The challenges of selecting the optimal catalyst for your FCC unit. MEDW 2013 Carel Pouwels, Ken Bruno

Transcription

1 The challenges of selecting the optimal catalyst for your FCC unit MEDW 2013 Carel Pouwels, Ken Bruno January 3, 2009

2 Outline 1.Is catalyst testing telling the truth? 2.The disconnect between catalyst testing and reality 3.Low Z/M catalyst performance in the FCC unit 4.FCC units versus laboratory tests 5.Summary and conclusions Page 2

3 1.0 Is catalyst testing telling the truth? The world is divided Page 3

4 Half of the FCC market is based on catalyst testing Testing vs non-testing Shares in Resid and VGO 24% 19% 28% 29% Resid Testing VGO Testing VGO Non Testing Resid Non Testing Page 4

5 High Z/M cats are predominantly used by refiners who test but non testers typically use low Z/M cats 100% 90% 80% Resid Applications High Z/M Low Z/M 70% 60% 50% 40% 30% 20% 10% 0% Testing Non-Testing 100% All Applications Remarkable is also the significant presence of dedicated V-traps in the testing segment, which we do not see in the non-testing segment 90% 80% 70% 60% 50% 40% 30% 20% 10% High Z/M Low Z/M Page 5 0% Testing Non-Testing

6 2.0 The disconnect between test and reality Example A Page 6

7 Catalyst comparison in a pilot plant shows typical high Z/M preference over low Z/M catalyst Competition UPGRADER high Z/M low Z/M YIELDS at constant conversion, wt% H Dry Gas LPG Gasoline LCO Slurry Coke Conversion Competition UPGRADER high Z/M low Z/M YIELDS at constant coke, wt% H Dry Gas LPG Gasoline LCO Slurry Coke On lab deactivated catalysts, pilot riser test data show Better bottoms cracking with UPGRADER: higher LCO and lower slurry at the same conversion But also very high coke and H2 at constant conversion Resulting in low conversion and high slurry at constant coke Conversion Page 7

8 Contrary to the lab results, the low Z/M catalyst outperforms the high Z/M catalyst in the FCCU Side-by-side Comparison Competition UPGRADER high Z/M low Z/M FEED QUALITY Density, g/ml RCR, wt% OPERATING CONDITIONS Feed rate, m3/day Base Base RxT, deg C CFT, deg C RgT, deg C delta coke YIELDS, wt% H Dry Gas LPG Gasoline LCO Slurry Coke Kcoke Much better performance with UPGRADER in FCC unit: 3 wt% lower bottoms 2 wt% more gasoline 2 wt% more LPG lower H2 and dry gas similar delta coke Conversion, wt% E-CAT QUALITY Ni, ppm V, ppm Page 8

9 Post evaluation of FCCU trial. Tests on E-cat are also not in line with FCCU yields RFCC Pilot Plant Bench Scale Unit Catalyst high Z/M low Z/M high Z/M low Z/M high Z/M low Z/M Coke, wt% Conversion, wt% Fuel gas, wt% H2, wt% LPG, wt% Gasoline, wt% LCO, wt% Slurry, wt% Kcoke, wt% Equilibrium catalysts were tested in a pilot plant and bench scale unit: Comparison made at equal coke as in the unit: Benefit in slurry yield for low Z/M diminished in pilot plant and even got worse in bench scale unit Low Z/M catalyst is penalized in coke selectivity (Kcoke) in both tests and opposite from the unit Effects in bench scale unit are worst of all Page 9

10 Example A Summary: Largest penalties are seen for bench scale units and/or when lab deactivation is applied Delta yields (low Z/M minus high Z/M) for different units and type of deactivation: Unit RFCC Pilot Plant Pilot Plant Bench Scale Deactivation Equilibrium Equilibrium Laboratory Equilibrium Coke, wt% Conversion, wt% Kcoke, wt% Slurry, wt% Type of test and type of deactivation impacts results All tests show worse performance than in the FCC unit for low Z/M catalyst Use of laboratory deactivation illustrates why low Z/M catalysts are not favored when catalyst selection is done by testing Page 10

