9-29: Effects of diverse catalysts and reaction kinetics towards selective production of 5-hydroxymethyl furfural (HMF) from algae biomass

5-HMF is a key intermediate and a flexible platform for producing chemicals and fuels that can substitute today’s petroleum-derived feedstocks. A key challenge in 5-HMF production from algae biomass (e.g. agarose) is to understand the mechanism of catalysis reactions. A series of experiments over a range of temperatures of 120°C - 220°C, catalysts (e.g. mineral acid, salts of alkali metal, salts of alkaline earth metal and salts of transition metal) concentrations of 0.1-5% (wt/wt), substrate concentrations of 2% (wt/wt), and residence times of 5-30min were carried out to validate route for selective production of 5-HMF. We observed that salts of alkali metal and salts of alkaline earth metal, such as NaCl, KCl and CaCl_2, showed better selectivity for formation of 5-HMF than salts of transition metals, e.g. CuCl₂ and ZnCl₂, which formed byproducts either levulinic acid and formic acid, or glyceraldehyde and lactic acid with varying yields in addition to 5-HMF production. Compared with these inorganic salts, treatment with mineral acid (e.g. H₂SO₄) resulted in the poorest selectivity with formation of various byproducts, including levulinic acid, formic acid, glyceraldehyde and lactic acid. A first order kinetic model was applied to the overall degradation process of agarose for catalyst selection to derive the formation of 5-HMF. Related by-products will also be addressed in this presentation.