Small- sized biorefineries as strategy to add value to sugarcane bagasse

Abstract

Small-sized biorefineries are not capital intensive and have lower transportation cost, lesser movements of liquid and solid streams, and lower heat transfer problems than high-sized ones. In this work, different scenarios were investigated in order to determine technical and economic viability of different processes to produce valuable products from sugarcane bagasse by small-sized biorefineries. Different alternatives were evaluated, as furfural and xylitol production from hemicelluloses, as well as energy generation and medium-density fibreboard (MDF) production from the residual solid after hemicelluloses hydrolysis. Experimental data obtained by the authors in previous works were used for pretreatment steps, and updated literature data was used for the other processes. A simplified kinetic model was developed for the extraction of xylose, and unit operations processes were selected and simulated. The most profitable option was determined for hemicelluloses use. In addition, costs and benefits that could be obtained exploiting the residual solid feedstock were estimated. The economic evaluation shows that recovery periods are extensive in both scenarios. However, optimization of different steps as liquid to solid ratio of pretreatment, evaporation, or fermentation, could represent attractive and innovative alternatives in order to reduce the recovery periods of capital costs.