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Outline Introduction Hydrocracking Chemistry Hydrogen consumption Hydrocracking process Conclusion

Introduction A process similar to catalytic cracking in its industrial purpose but effected under hydrogen pressure and on a catalyst > Purpose: process gas oil to break carbon- carbon bonds of large aromatic compounds » Hydrogenation (addition of hydrogen) » Cracking (aromatic bonds

This presentation uses a free template provided by FPPT.com INRODUCTION  Hydrocracking does a better job of processing aromatic rings without coking than catalytic cracking Hydrogen used to hydrogenate aromatics Hydrocracking not as attractive as delayed coking for resids high in resins, asphaltenes poison hydroprocessing catalysts  Feeds require large amounts of hydrogen

This presentation uses a free template provided by FPPT.com Hydrocracker Feeds  Typical feeds Cat cracker "cycle oil“ 1. *Highly aromatic with sulfur, small ring, catalyst fines 2.*Hydrocracked to form high yields of jet fuel, kerosene, diesel,  Gas oil from visbreaker 1.* Aromatic Gas oil from the delayed coker 2.*Aromatic, olefinic, with sulfur Usually more economical to route atmospheric 8 vacuum gas oils to the cat cracker to produce primarily gasoline & some diesel

This presentation uses a free template provided by FPPT.com Hydrocracker Products  Products Hydrocracking primarily to make distillates Intent is to minimize the production of heavy fuel oil  Light ends are approximately 5% of the feed.  Middle distillates (kerosene, jet fuel, diesel)

This presentation uses a free template provided by FPPT.com Hydrocracking Chemistry  Cracking reactions  Saturated paraffins cracked to form lower molecular weight olefins & paraffins  Side chains cracked off small ring aromatics & cycloparaffins (naphthenes)

This presentation uses a free template provided by FPPT.com Hydrocracking Chemistry  Hydrogenation reactions  Exothermic giving heat  Hydrogen inserted to saturate newly formed molecule from aromatic cracking  Olefins are saturated to form light hydrocarbons especially butane (naphthenes)  Aromatic rings hydrogenated to cycloparaffins  Carbon-carbon bonds cleaved to open aromatic &cycloparaffins (naphthenes) rings

This presentation uses a free template provided by FPPT.com Hydrocracker Products  Products Hydrocracking primarily to make distillates Intent is to minimize the production of heavy fuel oil  Light ends are approximately 5% of the feed.  Middle distillates (kerosene, jet fuel, diesel)

This presentation uses a free template provided by FPPT.com Hydrocracking Catalysts  Hydrocracking catalysts generally a crystalline silica alumina base  Catalysts susceptible to sulfur poisoning if hydrogen sulfide is present in large quantities Catalysts not affected by ammonia Sometimes necessary to remove moisture to protect the catalyst

Catalyst Deactivation & Regeneration  Catalysts deactivate & coke does form even with hydrogen present » Hydrocrackers require periodic regeneration of the fixed bed catalyst systems

This presentation uses a free template provided by FPPT.com Effect of Process Variables on Hydrocracking  Severity Mild operation for diesel or fuel oil from heavy gas oll Severe operation for kerosene or naphtha from a light gas oil  Temperature Temperature not used to increase severity >> Temperature adjusted to offset decline in catalyst activity >> Consider 650°F to 750°F as a descriptor of mild operations & 750°F to 850°F for severe operations

This presentation uses a free template provided by FPPT.com Effect of Process Variables on Hydrocracking  Pressure & Hydrogen Consumption Lower operating pressure: 1,200 psig: hydrogenconsumption 1, ,000 scf/bbl More severe operations to destroy heavier components & open rings: 2,000 psig: 2,000 to 3,000 scf/bbl or more  These hydrogen consumptions primarily for the hydrocracking reactions with low sulfur removal & olefin/aromatic saturation Mild or severe hydrocracking with extensive desulfurization or olefin/aromatic saturation willincrease hydrogen consumption, possibly by 25%

This presentation uses a free template provided by FPPT.com Hydrocracking Process Description  Single stage or two stage processes Severity of the operation Products desired Nature of the feedstock feed pretreating for contaminant removal  Two extremes Mild one stage hydrocracking system Severe two stage operation

Catalytic hydrocracking process

This presentation uses a free template provided by FPPT.com Conclusion  The process involves two reactions(cracking + hydrogenation)  It consumes a lot of hydrogen to saturate aromatic  > Produce products in Kerosene range (larger) than gasoline.