Estimation of NOx emissions associated with the natural gas consumption for residential heating in Italy

Among various emission pollutants, nitrogen oxides (NO
x
) include different nitrogen compounds such as nitrogen dioxide (NO
2
) and nitric oxide (NO). These compounds play an important role in the atmospheric reactions that create harmful particulate matters, ground-level ozone (smog) and acid rain. NO
x
forms when fuels are burned at high temperatures. In this scenario, this work aims to identify the contribution of emissions of NO
x
related to the use of natural gas for residential heating in Italy. The work includes the analysis of the basic data on the consumption of natural gas reported in residential building sector, after conducting an overview on historical nationwide emission levels of NO
x
. In order to assess a weighted emission factor for NO
x
according to the average class of installed boilers, an assessment has been made regarding the distribution of the main types of gas boilers currently installed in Italy. The analysis concludes with the preliminary estimation of emissions of NO
x
for the year 2007, also providing its distribution to the various provincial areas of Italy.