Atmospheric Emissions from Sources of Air Pollution in Petroleum Industry-Emission Inventory
Authors: Romic L. , vel-Cerovecki S. 
Published: December 2007

Abstract
Three main categories of pollutant emissions into the atmosphere from Croatian oil and natural gas activities are: fuel combustion, fugitive and carbon dioxide separated from natural gas.
The pollutants (or pollutant classes) emitted into the air are: main greenhouse gases such as CO2, CH4; indirect greenhouse gases such as NOx, CO and NMVOC gases (with no direct greenhouse effect, but they influence generation and disintegration of tropospheric and stratospheric ozon who has properties of a greenhouse gases); suspended particulate matter (SPM) and sulphur dioxide (SO2).
These pollutants are emitted into the air during normal well operations, production, processing and distribution of gas and oil products. SNAP94 for CORINAIR inventory three level hierarchical emission source nomenclatures (covers 4 main sectors, 9 sub-sectors and 33 activities) has been used to characterise the cause of the emissions and to relate it to anthropogenic activity in petroleum industry.
Point, line and area sources of air pollution in petroleum industry are considered. Emission estimations are based on detailed activity/technology information covering stationary sources.
IPCC simplified method (Tier 1-production based average emission factor approach) for estimating CO2 non-CO2 greenhouse gases emissions, based on activity level and average emission factors, has been used.
EMEP/CORINAIR detailed method (mass balance approach) to estimate fugitive emissions of ozone precursors (NOx, CO and NMVOC) from oil and natural gas activities has been also used.
Comparison (in graph form) between emissions of air pollutants from INA- Petroleum Industry and emissions in Croatia has been made.

Introduction
Three main categories of pollutant emissions into the atmosphere from INA Croatian petroleum industry are: fuel combustion, fugitive emissions and emissions of carbon dioxide removed from natural gas.
Fuel combustion result in emissions of carbon dioxide (CO2), and non-CO2 emissions such as emissions of methane (CH4), nitrous oxide (N2O), oxides of nitrogen (NOx), carbon monoxide (CO), nonmethane volatile organic compounds (NMVOC) and sulfur dioxide (SO2). Result of fugitive emissions are emissions of methane from oil and natural gas activities, emissions of ozone percursors (CO, NOx, NMVOC) and emission of SO2 from oil refining.
Removal of CO2 by amine scrubbing result in subseqent emissions of CO2 into the atmosphere.
The emissions of these polutants influence the air quality on local, regional and global level.
Local level: Emissions of NOx, SO2, (fines) suspended particulate matter (SPM), heavy metals (HM), such as Pb, Hg, Cd, As, Ni and smoke from emission sources (stationary fuel combustion, oil refining) at petroleum refineries contribute to air quality in the urban areas where refineries are located (Rijeka, Sisak). Today, ground level concentrations of SO2 and soot at the sources at petrolum rafineries primarily due to combustion of gas instead of liquid fuel has been decreased to degree that the air quality at this urban areas belongs to first category.
Regional level: Emissions from petroleum industry contribute to the problems on regional level, such as acid rains (SO2, NOx), eutrophication (NOx), high concentrations of tropospheric ozon (NOx), and pollutions with heavy metals and persistent organic pollutants (POP) such as polycyclic aromatic hydrocarbons (PAH) and dioxin. According to data, emissions of SO2, NOx from refineries (Sisak, Rijeka) contribute with 8 percent to total emissions of SO2, NOx from liquid fuels in Croatia (1).