Accession Number : AD0809288

Title :   THE STUDY OF HYDROCARBON FUEL VAPOR PHASE DEPOSITS.

Descriptive Note : Quarterly progress rept. no. 3, 16 Nov 66-16 Feb 67,

Corporate Author : ESSO RESEARCH AND ENGINEERING CO LINDEN NJ GOVERNMENT RESEARCH LAB

Personal Author(s) : Taylor, W. F. ; Wallace, T. J.

Report Date : 16 FEB 1967

Pagination or Media Count : 21

Abstract : It was demonstrated that trace levels of sulfur compounds can markedly influence the deposit formation process. This was done by doping a highly stable, sulfur free supersonic jet fuel with pure sulfur compounds, followed by testing of the doped fuel in a specially devised Screening Unit. Results with the isobutyl disulfide doped fuel indicate that the deposit formation rate markedly increased at 375 F, and that the quantity of deposits produced above this temperature correlates very well with the square root of the sulfur level. Results indicate that isobutyl disulfide undergoes extensive decompositions at 375 F and higher temperatures in the empty wing tank environment of the Screening Unit, and the decomposition products initiate free radical autoxidation in reactions which lead to deposit formation. Other doping studies with a series of alkyl thiols which differed in boiling point, confirmed the strong effect of trace levels of sulfur compounds and also demonstrated the importance of both volatility and reactivity of sulfur compounds in the deposit formation process. A study was completed of the effect of metal type on the deposit formation process in the Screening Unit. Titanium alloys catalyze the formation of deposits to a greater extent than either pure titanium or stainless steel. The increase in deposit formation tendency can be correlated with the increase in vanadium content of the titanium alloy. Results indicate that the metal surface functions as a catalyst in the initiation step of a free radical autoxidation process which leads to the formation of deposits.

Descriptors :   *DEPOSITS), (*JET ENGINE FUELS, (*SULFUR COMPOUNDS, DEPOSITS), (*PYROLYSIS, FREE RADICALS), FUEL TANKS, DOPING, BOILING POINT, TITANIUM ALLOYS, CATALYSIS, STAINLESS STEEL, VANADIUM, OXIDATION, HIGH TEMPERATURE, SULFIDES, ADDITIVES, HYDROCARBONS, MOLECULAR STRUCTURE, THIOLS, VAPORS, SUPERSONIC AIRCRAFT.

Subject Categories : Atomic and Molecular Physics and Spectroscopy
      Fuels

Distribution Statement : APPROVED FOR PUBLIC RELEASE