This paper presents a generic and integral methodological approach for the design and assessment of multiproduct biorefineries. The proposed methodology has been developed based on 2-stage strategy, conceptual design and optimization. In the conceptual design stage, the theoretical data about the biorefinery are collected in order to build the superstructure. In the optimization stage, the formulated superstructure based on surrogate models, is optimized in order to generate the optimal biorefinery configuration where the utilities are produced internally from biomass via a cogeneration system. The proposed framework is applied to evaluate the optimal exploitation of Coffee Cut-Stems (CCS). The results show that ethanol is the most interesting product following dilute acid pretreatment and the fermentation of C5 and C6 sugars due to the large yield of the process. However, an alternative scenario where energy is the protagonist, results in the selection of power and heat as main products. (C) 2019 Elsevier Ltd. All rights reserved.