In this paper a techno-economic and environmental analysis for a sugar cane bagasse biorefinery in Colombia is presented as a case study. An optimization procedure is shown in order to select the most promising process pathway for the production of fuel ethanol, poly-3-hydroxybutyrate (PHB), and electricity. Once the optimization procedure was done, the results served as criteria for the selection of technologies and raw materials distribution. The distribution results and technologies were used to feed the knowledge-based approach in process synthesis. Then three scenarios were simulated using the Aspen Plus software. The first scenario consisted of energy cogeneration, the second one was an arbitrary distribution, and the third one corresponded to the preselected pathway using the optimization subroutine. Each scenario was assessed from the technoeconomic and environmental point of view according to the Colombian conditions. The best was subjected to the configuration previously designed through the optimization subroutine. For this case, the obtained economic margin was 53.83%, the potential environmental impact was 0.16 PEI/kg products, and the biological GHG emissions of the processing stage represented 1.55 kg. of biological CO2-e/kg of bagasse.