Resumo: O Brasil passou por um período de crise energética em 2000. Contudo, este país apresenta vastas reservas de carvão que poderiam ser mais exploradas. Depois da crise o consumo de carvão teve algum incremento, mais estudos deveriam ser feitos a fim de minimizar as emissões de SOx e o aproveitamento das cinzas. As propriedades das cinzas dependem das características dos minerais que as originaram e da temperatura de combustão. A maioria dos sistemas empregados para queima é de combustão em leito pulverizado (1200-1600°C) ou fluidizado (850°C - mais comum fora do Brasil). Este artigo apresenta um estudo preliminar das características físicas do carvão, como tamanho e superfície, submetida a diferentes temperaturas com a finalidade de compreender seu comportamento nestas condições. A reconstrução mineralógica do carvão também foi desenvolvida.

Abstract: Brazil has experienced a small period of power crisis in 2000. However this country has larges resources of coal that could be more explored. Afterwards, coal consumption got some improvement, but studies about its properties should be made to minimize SOx emissions and to develop ashes utilization. The ashes properties are different according to the mineral characteristics and the combustion temperature. Most ordinary coal combustion systems are the pulverized (1200-1600°C) or fluidized (850°C) ones. This paper presents a preliminary study of coal physical characteristics, like particle size and surface, under different temperatures to understand its behavior. Mineralogical reconstruction of coal was also developed.

The present study aims at assessing the influence of pollution from mobile sources on air quality in the Metropolitan Area of Porto Alegre by means of an inventory based on methods applied specifically to vehicular emissions. The study uses the method described by CETESB, based on inventories on vehicular emissions, according to USEPA methodology. Following fuel types were taken into account: gasoline (24% ethanol), alcohol, diesel oil, and CNG (compressed natural gas). Results have shown that gasoline-powered vehicles are still responsible for emitting the highest CO and HC concentrations, while diesel-powered vehicles are the source of highest NOx, MP and SOx concentrations.