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These digital transcripts are meant to share information on process safety practices in order to help improve process safety performance and awareness throughout industry. The goal is to capture and share knowledge that could be used by other companies or sites when developing new process safety practices or improving existing ones. The documents being shared have been used by an industry member, but this does not mean it should be used or that it will produce similar results at any other site. Rather, it is an option to consider when implementing or adjusting programs and practices at a site.

BY THEMSELVES, THESE DIGITAL TRANSCRIPTS ARE NOT STANDARDS OR RECOMMENDED PRACTICES. THEY ARE NOT INTENDED TO REPLACE SOUND ENGINEERING JUDGMENT. THEY DO NOT PRECLUDE THE USE OF ALTERNATIVE METHODS THAT COMPLY WITH LEGAL REQUIREMENTS. A SUBJECT MATTER EXPERT SHOULD BE CONSULTED PRIOR TO DETERMINING WHETHER A PRACTICE CAN BE USED IN ANY SPECIFIC SITUATION.

(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 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 44: What is your recommended back up options for slide valve / plug valve Hydraulic Power Units? Are electric actuators an option? What are the response times?

What is your recommended back up options for slide valve / plug valve Hydraulic Power Units? Are electric actuators an option? What are the response times?

(2019) Question 45: What are your options to maximize light cycle oil from the FCCU (e.g. operating conditions, feedstock, recycle, equipment, catalyst, etc.)?  What are the typical unit constraints?  What projects have been considered at your facility to capture the increased value of diesel?

There are multiple ways to maximize light cycle oil from the FCC including reducing conversion, reformulating the fresh catalyst, utilizing additives, and adjusting fractionation.

(2019) Question 46: How often do you perform steam optimization in the FCC reactor? What process response and benefits do you typically see from performing "step tests" to feed nozzle, lift, and stripping steam flow rates?

How often do you perform steam optimization in the FCC reactor? What process response and benefits do you typically see from performing "step tests" to feed nozzle, lift, and stripping steam flow rates?

(2019) Question 47: For units not challenged by standpipe fluidization, are there benefits to reducing fresh catalyst 0-40 um particle content?

There are multiple benefits to reducing fresh catalyst 0–40-micron particle content for FCCs not challenged by fluidization. A significant portion of the 0-40 content cannot be retained in the FCC.

(2019) Question 49: What are your reliable methods to monitor expansion joint temperature?  Are some joints more critical than others?  What temperature range is acceptable?  How do you increase or decrease temperatures if they are out of the desired range?

What are your reliable methods to monitor expansion joint temperature?  Are some joints more critical than others?  What temperature range is acceptable?  How do you increase or decrease temperatures if they are out of the desired range?

Question 3: Please discuss your best strategies to prevent overheating of steam reforming furnaces?

The question is general; however, there are a variety of steam reformer designs with different operating and control strategies used industrially so a general answer is provided. Operators are urged to consult with their technology providers or qualified engineering contractors for specific guidance on this issue.

(2010) Question 4: In your experience, what options are available to debottleneck existing hydrogen systems and increase hydrogen production? Is hydrogen recovery from refinery off gas an economical option?

To focus the question, let us consider a refinery setup where the main hydrogen (H2) sources are the catalytic (naphtha) reformer off gas and an on-purpose steam methane reformer (SMR) for the supplemental H2.

(2010) Question 6: The use of infrared pyrometers for monitoring tube temperatures in steam reformers is a well known practice. What is your recommended frequency for use of these devices ( how many times per week)? Can you offer any recommended alternate devices or methods available such as fixed infrared pyrometer skin thermocouples or infrared imaging?

CITGO’s operating philosophy is to monitor our tubes with an optical pyrometer every shift. We monitor the tubes from multiple locations on each level of our terraced wall furnace. This method has been extremely effective in extending the life of the furnace tubes and catalyst.

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