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Reply To: Injecting DMDS to coker heater

Home Forums Coking Injecting DMDS to coker heater Reply To: Injecting DMDS to coker heater


Mike Kimbrell

I believe that there is enough sulfur in the normal Coker heater feed to generate sufficient amounts of H2S to react with the metal surface of the heater tubes. Addition of DMDS would not increase the H2S content enough to have a significant impact on heater coking rates.

The applications where this DMDS injection is utilized are those that do not have any sulfur in the feed. The CCR heater feed is typically desulfurized down to less than 0.5 ppm sulfur. Ethylene cracker heaters practice the same sort of sulfur passivation, but their feed is free of sulfur.

I think the addition of DMDS will not change the Coker heater fouling rate. Heat flux is probably the most leveraging parameter on heater fouling as it controls the film temperature followed by the concentration of coke precursors in the Coker feed and the residence time at temperature.

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