Monitoramento de emissões gasosas num forno de clínquer

Abstract

Issues related to atmospheric pollution have been highlighted in relation to the growth of emitting sources and the consequences that this has generated in society and the environment. Much of the air pollutants come from natural activities, but most of them come from industrial activities guided mainly by human action. An example of a high- impact activity is cement production using clinker kilns. CONAMA Resolution No. 499, of October 6, 2020, is the main regulation for industries in the cement segment aimed at regulating emission limits. The legislation provides technical guidelines for the monitoring of gaseous emissions, as well as adopts definitions regarding the emission sources, the pollutants emitted and the units, and brings mandatory expression of results. It is important to point out that correct sampling is one of the most critical points in an analysis of compounds in the atmosphere. In this way, the selection of the atmospheric sampling method depends, among other factors, on the knowledge of the chemical and physical forms in which the pollutants are found, their reactivity, their interactions with other compounds, as well as their concentration levels. A method widely used today is isokinetic sampling, which is performed under conditions such that the gas flow at the inlet of the sampling equipment, the CIPA (isokinetic atmospheric pollutant collector), has the same velocity as the gas flow want to analyse. In this sense, the work carried out a case study with a monitoring of gaseous emissions in a clinker kiln to assess whether they are within the limits specified in current legislation. For monitoring purposes, an isokinetic sampling of gases emitted from the clinker kiln chimney was carried out using CIPA, verifying the concentration of pollutants emitted during the process, based on EPA (Environmental Protection Agency), CETESB (Environmental Company of the State of São Paulo) and ABNT (Brazilian Association of Technical Standards), with the main substances to be analyzed being particulate matter, combustion gases, nitrogen oxides, sulfur oxides, dioxins and furans, as well as total hydrocarbons and metals. comparisons were made and thus it was verified that the operation of the kiln under study was in accordance with the legislation.