Avaliação da redução de ureia na fermentação da produção de etanol a partir do milho

Abstract

The high demand for fuels in the world, added to the unstable supply of fossil fuels and aligned with environmental needs, caused an increase in interest in renewable and sustainable energy matrices, such as biofuels. Currently, the main raw material used in Brazil to obtain ethanol is sugarcane, being in second place in the world chain, the United States as the first, whose source of production is corn. The use of this raw material began in 2012 through a plant that combines the production of ethanol from sugarcane and second-crop corn. Among the advantages of using corn for the production of ethanol are the ability to be stored for longer, without losing quality, and the co-production of animal feed products with high added nutritional and economic value. The main route of ethanol production, whether from corn or sugarcane, is via alcoholic fermentation, which requires specific control conditions, as well as the search to maximize production yield through medium supplementation. Nitrogen comes in as an essential source of nutrition for yeast. One of the components used as a nitrogen source in fermentation is urea, which has the advantage of good results in fermentation efficiency and is among the cheapest on the market. However, in recent months, this component has suffered an increase in its prices on a world scale, opening space to seek new concentrations of work, or even other sources. The present work aimed to provide a new methodology for urea dosage, reducing its consumption and facilitating the operation involved in this system, making it automatic. Sampling was carried out in a corn ethanol plant in the state of Mato Grosso, analyzing data on percentage of ethanol, glycerol, total sugars and conversion of 357 batches, in addition to the economic gain generated by the reduction. Results show that there was a decrease in ethanol yield in reduction batches, however without statistical significance. In addition, the batches that received the standard dosage of urea also obtained unsatisfactory results over the period, not justifying the results by the lack of nitrogen. As it is a relatively new technology in Brazil, it opens up space for new research by varying the concentration, as well as the source of nitrogen.