Análise da eficiência do tratamento de gases em função da quantidade de filtros no centro de tratamento de gases da Mozal

Abstract

Growing industrial development has resulted in a significant increase in air pollution levels. The aluminum production industry stands out for its high level of atmospheric emissions, such as carbon dioxide (CO2), fluorine gas (HF) and particulate matter. Fluorine emissions stand out due to their toxic nature and the associated environmental concerns. To mitigate environmental impacts, the aluminum production industries have implemented gas treatment centers in their systems. In Mozambique, the total fluoride emission standard for aluminum production industries is 2 mg/Nm³. This study is dedicated to analyzing the efficiency of gas treatment as a function of the number of filters in the gas treatment center (GTC) of MOZAL, an aluminum production industry located in the Beluluane Industrial Park in Maputo Province. MOZAL is currently planning to implement an energy efficiency project by stopping one filter in each gas treatment center (GTC). During the research, gas samples were taken in two conditions: with all filters operational (13 filters) and with one filter stopped (12 filters), respectively. The samples were taken on the roof of the pots, at the entrance and in the chimney of the gas treatment plant, with the aim of analyzing the efficiency of the treatment when operating with a stationary filter.Os resultados mostraram que a concentração de flúor, tanto com todos os filtros em funcionamento, quanto com um filtro parado, permanece dentro dos padrões legais estabelecidos. No entanto, observaram-se variações nas concentrações de flúor, onde, para o tecto dos potes, a média acresceu de 0.94 mg/Nm³ com todos os filtros operacionais para 1.27 mg/Nm³ com um filtro parado, à entrada do centro de tratamento de gases reduziu de 215.67 mg/Nm³ para 200.99 mg/Nm³, e na chaminé de 1.18 mg/Nm³ para 0.98mg/Nm³. Essas variações foram influenciadas por diferentes factores, como, operações nas células electrolíticas, fluxo de gás, quantidade de material electrolítico nos potes e o estado de conservação dos filtros. (TRADUÇAO NOSSA)