Q&A

(2015) Question 62: When increasing the vacuum tower cutpoint, what measures have you employed to mitigate the impact of chlorides in the overhead diesel or light vacuum gas oil sections of the vacuum tower?

Calcium chloride is likely the bigger culprit in vacuum towers. If there is a 100°F difference in crude and vacuum transfer temperatures, some hydrolysis in the vacuum tower will occur. If the desired vacuum tower cutpoint can be achieved in a different way other than maximizing vacuum heater temperature, such as lowering column pressure, hydrolysis and subsequent salt formation will be reduced.

(2015) Question 63: What type of facilities have you used to cool hot vacuum residue going to storage to avoid plugging problems and facilitate reprocessing?

I am going to focus on the system we have and also some of the issues we have experienced. The majority of our resid that is produced off the crude unit vacuum towers is sent through the hot resid system straight to the cokers. We have two crude unit trains.

(2015) Question 64: What are acceptable makeup water streams that can be used for coke cutting which will not affect the coke quality?

With regard to coke quality, a lot of the available streams are acceptable. A few of the additional considerations to take into account are: Is this makeup water stream going to add overall load to my wastewater treatment facility? Is this new water? Is this water that I can recycle? Streams that are acceptable are: stripped sour water. If you are not reusing this water at your desalters or FCC wet gas scrubbers, then it would be an acceptable stream.

(2015) Question 65: Discuss operating conditions and economic drivers to produce maximum diesel from the coker.

When your margins indicate the need to pull more diesel, you have two options: You can check the top of your tower, or you can adjust overhead temperatures and fractionations to confirm that you are pushing the maximum amount of heavy naphtha down into the diesel.

(2015) Question 66: Concerning new regulations for lower coke drum pressure prior to opening, what changes will you make?

Amec Foster Wheeler has several designs that could be incorporated in existing units to meet the expected EPA mandate of depressurizing the drums to 2 psig or less prior to opening the vent. Options include adding an ejector or vent gas compressor to lower the drum pressure.

(2015) Question 67: The industry continues to experience process safety incidents associated with FCC electrostatic precipitators. What are you doing to prevent these incidents?

Phillips 66 has six ESPs (electrostatic precipitators) in service. We have not been immune to serious incidents on our ESPs. In 1994, we had an ESP explosion, which led to a fatality. So, in order to minimize the likelihood of these kinds of incidents happening again, the company has a standard that all of the refineries are required to follow.

(2015) Question 68: How does your organization share operational and process safety information to foster an environment of continuous improvement?

MPC utilizes the AFPM Safety Portal to communicate and share experiences and knowledge within our FCC Advisory Group. It is a vital component of our goal to improve process safety performance. We also have a Process Safety Advisory Program to learn from external industry and internal MPC process safety events, significant near misses, and high value learning events.

(2015) Question 69: What criteria do you follow to decide installation of remote-operated isolation valves to arrest loss of containment from vessels, column bottoms, etc.? Do you recommend any safeguards to avoid spurious activation of these remote-operated valves?

Remotely operated isolation valves are used to isolate systems during loss of primary containment to prevent further leakage that can lead to pool fires or vapor cloud explosions. They are manual valves, which are activated by pushing a button on the local panel that is located at a safe distance from the valve.

(2015) Question 70: With environmental regulations becoming more stringent on FCC stack emissions, what are your available options to achieve the required level of SOx (sulfur oxide) and NOx (nitrogen oxide) emissions?

From both the SOx and NOx perspective, there is a cat feed hydrotreater that will reduce both your sulfur and nitrogen compounds in the feed to your cat cracker, which will produce lower SOx and NOx emissions. It will reduce your metals in the feed and increase the hydrogen content of the feed, which will improve FCC unit conversion.

(2015) Question 71: Describe your practices for minimizing flaring and flue gas emissions during startup, shutdown, and malfunction operations?

Our Marathon FCCs all have a flareless startup procedure, but the type of equipment we have at our different FCCs varies somewhat. I pulled together an overview of what we have at our different plants and some licensor recommendations I learned through discussions I have had with them. I think we all agree that it makes sense, from a financial standpoint, to recover that material enough, whether or not the environmental stance is compelling us. It is just a part of being a good neighbor to the community in which we operate.

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