Storage Stability of High Temperature Fuels. Part II. The Effect of Storage Upon Thermally Induced Deposition of Labeled Fuel Components.
Air Force Aero Propulsion Lab Wright-patterson AFB Ohio Tech Rpt AFAPL-TR-68-32 Pt II :116 pages
This investigation is concerned with the contribution of selected components and additives of high-temperature aircraft fuels to thermally induced deposits before and after 52 weeks storage at 130 deg. F. Of particular concern is the influence of these fuel constituents on thermal-stability quality of these jet fuels during storage. The study utilizes a micro fuel coker test apparatus to measure the thermal-stability of test fuels and blends. The contribution of selected fuel components, labeled with carbon-14, to deposit-forming mechanisms is determined by radioactive counting techniques. Twenty-three blends of a carbon-14 labeled component in a jet fuel matrix were added to the program, and 67 blends reached the 52-week interval of storage at 130 deg. F. These blends were tested to determine the extent of radiotracer contribution to thermally induced deposits. The greatest extent of reaction of the labeled hydrocarbon fuel systems studied was observed in blends containing methyl- and ethyl-substituted indenes. Other aromatic types also showed some contribution to the deposits. Special studies with 2 jet fuel antioxidants were conducted to determine the extent of thermal and chemical degradation during storage and testing. Tests with an additive of the amine-type showed substantial amounts of the antioxidant reaction and/or decomposition to form filterable deposits in the preheater section of the test apparatus.
Air Force Aero Propulsion Lab., Wright-patterson AFB, Ohio, Tech. Rpt. AFAPL-TR-68-32, Pt II