FCC Additives for Increased Residue Processing and Slurry Upgrading

Transcription

1 FCC Additives for Increased Residue Processing and Slurry Upgrading Ilya Kryukov Technical Sales Manager Process Technologies Intercat Johnson Matthey

2 Overview Evaluate upgrade potential Feed effects Histogram analysis Troubleshooting increased bottoms yields Optimize cracking severity Maximize catalyst circulation Optimize catalyst additions Optimize catalyst formulation Caveats of deep cracking The additive boost Nitrogen and poison adsorption Zeolite-to-matrix ratio optimization Summary 2

3 Feed Effects Slurry yield is strongly a function of feed density Slurry yield increases as feed becomes more dense Higher density implies more asphaltic molecules present Slurry yield increases as feed nitrogen increases Nitrogen acts as a temporary FCC poison reducing catalyst acidity Reducing or absorbing nitrogen effectively increases slurry conversion 3

4 Feed Effects Slurry yield increases as feed UOP K decreases UOP K is a measure of feed paraffins & thereby crackability A lower UOP K implies increased aromaticity Feed quality is the most significant factor determining slurry yield Slurry density analysis is the most reliable manner to determine slurry upgrading effectiveness 4

5 Evaluating Slurry Upgrade Potential Histogram analysis defines operation Target: Example: Typical density: Frequencies: At typical: 76% Above typical: 22% Below typical: 2% Slurry yield vs. slurry density determines upgrade potential In this example, potential benefits are vol% slurry yield 5

6 Troubleshooting Slurry Increases Troubleshooting slurry requires monitoring slurry density An increase in yield may be due to a feed quality shift (Case A) An increase in yield may indicate an increase in cracking severity required (Case B) Case A Case B High slurry yield does not immediately imply that the base catalyst is improperly designed 6

7 Overview Evaluate upgrade potential Feed effects Histogram analysis Troubleshooting increased bottoms yields Optimize cracking severity Maximize catalyst circulation Optimize catalyst additions Optimize catalyst formulation Caveats of deep cracking The additive boost Nitrogen and poison adsorption Zeolite-to-matrix ratio optimization Summary 7

8 Conversion Determines Slurry Yield Slurry conversion directly follows conversion as expected Variable shifts which influence conversion will control slurry yield However, conversion is a dependent variable Slurry destruction is primarily controlled by the following variables: Catalyst circulation rate Catalyst composition Catalyst addition rate 8

9 Maximize Catalyst Circulation Increase cat-to-oil: -1.4% slurry for +1 cat-to-oil However, the catalyst circulation rate is a dependent variable How do we increase the catalyst circulation rate? Riser outlet temp, preheat temp, steam optimization, reduce delta coke, etc. Increase riser temperature -1.0% slurry for +5 C 9

10 Maximize Catalyst Circulation Optimize dispersion steam rate -0.75% slurry for +1% dispersion Dispersion steam applies mechanical force to disperse feed Enhanced dispersion leads to increased conversion & lower delta coke Reduce regenerator temp -0.5% slurry for -5 C 10

11 Maximize Catalyst Circulation Why does regen temp drive slurry yield Delta coke increases regen temp Increased regen temp reduces cat circulation Reduced cat circulation reduces catalytic cracking Delta coke is one of the primary driving forces for catalyst circulation Use coke selective catalysts Optimize feed dispersion Passivate ecat metals 11

12 Optimize Catalyst Addition Rate Increasing catalyst additions increases slurry destruction Step changes are recommended to determine the where the inflection point lays Return-on-investment calculation recommended 12

13 Optimize Catalyst Formulation Increase equilibrium catalyst alumina oxide concentration A proper balance is needed as increasing Al 2 O 3 also increases delta coke Increase equilibrium catalyst surface area However, zeolite surface area has minimum effect on slurry conversion Matrix surface area plays the main role 13

14 Optimize Catalyst Formulation Slurry destruction responds to increased meso surface area MSA is a strong indication of meso pore volume in catalyst particles Meso pores have sufficient pore diameter to allow diffusion of residue molecules into catalyst allowing cracking reactions to occur Increased zeolite-to-matrix ratio increases slurry yield Increased Z-to-M implies more zeolite & less active alumina 14

15 Caveats of Deep Cracking Negative effects of cracking to deep: Too low slurry steam generator velocity Too low tube velocity which may lead to fouling or blockage Excessive slurry viscosity Potential limit to slurry recirculation rate Better to dilute high viscosity with LCO than to drop conversion Possible asphaltine deposition Occurs very infrequently and then only with specific crude sources Reducing slurry conversion may be the only solution Fractionator bottoms coke fouling Ensure slurry rate is at least 1.5 times feed rate Ensure bottoms temperature is not too high Prevent polymerization with best available cracking technology Test for polymerization: Slurry 90% < feed 90% 15

16 Summary Primary variables for maximizing slurry conversion: Maximize catalyst circulation Optimize fresh catalyst additions Best available slurry conversion catalyst Intercat offers an additional independent variable for slurry destruction 16

17 Overview Evaluate upgrade potential Feed effects Histogram analysis Troubleshooting increased bottoms yields Optimize cracking severity Maximize cat-to-oil Optimize catalyst additions Optimize catalyst formulation Caveats of deep cracking The additive boost Nitrogen and poison adsorption Zeolite-to-matrix ratio optimization Summary 17

