Sugarcane biorefineries: Case studies applied to the Brazilian sugar–alcohol industry

Highlights: • Advanced system of co-generation improves the energy performance of biorefineries. • Sugarcane straw as additional source of fuel in the biorefinery resulted positive. • The farming and transport of sugarcane cause the main environmental impacts. - Abstract: The use of biomasses is becoming increasingly appealing alternative, to give an partial solution lack of energy, with an ecofriendly approach, having on sugarcane a solid fundament; that receives the new and valuable complement of the innovative concept of the biorefineries it is productive installations, that can be summarized as to reach the higher overall yield from the raw materials, with the lowest environmental impact, at minimum energy input and giving the maximum of the energy output. The biorefinery is the true valuable option of a wide diversification, with by-products like the single cell protein and biogas from the distillery vinasse, new oxidants like methanol, second generation biofuels, biobutanol, etc. In this context this paper presents a study of five different configurations of biorefineries. Each case study being a system based on an autonomous distillery or sugar mill with an annexed distillery and coproduction of methanol from bagasse. The paper includes the use of sugarcane harvest residues (mainly straw) and a BIG–GT plant (Biomass Integrated Gasification–Gas Turbine) as alternatives to fulfill the energy demands of the complex