ERTC 2025
These insights underpin the design of CAT-AID additive, a metals trap that cap- tures both iron and silica, preventing the formation of harmful nodules. How CAT-AID additive works CAT-AID additive is added at ~10% of the circulating inventory. Initially silica-free, it accumulates mobile silica in the regenera- tor. It is proposed that when an iron-con- taminated base catalyst particle collides with a CAT-AID particle, silica in the iron– silica layer reacts with magnesium in the additive to form stable magnesium sili- cate. This immobilises silica and captures iron on the additive surface ( Figure 1 ). The result is twofold: u Restored base catalyst activity by pre- venting new nodules and alleviating exist- ing poisoning. v Improved metal management overall, as CAT-AID additive also traps vanadium and contributes to SOx reduction. Microscopy confirms smoother Ecat surfaces and fewer nodules when CAT-AID additive is used. Figure 2 presents Ecat particles before and after the use of CAT- AID metals trap. Refinery case study An Asian refiner is processing a mixture of Arabian and local crudes. Its two-stage RFCC unit processes a mixture of light vacuum gas oil (VGO), coker gas oil (CGO), and heavy atmospheric residue (AR), and had relied on high fresh catalyst usage to manage metals. The refinery is primarily seeking to maximise high metals feed (AR) while increasing LPG and gasoline yields. CAT-AID additive was selected to manage metals contamination. Thanks to a sep- arate addition system, the additive was base-loaded to expedite the additive con- centration build-up in the circulating cata- lyst inventory, and then was evaluated at a steady-state concentration. Results included ( Table 1 ): • Increased usage of heavier feed. • Improved conversion at a similar riser severity despite heavier feed. • At a similar coke yield, the regenerator
Results of the CAT-AID additive trial
did you know? With targeted solutions like CAT-AID additive, refiners can mitigate iron poisoning, restore catalyst performance, and enhance profitability
w/o CAT-AID
w/CAT-AID 34.2/4,926
Delta
Feed rate (KBPD/TPD) Per cent heavy AR (%) Riser temp (F/°C) Regen 1 temp (F/°C) Regen 2 temp (F/°C) Delta coke regen 2 (wt%)
33.7/4,847
-+0.5/+79
42.0
46.7
+4.7
912/489
915/490 1,179/637 1,302/706
+3/+1
1,201/650 1,313/712
-22/-12
-11/-6 -0.03
0.68 71.0
0.65 72.2
Ecat activity (wt%)
+1.2 +207 +185 +3.7 -0.3 +1 .5 +2.6
Ecat V (ppm)
6,043 5,776
6,250 5,961
Ecat Fe 2
O
(ppm)
3
Conversion (wt%) Dry gas yield (wt%)
75.0
78.7
4.6 21.1
4.3
LPG yield (wt%)
22.6 44.2 15.3 6.0
Gasoline yield (wt%) LCO yield (wt%) Slurry yield (wt%)
41.6 18.4
-3.1
6.6
-0.6 -0.1
Coke yield (wt%)
7.7
7.6
Table 1
a mismatch from heaven, PTQ, May 2014 3 Todd Hochheiser, Yali Tang, Mehdi Allahverdi and Bart de Graaf, FCC addi- tive improves residue processing eco- nomics with high iron feeds, AFPM Annual Meeting, 2014 4 Adam Toenjes, Todd Hochheiser, Heather Blair, Setting the trap, Hydrocarbon Engineering, March 2019 5 Kalirai, U. Boesenberg, G. Falkenberg, F. Meirer, B.M. Weckhuysen, ChemCatChem 7 (2015) 3674–3682. X-ray Fluorescence Tomography of Aged Fluid-Catalytic- Cracking Catalyst Particles Reveals Insight into Metal Deposition Processes 6 Zhaoyong Liu, Zhongdong Zhang, Pusheng Liu, Jianing Zhai, and Chaohe Yang, “Iron Contamination Mechanism and Reaction Performance Research on FCC Catalyst” Journal of Nanotechnology, Volume 2015, Article ID 273859 7 J.M.M.; Sousa-Aguiar, E.F.; Aranda, D.A.G. “FCC Catalyst Accessibility – A review”, Catalysts 2023, 13, 784 8 Question 81: Under what conditions is iron on FCC catalyst mobile, and how does this affect catalyst performance? 2015 AFPM Q&A AND TECHNOLOGY FORUM
• Reduced SOx emissions, SOx reduction additive usage, and/or scrubber caustic soda consumption. • Improved Ecat circulation/fluidisation. Conclusions Metals-rich crudes present both risk and opportunity. Left unmanaged, iron con- tamination reduces catalyst efficiency and increases costs. With targeted solutions like CAT-AID additive, refiners can miti- gate iron poisoning, restore catalyst per- formance, and enhance profitability. Advances in characterisation techniques have revealed the mechanisms of iron dep- osition and mobility, enabling smarter, more effective additives. By combining fundamental science with proven commer- cial performance, refiners can confidently process lower-cost, high-iron crudes and unlock greater value. References 1 Zhu Yuxia, Du Quansheng, Lin Wei, Tang Liwen, Long Jun, Studies in Surface Science and Catalysis, Volume 166, 2007, Pages 201-212, “Studies of Iron Effects on FCC Catalysts” 2 Bart de Graaf, Yali Tang, Jeff Oberlin and Paul Diddams, Shale crudes and FCC:
temperature decreased. The new operat- ing window resulted from a reduction in delta-coke with CAT-AID additive. • Increased Ecat activity despite higher metals loading, enabling deeper cracking, leaving less coke on the spent catalyst for the same coke yield per feed. • Maximised gasoline and LPG yields, as per refinery objectives. Overall, the refinery realised an addi- tional $0.80 per barrel of feed margin, equating to ~$10M/year additional profit, net of CAT-AID additive cost. Broader benefits Beyond this case, CAT-AID additive gives refiners the flexibility to optimise opera- tions. By trapping iron and vanadium, it leads to more desirable reactions, lowering delta coke and enabling refiners to capture multiple benefits: • Increased feed rate and residue processing. • Lower regenerator temperature and improved heat balance. • Higher conversion, decreased H₂/dry gas. • Increased LPG olefinicity. • Lowered fresh and/or flushing Ecat addi- tion rates.
Contact: Marie.Goret-Rana@matthey.com
digitalrefining.com is the most extensive source of freely available information on all aspects of the refining, gas and petrochemical processing industries.
It provides a constantly growing database of technical articles, company literature, videos, industry news and events.
10
dr half 22.indd 1
05/04/2022 12:41:58
Powered by FlippingBook