Published: November 1985
Historically the coking process has had two purposes: the production of high value coke primarily for the electric arc steel and aluminum industries, and the upgrading of "bottom-of-the barrel" crude oil. Coking reduces production of loss-making residual fuel oil, and at the same time increases production of gasoline and distillate. In the latter function, the coke is usually a low value, unwanted by-product. Until recent years, however, coking was essentially the only means of achieving significant reductions in residual fuel oil production.
Since our 1976 report on petroleum coke (PEP Report 72A1) there has been considerable activity in the construction of coking units, despite the fact that the traditional outlets for high value coke have not expanded. At the same time:
- Throughout the industrialized world, the demand for residual fuel oil continues to decline rapidly.
- Alternative processes for residual fuel oil reduction (avoiding by-product coke) continue to be developed.
- The likelihood of having to refine an increasingly heavier crude slate, somewhat perversely, will progressively increase the amount of bottom-of-the-barrel material.
To some extent these developments are conflicting. The purpose of this report, therefore, as well as reviewing petroleum coking (and associated) technology, is to evaluate coking economics in relation to alternative processing in the present and likely future environment of the refining industry.
Finally, in view of the prospect of substantially higher volumes of inferior grade cokes becoming available, this report will briefly review the potential impact on present and future coke markets.