654. ------. [FETTERLY, L. C.] (N. V. de Bataafsche Petroleum Maatschappij). [Fractional Extraction and Extractive Crystallization of Isomeric Hydrocarbon Mixtures.] French Patent 969,716, Dec. 26, 1950; appl. filed July 27, 1948. Chem. Zentralb., 19

Patent Abstracts

654. ------. [FETTERLY, L. C.] (N. V. de Bataafsche Petroleum Maatschappij). [Fractional Extraction and Extractive Crystallization of Isomeric Hydrocarbon Mixtures.] French Patent 969,716, Dec. 26, 1950; appl. filed July 27, 1948. Chem. Zentralb., 1951, I, p. 2109.

Hydrocarbons containing at least 6 C atoms are separated by urea or thiourea, which selectively forms crystalline compounds with normal paraffin hydrocarbons, olefins, alcohols, ethers, etc. This patent describes the separation of octane and isooctane. Likewise straight-chain hydrocarbons are separated from branched-chain, cyclic aromatic, and naphthenic hydrocarbons. Thiourea forms crystalline complex compounds with branched or cycloaliphatic hydrocarbons, whereas straight-chain hydrocarbons do not react.