Emissions from fuel combustion by stoves in residential kitchens in São Paulo – Brazil

Abstract. This study investigates greenhouse gas (GHG) emissions and indoor air quality associated with residential cooking practices in São Paulo, Brazil. Measurements were conducted in 30 households, focusing on kitchens using natural gas (NG) or liquefied petroleum gas (LPG) stoves. A measurement protocol was developed to assess emissions of carbon dioxide (CO₂), methane (CH₄), and nitrogen oxides (NO_x) under different operational conditions. Emission rates and factors were calculated using 5 mass balance approaches, considering kitchen volume, air exchange rates, and gas concentrations. The results show different behavior for the type of fuel, especially for methane, which has a significant response to the use of NG, unlike LPG. It was also possible to observe a difference between the temporal variability cycles, as the burners responded quickly to the increase in concentration, while the oven showed a delayed increase observed in the environment. There was a high variability in the concentrations in the different residences, which may be associated with factors such as the age of the stove, model, leak 10 and internal influence. The emission factors obtained were three times higher than the IPCC considering only the close values, but when considering the outliers it is up to 10 times higher for CH₄ in the case of NG. For CO₂ the factor obtained was lower than the IPCC. The findings highlight the importance of considering fuel type in evaluating GHG emissions from residential cooking and the need for robust data on residential emissions in Brazil.