As long as gasoline is the main transportation fuel and residual fuel oil value is priced below crude oil, refiners will continue to convert heavy fractions to lighter products. Future challenges to this process will evolve around the development of more economic pretreatment processes to handle very heavy feeds and improve catalyst cost and the development of a better understanding of catalyst deactivation and regeneration. These residues contain metallic contaminants and asphaltenes that concentrate through distillation and have a tendency to coke on pyrolysis.
Many methods have been introduced to overcome these problems. One of these approaches is the pyrolysis of vacuum residues using a batch-type reactor having two different reaction zones controlled at different temperatures: 400-500 and 500-700 8C, respectively. Vacuum residues are pyrolyzed in the first low-temperature stage to produce cracked oils using Pt as a catalyst. An argon flow then carries the cracked oils to the second high-temperature stage for subsequent catalytic pyrolysis. Because pyrolysis residues are left behind in the first stage, the catalyst used in the second stage is not affected by these metallic contaminants. The procedure is defined as ''two-stage pyrolysis''. This method has proved to be excellent for production of C 2 -C 4 olefins.
The present work is an attempt to investigate the catalytic two-stage pyrolysis of bitumen 80/100, using Ca 2+ catalyst with the intention of producing unsaturated hydrocarbons. The maximum yield of the unsaturated hydrocarbon is 33.6 wt%.