Q&A

(2010) Question 89: In shifting from partial burn to full burn in a side by side unit, what has been your observed impact on the NOx emissions? What is necessary to achieve 20 ppm NOx?

Several Grace customers successfully operate with NOx emissions less than 20 ppm in full combustion without the use of NOx removal hardware in the flue gas circuit.

(2010) Question 90: Does any refiner use an on-line particulate emissions (PM) analyzer to measure PM concentration and/or particle size distribution in the flue gas? Are any of these analyzers using continuous emission monitoring systems (CEMS)? How reliable and accurate have these systems been?

Sunoco currently has a particulate matter (PM) analyzer in one location on the stack of a Wet Gas Scrubber. It is there to measure Filterable PM only, not particle size distribution. This was installed as a requirement of a local environmental permit.

(2010) Question 91: Assuming the FCCU already has a third stage separator, what are the various options you consider for further reduction of particulate emissions (PM) and what is the expected level of PM to be achieved?

The first thing to consider is the fourth stage collector. For designs that re-introduce the collected fines downstream of the expander, a fourth stage collector with fines removal and filter on the TSS underflow gas will aid in reducing PM.

(2019) Question 33: What downstream processing issues have been associated with the overfeed of NaOH at the crude unit?

Caustic is injected with the crude charge on some units to reduce chlorides in the crude overhead system and impact the salting and corrosion potential.

Question 34: What strategies (operational, technological, logistical) do you consider for slurry streams that will not meet the IMO specifications?

What strategies (operational, technological, logistical) do you consider for slurry streams that will not meet the IMO specifications?

(2019) Question 35: What is the importance of sodium to reliability in the coker? What are some of the potential sources of the sodium in coker feed? In light of IMO how should sodium be managed in purchased coker feed?

Sodium in the coker feed can be introduced via sodium content of the salts in crude, caustic addition at the crude unit for corrosion control purposes, as a contaminant in recovered oil material in the refinery, sodium content of other purchased feedstocks (as mentioned in the question) among others.

(2019) Question 36: With higher anticipated charge rates at the coker due to IMO, what are your best practices around defoamer application to minimize impact on hydrotreater catalyst life?

With higher anticipated charge rates at the coker due to IMO, what are your best practices around defoamer application to minimize impact on hydrotreater catalyst life?

(2019) Question 37: With higher anticipated charge rates at the coker due to IMO, what are your best practices around defoamer application to minimize impact on hydrotreater catalyst life?

As equipment ages and reaches end of useful life, the opportunity arises with necessary replacement to include enhancements or upgrades at little additional cost.

(2019) Question 40: What rationale have you used to justify replacing the FCCU regenerator or reactor vessel?

What rationale have you used to justify replacing the FCCU regenerator or reactor vessel?

(2019) Question 41: How reliable are main air blower check valves?  What are some improved designs or some things to avoid?  Are there any alternatives?  If multiple branches, is there one check valve in the main branch or one check valve per branch, where is it located?  What is your maintenance or inspection best practices?

How reliable are main air blower check valves?  What are some improved designs or some things to avoid?  Are there any alternatives?  If multiple branches, is there one check valve in the main branch or one check valve per branch, where is it located?  What is your maintenance or inspection best practices?

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