Assessment of nitrous oxide emission from cement plants: Real data measured with both Fourier transform infrared and nondispersive infrared techniques

Silvia Mosca,Paolo Benedetti,Ettore Guerriero,Mauro Rotatori

doi:10.1080/10962247.2014.936986

Abstract

Nitrous oxide (N2O) is the third most important greenhouse gas after carbon dioxide and methane, and contributes about 6% to the greenhouse effect. Nitrous oxide is a minor component of the atmosphere, and it is a thousand times less than carbon dioxide (CO2). Nevertheless, it is much more potent than CO2 and methane, owing to its long stay in the atmosphere of approximately 120 yr and the high global warming potential (GWP) of 298 times that of CO2. Although greenhouse gases are natural in the atmosphere, human activities have changed the atmospheric concentrations. Most of the values of emission of nitrous oxide are still obtained by means of emission factors and not actually measured; the lack of real data may result in an underestimation of current emissions. The emission factors used for the calculation of N2O can be obtained from the “Guidelines for the implementation of the national inventory of emissions” of the Intergovernmental Panel on Climate Change, which refer to all nations for the realization of their inventory. This study will present real data, measured in several Italian cement plants with different characteristics. The work also shows a comparison between N2O concentration measured with in situ Fourier transform IR (FTIR) and the reference method EN ISO 21258 based on nondispersive IR (NDIR), in order to investigate the interfering compounds in the measurement with NDIR.Implications:N2O may arise as an unwanted by-product of nitrogen oxide (NOx) abatement systems, in particular selective noncatalytic reduction (SNCR). Since it is applied in the cement plants, N2O emission from cement industry is evaluated, with both FTIR and NDIR instrument. Several considerations emerged from the results. First of all, the emission from this industrial sector is not negligible, and for that reason N2O concentration should be regulated; another observation is that the reference method based on the NDIR technique is not as selective as FTIR could be.

Highlights

The major greenhouse gases (GHGs) emitted into the atmosphere through human activities are carbon dioxide (CO2), methane, nitrous oxide (N2O), and fluorinated gases
It is interesting to observe that plants A and B emit the higher concentrations of nitrogen oxide (NOx) among all the facilities concerned
The Technical Committee ISO/TC 146, Air quality, Subcommittee SC 1, Stationary source emissions, is preparing a standard about quality assurance procedures for calibration and ongoing quality control needed to assure that automated measurement systems (AMS), installed to measure emissions of greenhouse gases to air

Summary

Introduction

The major greenhouse gases (GHGs) emitted into the atmosphere through human activities are carbon dioxide (CO2), methane, nitrous oxide (N2O), and fluorinated gases. Some of these gases are produced almost entirely by human activities; others come from a combination of natural sources and human activities. Many of the major greenhouse gases can remain in the atmosphere for tens to hundreds of years after being released. They become globally mixed in the lower atmosphere, reflecting contributions from emission sources worldwide.

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