EFFECTS OF SULFUR COMPOUNDS ON CARBON DEPOSITION FROM DODECANE AND METALSULFIDE FORMATION ON SUPERALLOYS

摘要

Deposition of solid carbon and formation of sulfides on metal alloy surfaces upon exposure to sulfurrncontaining hydrocarbon fuels present problems in the operation of engine fuel systems and hydrocarbonrnconversion reactors. Jet fuel samples with different sulfur contents were used in flow reactor experiments to studyrncarbon deposition on commercial superalloys, including different commercial superalloys Inconel 600, Inconelrn718, Fecralloy, Hastelloy-C 276 at 525℃ wall temperature and 34 atm for 5h at a flow rate of 4 mL/min. Effectsrnof sulfur compounds were further studied by adding 300 ppm benzyl-phenyl sulfide (BPS) to n- dodecane that wasrnstressed on the same alloys and on single metal foils Ni, Fe, Cr, Ti, and Al under the same conditions to monitorrnsulfide formation and carbon deposition. Neat n-dodecane was also stressed in the flow reactor with the samernsubstrates to establish baseline data. Temperature programmed-oxidation (TPO) and SEM analysis showed thatrnpresence of some sulfur compounds facilitated carbon deposit formation due to significant amount of metal sulfidern(Ni_(1-x)S, Ni_2S_3, Fe_(1-x)S) formation particularly on Inconel 600, Inconel 718, and Hastelloy-C 276 surfaces. However,rnFecralloy did not collect solid carbon or suffer from sulfur attack because of higher Cr, Al, and Y contents.