ionic liquids – new process chemistry for heavy industry: ilkka kilpeläinen, university of...

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Ionic liquids

- new process chemistry for heavy industry

Ilkka Kilpeläinen

16.5.2014

Matemaattis-luonnontieteellinen tiedekunta /

Henkilön nimi / Esityksen nimi 1

Background – Ionic liquids

2 Fig. source: http://acscinf.org/docs/meetings/230nm/presentations/230nm74.pdf

‘Ionic Liquids’ are essentially

‘molten salts’ containing one

or more organic ions!

Unsolvated ‘Molten Salts’ (m.p.)

– NaCl 801 oC

– [mmim]Cl 125 oC

– [emim]Cl 87 oC

– [emim][NTf2] -3 oC

– [emim][OAc] -45 oC


Wood ”dissolution”

Trials with wood (Microscope):

-Somewhat later we realized that this has been already patented by Kemira

(V. Myllymaki and R. Aksela, WO Pat, 2005/017001, 2005. )


Possibilities of ILs – Wood fractionation?

Complete dissolution followed by precipitation by

adding a non-solvent:

-However, it seems that these work only partially (enrichment of

cellulose/lignin/hemicellulose in certain fractions)

Sun, Rahman, Qin, Maxim,

Rodríguez and Rogers,

Green Chem., 2009, 11, 646 - 655,


Wood Fractionation –ILs

Treatment of wood chips with ILs

IL1

IL2

-Softwood chip treatment

with ILs: No mechanical

stirring (or any agitation)

at 90 oC


EM of IL-fibrillated

wood

SEM images of spruce latewood treated with

[emim]Me2PO4 - note the “spiral” form


Softwood (spruce) fibrillation with [emim]Me2HPO4

: No changes in amount or structure of lignin. However, monosaccharide

analysis shows something interesting:

Only pectins have dissolved

– (Lignin is still there.)

225239Total

0.60.7Unknown

1.11.4Unknown

2.83.61,4-bis-O-

MeGlcA

4737Glucose

2315Galactose

87106Mannose

1.710.2Galacturonic

Acid

0.40.0Glucuronic

Acid

1.12.1Rhamnose

5251Xylose

911Arabinose

Fibrillated

Sample 1

Wood ChipsMonomer

225239Total

0.60.7Unknown

1.11.4Unknown

2.83.61,4-bis-O-

MeGlcA

4737Glucose

2315Galactose

87106Mannose

1.710.2Galacturonic

Acid

0.40.0Glucuronic

Acid

1.12.1Rhamnose

5251Xylose

911Arabinose

Fibrillated

Sample 1

Wood ChipsMonomer


Is our understanding of

wood structure ”complete”?

wikipedia: Lignin fills the spaces in the cell wall between cellulose, hemicellulose,

and pectin components, especially in tracheids, sclereids and xylem. It is

covalently linked to hemicellulose and thereby crosslinks different plant

polysaccharides, conferring mechanical strength to the cell wall and by extension

the plant as a whole.

If lignin is the ”glue”, how

can the removal of pectins

fibrillate wood?


First generation (Imidazolium-based)

16.5.2014

Matemaattis-luonnontieteellinen tiedekunta /

Henkilön nimi / Esityksen nimi 9

+dissolve cellulose efficiently, so far the “best” one is propably [emim][OAc],

- Expensive

- Difficult to purify (recycling?)

- Almost all atleast somewhat poisonous

- [emim][OAc] restricts carrying out acylation reactions )-> only acetylation (?)

- Side reactions (e.g. With the reducing end of cellulose & hemicellulose

deacetylation)


Ionic Liquids ”the next generation –

distillable IL’s”

Distillation: > 99 % recovery, > 99 % purity

Dissolves cellulose up to ~20 m-%

Cellulose can be recovered by addition of nonsolvent

(fibers/films), or by direct distillation

16.5.2014 10

‘Distill’

Acid: HA

Base: B

+ IL: [A][BH]

- IL under 100 oC

Mix

Acid: HA

Base: B

+ dissociates

at 140 oC

N N

NH

CH3

CH3

CH3

CH3

CH3

O

OH

[TMGH+][Ac-]

CH3

O

OH

N N

NH

CH3

CH3

CH3

CH3


[EMIM]OAc/PHK-Euca 20 wt-%

• Textr. = 95ºC

• Vextr. = 0.8 cm3/min

ILHU/PHK-Euca 13 wt-%

• Textr. = 80ºC


NMMO/H2O/PHK-Euca 13 wt-%

• Textr. = 100ºC


BREAK-UP in

the spinning

bath when

stretched

UNSTRETCHED STRETCHED

Fiber spinning –Aalto (Sixta)

11


Comparison of Fibers

12

Viscose Modal NMMO

(Tencel®) ILHU

Titre [dtex] 1.4 1.3 1.3 1.2

Tenacity cond. [cN/dtex] 23.9 33.1 40.2 50.5

Elongation cond. [%] 20.1 13.5 13.0 8.5

Tenacity wet [cN/dtex] 12.5 18.4 37.5 46.4

Elongation wet [%] 22.0 14.1 18.4 9.6

TencelPolynosic Cupro CV CMD[DBNH]OAcNMMO0

10

20

30

40

50

Tenacity [cN

/tex]

Cond. wet

ILHU

NMMO

Commercial fibers Aalto

0

2

4

6

8

10

Titer

[dte

x]

0 5 10 15 20 250

5

10

15

20

25

30

35

40

45

Tenacity

cond [cN

/tex]

Elongationcond

[%]

CMD ILHU

CV NMMO

Cupro


Marimekko

5/16/2014 13


Persons

Present: Alistair King, Pirkko Karhunen, Jorma Matikainen, Ashley Holding, Jussi Helminen, Uula Hyväkkö, Jari Kavakka, Sara Labaf, Paula Hirsilä

& Collaborators

And many former members

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