Sulfiding of HydrotreatingCatalysts Temperature H2 + Sulfiding Agent Oxide catalyst Sulfided catalyst Polymolybdate structure Lamellar structure Mo7O24 6- MoS2 slabs
CoMo CatalystActive Phase Structure «CoMoS» S Mo 0,615 nm Co (0002) Alumina
NiMo CatalystActive Phase Structure Morphology of an activated NiMoS Structure (STM Picture)
STM Images of Co-Mo-S / Au Co-Mo-S Nanocrystal MoS2 MoS2 + Co Courtesy of Haldor Topsoe
Sulfur Vacancies When exposed to H2 atoms, MoS2 forms two S vacanciesCourtesy of Haldor Topsoe
Active Phase g-alumina supported Co(Ni)MoS MET image of CoMoS 10 nm <L> = 3.9 nm <n> = 1.6 nm Layer structure of MoS2 edge decoration by Co or Ni <L> n g-aluminaCourtesy of IFP Molybdenum Co / Ni Sulfur
Sulfiding Reactions MoO3 + 2 H2S + H2 MoS2 + 3 H2O CoO + H2S CoS + H2O 3 NiO + 2 H2S + H2 Ni3S2 + 3 H2O WO3 + 2 H2S + H2 WS2 + 3 H2O Sour Water Produced: Approximately 10 wt% of catalyst Hydrogen Consumption: Approximately 1 wt% of catalyst
Sulfiding Techniques YOUR SITE Activated Catalyst Oxidic Catalyst OUR SITE
In-situ Sulfiding Issues Catalyst Quality • Requires careful attention and takes up valuable operating time – typically 1-7 days • If the active phase is not properly formed, catalyst activity will be affected. • Exposure of the catalyst to H2 at elevated temperatures (>450°F) can cause permanent damage.
In-situ Sulfiding Issues Safety and Environmental • Requires handling of hazardous and malodorous sulfiding chemicals such as DMDS or DMS • Outside contractors may be needed for DMDS injection • 2-3 personnel required for H2S sampling • Risk of H2S stack emissions • Tail Gas Unit startups • SRU overload • Lube units
In-situ Sulfiding Issues Processing • Off-spec product during startup has to be reprocessed or downgraded. • Process interruptions during the startup can result in restarting the sulfiding step • Additional hydrogen required (reformer may be down) • Sour water formation • Risk of temperature excursions • Corrosion caused by high H2S concentrations
What is Totsucat®? Totsucat = Totally Sulfided Catalyst The catalyst is preactivated, not just “presulfided”.
The Totsucat Process Patented • Totsucat is a proprietary patented process Carefully controlled sulfiding • Homogenous sulfiding – All oxidic metal sites are sulfided • Uses high purity H2S and H2 • Samples tested every two hours to ensure that the catalyst is adequately sulfided
Totsucat Benefits Load-and-Go reactor startups No exotherms Minimal sour water formation No additional H2 needed at startup Negligible amounts of H2S released No odors No handling of sulfiding chemicals Catalyst performance is maximized Upset conditions will not damage the catalyst
Typical Totsucat Applications Temperature Sulfur Sensitive Units ProcessingCritical Path Units Limited Units Units Cracked Feeds• The cost of • Some units • Reformers and • CFP version of downtime cannot achieve Isom units Totsucat allows typically the temperature contain precious startups utilizing outweighs the levels required metal catalysts cracked stocks cost of Totsucat for sulfiding, that are preactivation resulting in sensitive to H2S inadequately contamination sulfided catalysts that will not perform as designed
Startup with In-Situ SulfidingLiquid phase with SR FeedTemperature (°F) Cracked feed 750 H2S breakthrough Stop DMDS 575 DMDS Secondary Sulfiding SR Feed Initial •SR Feed + DMDS at 175-300°F 390 •Monitor H2S at outlet Sulfiding •Sulfide at 600-660°F •Sulfiding 3 days of SR feed 200 Drying step •completed in 15-24 hrs 6 12 18 hours 3 days
Totsucat G StartupLiquid phase with SR FeedTemperature (°F) Cracked feed 750 Straight Run 575 feed SR Feed introduction at low T (175-450°F) Go to Start of Run Temp in only 6-10 hours 390 SR Feed for 3-4 Days Progressively switch to cracked feed 200 Advantages: Simple startup procedure. No risk of event which could damage the catalyst 6 12 18 hours 3 days
