dep. de química, universidade de aveiro,...

PATh

Dep. de Química, Universidade de Aveiro, Portugal

+

-

PATh

1. Introduction

1.1 ILs – Properties

1.2 ILs – Applications

1.3 Work Motivations

2. Methods to remove ILs from Water

2.1 Water Treatment Methods

2.2 Proposed Methods for Water Treatment

3. Materials and Results 3.1 Materials - Adsorption

3.2 Adsorption Results

3.2.1 Alkyl side chain length

3.2.2 Isomers

3.3 Materials - ABS

3.4 ABS Results

3.4.1 ABS measurements

3.4.2 Recovery efficiency

3.5 Process proposal

4. Conclusions

5. Future work

Summary

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1. Introduction

1.1 ILs – ILs properties

Ionic Liquids (ILs)

Cations Anions

-Large -Organic - Asymmetric

-Organic or inorganic

Do not have a crystalline form!

Liquids at T ≤ 373 K and p = 1 atm

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1. Introduction

1.1 ILs – ILs properties

Property ILs

Chemical stability

Thermal stability

Nº of Combinations

Melting Temperature

Vapour Pressure

High

High

> 106

Low

Low

“Designer

solvents”

“Green

solvents”

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1. Introduction

1.2 ILs – ILs applications

ILs applications

Biotechnology

Physical Chemistry

Analytical Methods

Solvents and Catalysis

Engineering

Medical uses

Energy

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ILs Log(EC50 / µM) VOCs Log(EC50 / µM)

[C4mim][BF4]

[C5mim][BF4]

[C6mim][BF4]

[C7mim][BF4]

[C8mim][BF4]

[C9mim][BF4]

[C10mim][BF4]

[C4mim]Cl

[C4mim]Br

[C4py]Br

[C4mpy]Br

[C6mpy]Br [C8mpy]Br

3.55

3.14

2.15

2.44

1.41

0.72

-0.18

2.95

3.07

2.73

2.12

1.48

0.25

Methanol

Acetone

Dichloromethane

Benzene

Toluene

Phenol

O-Xylene

5.00

4.29

3.40

2.03

1.50

1.49

0.97

Toxicity tests with luminescent marine

bacteria Vibrio fisheri* (15 min)

Lower

log(EC50)

Higher

Toxicity

1. Introduction

1.3 Work motivations

*J. Kärkkäinen, Master Thesis, Department of Chemestry, University of Oulu, Finland, 2007.

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285

290

295

300

305

310

315

320

0.0000 0.0004 0.0008 0.0012 0.0016 0.0020

x IL

T/

K

[C2mim][Ntf2]

[C3mim][Ntf2]

[C4mim][Ntf2]

[C5mim][Ntf2]

[C6mim][Ntf2]

[C7mim][Ntf2]

[C8mim][Ntf2]

Non-negligible solubility in water* (even

those considered hydrophobic)

0.72 wt %

Use in a

large scale leads to

aquatic

environmental

impact

1. Introduction


*M. G. Freire, C. M. S. S. Neves, P. J. Carvalho, R. L. Gardas, A. M. Fernandes, I. M. Marrucho, L. M. N. B. F. Santos, and J. A. P.

Coutinho, The Journal of Physical Chemistry B, vol. 111, pp. 13082-13089, 2007.

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Production* /

Application * * of ILs

Removal of ILs from

Aqueous effluents

*P. T. Anastas, P. Wasserscheid, and A. Stark, Handbook of Green Chemistry, Volume 6: Ionic Liquids, 2010

**A. Kokorin, Ionic Liquids: Theory, Properties, New Approaches. InTech, 2011

Aqueous

effluents

Recover of ILs

Recycle of ILs

Aqueous

effluents

1. Introduction


How to

Remove

ILs?

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2. Methods to remove ILs

2.1 Water treatment methods

Oxidative Methods*

ILs degradation

By products

Thermal Methods**

ILs degradation

Very high temperatures

By products

Biological Methods***

ILs degradation

Low biodegradability

*T. P. Thuy Pham et al., Water Research, vol. 44, pp. 352-372, 2010 **A. Kokorin, Ionic Liquids: Theory, Properties, New Approaches. InTech, 2011 ***C. Abrusci, et al., Green Chemistry, vol. 13, pp. 709-717, 2011

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2.1 Proposed methods to water treatment

Adsorption for Hydrophobic

ILs onto Activated Charcoal

Thermally stable

Highly

developed

porosity

High surface

area

Special surface

reactivity

Highly inert

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2.1 Proposed methods to water treatment

IL – rich phase Salt – rich phase

Aqueous Biphasic Systems (ABS)

for Hydrophilic ILs

Short processing

time

Low energy

consumption

Biocompatible Readily scaled up

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3. Materials and Results

3.1 Materials - Adsorption

-

Based ILs

bis(trifluoromethylsulfonyl)amide ► [NTf2]-

N+

N

R

N+

N

R'

R'

CnC1im series CmCmim series

Activated Charcoal

R = 1,2,3,4,5,6,8,12 R’ = 1,2,3

T = 308 K

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0.0

0.2

0.4

0.6

0.8

1.0

1.2

0.0 0.5 1.0 1.5 2.0 2.5

0.0

0.4

0.8

1.2

0.0 0.5 1.0 1.5 2.0 2.5


3.2.1 Adsorption – Alkyl side chain length

CnC1im series and CmCmim series:

Ce / (mmol/L)

qe /

(m

mo

l/g

)

() [C1C1im], (■) [C2C1im], () [C3C1im], (▲) [C4C1im], () [C5C1im], (×) [C6C1im]; (○) [C2C2im][NTf2], ()

