Hydrocracking Technology for Middle Distillate

Published October 2001

The objective of this review is the production of middle distillate, 300-650°F cut point, while maximizing diesel (550-650°F) yield. The new UOP's new HyCycle (TM) Unicracking hydrocracking technology is the basis of the evaluation. US Patents 5,980,729, 5,885,440 and a 2001 NPRA publication [R98-07-001] have been served as a basis for evaluating the technology. The key attributes to this technology are:

• Reverse arrangement of reactors system. The hydrocracking, with low conversion per pass, about 33%, comes first followed by hydrotreating. The preheated feed enters the hydrotreating reactor along with hydrocracker outlet product, for very deep sulfur.
• The cracked products are separated from the reactor loop at about 1,800 psig in hydrogen rich vapor phase. Product is condensed outside reactor loop prior to conventional products recovery. An overall conversion of above 98% and below 650°F point is achieved.
• Reactor loop nominal pressure of about 1,800 psig as opposed to 2,400 psig in more conventional double reactor system.
• For 21.5 API, 2.5 wt% sulfur, 980°F TBP cut POINT VGO, the yield is 38 vol% diesel, 42 vol% kerosene and 29 vol% naphtha. The equivalent yield in conventional double reactor system with 97% conversion to 650°F cut point is 19 vol% diesel, 54 vol% kerosene and 36 vol% naphtha.
• The system comprises a finishing reactor, and naphtha product, meeting the 1 ppm sulfur specification for typical downstream processing such as catalytic reforming. o The hydrogen consumption for the above yield basis is reduced from 1,950 Scf/bbl in conventional double reactor to 1,700 Scf/bbl in HyCycle.