Totsucat Versions G D HC N Light End Distillate Hydrocracker HydrocrackingApplications ULSD PretreatNaphtha HT 10 Approved by Tail Gas 6 References References UOP and CLG Gasoline 2 Repeats 4 Repeats 3 References Post-Treat
Totsucat HC Totsucat for Hydrocrackers • 3 Commercial References thus far in 2011 Applied Commercially to: UOP TOPSOE CRITERION CLG AXENS HC-24 TK-907 Testing Approved Approved HC-26 Soon HC-140 HC-150
Version – Totsucat E For units with sufficient sulfur in the feed (>0.5%) and capable of reaching 600F Majority of active sites are sulfided Sulfur in the feed completes the sulfiding process during a four hour finishing step at startup. Hydrocarbon passivation is available for loading in air
Case Study – Totsucat E for VGO Unit • Large VGO Unit contained 1.6 million poundsVGO Unit (725 MT) of catalyst • In-situ sulfiding would require 72-96+ hours and In-Situ produce 20,000 gallons (75K liters) of sour water • With Totsucat E Preactivation, the unit was online in 12 hours with less than 50 gallons (190Totsucat liters) of water removed from the separator
Totsucat E vs. DMDS – HVGO Unit Time Gain TOTSUCAT E vs DMDS: 48+ hrs Liquid Heat Up rate @ 17C/hr S content S >> 0.5 wt% Gas Phase Heat up Rate @ 4C/hr
Totsucat Properties Sulfides are sensitive to oxidation by air • Classified as self-heating solids • Class 4.2, UN 3190 Two Types Available • Non-Passivated - Requires inert loading • Hydrocarbon Passivation - Allows for loading under air
Issue of Cracked FeedCracked Feeds contain olefins, di-olefins, and aromatics that form gums and tars when exposed to hyper-active sites on freshly sulfided catalysts.
Issue of Cracked Feeds Gums and tars formed during startup Compounds readily deposit on catalyst surface The deposits block catalyst pores and active sites Leading to a permanent loss in catalytic activity
Issue of Cracked Feed To avoid this problem, catalyst manufacturers recommend a break-in period of at least three days using only less reactive straight run feed at startup. Processing the straight run will form a small amount of soft coke on the catalyst surface. This coke gradually reduces the hyperactivity of the catalyst. Cracked feeds can then be introduced without excessive tar and gum formation.
Issue of Cracked Feed Delaying the introduction of cracked feeds can have significant costs: • Lost profits from processing cracked and heavy feeds. • May need to purchase additional straight run feed for startup. • Storage costs for a sufficient quantity of straight run feed required at startup. • Storage costs for cracked feeds that must be held for processing later.
Solution: Totsucat CFP CFP = Cracked Feed Protection • In addition to Totsucat preactivation, Totsucat CFP has carbon carefully deposited on the catalyst surface • Hyper-active sites are moderated • Catalytic acidity is also reduced
Totsucat CFP BenefitsTotsucat CFP allows the direct introduction ofcracked feeds at 175-450°FProvides normal cycle lengths without waiting3-4 days before adding cracked feedsNo additional SR requiredNo need to store cracked feeds during startup
Case Study 1 - Totsucat CFP inULSD Service
Comments at 90 days on Oil withTotsucat CFP in ULSD ServiceThe start of run severity for Cycle 25 was worse compared to the last cycle (24). Cycle 24 did not have any back up LCO to work off after the shutdown, whereas cycle 25 (current cycle) needed to process 325 MBBLs of LCO that had been stored off-site during the ULSD outage. Backup LCO was blended in at 3-5 MBD on top of normal LCO productionWe are currently ~90 days into this cycle and our actual and normalized average bed temperatures are 10-15 degrees F below typical for this point in the cycle.Deactivation appears to be on the order of 3-5 deg/month, which is significantly better than our previous average of nearly 20 deg/month.
