BIOENERGY INTEGRATION IN ETHANOL PLANTS: AN ALTERNATIVE END USE FOR BIOGAS TO ENABLE 2G ETHANOL PRODUCTION

The pressure of the recent environmental accords may lead to production of 2G fuels, increasing biofuels availability and reducing environmental impacts. Sugarcane ethanol is a renewable fuel produced from either the 1G or the 2G route. In Brazil, the 1G route is very well stablished due to the role of ethanol in the transportation sector. Currently, the ethanol plants have also a role in the energy sector in Brazil, due to sugarcane bagasse burning in CHP systems. Brazilian ethanol plants are energetically independent and sell its energy surplus, which generates a part of the plant's income. The pursue for more bioethanol goes through the use bagasse for 2G fuels. However, using sugarcane bagasse solely for 2G ethanol production would cause an imbalance on the ethanol plant energy matrix and revenue. Thus, an alternative renewable fuel is necessary to replace the bagasse, enabling 2G ethanol production from it. This paper's objective is to assess the amount of bagasse spared by burning biogas produced from vinasse as such fuel. Results show that it is possible spare up to 44.5% of the bagasse using combined cycle technology for power generation. To spare all the bagasse, an energy amount of 293.2 kWh/t(cane) would lack, even with higher biogas consumption. Future studies should assess if this lacking energy income could come from another renewable energy source, such as bagasse straw.