Ionic Liquids in Catalytic Biomass Transformation

1.1 Alternatives to fossil fuels biomass For the past 150 years, coal, natural gas and petroleum functioned as our main sources of energy and chemicals. They provide an estimated 86% of energy and 96% of organic chemicals [1]. However, these natural resources will be depleted in the near future as studies has predicted that the global energy demand will grow over 50% by 2030 as shown in Figure 1 [2]. In addition, problem concerning global warming brought about from the emission of fossil fuels remains a major concern. Hence, there is an urgent need for us to seek alternative renewable and greener energy sources; the answer lies in biomass which possesses huge amounts of stored chemical energy. The stored chemical energy in biomass has the potential to be tapped to meet the rising energy demand. Biomass is one of the most valuable products from living things where simple molecules such as H2O, CO2, N2 are transformed into complex substances activated or catalyzed by biochemical processes (e.g. photosynthesis). Trees trap approximately 1% of solar energy and transform them into biomass. This energy is stored in the form of complex molecules such as lignin, carbohydrates, proteins, glycerides and others. Carbohydrates or saccharides (cellulose, hemicelluloses and starch) constitute 75% of the plant biomass, with 40% of the carbohydrate fraction of biomass being cellulose and 25% being hemicelluloses. Biomass energy is derived from five distinct energy sources: garbage, wood, waste, landfill gases, and alcohol fuels. Being the most abundant renewable resource as described in Figure 2, with approximately production of 1.0 x 1011 tons annually, biomass was recognized as the best candidate to replace fossil fuels [3]. The transformation of biomass into value added chemicals gives little or no harmful side products which address the pressing issue for greener alternatives to fossil fuels. Other than being renewable and abundant, biomass is a cost effective feedstock. Cellulose, the major component of the carbohydrate fraction of biomass is hard to deal with. It is insoluble in most conventional organic solvent and water, which hinders the ease of