(738a) Reduction of the Generated Sugarcane Vinasse in Distillation through HEAT Integration.

Despite the well-known benefits of ethanol as a renewable, environmentally friendly and fossil-free source of energy, the enormous and still increasing volume of sugarcane processed over the years has been generating impacts. Sugarcane vinasse is the most voluminous by-product generated in ethanol production and is characterized by high minerals and organic matter concentrations. Highly nutritional, it has the potential to replenish most of the minerals taken by sugarcane plants during the season, promoting natural development of the soil, reducing costs with chemical fertilizers. However, despite its benefits, it can also be highly pollutant if treated or disposed incorrectly, injecting excessive levels of compounds and organic matter in the soil, compromising crops efficiency by overfertilization, polluting rivers and groundwater, generating a high environmental impact. To mitigate such impacts in Brazil, environmental standards such as CONAMA 430/11 and CETESB P 4.231/15 defines criteria for the correct handling, storing and application of vinasse in the crop, leading the need to distribute it throughout wider areas, demanding a larger and more expensive infrastructure, thus shortening its economic radius for application. Vinasse is composed almost entirely by water (~ 95% in volume) being a fraction of it removed by evaporation in the end of the process, however vinasse reduction systems as applied today have poor efficiency, demanding extra steam from the plant, making it unfeasible in most cases. The solution proposed by this work uses pinch analysis and heat integration techniques between distillation columns and evaporators in order to efficiently reduce the volume of vinasse still during distillation step, using the heat generated by the system and demanding no extra steam. Preliminary process simulations showed promising results, dropping vinasse volume rate from 12:1 to 5:1 without the need of a dedicated evaporation system nor demanding extra steam from the plant.