During the formulation of EPA’s Tier 2 sulfur control program, MathPro Inc. conducted a series of studies for the American Petroleum Institute (API) and, independently, for the American Automobile Manufacturers Association (AAMA) and then the Alliance of Automobile Manufacturers (AAM). All of these studies were commissioned to estimate the per-gallon costs and investment requirements for reducing the average sulfur content of conventional and reformulated gasoline to specified average levels, ranging from 200 ppm to 5 ppm. The studies applied to mainly to refining capacity in PADDs 1, 2, and 3. Two studies dealt specifically with PADD 4. One study dealt with gasoline supplies to the Atlanta area.

Collectively, these studies delineated the refining economics of gasoline sulfur control using both conventional desulfurization technology and commercially ready new technology.

The studies employed formal refinery modeling using MathPro Inc.’s ARMS refinery LP modeling system. Results of the analyses, made available to EPA and other interested parties, contributed to the debate over national sulfur standards that led to the Tier 2 gasoline sulfur standard promulgated by EPA.