(558y) Enhancing Lactic Acid Production from the Dihydroxyacetone By Extra Framework Alumina

This study explores the effect of introducing extra framework alumina (EFAl) into the zeolite structure for the conversion of dihydroxyacetone (DHA) to lactic acid (LA). Glycerol is a by-product from biodiesel production and currently underutilized. Conversion of glycerol to value-added chemicals will bring additional revenues to the biodiesel industry. Conversion of DHA to LA follows a two-step cascade reaction pathway. Firstly, DHA is dehydrated to the pyruvaldehyde (PA) in the presence of the Bronsted acid sites. Secondly, hydration and benzilic acid rearrangement of PA take place and form LA over Lewis acid sites. Zeolites can be used for this reaction, but their LA selectivity is low due to the low Lewis-Bronsted acid ratio. Here we show that by introducing the extra framework alumina (EFAl) into the zeolite structure by post-synthesis modification enabled an increase in Lewis-Bronsted acid ratios. The increase in Lewis-Bronsted acid ratio resulted in a 60 mol% LA yield at 98% DHA conversion at 140C for 3h. This study shows the potential of the simple thermal post modification process to improve the catalytic selectivity on the conversion of biomass to selective chemical products.