Studies on catalysis by molten metals. 14. Catalytic cracking of asphalts at low temperature

The catalytic effects of liquid metals for low-temperature (336 °C) asphalt-cracking have been examined using a semi-batch reactor. All the liquid metals examined (Bi, Cd, Ga, In, Pb and Sn) effectively catalysed the reduction of molecular weight with minimal gasification (<1 wt%). Gasification had a positive correlation with the reduction in molecular weight in the processed asphalts. The catalytic activities of liquid metals tor these two reactions were proportional to a parameter which represents the interaction between the atoms of the catalyst metal and the radicals formed in the course of the reaction. Mass flow among four fractions (saturates, aromatics, resins and asphaltenes) had two independent paths: conversion of resins to saturates and of aromatics to asphaltenes. The former path dominated when catalytic dehydrogenation activity was relatively low, whereas the latter dominated when the catalytic activity was high.