Application: Upgrade and/or convert atmospheric and vacuum residues using the Hyvahl fixed-bed process.
Products: Low-sulfur fuels (0.3% to 1.0% sulfur) and RFCC feeds (removal of metals, sulfur and nitrogen, reduction of carbon residue). Thirty percent to 50% conversion of the 565°C+ fraction into distillates.
Description: Residue feed and hydrogen, heated in a feed/effluent exchanger and furnace, enter a reactor section—typically comprising of a guard-reactor section (PRS), main HDM and HDS reactors.
The guard reactors are onstream at the same time in series, and they protect downstream reactors by removing or converting sediment, metals and asphaltenes. For heavy feeds, they are permutable in operation (PRS technology) and allow catalyst reloading during the run. Permutation frequency is adjusted according to feed-metals content and process objectives. Regular catalyst changeout allows a high and constant protection of downstream reactors.
Following the guard reactors, the HDM section carries out the remaining demetallization and conversion functions. With most of the contaminants removed, the residue is sent to the HDS section where the sulfur level is reduced to the design specification.
The PRS technology associated with the high stability of the HDS catalytic system leads to cycle runs exceeding a year even when processing VR-type feeds to produce ultra-low-sulfur fuel oil.
Yields: Typical HDS and HDM rates are above 90%. Net production of 12% to 25% of diesel + naphtha.