Fuel instability studies: The chemical validation of ASTM method D5304

The current ASTM (D5304) procedure for determining storage stability involv es rather drastic conditions, namely, 16 hours at 90 degreesC and under 100 psig of oxygen. These mandated test conditions give rise to the question, "Does the reaction conditions induce chemical instability, or is it an accu rate measure of the true instability process?" Several organo-sulfur functi onal groups are known to be present in petroleum derived fuels. Thiophenes, benzothiophenes, sulfides, disulfides, and trace amounts of thiols are the organo-sulfur compounds most prevalent. The reaction of organo-sulfur comp ounds under the ASTM reaction conditions have not been investigated. The pu rpose of the present research is to determine if the ASTM reaction conditio ns induce a reaction in an otherwise stable fuel matrix.