The present paper proposes a flexible modular linear model of decision-making for the selection of processes and unit operations for lignocellulosic bioethanol production. The methodology begins by suppressing the commonly accepted bilinear restrictions for flows and compositions, and there after allows building the identity of the synthesis problem by easing the introduction of components, interconnection specifications or block characteristics and performance. A case study in second generation ethanol production using biomass from sugarcane bagasse as raw material is presented to test the developed process synthesis tool, using GAMS. Results show that the diluted acid pretreatment, the SSCF configuration for hydrolysis and fermentation, and the extractive distillation as the selected blocks. The methodology demonstrated a low computational cost and a simplified management of the problem complexity. These approach is suitable for process screening when missing or restricted data from the process alternatives is available.