3.2.2 Geographic Distribution
Because some fuels will be produced outside of California, emissions from the entire fuel-cycle will not directly impact California urban areas. For this reason, it is important to identify the percentage of feedstock extracted or fuel produced in each area. In order to help evaluate the impact on local emission inventories and air quality as well as considering the differences between local emission rules, the emissions were geographically categorized. Emissions from fuel production can then be allocated according to the locations in Table 3-3. This table also shows the acronyms used to identify each of these areas for this report.
Table 3-3: Location of Emissions and Acronyms
Within the SoCAB
Within California, but outside the SoCAB
Within the U.S., but outside of California
Rest of the World, outside the U.S.
Emissions for fuel or feedstock transportation and distribution are also divided into the four geographic distribution categories. For example, emissions for ships entering and exiting the San Pedro ports were attributed to the SoCAB for a portion of the trip. The balance of these emissions was attributed to the rest of the world. Both land and sea transport emissions were allocated proportionally according to their transport route.
This study is intended to be used to evaluate marginal emissions from fuel production. Information is also provided to determine average emissions. The interpretation of which emissions correspond to marginal fuel production depends on several factors that are discussed in Section 3.3. The focus on marginal emissions raises questions of transporting emissions into and out of the state. For example, methanol could be sold for vehicle use in the SoCAB without any production emissions affecting local air quality. Similarly, gasoline is transported to other states from the SoCAB while the refinery emissions contribute to emission inventories in the SoCAB.
3.3 Marginal Emissions
This study pays considerable attention to the marginal fuel-cycle emissions. Many industry stakeholders participated in the 1996 Acurex study. During the course of projects meetings, it was clear that the subject of marginal emissions was important to the stakeholders. When the subject of fuel-cycle emissions becomes meaningful in a regulatory or economic sense, stakeholders become acutely interested in the outcome of