Resumo:
The use of renewable energy sources has emerged as a viable alternative to meet
the growing global energy demand. Among these, lignocellulosic biomass has great
potential for generation. Therefore, the idea of a biorefinery using sugarcane biomass
emerges as a promising alternative for energy use. Several case studies were conducted
to compare the conventional model of a sugar and alcohol plant with other biorefinery
configurations. Biochemical alternatives were considered for the production of
lignocellulosic ethanol and biobutanol, as well as thermochemical alternatives for the
production of syngas. Second-generation ethanol allows for better land use, and
biobutanol is an important input for the chemical industry. The thermochemical process
for the production of syngas, a highly versatile product that can be used to manufacture a
variety of products, was also considered. This study considered its use for the production
of diesel, gasoline, waxes, and greases through Fischer-Tropsch synthesis. For a
qualitative examination of the energy generated, the methodology used was the
exergoeconomic analysis of the process. A technical and economic analysis of the
different biorefineries was then carried out from the perspective of the 2nd law of
thermodynamics, since the inherent study of the 1st law is already widespread. With this,
lignocellulosic ethanol and cellulosic butanol were also defined as plant products, in
biochemical processes, and syngas, in a thermochemical process. The limit values for the
distribution of sugarcane bagasse and syngas for each route were determined and the
Kriging modeling methodology from previous studies was used to improve the
distribution of biomass. The results of the evaluations showed that from the energy and
exergoeconomic point of view, it is interesting to prioritize the production of FT fuels.
The exergoeconomic analysis showed that, from the perspective of the main products, the
unit costs of output from the external valorization matrix decrease with the increase in the
share of bagasse for the biorefinery processes.
