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(2014) Question 87: The increase in light tight oil as a percentage of North American crude slate has resulted in lower FCC feed production, and consequently a reduced FCC feed rate at several refineries. To address these issues, what strategies have you implemented operationally and catalytically? Are you looking at sending new streams to the FCC or increasing the proportion of existing streams such as resid?

The increase in the quantity of tight oil as a percentage of the North American crude slate has resulted in numerous changes at refiners. Tight oils, like other light sweet crudes, have a much higher ratio of 650°F- to 650°F+ material when compared to conventional crudes.
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(2014) Question 89: What are the best practices in the industry for profitable LCO maximization? Please elaborate on (a) FCC catalyst/additive technologies, (b) Cetane maximization, (c) process design and operations strategies and (d) any impact on naphtha octane and how you mitigate it?

Maximizing light cycle oil (LCO) is largely a slurry management process. To increase LCO, refiners can simply change operating conditions and lower catalyst activity to shift operations into a lower conversion regime.
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(2014) Question 92 What is the impact of high iron you have seen in some tight oil feeds? What level of Fe on the equilibrium catalyst causes problems, and what are the typical symptoms? What changes to FCC units hardware, catalyst and operation have you implemented to manage Fe poisoning? What is the impact of other uncommon contaminants such as K, Ca and Mg?

Tight oil feeds generally have high levels of iron and calcium present in them. Iron can have a negative effect on catalyst performance. While particulate tramp iron from rusting refinery equipment does not have a significant detrimental effect on catalyst, finely dispersed iron particles in feed (either as organic compounds or as colloidal inorganic particles) can deposit on the catalyst surface, reducing its effectiveness.
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(2014) Question 93: What is your process safety concerns in withdrawing equilibrium catalyst from the FCC regenerator? How do you manage catalyst transfer piping and spent catalyst hopper temperatures? What materials of construction are appropriate (or inappropriate) for these services?

What is your process safety concerns in withdrawing equilibrium catalyst from the FCC regenerator? How do you manage catalyst transfer piping and spent catalyst hopper temperatures? What materials of construction are appropriate (or inappropriate) for these services?
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(2014) Question 94: To reduce the risk of igniting the gas mixture in the electrostatic precipitator (ESP), we are considering safety interlocks for de-energizing the ESP when carbon monoxide content gets too high. Please share your experience regarding (a) setting an appropriate trip point, (b) other interlocks to consider, and (c) advantages over operating procedures.

Automatic trip points should be set so that the CO gas concentration is well below the Lower Explosive Limit (LEL). Consideration should also be given to adding interlocks to trip the ESP based on high concentrations of methane, especially if the ESP is downstream of a CO Boiler or if there are other potential sources of fuel gas/natural gas to the ESP (even during upset conditions).
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