11 Key deactivation and testing shortcomings Deactivation: Insufficient deactivation of matrix Too high activity of metals Unrealistic simulation of AAI Testing: Too long contact time Too long stripping time Difference in coke profile Hydrocarbon partial pressure General Magnitude of Coke penalty depends on deactivation and testing method And typically Slurry benefits in tests are significantly smaller than in the FCCU Page 11

12 3.0 Low Z/M catalyst performance in the FCC unit The commercial reality Page 12

13 Is Example A an exception or common reality? More than a dozen side-by-side comparisons were made: Comparing high Z/M cat versus low Z/M cat in same unit Including ALB versus ALB catalysts Including ALB versus competitive catalysts Comparing at equal/normalized conditions Covering Resid applications, but also (H)VGO cases Page 13

14 ZSA/MSA Side by side comparisons in FCC units: Z/M ratios of all the case studies High Z/M cats Low Z/M cats Page 14

15 Cases studied focused on the main drivers in catalyst selections: Coke and Slurry selectivity In these SBS comparisons we looked at the following three parameters that reflect the coke selectivity: Kinetic Coke: Coke/2nd order Conversion Delta coke: Coke/Cat to Oil ratio Regenerator temperature To complete the picture we compared the catalysts on the magnitude in slurry yield In the next graphs, Example A is highlighted for illustration purposes Page 15

16 KCoke hi Z/M, wt% High matrix (resid) catalysts do not lead to worse coke selectivity as expressed by kinetic coke All cases Example A Low Z/M catalysts do not lead to higher KCoke KCoke low Z/M, wt% Page 16

17 dcoke hi Z/M No penalty in delta coke in the FCC unit for low Z/M catalysts All cases Example A No penalty is found for high matrix catalysts dcoke low Z/M Page 17

18 RgT hi Z/M, C High matrix catalysts do not necessarily lead to higher Regenerator Temperature All cases Example A Low Z/M catalysts do not lead to higher Regenerator Temperature RgT low Z/M, C Page 18

19 Slurry hi Z/M, wt% Low Z/M catalysts always reduce slurry compared to high Z/M catalysts All cases Example A 10 5 Low Z/M catalysts always yield lower slurry Slurry low Z/M, wt% Page 19

20 4.0 FCC units versus Lab tests The commercial reality compared multiple times Page 20

21 The impact of lab deactivation High Z/M catalysts and low Z/M catalysts like in the commercial cases were also tested in the laboratory Realistic deactivation: E-cat Lab deactivation: D-cat The impact is illustrated in the Slurry Benefit versus Coke Penalty chart Page 21

22 Slurry (low Z/M) - Slurry (high Z/M), wt% Commercial versus lab tests Testing: (large) coke penalty and only little slurry benefit 2 1 FCC Unit E-cat D-cat 0 Large Coke Penalty Slurry Benefit Coke Penalty -4 Coke (low Z/M) - Coke (high Z/M), wt% Page 22

23 Slurry Benefit for low Z/M cats Catalyst lab studies usually lead to unrealistic coke yields, too small differentiation in slurry and penalizes low Z/M catalysts 1 Unit E-cat Testing D-cat testing Coke Penalty for low Z/M cats Page 23

24 5.0 Summary and conclusions Page 24

25 Summary and conclusions Half of the FCC market is based on catalyst testing Those refiners typically select and apply high Z/M catalysts Non-testing refiners predominantly use low Z/M catalysts Catalyst selections by testing are flawed by artifacts in lab deactivation and test Compared to a high Z/M catalyst in the test, the low Z/M catalyst has an insurmountable coke penalty and too small slurry benefit Catalyst suppliers typically design best in class high Z/M catalysts to win the test Refiners who rely solely on testing in many cases miss opportunities It is recommended that refiners who test, consider other methods in parallel to testing to evaluate potentially more profitable catalysts: Most valuable is to check experience of references Or greatly discount or completely eliminate any difference in laboratory coke between high and low Z/M catalysts Page 25

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