Efficient conversion of biomass into energy resources remains one of the biggest challenges faced by humanity in the search for a sustainable energy future. Bioethanol, the most important biofuel, currently produced from first generation feedstock like sugarcane may also be produced from lignocellulosic materials like sugarcane bagasse and straw, which are not a primary food source. Efficient technologies for production of lignocellulosic (or second generation) ethanol, however, are still under development, and challenges concerning its technical, economic and environmental feasibility remain to be solved. Integration of first and second generation ethanol production processes can be more economical, efficient and present lower environmental impacts than stand-alone second generation; thus, integrated first and second generation ethanol production can improve the feasibility of lignocellulosic ethanol and foster its industrial implementation.
In this study the integrated production of first and second generation ethanol from sugarcane, including some of its technical, economic and environmental aspects are discussed. The biochemical route for second generation ethanol production, comprised by feedstock pretreatment and enzymatic hydrolysis, is taken as an example. Features of both first and second generation processes that are required to promote an adequate integration are discussed, providing guidance for development of experimental works, especially in second generation process.