[C3C3im][NTf2]

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IL Kd / (L/kg)

[C1C1im] + 512.6

[C2C1im] + 540.8

[C3C1im] + 621.9

[C4C1im] + 660.2

[C5C1im] + 689.1

[C6C1im]+ 653.7

[C8C1im]+ 601.1

[C12C1im]+ 546.3

IL Kd / (L/kg)

[C1C1im] + 512.6

[C2C2im] + 545.9

[C3C3im] + 748.0


3.2.1 Adsorption – Alkyl side chain length

CnC1im series and CmCmim series:

Apparent distribution coefficient

[C1C1im]+ < [C2C1im]+ < [C12C1im]+ < [C8C1im]+ < [C3C1im]+ < [C6C1im]+ <

[C4C1im]+ < [C5C1im]+

Decrease in

adsorption

Higher

adsorption

[C1C1im]+ < [C2C2im]+ < [C3C3im]+

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3.2.2 Adsorption – Isomers

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0.0 0.5 1.0 1.5 2.0 2.5

qe /

(m

mo

l/g

)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0.0 0.5 1.0 1.5 2.0 2.5 0.0

0.2

0.4

0.6

0.8

1.0

1.2

0.0 0.5 1.0 1.5 2.0 2.5

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0.0 0.5 1.0 1.5 2.0 2.5

(*) [C2im], () [C1C1im]; b), () [C3C1im], (○) [C2C2im], (▲) [C4C1im], ( ) [C2C3im], () [C5C1im], () [C3C3im].

alkyl side chain length increase

CnC1

CmCm

CmCm

CnC1

Comparison between CmCmim series and CnC1im series:

Ce / (mmol/L)

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3.3 Materials- ABS

Na2CO3 as phase promoter agent due to its good

salting-out ability

N+

N

[C(n=2,4 e 6)mim]+

N+

[C4mpyr]+

N+

[C4-(n=0,2,3,4)-mpy]+

N+

[C4-4-mpy]+

N+

[N4444]+ [P4444]

+

P+

[C4mpip]+

N+

[N(CN)2]-

S-N

[SCN]-

S

O

O

O

O-

[CH3SO4]-

S

O

O

-O

[C2H5SO3]-

SO O

O-

[CH3SO3]-

S

O

O

O-

[TOS]-

P

O

OO

O-

[DMP]-

S OO

O-

F

F

F

[CF3SO3]-

Br-

Cl-

N

C C

N N

T = 298 K

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3.4.1 ABS – Measurements

0

5

10

15

20

25

30

35

40

45

0 5 10 15 20

[P4444]C

l / w

t %

[NaCO3] / wt %

Biphasic region

Monophasic region

Mixture point Two phases separation Bottom and top

phase weight

Calculation of the bottom

and top weight fractions by

the Merchuk equation

Merchuk, J. C.; Andrews, B. A.; Asenjo, J. A. J. Chromatogr., B 1998, 711, 285−293.

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100%SaltSaltILIL

ILIL

mILmIL

mILR


3.4.2 ABS – Recovery efficiency

Lower salt concentration Higher salt concentration

[C4C

1im

]Cl

[C4C

1im

]Br

[C4C

1im

][C

F3S

O3]

[C4C

1im

][T

OS

]

[C4C

1im

][N

(CN

) 2]

[C4C

1im

][C

H3S

O4]

[C4C

1im

][C

H3S

O3]

[C4C

1im

][D

MP

]

[C4C

1im

][C

2H

5S

O4]

[C4C

1im

][S

CN

]

[C4C

1p

ip]C

l

[C4C

1p

yr]

Cl

[C4p

y]C

l

[C4-2

-C1p

y]C

l

[C4-4

-C1p

y]C

l

[C2C

1im

]Cl

[C6C

1im

]Cl

[aC

1im

]Cl

[C4-3

-C1p

y]C

l

[P4

44

4]C

l

[N4

44

4]C

l

90.5

0

90.8

5

92.7

3

95.8

2

93.2

5

99.7

5

93.4

3

99.1

2

93.6

5 9

4.8

6

94.0

6

94.8

4

95.7

7

95.8

8

96.1

5

96.2

1

96.1

9 97.2

2

96.3

7

96.4

8

99.6

5

97.2

2

97.3

5

98.1

6

97.0

5

97.4

6

97.2

5

97.6

3

97.4

3

97.6

3

99.4

1

97.9

7

98.1

8

98.7

7

99.3

2

99.6

7

99.4

1

99.9

7

80

85

90

95

100

% R

Salt % IL %

Range 3.4 - 14.0 20.0 - 34.0 > 90 %

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3.5 Process proposal

Aqueous effluent

IL-rich current

Diluted inorganic salt solution

Concentrated inorganic salt solution

Water

ABS

HCl

IL

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PATh 4. Conclusions

Adsorption of ILs onto AC is effective at low

concentrations.

Adsorption increases with the alkyl side chain length

increase for both series studied.

Aqueous Biphasic Systems are a potential asset for the ILs

Recovery. The recovery efficiencies obtained were

always higher than 90%.

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PATh 5. Future Work

Recovery of ILs from AC (acetone*)

≠ T e ≠ Adsorbents

≠ anion families

Ionic exchange from the two salts

*J. Palomar, J. Lemus, M. A. Gilarranz, and J. J. Rodriguez, Carbon, vol. 47, pp. 1846-1856, 2009.

Adsorption:

ABS:

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≠ salts with higher recovery efficiencies and low salt

content

PATh Acknowledgments

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dep. de química, universidade de aveiro,...

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