18 Cat-Aid: Adsorbing N & Trapping V Cat-Aid traps FCC feed contaminants Benefits when using Cat-Aid: Improved catalyst stability Fresh adds decreased by up to 50% Improved coke selectivity Ability to process heavier, more contaminated feed-stocks Increased FCC unit conversion Cat-Aid reduces nitrogen poisoning effect Reduced SOx emissions Secondary sulfur trap protects contaminant trapping functionalities Cat-Aid adsorbs N which is a fresh catalyst poison Retains active sites for slurry conversion 18

19 Cat-Aid Commercial Example US West Coast refiner injects Cat-Aid in order to: Reduce costs Improve yield selectivities Results: Operations Increased residue processing Cat-Aid additions at 8.4% Catalyst additions reduced 46% WGS caustic injections reduced 61% Selectivities Conversion higher by 2.8% Slurry decreased by 1.7% 19

20 BCA: Optimizing Z-to-M BCA has been used successfully in over 42 FCC units Used for 14+ years in FCC units 29 maximum gasoline operations 13 maximum LCO operations Mechanism Upgrades the most difficult to crack portion High molecular weight, sterically hindered molecules Swiftly adjusts circulating inventory Z-to- M Yield pattern determined by base catalyst & FCC operating parameters BCA overall experience 20

21 BCA Commercial Experience Design Criteria Charge Yield Additions Yield selectivity, wt% Region Unit Catalyst vendor API CCR Bottoms Cat, TPD ВСА, % Dry Gas LPG Gasoline LCO Slurry Coke Europe A A 23, ,0 6,5-0,60 0,0 1,0 1,1-1,5 0,0 N America B B 22,5 2,28 17,8 10,0 10,0 0,00 0,0 0,0 3,3-3,3 0,0 Asia C C 26,6 3,7 9,6 7,3 8,0-0,05-1,2-1,2 3,85-0,5-0,9 N America D D 24,1 8,8 4,5-0,05 0,0-0,8 2,25-1,0-0,4 N America E A 23,3 2,3 4,5 9,0 0,0 0,0-0,7 2,7-2,0 0,0 Europe F A 20,0 4,7 10,5 5,0 12,0-0,10 0,0 2,0 2,0-3,9 0,0 N America G B 24,4 0,2 14,3 2,0 6,5 0,00 0,4 1,1 2,0-3,5 0,0 N America H B 26,3 8,8 2,9-0,90 0,9-1,0 1,8-0,6-0,2 Asia I C 20,7 0,3 13,0 1,5 3,0-0,05 0,25-0,2 1,7-1,7 0,0 N America J D 24,7 5,8 1,4-0,24 1,5 0,3 0,64-1,4-0,8 Asia K C 21,7 2,39 12,0 5,0 6,9 0,00 0,0 0,0 1,3-1,3 0,0 Asia L B 20,0 4,9 16,0 6,5 0,00 0,0 0,0 1,0-1,0 0,0 N America M B 22,7 0,29 9,8 3,0 10,0 0,00 0,0 0,0 1,0-1,0 0,0 Operational applications: Nearly every FCC design Hydrotreated VGO s High N & metal residues Partial burn operations Full burn operations Catalytic applications: Over fully optimized systems Over each cat supplier & technology Over high accessibility catalysts Over high pore volume catalysts Over mod & low Z-to-M catalysts 21

22 BCA Commercial Experience BCA reduces slurry by approximately 1.7 wt% Drygas yield drops slightly in most applications Delta coke drops slightly No impact from BCA on base loading Drygas & coke not impacted Enables swift transitions to LCO or gasoline mode operations BCA is a low risk option to maximize slurry conversion Min Average Max Feed Quality API 20,0 23,1 26,6 Sulfur, wt% 0,20 1,20 2,30 CCR, wt% 0,20 2,19 4,90 Nitrogen, ppm Operations Reactor Temperature, Degree.С Regen. Temperature, Degree.С Cat adds, TPD 1,4 4,3 10,0 ВСА concentration, % 3,0 7,8 12,0 Equilibrium catalyst МАТ Ni, ppm V, ppm Yield Selectivity Dry Gas -0,9-0,2 0,0 LPG -1,2 0,2 1,5 Gasoline -1,2 0,3 2,0 LCO 1,0 2,3 3,85 Slurry -3,9-1,7-0,5 Coke -0,9-0,3 0,0 22

23 Overview Evaluate upgrade potential Feed effects Histogram analysis Troubleshooting increased bottoms yields Optimize cracking severity Maximize cat-to-oil Optimize catalyst additions Optimize catalyst formulation Caveats of deep cracking The additive boost Nitrogen and poison adsorption Zeolite-to-matrix ratio optimization Summary 23

24 Conclusion Slurry conversion is readily controlled by three variables including: Catalyst circulation rate Catalyst addition rate Catalyst formulation JM offers to the industry two additives which increase the degrees of freedom available to the aggressive refiner: Cat-Aid for N adsorption & V trapping BCA for circulating inventory zeolite-tomatrix ratio control JM offers state-of-the-art additive loaders free of charge to any refiner wishing to inject these additives into their unit 24