Abstract: Vanadium in marine diesel lubricating oils resulting from raw fuel dilution is detected and quantified by way of an analytical technique employing electron spin resonance (ESR). Dilution of the lubricating oil with residual fuel oils results in the presence of vanadium in the lubricating oil in a form which is capable of being observed by ESR; by contrast, vanadium resulting from the presence of fuel oil combustion products (pentavalent vanadium) in the lubricating oil is not observed by ESR. The method therefore enables fuel vanadium, typically present as vanadyl porphyrins, to be differentiated from vanadium resulting from blow-by in the engine so that the operating condition of the engine may be monitored.

Abstract: Zeolite Y and other faujasite type zeolites are made stable to acid by calcination in a steam-containing atmosphere with a slow, controlled heating rate in the temperature range at which chemically bound water in the zeolite is given off, generally from 500.degree. C. to 650.degree. C. The stabilized product may be extracted with acid to produce a zeolite having a higher silica:alumina ratio. The high silica forms of zeolite ZSM-20 which may be produced by this method are novel materials.