Hey You, Analyze This: Very Low Sulfur in Motor Fuels

摘要

As the American refining industry enters a new era of mandatory production of very low sulfur motor fuels, analysts must provide and regulators must allow robust measurement technologies. These test methods must yield valid sulfur determinatioosn at levels drastically lower than those present in most of today's conventional gasoline and diesel. Consequently the search for rugged and versatile low-level sulfur testing methods is on. A review of a fitness-for-use study (1) that examines the dominant ASTM sulfur test methods for motor fuels and testimony (2) give nat four U.S. EPA hearings, provides a rigorous examination of the two alternate test methods that were included in the proposed/final Tier 2 rulemaking. Equivalence of results, a search for compound bias and limits of test method capability , are examined for ASTM D5453(3) (sulfur by UVF) and D2622 (4) (sulfur by WDXRF) down to near-zero (<5 mg/kg) levels. Factors such as testing interference, laboratory/in-process applicability and overall costs are also evaluated.