Avaliação termodinâmica e ambiental de complexos integrados de biorrefinarias que utilizam cana e palma.

Abstract

The present work aimed to perform a thermodynamic and environmental evaluation of integrated biorefinery complexes using sugarcane and african palm (Elaeis guineensis) for brazilian conditions. To this end, four case studies were proposed, located in the North or Northeast regions, since in these regions there are more than 31 million hectares of degraded lands that have favorable edaphoclimatic characteristics for the cultivation of cane and palm crops. The base case (C-I) was conceived with the intention of being a reference for the other studies, in which there is no type of integration (industrial or agricultural) and is composed of (i) a sugar and alcohol plant, (ii) a palm oil extraction plant, (iii) a palm oil refining and transesterification plant, and (iv) a cogeneration system, in the subsequent case studies there is an agricultural and industrial integration, and in case II a 2G ethanol plant is incorporated, while in case III a 2G methanol plant was incorporated and case IV is an extension of case III where advanced cogeneration concepts were applied, specifically the BIG/GT technology (Biomass Integrated Gasifier-Gas Turbine). For the evaluation of the studies from the thermodynamic and environmental point of view, the LCA and performance indicators based on the 1st and 2nd Law of Thermodynamics. The results obtained from the thermodynamic evaluation show the advantage of obtaining a larger energy portfolio from several raw materials (sugar cane and palm), and C-IV stands out from the others, since it has a superior performance in the ηGlo (53.4%), Iexced (86.6 kWh/tMP), σMP (257 GJ/ha-year) e ηexe (62.7%), by integrating the technology of gasification and gas turbine (BIG/GT), verifying the attractiveness that it is for agroindustries. While the results obtained in the LCA showed the potential environmental benefits that brings the total replacement of fossil diesel by biodiesel (whether ethyl or methyl), both in cane and palm cultivation, making it possible to reduce the consumption of fossil energy by 74.7% (cane) and 64.8% (palm) by the ethanol route or 79.6% (cane) and 69.2% (palm) by the methyl route. Consequently, one could achieve an increase in NER up to 9 units and a renewability (LCEE) of up to 18.4% of cane bioethanol could be achieved.