emissions were allocated to gasoline, diesel, and LPG in proportion to the energy requirements for refinery units. The refinery model was also used to determine changes in refinery energy needed to produce reformulated gasoline. This approach results in the average emissions from refineries.
Emissions from refinery units in the model were allocated to the petroleum products produced by each refinery unit. For example, all of the combustion emissions associated with the diesel hydrodesulfurization unit are attributed to diesel fuel. Table 4-14 shows the allocation of crude oil energy input and imported energy to gasoline, diesel, kerosene (same as jet fuel), and LPG.
Table 4-14: Allocation of Product Output and Energy Consumption for Refineries
Energy Inputs (Btu per Gallon of Product)
Product Output Btus (%)
Total Energy Ratio (%)
a The combustion energy allocation applies to emissions and energy use expressed on g/gal of gasoline basis and determines the emissions allocated to the specific fuel on a g/gal basis.
The SCAQMD emissions inventory provides insight into emissions from oil production, refining, and distribution in the four county SoCAB. Refineries and oil producers submit emission fee forms annually to the SCAQMD. Emissions for these forms are determined from either published emission factors or from source testing. These values make up SCAQMD's base year inventory.
Most of the emission rates are determined from calculations that depends on equipment type and throughput using SCAQMD and AP-42 emission factors. Other emissions are determined from source testing.
The SCAQMD inventory is determined for average days as well as summer and winter days. The summer inventory was examined in this study since it is intended to represent conditions for maximum ozone formation. The summer inventory may not be representative of the petroleum industry since refineries operate at fairly constant capacity and are not affected by seasonal activities. The summer inventory may also be adjusted for increases in temperature and higher evaporative emissions. Higher RVPs in