Cello-oligosaccharides and fermentable sugars production: An integrated deacetylation-delignification process to biomass pretreatment by using a mixture of protic ionic liquids

Abstract

Sugarcane straw is a residual which can be used to obtain bioproducts in a biorefinery. In this study, the pretreated biomass was used to produce both high added value products and bioenergy biomolecules from enzymatic hydrolysis by optimizing the operating conditions of the process. Cello-oligosaccharides (COS) release of 102.2 mg g_biomass⁻¹ was obtained from 6 h of reaction, corresponding to a productivity of 16.6 mgCOS g_biomass⁻¹ h⁻¹ and a specific productivity of 3.3 mgCOS FPU⁻¹ h⁻¹ after pretreatment conditions optimization using mixture of ionic liquids (110 °C, 35 % w w⁻¹ water content, and 15 % w w⁻¹ [Mea][Hex]). This study also developed a one-step process integrating two important operations involved in the pretreatment of lignocellulosic biomasses named deacetylation and lignin removal. The method described can be used for fermentable sugars (cellulose digestibility of 88 %) and oligosaccharides production under optimized pretreatment conditions using a mixture of protic ionic liquids with gains in productivity, cost and sustainability.