Extraction of furfural inhibitor from biomass hydrolysate of rice husk

Abstract

The production of second generation ethanol (E2G) has proven to be an alternative to non-renewable fuels, through transforming lignocellulosic waste into renewable fuel. In turn, rice husk has great potential due to its availability and composition. The conversion of lignocellulosic biomass to biofuel comprises a fundamental pre-treatment step, however, at this stage, the formation of degradation products (inhibitory compounds) occurs, among them, furfural, which cause negative effects on the viability of fermentative cells, making the production of E2G unfeasible. Given the above, the objective of this work was to remove the furfural inhibitor present in the lignocellulosic broth after the pre-treatment process, using oleic acid, through liquid-liquid extraction. The quantification of total reducing sugars in the hydrolyzate did not show significant variation between the pre and post extraction stages. Regarding the furfural inhibitor, in tests performed with a solution made in the laboratory, removal of up to 62.30% was obtained when the initial concentration was 5.00 g.L-1. With respect to the tests with the hydrolyzate from the rice husk pre-treatment, the maximum removal observed was 10.40%, but the initial concentration of furfural was 1.64 g.L-1. The results obtained indicate the possibility of using oleic acid as an extracting agent of the furfural inhibitor from lignocellulosic hydrolysates.