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(2011) Question 41: What is your best method for detecting nitrogen levels in reformer feeds? How effective is naphtha hydrotreating in reducing nitrogen levels?

Nitrogen in naphtha feedstock can be detected using analyzers based on pyro chemiluminescence or electrochemical measurement. Pyro chemiluminescence-based analyzers appear to be more prevalent in the industry and can detect nitrogen levels over a wide range (from ppb levels to several hundred ppm) in a matter of minutes. ASTM D4629 is a standard test method for trace nitrogen detection in liquids based on pyro chemiluminescence.
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(2011) Question 42: Are you adding hydroxyl generating compounds (methanol or other alcohols) to the chlorination zone of the continuous catalytic regeneration section of their reforming unit? What are the observed results of this procedure?

Whether or not methanol or another hydroxyl in injected into the oxy-Chlorination zone is based on the design of the regenerator. UOP designed units do not inject hydroxyls into the oxy-Chlorination zone, UOP recommends you contact the process Licensor before making any alternations to the Regeneration Tower flows or controls.
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(2011) Question 43: In order to meet RMACT 2 regulations for reducing regenerator vent gas HCl and Total Organic Carbon, some refiners use caustic scrubber vent gas wash tower systems for treating the regenerator vent gas. What has been your experience with respect to corrosion problems? Which equipment (Venturi scrubber, wash tower) and piping have corroded more often? What changes have been made in procedure and/or metallurgy to minimize corrosion?

We have three CCRs with vent gas scrubbers; all are carbon steel, and all have experienced corrosion problems.
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(2011) Question 44: What are the operating parameters, including water or chloride additions, to adjust and monitor on a continuous catalytic regeneration reforming unit when it is required to operate for a short period of time (hours/days) with the regeneration section shut down (for instance if operating in low-coke mode)?

We have four CCR/Platformers in our refineries. While two operates for gasoline production, one operates in mix mode i.e., for BT as well as for gasoline production. The other solely operates for para-xylene production.
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(2011) Question 45: What tools are you using to predict the yields of Xylene, Benzene, Toluene and other aromatics in a catalytic reformer? What methods do you use and how often do you test the feedstock for these variables? Other than feedstock quality, what factors are you accounting for in the individual yields (unit pressure, RON, etc)? Do you have any rules of thumb for conversion of certain species of aromatics?

Dedicated simulators are run for prediction, either using correlations or kinetic models. To be able to perform accurate predictions, feed analyses shall be performed every time the feedstock quality is changed: the most important one is detailed hydrocarbon analysis by gas chromatography (for instance Carburane).
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(2011) Question 46: Ethanol blending, and benzene management has shifted refinery octane and hydrogen balances. How are you managing hydrogen demand without giving away octane? Conversely, how are you, with excess hydrogen, maximizing availability for volume swell?

Mandated ethanol blending and limits on benzene in gasoline tend to lower the ceiling on the operating severity of catalytic reformers. While lower severity operation is theoretically desirable, in practice it can constrain H2 production, and impact regenerator operation due to lower coke make, which may require operational workarounds.
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