Hydrocracking

Hydrocracker Feed & Product
Various configurations of Hydrocracker Units
Hydrocracking Chemistry
Why we use of Hydrocracking

1. Hydrocracking By: Kavaiya Ashish Rajeshkumar 15042022 Dept. of Chemical Eng. & Tech, IIT BHU, Varanasi, UP-221005

2. Content : Introduction Alternate Cracking Process Hydrocracking Chemistry Various configurations of Hydrocracker Units Hydrocracker Feed & Product Hydrocracking Catalyst Process Variables Hydrocracking Technology Provider Advantage of Hydrocracking

3. INTRODUCTION Hydrocracking The process of converting higher molecular weight hydrocarbons into more valuable lower molecular weight hydrocarbons C 22 H 46 + H 2  C 16 H 34 + C 6 H 14 In presence of Hydrogen At high temperatures(290 –455 O C) & high pressures (105-190 Kg/cm 2 g) In presence of catalyst The products are clean, saturated & high in value

4. Why we use of Hydrocracking (1) The demand for petroleum products has shifted to high ratios of gasoline and jet fuel compared with the usages of diesel fuel and home heating oils, (2) By-product hydrogen at low cost and in large amounts has become available from catalytic reforming operations, (3) Environmental concerns limiting sulfur and aromatic compound concentrations in motor fuels have increased.

5. ALTERNATE CRACKING PROCESS Residue up gradation into middle distillates and light distillates is currently being done in the Refineries primarily by employing FCC process, delayed Coking process & visbreaking. Visbreaking is adopted primarily to reduce the viscosity of the residue thereby making it marketable. Delayed coking is adopted if Coke is also to be a product. The quality of products obtained from FCC, delayed Coker & Visbreaker are relatively poor in quality with respect to stability, & sulphur and have to be blended with other straight run products to be able to market them. Otherwise, product treatment would be necessary (Hydro-treatment, Merox treatment etc.) In view of these problems Hydrocracking process is gaining more and more popularity for upgrading residues into higher value products.

6. Comparison

7. Hydrocracking Chemistry Cracking Reactions Saturated paraffins cracked to form lower molecular weight olefins & paraffins Side chains cracked off small ring aromatics(SRA) & cycloparaffins( naphthenes ) Side Chain cracked off resins & asphltenes leaving thermally stable polynucler aromatics(PNAs)

8. Hydrogenation Reactions Exothermic giving off heat Hydrogen inserted to saturate newly formed molecule from aromatic cracking Olefins are saturated to form light hydrocarbons, especially butane Aromatic rings hydrogenated to cycloparaffins ( Naphtthenes ) Carbon-carbon bonds cleaved to open aromatic & cycloparaffins( naphthenes ) Heteroatoms form hydrogen sulfide , ammonia, water , hydrogen chloride

9. Isomerization Reactions Isomerization Provides branching of alkyl groups of paraffins and opening of naphthenic rings. Condensation Reactions Suppressed by Hydrogen Coking Reactions Polyaromatics + Olefins  Alkylation – H 2  Cyclisation –H 2  Coke Precursors

10. 1.Single stage Once through Hydrocrakerunit (SSOT): Feed and Hydrogen is passed through reactors only once for 60 –80 % of partial conversion. Unconverted Oil is sent to FCCU. 2. Single stage recycle ( SSRec ) : Unconverted oil is recycled back to feed for 100% conversion. 3.Two stage HydrocrakerUnit: Unconverted Oil of SSOT is sent to another reactor for 100% conversion Various configurations of Hydrocracker Units

11. Hydrocracker Feed & Product Feed: Straight run gas oil, Vacuum gas oils, Cycle oils, Coker Gas oils, thermally cracked stocks, Solvent deasphalted residual oils, straight run naphtha, cracked naphtha. Product : Liquefied petroleum gas (LPG), Motor gasoline, Reformer feeds, Aviation turbine fuel, Diesel fuels, heating oils, Solvent and thinners, Lube oil, FCC feed

12. Two Stage Hydrocracking Process

13. Catalyst Hydrotreating Catalyst Metal based catalyst Ni‐Mo for higher hydrogenation activity Co‐Mo for lower severity…better desulfurising Hydrocracking Catalyst Bi‐functional Amorphous Silica Alumina catalyst Zeolite based catalyst for higher cracking activity Acid sites for cracking reactions–Metal sites for hydrogenation, dehydrogenation

14. PROCESS VARIABLES : Reactor Temperature Reactor Pressure Hourly feed velocity of the feed Hydrogen partial pressure Hydrogen recycle ratio Hydrogen Sulfide Nitrogen Content

15. HYDRO-CRACKING TECHNOLOGY PROVIDER Chevron: Isocracking UOP: Uni -cracking IFP: Hydrocarcking B.P. U.K: Hydrocracking Shell: Hydrocracking Standard Oil: Ultracracking Linde : Hydrocarking Union Oil Co.: Uni -cracking

16. Advantages of Hydrocracking 1. Better balance of gasoline and distillate production 2. Greater gasoline yield 3. Improved gasoline pool octane quality and sensitivity 4. Production of relatively high amounts of isobutane in the butane fraction 5. Supplementing of fluid catalytic cracking to upgrade heavy cracking stocks, aromatics, cycle oils, and coker oils to gasoline, jet fuels, and light fuel oils

17. Reference : GHC Unit Flow Sheet From, IOCL Vadodara James H. Gary,Glenn E. Handwerk , “Petroleum Refining Technology and Economics” Frouth Edition. J. W. Ward, R. C. Hansford, A. D. Reichle , and J. Sosnowski , Oil Gas J. 71(22), 69–73 (1973). W. L. Nelson, Oil Gas J. 65(26), 84 (1967). R. P. VanDriesen , Altering Today’s Refinery, Energy Bureau Conference on Petroleum Refining, Houston, Texas, Sept. 28, 1981. A. G. Bridge, Handbook of Petroleum Refining Processes, 2nd Ed. R. A. Meyers, Ed. (McGraw-Hill, New York, 1997), Sections 7.21–7.40.

18. Thank You