1818. KOCH, H., AND BILLIG, R. [Investigation of the Solid Paraffin Hydrocarbons Produced in the Benzine Synthesis of F. Fischer and H. Tropsch Atmospheric Pressure Synthesis.] Brennstoff-Chem., vol. 21, 1940, pp. 157-167; Chem. Abs., vol. 35, 1941, p. 3803.

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Literature Abstracts

Previous work reviewed briefly. By use of apparatus previously described, the solid products recovered with the liquid hydrocarbons in the train beyond the catalyst tube and the high-melting ceresins extracted from the catalyst itself after prolonged use have been investigated. Similarly, quantitative relations between molecular weight and melting point of products solid at room temperature, establishment of isoparaffins by physical and chemical data, and conversion of fractionated extracts into lubricants have been studied. Appreciable increase of extracted ceresin, accompanied by decreased yield of other products and the elevation of average boiling range of condensates, followed the alkalization of the Co-Th on kieselguhr catalyst with 0.25-2% Na₂CO₃ and 0.5-1% K₂CO₃ in 4-l.-per-hr. tests with 29% CO-59% H₂ gas mixtures at 190°-200°. As much as 50% more solid paraffins were found in the fraction boiling >300°. Paraffin precipitation was carried out over the range +5° to –20°, with 1:5 to 1:100 oil:solvent ratios. Between certain limits, the amounts of solid paraffins decreased steadily with increasing melting point. The regularity of the relation was found also in products of Fe-Cu and technical-scale syntheses. By fractional extraction of a Kogasin paraffin with 3:2 ether-alcohol mixture and of the ceresins with ether, 13 and 15 close fractions were obtained, respectively. The synthetic ceresin and several fractions thereof, treated with HSO₃Cl, decreased 1.3°-1.9° and increased 1°, respectively, in melting point, and their average molecular weights increased by 10-40. The reaction was preferential for isoparaffins. Hydrogenation under 80 atm. pressure around 190° with Ni catalyst gave colorless products, increases of 0.0002 in n_D, and 1° in melting point. In solidification curves, the ceresin fractions exhibited define points of heat of crystallization as compared to the perfectly smooth-cooling curve of the whole ceresin. 15 refs.