2661. ------. [PIER, M., AND FREE, G.] (W. E. Currie). Antiknock Motor Fuels. United States Patent 2,245,157, June 10, 1941; appl. filed Aug. 12, 1938, Serial No. 224,488, in Great Britain July 15, 1937; 3 claims (Cl. 196-50). Chem. Abs., vol. 35, 1941, p. 6433.

Describes arrangement of apparatus and a process for producing safety fuels stable to knocking, which comprises subjecting to cracking higher boiling mainly aliphatic hydrocarbon oils, in particular those having a high content of paraffinic constituents, such as higher boiling fractions of CO reduction products, and further cracking in the vapor phase at a temperature 400°-700° and in a separate reaction zone. The fraction of the resulting product b. about 150°-300° and consists mainly of unsaturated aliphatic hydrocarbons in the presence of > about 10% of an added cyclic hydrocarbon, which under the reaction conditions is vaporous but in the absence of a substantial amount of added H₂ or of a gas supplying H₂.