Emission controls from refinery flares
Carbon absorption, refrigeration, and incineration of fugitive hydrocarbons
Emissions controls from bulk terminals
If a significant amount of gasoline output were replaced with diesel, the operation of some energy intensive processes such as reforming and alkylation would be reduced with a net reduction of energy for refining. Such a displacement of emissions would result in the reduction of some refinery heat energy inputs with a reduction in combustion emissions. Total NOx emissions from refineries would not be affected by a change in combustion emissions as refinery NOx is under a cap through the RECLAIM program. NMOG emissions from combustion sources would however be reduced if fuel combustion were reduced due to a reduction in gasoline output and an increase in diesel output. As shown in Section 4.3, combustion NMOG emissions represent a smaller share of NMOG sources within oil refineries than do fugitive NMOG emissions. Variations in throughput have little impact on fugitive emissions.
Producing reformulated diesel would also affect refinery operations. Reformulated diesel will contain less sulfur and may also have a higher cetane index. Removing additional sulfur beyond current levels could be accomplished with severe conventional hydrotreating. The effect of producing reformulated diesel was estimated to be reflected by a change in sulfur from 150 ppm to 20 ppm for on road diesel. MathPro performed an LP model analysis of such a change in diesel fuel formulation (MathPro 1999). The results of the model reflected a change in energy inputs to the refinery that are discussed in Section 4.3. The model shows primarily an increase in electric power demand by the refinery with a small increase in crude oil imports. Emission impacts were estimated to correspond to the generation of power and combustion of additional refinery fuel.
Producing additional LPG was estimated to have zero marginal emission impacts from refineries in the SoCAB. The marginal uses of LPG are selling the product as a fuel or use as a refinery fuel or feedstock. Selling additional LPG for vehicle use would displace LPG sales to other customers and also displace LPG as a refinery fuel where is might be replaced with natural gas. Oil refineries may burn propane if the demand for it as a home heating or vehicle fuel is low. However, higher market prices (demand) would probably divert propane for use as a vehicle fuel (refineries would burn natural gas as a replacement). California imports a significant quantity of LPG. This LPG comes from natural gas processing facilities in Canada and the southwest United States. Some LPG is also imported from refineries in Utah. Future demand for LPG could be so high that marginal demand must come largely from natural gas liquids. However, given the opportunities for displacing LPG from refinery use, and the source of current LPG, this study assumes refinery-based and natural-gas-based LPG production.
3.4.4 Diesel Storage and Distribution