THE REACTION OF 3-METHYL INDOLE WITH PARA-ETHYLBENZENE SULFONIC-ACID - FUEL INCOMPATIBILTY REACTIONS

Polar Heteroatomic species have been correlated with incompatibility r eactions in middle distillate fuels. Instability is defined as the for mation of filterable sediments and fuel insoluble gums. Heteroatoms (o xygen, nitrogen and sulfur) have been found to be greatly enriched in such sediments. Trace levels of certain organo-sulfur compounds, espec ially sulfonic acids in model fuel systems, have been found to signifi cantly increase deposit formation. The effectiveness of organic amines as additives suggests that acid/base chemistry is also involved in th e formation of deposits. This paper reports on a study of p-ethylbenze ne sulfonic acid reacting with 3-methyl indole in model systems. A pos sible reaction mechanism and a proposed structure for the product is r eported. The results of the model system are contrasted to results fro m previous actual fuel systems.