(74e) Ionic Liquids In Biorefining and CO2 Capture

For centuries the Nordic countries have been relying on their natural resources, particularly forest, to make value-added products exported throughout the world. At the same time, this helped the societies to create wealth, job opportunities and social welfare. The global changes taking place today have gradually rendered these industries less competitive and profitable upon increasing competition when the consumption of such bulk products like paper and pulp have declined in the western word. The rise of the digital era, i.e. increasing use of electronic information and documentation, has meant that the volumes needed are in the decline in the developed world whereas the developing world still has room for growth in these products. Consequently, the industry has been forced to adapt and change, moving a lot of production capacity to there were the demand is. At the same time, increasing efforts are made to transform and trim the production in the original ‘homeland’ plants towards new, more innovative and more sophisticated products and, importantly, towards production of bio-based energy, transportation fuels, chemicals and commodities. This, however, is not easy since the industry is very conservative and the mindset is focused to maintaining the earlier business models.

Novel technologies based on the utilization of abundant and non-toxic carbon dioxide (CO₂) for the synthesis of materials and chemicals may significantly contribute towards the development of sustainable industrial practices. In nature, myriad of substances are photo-synthesized from CO₂ and water and consumed by humans. The use of CO₂ in the synthesis of ‘switchable’ ionic liquids (SILs) constitutes an environmentally attractive alternative to hazardous and toxic reagents thus resulting in waste minimization. ‘Switchable’ ionic liquids are compounds which can be switched from molecular compounds to ionic liquid by bubbling an acid gas such as CO₂ or SO₂ through a liquid mixture of precursors. The formed ionic liquid can typically be switched back to molecular building blocks – and the acid gas released - by bubbling with an inert gas (e.g. N₂), rising the temperature to above the thermal decomposition temperature of the SIL or by vacuum distillation at sufficiently high temperatures.

As another example, new materials such as polymeric ionic liquids were utilized to selectively remove carbon dioxide. Also, the performance of ‘classical’, ‘switchable’ and polymeric ionic liquids was compared to that of established, alkanol amine based solutions. In essence, our groups have synthesized and successfully demonstrated the use of new families of various kinds of ionic liquids including BILs and SILs in applications such as fractionation of lignocellulose, cellulose dissolution, purification of biogas and CO₂ capture. SILs are also attractive in terms of synthesis practices since no special organic chemistry laboratory infrastructure is needed. Moreover, they are surprisingly tolerant towards water and do not lose their ability to dissolve even humid biomass.

In this talk an overview of the technological efforts towards future bio-based economies and industries will be given in light of selected research projects currently in progress.