Simulação e análise de sensibilidade da produção de biodiesel a partir da borra de café

Abstract

The numerous harmful effects produced by the use of fossil fuels and the consequent environmental concern encourage the search for alternative energy sources that help reduce the constant impacts. From this trend, we can mention the use of biofuels, specifically biodiesel, which is derived from lipid biomass and classified as renewable and less polluting. The non-competition with food sectors, the high availability, the low cost and the favorable lipid composition demonstrate the main characteristics of coffee grounds as a potential by-product to be valued, being defined as a sustainable raw material in the production of biodiesel. Thus, the present work aims to develop simulations of the synthesis of biodiesel from the oil extracted from coffee grounds via homogeneous alkaline catalysis, using the DWSIM software. Thus, it is possible to establish real conditions and analyze the operation of the process on a large scale. In the nine simulations performed, the amount of oil input was based on the availability of the residue in the state of Paraná, Brazil. Furthermore, variations in conditions that influence the transesterification reactions and, consequently, the biodiesel purity and productivity results, such as catalyst and alcohol content, temperature and agitation intensity, were addressed. The best result in oil conversion, ester purity and productivity was obtained under the condition of maximum quantity of reacted alcohol, with an alcohol:oil molar ratio of 20:1. The sensitivity analysis was based on the optimization of the reactor volume, reaction temperature and amount of alcohol compared to the simulated process with the best result. The optimized transesterification plant is economically viable, but not with extra steps. In this case, an alternative to improve the economic viability of the process is the valorization of generated by-products.