Q&A

Question 9: Are there specific lab studies or commercial examples regarding the effect of regenerator temperature on catalyst deactivation and particle integrity, specifically attrition properties, apparent bulk density, and morphology?

There is a very definite correlation between activity degradation and regenerative temperature. Some catalysts are more susceptible to thermal deactivation depending on the technology and the poor architecture used.

Question 10: What is your recent experience regarding the maximum level of equilibrium catalyst metals (Ni, V, Na, Fe, Ca) in FCC units processing residual feedstocks? Have there been any recent improvements in vanadium passivation technologies? At nickel levels approaching 10,000 ppm, have you experienced increased catalyst deactivation as evidenced by lower equilibrium zeolite surface area?

Here we see data regarding one of our FCCUs that operates at e-cat nickel levels exceeding 10,000 ppm. We observe that the MAT generally remains within the same range until high e-cat nickel concentrations are approached.

Question 37: What is the impact of CO (carbon monoxide) and/or CO2 (carbon dioxide) on noble metal catalyst performance?

CO and CO2are poisons for noble metal catalysts, with CO being a very strong poison. Contamination level as low as 50 to 100 ppm can result in significant and permanent loss of activity. CO should be limited to less than 10 ppm. In our experience, units which achieve long cycles (10 years plus) typically have CO levels less than 5 ppm.

Question 6: Do LTOs contain higher concentrations of nitrogen? If so, how has this higher concentration effected gasoline processing units?

The LTOs generally do not contain a higher concentration of nitrogen. LTOs are typically characterized as light, sweet, low-sulfur, low-nitrogen crudes. For example, the Eagle Ford and the Bakken nitrogen typically contains less than 2 ppm. Nonetheless, the gasoline processing units are impacted when refineries process higher percentage of the LTOs because of the crudes.

Question 2: What are the operating constraints in co-processing coker naphtha in a ULSD (ultra-low sulfur diesel) and/or a gas oil hydrotreater unit?

There are some constraints relative to processing coker naphtha. I have outlined a few of them on the slide. Key with coker naphtha are the changes in the process chemistry that occur starting, perhaps, with the dilution of the hydrogen partial pressure due to the vaporization of the naphtha.

Question 79: What tools are being used to monitor FCC performance? What are the key performance indicators and expectations?

These are two broad categories for the use of these indicators. The first category is capacity utilization and yield performance, which covers process performance, operating constraints, and optimal use of any inherent design margins.

Question 86: What test method (e.g., ASTM D86, D1160, or D2887) do you currently use to determine the distillation of FCC gasolines, cycle oils, and fractionator bottoms?

I put distillation methods into two different categories. One is simple distillation or acts of distillation, which is either a D86 or D1160. D86 is at atmospheric conditions; the D1160 would be at a vacuum.

Question 44: How is coke on catalyst in fixed-bed and moving-bed reforming units tracked? How is this data used to adjust the reactor inlet temperatures in order to maintain constant product octane?

In our cyclic units, just based on the air consumption, we can measure the coke each time a reactor comes out for a regen. We are not grabbing samples. Our experience with the cyclics is that if you get up around 8% coke on catalyst, the unit will be pushed a little too hard. You will then need to think about backing it down on feed rate octane, finding a better-quality feed, or possibly increasing the hydrogen/oil ratio.

Question 49: Does the panel have any experience using flexible thermocouples in the regeneration section of a moving-bed reforming unit? What considerations should be given to revamping units that do not have these installed?

Flexible thermocouples, as I understand, are now a part of the standard design for regenerators of moving-bed units. At a refinery in which I worked; we replaced the original slider thermocouples with multipoint thermocouples.

Question 28: What is the panel's experience in block mode operating between VGO and diesel modes? What is the frequency of change of mode and do they see any impact on catalyst activity after each switch?

While Suncor Energy, Inc. does not have any hydroprocessing units designed to routinely operate in block mode between VGO and diesel, at our Denver Refinery we have operated our ULSD unit in AGO/VGO service and routinely operate our gas oil unit in ULSD service for various reasons.

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