Case Study 2 – NHT with Totsucat CFP Naphtha Hydrotreater Feed: 25-50% Coker Naphtha Feed Rate: 35,000 BPD Catalyst Type: NiMo Catalyst Quantity: 53,000 lbs
Case Study 2 – NHT withTotsucat CFP Data from 2 Runs Run 1 – In-situ Sulfiding with 3 Day Break In – Catalyst A, Sock loaded Run 2 – Totsucat CFP Preactivation – Startup with 20% cracked feed – Catalyst A, Dense loaded
Case Study 2 – NHT with Totsucat CFP Reactor Temperature Reactor Temperature Reactor Temperature 700 600 Temperature (°F) 500 Inlet Temp - In-Situ Sulfided 400 Inlet Temp - Totsucat CFP 300 Bottom to Inlet ΔT - In-Situ 200 Bottom-Inlet ΔT - Totsucat CFP 100 0 0 50 100 150 200 250 300 350 Days
Case Study 2 – NHT with Totsucat CFP Coker Feed Rate Reactor Temperature 200 180 In-Situ Sulfided 160 140 Totsucat CFP 120 CBPD 100 80 60 40 20 0 0 100 200 300 400 Days
Case Study 3 – CFHT with Totsucat CFP Cat Feed Hydrotreater Feed: HVGO / HCGO Feed Rate: 24,000 BPD Catalyst Type: NiMo Catalyst Quantity: 107,000 lbs
Case Study 3 – CFHT In-situ Sulfided Run Coker Naphtha Feed Rate LargeradialspreadinbottomTI’sincreasedafter HCGO introduction. Hot spots likely to limit cycle length and/or throughput. MinTI’sofbottombedarenot much different than Rx Inlet T indicates maldistribution and/or non-uniform activity.
Case Study 3 – CFHT In-situ Sulfided Run Coker Naphtha Feed Rate Mid-bed and Bottom Radial Spreads Increased as Cracked Stocks were introduced HCGO Ramped to 85% of Feed at Day 70 Decreasing effectiveness of the top bed is indicated by a decline in the % of total bed axial delta T by the mid- bed and increasing radial spreads in the mid-bed.
Case Study 3 – CFHT with Totsucat CFP Totsucat CFP Enables Early Introduction of Heavy Coker Gas Oil: Ten Hours After Heatup to 600 F Reactor Inlet T Coker Naphtha Feed Rate 160 700 140 600 120 500 HCGO Ramped to 90% of Feed 10 hours from heat up 100 Temperature, F 400 % 80 300 60 Rx Inlet T, F Top Bed Delta T Stable 200 After HCGO In 40 Btm of Bed 1 Avg, F Bed 1 Delta T, F 100 20 % HCGO in Feed 0 0 0 10 20 30 40 50 60 Hours after Feed-in
Case Study 3 – CFHT with Totsucat CFP Totsucat CFP Run – Mid and Bottom Bed Radial Spreads Mid-bedTI’sstableasa%oftotalbeddeltaT Radial spread of Mid-bedandBottomTI’smuch lower than previous run
Case Study 3 – CFHT with Totsucat CFP Totsucat CFP Run – Bottom Coker Naphtha Feed RateBed
Startup with Totsucat CFPLiquid Phase with Cracked Feed Temperature (°F) SOR 750 Progressive Introduction of 575 Cracked Feed Introduce cracked feed at 175-450°F Heat up at 35°F/h up to 475°F 390 After 475°F Heat up at 20°F/h up to SOR. Advantages: Safe fast start-up; Additional 3 to 4 days of cracked feed processed; No 200 need for SR or Cracked Feed storage 6 12 18 hours 3 days
Catalyst Companies Approving Totsucat
Totsucat Commercial Experience Over 800 Totsucat Lots Treated at EUS totaling 40+ million pounds of catalyst HDS/HDN Selective Pyrolysis • Wide variety of Hydrogenation Gasoline hydrotreating • NiMo and CoMo • CoMo catalysts catalysts Catalysts Wax Lube Hydrofinishing Hydrofinishing • NiW catalysts • CoMo catalysts
Totsucat Processing Sites Europe – Bitterfeld, GermanyUSA – Pasadena, Texas Europe – Gela, Italy
Pasadena, TX Facility
Other Eurecat Services Analysis and Regeneration of Spent Hydrotreating Catalysts HDS Activity Testing Resale of Regenerated Catalysts • High activity regenerated catalysts available for immediate delivery Bulk Nickel Sulfur Guards REACTIVATION of Palladium on Alumina Catalysts
Eurecat Contact InformationRandy Alexander Frederic Jardin Tony Loverdi Regional Sales Manager – Director of Sales and Marketing Executive Vice President Gulf Coast Randy.Alexander@Eurecat.com Frederic.Jardin@Eurecat.com Tony.Loverdi@Eurecat.com Phone: 832.284.0612 Phone: 832.284.0614 Phone: 832.284.0607 Nilanjan“Babu”Chris Buffington Bob Stults Brahma Regional Sales Manager – International Sales Manager Technical Support Manager Western Region Chris.Buffington@Eurecat.com Nilanjan.Brahma@Eurecat.com Bob.Stults@Eurecat.com Phone: 832.284.0608 Phone: 832.284.0609 Phone: 832.284.0602
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