Ionic liquids. - new process chemistry for heavy industry

Transcription

1 Ionic liquids - new process chemistry for heavy industry Ilkka Kilpeläinen Matemaattis-luonnontieteellinen tiedekunta / Henkilön nimi / Esityksen nimi

2 Background Ionic liquids Ionic Liquids are essentially molten salts containing one or more organic ions! Unsolvated Molten Salts (m.p.) NaCl 801 o C [mmim]cl 125 o C [emim]cl 87 o C [emim][ntf 2 ] -3 o C [emim][oac] -45 o C Fig. source: 2

3 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, )

4 Possibilities of ILs Wood fractionation? Complete dissolution followed by precipitation by adding a non-solvent: Sun, Rahman, Qin, Maxim, Rodríguez and Rogers, Green Chem., 2009, 11, , -However, it seems that these work only partially (enrichment of cellulose/lignin/hemicellulose in certain fractions)

5 Wood Fractionation ILs Treatment of wood chips with ILs -Softwood chip treatment with ILs: No mechanical stirring (or any agitation) at 90 o C IL1 IL2

6 EM of IL-fibrillated wood SEM images of spruce latewood treated with [emim]me 2 PO 4 - note the spiral form

7 Softwood (spruce) fibrillation with [emim]me 2 HPO 4 : No changes in amount or structure of lignin. However, monosaccharide analysis shows something interesting: Monomer Wood Chips Fibrillated Sample 1 Arabinose 11 9 Xylose Rhamnose Glucuronic Acid Galacturonic Acid Mannose Galactose Only pectins have dissolved (Lignin is still there.) Glucose 1,4-bis-O- MeGlcA Unknown Unknown Total

8 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?

9 First generation (Imidazolium-based) +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) Matemaattis-luonnontieteellinen tiedekunta / Henkilön nimi / Esityksen nimi

10 Ionic Liquids the next generation distillable IL s O O H 3 C OH H 3 C OH Acid: HA + IL: [A][BH] Base: B CH 3 CH 3 N N H 3 C CH 3 NH Mix [TMGH + ][Ac - ] - IL under 100 o C dissociates at 140 o C Acid: HA + Base: B CH 3 CH 3 N N H 3 C CH 3 NH Distillation: > 99 % recovery, > 99 % purity Dissolves cellulose up to ~20 m-% Cellulose can be recovered by addition of nonsolvent Distill (fibers/films), or by direct distillation

11 Fiber spinning Aalto (Sixta) NMMO/H 2 O/PHK-Euca 13 wt-% T extr. = 100ºC V extr. = 0.8 cm 3 /min UNSTRETCHED STRETCHED IL HU /PHK-Euca 13 wt-% T extr. = 80ºC V extr. = 0.8 cm 3 /min [EMIM]OAc/PHK-Euca 20 wt-% T extr. = 95ºC V extr. = 0.8 cm 3 /min BREAK-UP in the spinning bath when stretched 11

12 Tenacity [cn/tex] Titer [dtex] Tenacity cond [cn/tex] Comparison of Fibers Cond. wet TencelPolynosic Cupro CV CMD[DBNH]OAcNMMO NMMO IL HU Commercial fibers Aalto CMD CV Cupro Elongation cond [%] IL HU NMMO Viscose Modal 12 NMMO (Tencel ) IL HU Titre [dtex] Tenacity cond. [cn/dtex] Elongation cond. [%] Tenacity wet [cn/dtex] Elongation wet [%]

13 Marimekko 5/16/

14 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