Asim Bhaumik and Piyali Bhanja
Advancement of human civilization is largely dependent on the use of natural fossil fuel resources and with the rapid technological development its reserve depleting very fast. To cop-up with this concern bio-refinery is an emerging and necessary approach as a substitute of primary energy sources. Liquid fuels and highly valuable fine chemicals, which are derived from petroleum resources can be produce very effectively from biomass via platform chemical 5-hydroxymethylfurfural (HMF) and this has great significance in the context of green chemistry. US department of energy has enlisted top ten high value bio-based chemicals among which HMF, furfural and 2,5-furandicarboxylic acid (FDCA) can be derived from biomass via catalytic processes. Thus the objective of the present review is to summarize various catalytic methods to produce 5-hydoxymethylfurfural and 2,5dimethylfuran from a variety of monomeric bioresources such as glucose, fructose, dimeric (sucrose) and also polymeric carbohydrates like starch, cellulose, inulin and biomass derived carbohydrate (raw biomass) for preparing liquid energy fuel. To produce these chemical and fuel artificially, porous nanomaterials have huge potential to be explored as catalyst and these materials play pivotal role in the bio-transformation processes due to their high surface acidity and porous nanostructure. Moreover, the diversity of various catalysts used for production of these energy substitutes, specific reaction mechanism, drawbacks, its economical significance are highlighted in this review. Roles of several porous catalytic materials like porous resin, micro/mesoporous carbon, microporous zeolite, mesoporous metal oxides, porous organic polymer to upgrade the selectivity of biomass conversion with yield and their thermal, hydrothermal stability and controllable acidity have also been discussed in detail in this review. Examples of new porous nanomaterials with functionalised surface in comparison to that of the conventional acidic materials have also been discussed.
