqueous rich phase
PIL-aqueous rich phase
Thermoreversible IL-ABS
Back extractions and recycling of ILs
Caffeine extraction
from guaraná seeds
using aqueous
solutions of ionic
liquids
Ana Filipa Cláudio, Ana MC Ferreira, Mara G. Freire and Joao A.P. Coutinho Green Chemistry 15 (2013) 2002-2010
T = [65 , 85] ˚C;
Re
su
lts
R;
Response surface methodology:
Factorial planning 23 (T, R, C )
Constants
parameters
t = 30 min
d < 0.4 mm
C ( ≥ 1.5 M ).
Response
surface plots
and contour on
the extraction of
caffeine.
T vs R C vs R C vs T
Caffeine
extraction
9
Extraction of Caffein
Effect of butanol on
IL solutions?
21.93
0.09
13.75
20.99
18.92
1.92
16.89
7.24
17.68 17.69
0
5
10
15
20
25
[Caf
fein
e] /
(g.
L-1)
Recyclability
Best extraction solvents:
Chloroform;
Methylene chloride.
Butanol can be a good candidate to re-extract caffeine .
The IL solutions don’t lose their
extraction efficiency after the re-
extraction with butanol. substitute
Aim
R
es
ult
s
10
To choose organic solvent non-
miscible with water capable of re-
extracting caffeine from the IL
medium.
Concentration of caffeine after the liquid-liquid extraction
Aqueous solution of [C4mim]Cl at
the optimized operational conditions.
Reusability
Aim
R
es
ult
s
Recovery of caffein: reextraction
8,56
17,41
25,63
9,3487
17,8
0
5
10
15
20
25
30
[caf
fein
e]/
g. L
-1
Recovery of caffein: reextraction
0
50
100
150
200
250
0 5 10 15 20 25
[Van
illin
] / g
.L-1
[IL] in water / wt %
11
Solubility
up to
18-fold
Only water
Recovery of vanilin: antisolvent
ABS
IL-rich phase
60 ⁰C
Filtration (0.45 μm) + water 84% dye recuperation
Sudan III
4 ⁰C
Filtration (0.45 μm)
Indigo Blue
76% dye recuperation
Dye recovery: antisolvent/ temperature
[P4441][CH3SO4] +
organic salt
syringic acid vanillic acid gallic acid
Recovery of phenolic compounds
A.F.M. Cláudio, C.F.C. Marques, Isabel Boal-Palheiros, Mara G. Freire and João A.P. Coutinho Green Chem 16 (2014) 259-268
[C4C1im]+
15 20 15 15 15 20 15 wt % of Salt
Br - [N(CN)2]-
[C2H5SO4 ]- [CH3SO4 ]
- [CF3SO3]-
88,90 89,93
97,05 98,53 93,37 94,56 96,84
0
20
40
60
80
100
% EE
IL- rich phase
Extraction efficiencies (%EE) of gallic acid for the IL-rich phase in ATPS composed of 25 wt% of [C4C1im]-based ILs and variable concentrations of Na2SO4 at 25 ºC.
Recovery of phenolic compounds
Extraction efficiencies (%EE) of gallic acid for the inorganic-salt-rich phase in ATPS composed of 10 wt% of Na2CO3 and variable concentrations of [C4C1im]-based ILs at 25 ºC.
Recovery of phenolic compounds
Recovery of phenolic compounds
A.F.M. Cláudio, C.F.C. Marques, Isabel Boal-Palheiros, Mara G. Freire and João A.P. Coutinho Green Chem 16 (2014) 259-268
Recovery of phenolic compounds
gallic acid
Extraction efficiencies (%EE) of syringic and vanillic acid in sequential ATPS composed of 25% of IL + 20% Na2SO4) (orange bars) and 20% of IL + 10% Na2CO3 (blue bars) at 298 K
Recovery of phenolic compounds
Protein
Ionic Liquid
Purification Strategies
• Immunoaffinity chromatography
• Centrifugation
• Dialysis
In order to establish a sustainable and low-cost process, the recovery of protein from the IL-aqueous solution for further reuse is required…
Recovery of proteins
Protein
IL – aqueous solution
• Dialysis removes any excess IL from protein aqueous solution
• Recycled IL can be use subsequent extraction step.
Dialysis procedure
ILs can be reused
12 h Room temperature Moderate agitation
Purified protein
Dried under vacum at 60 ◦C
IL recovery of > 99 wt%
Recovery of proteins
Recycling ionic liquids
• The non-volatile nature of ionic liquids provides the opportunity to reduce, or even completely eliminate, hazardous and toxic emissions to the atmosphere.
