ATMOSPHERIC EMISSIONS INVENTORY IN AN MEDIUM-SIZED ANDEAN CITY FROM ON-ROAD MOBILE SOURCES. APLICATION OF COPERT 5.3 MODEL

Abstract:

Atmospheric emissions inventory (AEI) from on-road mobile sources (emissions exhaust hot and cold, evaporative and non-exhaust) in the medium-sized Andean city of Manizales - Colombia, was estimated using the COPERT 5.3 model for the year 2017. Emissions were estimated for five vehicle categories: passenger car, motorcycle, taxi, bus and truck. Criteria pollutants (CO, NO_x, SO₂, PM₁₀, PM_2.5), black carbon (BC), volatile organic compounds (VOC), volatile organic compounds not methane (NMVOC) and greenhouse gases – GHG (CO₂, CH₄, N₂O) were estimated. The input base information corresponded to the AEI from on-road mobile sources previously estimated using the IVE model. A comparative exercise of results between these two methodologies was performed.

Among criteria pollutants, the predominant emission corresponded to CO 11,429.6 ton / yr, while from the GHG species, CO₂ 319,533.5 ton / yr was the main pollutant emitted. The emissions profile followed the order of CO₂ > CO > VOC > NMVOC > NO_x > CH₄ > PM_2.5 > BC > SO₂. The categories that represent 95% of the automotive fleet (passenger cars and motorcycles) fueled by gasoline mainly contributed to higher emissions of CO, VOC, NMVOC 94% > SO₂ 83% > N₂O 81% > CH₄ 77% > CO₂ 52%. Vehicle categories fueled with diesel (buses and trucks), which comprise a low participation in the automotive fleet (3.2%), reported a significant contribution to emissions of BC 79% > NO_x 66% > PM_2.5 51%. Regarding non-exhaust type emissions of PM_2.5 represent 25% of total emissions.

Changes in total emissions estimated by the IVE and COPERT models were analyzed. There are significance difference between both inventories, the estimation of the emissions by COPERT are underestimated comparing with IVE in the following order: CH₄ -90% > PM₁₀ -79% > CO -60% > NO_x -58% > VOC - 57% > CO₂ -38%. The differences are possibly due to the fact that the emission factors (EF) of COPERT 5.3 are function of the average speed of the vehicle, and probably not represent the orography of the city (high road slopes) as the IVE model (EF depending on the vehicle acceleration).

COPERT is a model that constantly updates EF and includes the estimation of other emissions (non-exhaust, metals) that are no considered in IVE. In this way, COPERT is a tool of great advantage in the estimation of the AEI, indispensable instrument for air quality management.