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This study investigates the effects of several blends of gasoline and anhydrous ethanol on exhaust emission concentrations of carbon monoxide (CO), total hydrocarbons (HCs), and nitrogen oxides (NO) from a small spark-ignited non-road engine (SSINRE). Tests were carried out for different air/fuel equivalence ratios as measured by lambda (λ). A 196 cm single-cylinder four-stroke engine-generator operating at a constant load of 2.0 kW was used; pollutant gas concentrations were measured with an automatic analyzer similar to those typically used in vehicle inspections. The results showed that as the ethanol content of the mixture increased the concentrations of CO, HCs, and NO reduced by 15, 53, and 34%, respectively, for values of λ < 1 (rich mixture) and by 52, 31, and 16% for values of λ > 1 (lean mixture). Overall, addition of anhydrous ethanol to the gasoline helped to reduce emissions of the pollutant gases investigated, what contributes to photochemical smog reduction and quality of life in urban areas.

Ethanol is a renewable fuel and it is considered an alternative to gasoline in Otto-cycle engines. The present study evaluated the behavior of exhaustion gas carbon monoxide (CO) and total hydrocarbons (THC) according to the levels of anhydrous ethyl alcohol (AEA) added to gasoline in different proportions (E0, E10, E20, E27, that is, pure gasoline and its blends with AEA at 10, 20, and 27% v/v) in the use of non-road single cylinder engines of different powers (13 and 6.5 hp), to the loads applied to engine-generators and the air-fuel ratio (A/F) admitted to the engine cylinders. Also, the performance of engine-generators was verified in terms of mass, specific and energetic consumption and efficiency of the evaluated systems for the same blends and loads. The results showed that an increase in the AEA content in the blend resulted in significant drops in CO and THC concentrations for both engine-generators, while fuel consumption showed a slight upward trend; the increases in applied loads resulted in an increase in CO and THC concentrations and fuel consumption. In general, a higher AEA content (oxygenated) in the blends had a greater effect on gaseous emissions compared to the effect on consumption and system efficiency.

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A preocupação com a preservação do meio ambiente e a necessidade de diversificação da matriz energética são alguns dos fatores que têm impulsionado a busca por energias alternativas. Nesse contexto, o presente trabalho analisou o processo de digestão anaeróbia de resíduos alimentares provenientes de um restaurante popular, observando o potencial bioquímico da geração de metano. O experimento consistiu no uso de reatores anaeróbios em regime batelada com volume de 250 mL, sendo 150 mL de volume útil à geração de biogás (headspace) e 100 mL remanescente preenchido nas proporções de 1:1 de substrato:inoculo, em relação ao teor de sólidos voláteis (gSVinoculo:gSVsubstrato). Os reatores foram operados por 30 dias sob temperatura constante em 30°C. Os resultados obtidos apresentam o teor de sólidos voláteis dos resíduos alimentares de 85,21% e uma relação C/N de 18,81. Foi possível alcançar uma produção específica de metano de 0,311 Nm³.kgSVr-1 e reduções de 23,58% para SV e de 81,27% para DQO.