Application: Hydrotreat atmospheric and vacuum residuum feedstocks to reduce sulfur, metals, nitrogen, carbon residue and asphaltene contents. The process converts residuum into lighter products while improving the quality of unconverted bottoms for more economic downstream use.
Products: Residuum FCC feedstock, coker feedstock, SDA feedstock or low-sulfur fuel oil. VGO product, if separated, is suitable for further upgrading by FCC units or hydrocrackers for gasoline/mid-distillate manufacture. Mid-distillate material can be directly blended into low-sulfur diesel or further hydrotreated into ultra-low-sulfur diesel (ULSD).
The process integrates well with residuum FCC units to minimize catalyst consumption, improve yields and reduce sulfur content of FCC products. RDS/VRDS also can be used to substantially improve the yields of downstream cokers and SDA units.
Description: Oil feed and hydrogen are charged to the reactors in a once-through operation. The catalyst combination can be varied significantly according to feedstock properties to meet the required product qualities. Product separation is done by the hot separator, cold separator and fractionator. Recycle hydrogen passes through an H2S absorber.
A wide range of AR, VR and DAO feedstocks can be processed. Existing units have processed feedstocks with viscosities as high as 6,000 cSt at 100°C and feed-metals contents of 500 ppm.
Onstream Catalyst Replacement (OCR) reactor technology has been commercialized to improve catalyst utilization and increase run length with high-metals, heavy feedstocks. This technology allows spent catalyst to be removed from one or more reactors and replaced with fresh
while the reactors continue to operate normally. The novel use of upflow reactors in OCR provides greatly increased tolerance of feed solids while maintaining low-pressure drop.
A related technology called UFR (upflow reactor) uses a multibed upflow reactor for minimum pressure drop in cases where onstream catalyst replacement is not necessary. OCR and UFR are particularly well suited to revamp existing RDS/VRDS units for additional throughput or heavier feedstock.
Licensor: Chevron Lummus Global LLC.