Modifying carbonization properties of pitches. 2. Attempts to improve the yield of fusible material from the quinoline-insoluble fraction of a petroleum pitch

Abstract

Some attempts to modify the quinoline-insoluble fraction (QI) of a petroleum pitch with the aim of increasing the yield of fusible matter which yields anisotropic needle coke on carbonization are reported. Alkylation with ethyl iodide and metallic potassium converted 60% of the QI into material soluble in benzene (BS) but this was infusible. In contrast Birch reduction yielded fusible chloroform-soluble material, but in a yield of only 15%. By combining both methods of modification, the yield of fusible matter reached 70%. The modification of unfractionated petroleum pitch by these reactions was also studied and it was found that the presence of quinoline-soluble material helped to increase the conversion of QI to fusible soluble matter to 80%. Catalytic hydrogenation of the alkylated QI was also tried, but resulted in thermal dealkylation, reconverting the alkylated QI to insoluble QI; on the other hand, the quinoline-soluble fraction was smoothly hydrogenated.