• But they present a non-negligible solubility in water, even those considered hydrophobic, thus leading to aquatic environmental concerns.
• Their toxicity is inversely proportional to their hydrophobicity
• Process costs are related to IL recycling
𝑅𝑒𝑡𝑢𝑟𝑛
𝑘𝑔 𝑏𝑖𝑜𝑚𝑎𝑠𝑠= 𝐶𝑝𝑟𝑜𝑑 × $𝑝𝑟𝑜𝑑 − $𝑏𝑖𝑜𝑚 − 𝑉𝐼𝐿 × $𝐼𝐿 × 𝑟𝐼𝐿 𝑙𝑜𝑠𝑡 × 𝛼 + 𝛽
70
75
80
85
90
95
100
% R
10 wt % Al2(SO4)3 + 45 wt %IL
13 wt % Al2(SO4)3 + 45 wt %IL
16 wt % Al2(SO4)3 + 45 wt %IL
15 wt % Al2(SO4)3 + 40 wt %IL
2 wt % AlK(SO4)2 + 51 wt % IL
10 wt % Al2(SO4)3 + 45 wt % IL
13 wt % Al2(SO4)3 + 45 wt % IL
16 wt % Al2(SO4)3 + 45 wt % IL
15 wt % Al2(SO4)3 + 40 wt % IL
2 wt % AlK(SO4)2 + 51 wt % IL
Recovery
Recovery
70
75
80
85
90
95
100
R%
10 wt % Al2(SO4)3 +45 wt % IL
13 wt % Al2(SO4)3 +45 wt % IL
16 wt % Al2(SO4)3 +45 wt % IL
15 wt % Al2(SO4)3 +40 wt % IL
2 wt % AlK(SO4)2 +51 wt % IL
10 wt % Al2(SO4)3 + 45 wt % IL
13 wt % Al2(SO4)3 + 45 wt % IL
16 wt % Al2(SO4)3 + 45 wt % IL
15 wt % Al2(SO4)3 + 40 wt % IL
2 wt % AlK(SO4)2 + 51 wt % IL
Aqueous IL effluentIL rich current
Diluted salt solution
Concentrated salt solution
Water
Conceptual process
Catarina M. S. S. Neves, Mara G. Freire and João A. P. Coutinho RSC Advances 2 (2012) 10882-10890
Catarina M. S. S. Neves, Mara G. Freire and João A. P. Coutinho RSC Advances 2 (2012) 10882-10890
Proof of concept
Catarina M. S. S. Neves, Mara G. Freire and João A. P. Coutinho RSC Advances 2 (2012) 10882-10890
Proof of concept
[Pi(444)1][Tos]
S
IL
S
IL
SS
ILILIL-rich phase
Protein
Salt-rich phase
Recycling ionic liquids in ILTPPS
Enrique Alvarez-Guerra, Sónia P.M. Ventura, João A.P. Coutinho and Angel Irabien Fluid Phase Equilibria 371 (2014) 67–74
Recycling ionic liquids in ILTPPS
Alternatives to recover the ionic liquid:
a) No additional recovery steps are considered.
b) Extra salt is added to increase the salt mass fraction and to reduce DIL.
c) Vacuum evaporation is used to remove water from the salt-rich phase.
Enrique Alvarez-Guerra, Sónia P.M. Ventura, João A.P. Coutinho and Angel Irabien Fluid Phase Equilibria 371 (2014) 67–74
Recycling ionic liquids in ILTPPS
Alternative: b) Addition of extra salt:
o Curve zone: a higher fraction of the salt-rich phase would increase the total mass of the system increases.
o Constant zone: a higher fraction of the salt-rich phase would increase the overall salt concentration.
Increasing additions of extra salt
Enrique Alvarez-Guerra, Sónia P.M. Ventura, João A.P. Coutinho and Angel Irabien Fluid Phase Equilibria 371 (2014) 67–74
Recycling ionic liquids in ILTPPS
o Higher [LF]F values: a complete recovery of both ionic liquid and salt is achieved.
Alternative: c) Vacuum evaporation of water from salt-rich phase:
o Lower [LF]F values: desired concentrations cannot be reached due to the high water content of the feed stream.
Enrique Alvarez-Guerra, Sónia P.M. Ventura, João A.P. Coutinho and Angel Irabien Fluid Phase Equilibria 371 (2014) 67–74
Each path engenders new paths
Aqueous Biphasic Systems: Review
Path (path.web.ua.pt)