Naphtha color stability

Advantage of a multiple system, i.e. combination of HDM, HDS and HDN combination catalyst, over that of a dual-catalyst system is not conclusive. However, HDN catalyst is expected to impart color stability to naphtha and distillate products. 

Other stocks which may be upgraded by hydrotreating are thennally and catalytic cracked naphthas, straight-run naphthas abnormally high in contaminants, and coker gasolines. The latter are produced by the high-temperature pyrolysis of reduced fuel to coke and distiUate fractions. Naphthas to be used as specialty solvents also are treated to obtain premium products with respect to color, odor, and stability. 

Among the special requirements of solvents may be white color low unsaturated and aromatic content for stability high aromatic content for solution of lacquers or synthetic resins or low boiling for rapid volatilization. In general, however, naphthas should be free from acidity, noncorrosive by the copper-strip test, free from gums or suspended matter, sweet smelling so that a petroleum odor is not imparted to the... 

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