Utilização do lodo de esgoto como alternativa para o coprocessamento na indústria cimenteira sergipana

Abstract

The increase in energy consumption over the years has increased the predominance of the use of fossil fuels and, consequently, has accelerated the degradation of environmental compartments (air, soil, and water). As an alternative to reduce this consumption, countries began to develop studies and technologies for sustainable energy generation that would cause less impact on the environment and that could replace fossil fuels. From this, among the possibilities, the production of energy from solid waste in co-processing cement factories emerged. Regulated by the National Solid Waste Policy as a form of environmentally adequate disposal, this alternative aims to reintegrate a material previously discarded into a new production cycle. In this sense, as a possibility, there is the energy use of sewage sludge, waste generated in large quantities in sewage treatment plants without an environmentally adequate final destination. Thus, this work aimed to evaluate the possibility of using the sludge generated in two sewage treatment plants, located in the municipality of Aracaju, Sergipe, as an energy alternative for the cement industry in Sergipe. From the sludge samples, analyses of the physical-chemical variables were carried out to identify the characteristics of the sample, and the analysis of the parameters of higher calorific value, ash, chlorine, and humidity, to study the feasibility of use in co-processing according to the limit values proposed by the legislation. The results obtained showed that, although the stations present an organic matter content between 63% and 65% for a month with high rainfall in the region, the higher calorific value value obtained for all samples was higher than that proposed by the legislation and higher about the limit value adopted by a cement company in Sergipe for other types of waste. In addition, for the sample that showed the highest PCS, the replacement ratio of petroleum coke, the main fuel used by cement factories, was 2.5 tons of sludge for 1 ton of coke. In addition, sewage sludge proved to be a great alternative for co-processing, both for the possibility of replacing fossil fuels and for its positive impact on atmospheric emissions, as it is pure biomass, that is, carbon neutral.