Viabilidade técnica e econômica da utilização da vinhaça para geração de energia elétrica (estudo de caso)

Abstract

This paper refers to a case study that aimed to assess the technical and economic feasibility of the use of stillage to produce electricity in an ethanol plant, located in the northwestern region of the state of Paraná. The criteria considered in decision making based on economic viability analysis, were Internal Rate of Return (IRR), Net Present Value (NPV) and discounted payback. Two scenarios were adopted to analyze the economic feasibility of the project. The first scenario considered the possibility of selling the electricity produced to Company Paranaense of Energy - COPEL, from three distinct operations varying the time of operation of the biogas plant and the sale price of energy. The second scenario considered the use of the energy produced for own consumption in substitution of bagasse that would be sold. Also, for the second scenario, three operations that vary the time of operation of the biogas plant and the sale value of bagasse were considered. Still, a sensitivity analysis of the NPV was performed due to the variation of the selling price of electricity (scenario 1) and sugarcane bagasse (scenario 2), the amount sold and the fixed costs involved. Also held one-Probability Risk Analysis, from 1000 simulations of NPV, whereas the variation of the selling price of electricity from sugarcane bagasse and has a normal distribution in both cases. Comparing these economic indicators and analyzes, we can conclude that the project is viable for both scenarios evaluated, and for scenario 2 there is only 0.10% probability of injury for each operation. Thus, considering the scenarios studied and the operations performed on each one, it can be stated that the substitution of bagasse, which would be sold by the vinasse in the generation of electricity for own consumption of the plant, appears more economically viable than energy production from vinasse, whose goal would be to sell to COPEL