The analysis of loading losses from tank trucks

The quantity of loading losses, which are the primary source of evaporative emissions from tank cars and trucks was analyzed in this paper. Loading losses occur as organic vapors in "empty" cargo tanks are displaced to the atmosphere by the liquid being loaded into the tanks. Emissions from loading petroleum liquid were estimated using three methods: the API (American Petroleum Institute) method, the VDI (Verein Deutscher Ingenieure -Association of German Engineers) method and the Yugoslav Standard JUS B.HO.531 method. The mass of evaporative losses from loading operations is a function of the following parameters: the method of loading the cargo, the physical and chemical characteristics of the cargo and the ambient temperature during loading. Evaporation losses from the loading of motor gasoline (MB-95, BMB-95, MB-98 and MB-86) and diesel fuels (D-2, Euro D-2) were calculated. Losses on a monthly and annual basis were presented for an assumed amount of loaded cargo. It was estimated that the highest loading losses occur in the summer period because of high ambient daily temperatures and in the period of higher transporting levels. It should be pointed out that the loading losses of diesel fuel calculated using an empirical coefficient according to JUS B.HO.531 are significantly higher in comparison with the loading losses calculated using emission factors from the EPA and the VDI method. The gasoline loading losses calculated using emission factors derived from the three methods are similar