average oil production mix for California. However, as discussed previously, an increase in diesel demand due to additional diesel consumption related to fuel switching (rather than a drop in prices) is estimated to result in no change in oil import emissions.
Table 3-7: Petroleum Transport for Average SoCA
One Way Distance (mi)
South Coast (SC)
3.4.3 Oil Refining
A variety of fuels are produced by oil refineries in the SoCAB. Products from refineries include several grades of gasoline, diesel, kerosene (jet fuel, heating oil, No. 1 Diesel), LPG, heavy oil, petroleum coke, sulfur, and asphalt. Energy inputs to refineries include crude oil, electric power, natural gas, gasoline blending stocks such as alkylate (high octane components such as iso-octane), and oxygenated compounds such as methanol, MTBE, and ethanol. The specifications for fuel in California have been changing over the years with sulfur reductions in diesel, reformulations of gasoline, low aromatics and equivalent diesel, and reductions in the use of MTBE. At the same time, emissions from refineries in the SoCAB have been declining steadily. The combination of feedstocks, products, and emissions makes allocating emissions to refinery products difficult.
As a first order estimate, there are no marginal emissions associated with producing more conventional diesel or LPG in a refinery. Several possibilities exist for adjusting refinery operation for changes in fuel output. If gasoline demand were reduced, it is likely that imports of finished gasoline would simply be reduced. Increased diesel demand at the expense of gasoline sales could be met by increasing the mix of diesel products that are imported to the SoCAB or adjusting refinery operations to produce more diesel. Analyzing the effect of changing the shift in refinery products would ideally be accomplished by a linear programming (LP) model that optimizes all of the refinery streams for an optimal economic and fuel specification output. Such LP analyses are not readily available for the displacement of gasoline with diesel.
Emissions from oil production in the SoCAB are expected to reduce over the next 20 years with the following measures:
NOx controls on refinery fluid catalytic cracking units
Emission controls on off shore oil production