Valorização do uso agrícola da cinza residual do bagaço de cana-de-açúcar

Abstract

The Brazil is classified as the largest producer and exporter of sugar, and has prominence in ethanol production originated from cane sugar. With the appearing of new industrial plants and the expansion of planting areas the amount of bagasse has increased substantially, providing through the process of burning the increased generation of residual ash. The destiny of ash sugarcane mills in Parana is mostly landfills not being applied agronomic criteria for their disposal. This research has objective the technical and economic viability of the agricultural use of the ash originated in the process of burning of bagasse, taking as object of study the residual ash from a distillery located in the northwest of the state of Paraná in 2012/13 crop. Initially was fulfilled descriptive a research about the process of generation and disposal of residual ash in the sugar industry selected. The investigation was also documentary, because it was worth of internal industry documents, such as production reports, reports issuing effluent criteria benchmarks for fertilizer recommendation on sugarcane. To get this information, we used the research field, through visits to industrial plant and interviews. After the survey was used for data evaluation methodology to identify the economic internal rate of return (IRR), which is an indicator of the profitability of the project and the simple payback that provides the time required to recover the initial investment. Originated 21,806, 200 tons of residual ash in the season 2012/13, calculated the proportions of nutrients in the ash identified in chemical analysis totaling 6.59 tonnes of N, 28.72 tons of P2O5 and 128.55 tonnes of K2O. Based on the amounts of nutrients observed in the analysis and the amounts paid by mineral fertilizers, we obtained a final value of R $ 557,081.40 (Five hundred and fifty-seven thousand, eighty-one dollars and forty cents), which although significant is not enough to make economically viable investment of U.S. $ 5,000,000.00 (Five million dollars) to implement a circuit soot. However, it is noteworthy that the current environmental legislation requires the proper disposal of this waste, and only with the separation of circuits wash water from washing the cane and removal of gases and soot from the boiler grates, it is possible to obtain a ash in conditions of chemical characterization and soil application of environmentally responsible manner.