11. Hydrocracking

Question 1

■ Objective and description of Alkylation process?
■ The process?
■ Main Units?

Answer 1

■
▪ Can stand alone in a refinery as the only cracking unit.
▪ Hydrocracking can take care of many of the headaches that refiners experience as the market changes from month to month or season to season.
▪ Gasoline from light or heavy gas oils
▪ Cracked gas oils
▪ Jet fuel (light distillate) from heavy gas oil.
▪ Diesel fuel (light distillate) from heavy gas oil.
▪ Refineries use hydrocrackers to move from max diesel and distillate fuels in winter to max gasoline and maybe even jet fuel in summer.
▪ By using hydrocracking there is no leftovers (coke, residuals) only light oil, gasoline, jet fuel, and/or distillate fuel.

■ 
▪ simple catalytic cracking in presence of hydrogen
▪ using ctalysts
– Cobalt
– Molybdenium
– Neckel plus Aluminia

Question 2

■ Feedstock (sources), output & disposition?

Answer 2

■ Feedstock:
▪ CAT-cracked light gas oil
▪ CAT cracked cycle ol
│
■ Output:
▪ Propane (C3H8)
▪ Isobutane (C4H10)
▪ N-Butane (C4H10)
▪ Hydrocrackate — Blending components heading for the gasoline blending pool
▪ Kerosene range
▪ Light gas oil range