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Improve Atmospheric Column Overhead Corrosion Mitigation through Cloud-Based, Continuous Salt Point Corrosion Monitoring

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Corrosion in atmospheric column overheads in refineries presents significant challenges to the integrity and efficiency of these critical units. To mitigate the detrimental effects of corrosion, effective monitoring and control strategies are essential. This conference paper introduces an innovative approach to enhance corrosion mitigation in atmospheric column overheads through cloud-based, continuous salt point corrosion monitoring.

Product Number: MECC23-19941-SG
Author: Ezequiel Vicent
Publication Date: 2023
$20.00
$20.00
$20.00

Atmospheric Crude Unit Overheads are highly susceptible to corrosion and fouling due to the inefficient removal of chlorides in the desalter and subsequent hydrochloric acid (HCl) generation in the crude furnace. Refiners apply neutralizing amines to raise the condensed phase pH and add water wash (if an injection system exists) to wash away salts that may form and prevent corrosion.


Understanding the overhead chemistry as it relates to the temperature and pressure conditions that dictate the targeted product (gasoline or diesel mode) is crucial to maintain an on-stream factor of 95% or better. Operating the overhead in ranges where an acidic ionic slurry forms (salt point corrosion) or where solid salts are allowed to form and deposit (corrosion and fouling) can lead to unexpected shutdowns.


Such an unexpected shutdown may last an average of 7 to14 days, corresponding to a 4% reduction in the unit’s annual onstream factor. For a 150 kbpd unit with a crack spread of $10/bbl, this amounts to an $11MM USD to $21MM USD loss in revenue. For example, a refinery in the US [1] shut down its small CDU, which processes 80 kbpd of crude. The refinery shut down the unit on July 9, 2018 and expected the downtime to last until July 25, 2018 for a duration of 16 days and revenue loss of 12.8 MMUSD (assuming the crack spread is $10/bbl). Eliminating, mitigating, or even reducing this risk allows refiners to avoid these unplanned shutdowns and profit losses.


In this paper, we discuss why deep electrolyte and ionic modeling are critical for rigorous and accurate ionic dew point and salt deposition predictions. We will discuss how the OLI’s Mixed Solvent Electrolyte (MSE) thermodynamic model, now accessible through OLI’s cloud APIs, can be adapted to automatically calculate the performance of neutralizing amines in multi-phase systems while adapting to the effects of changing operating conditions. We will also discuss how these models for continuous corrosion monitoring and mitigation will enable rapid and cost-effective response and empower operational asset management through digital transformation of this critical unit.

Atmospheric Crude Unit Overheads are highly susceptible to corrosion and fouling due to the inefficient removal of chlorides in the desalter and subsequent hydrochloric acid (HCl) generation in the crude furnace. Refiners apply neutralizing amines to raise the condensed phase pH and add water wash (if an injection system exists) to wash away salts that may form and prevent corrosion.


Understanding the overhead chemistry as it relates to the temperature and pressure conditions that dictate the targeted product (gasoline or diesel mode) is crucial to maintain an on-stream factor of 95% or better. Operating the overhead in ranges where an acidic ionic slurry forms (salt point corrosion) or where solid salts are allowed to form and deposit (corrosion and fouling) can lead to unexpected shutdowns.


Such an unexpected shutdown may last an average of 7 to14 days, corresponding to a 4% reduction in the unit’s annual onstream factor. For a 150 kbpd unit with a crack spread of $10/bbl, this amounts to an $11MM USD to $21MM USD loss in revenue. For example, a refinery in the US [1] shut down its small CDU, which processes 80 kbpd of crude. The refinery shut down the unit on July 9, 2018 and expected the downtime to last until July 25, 2018 for a duration of 16 days and revenue loss of 12.8 MMUSD (assuming the crack spread is $10/bbl). Eliminating, mitigating, or even reducing this risk allows refiners to avoid these unplanned shutdowns and profit losses.


In this paper, we discuss why deep electrolyte and ionic modeling are critical for rigorous and accurate ionic dew point and salt deposition predictions. We will discuss how the OLI’s Mixed Solvent Electrolyte (MSE) thermodynamic model, now accessible through OLI’s cloud APIs, can be adapted to automatically calculate the performance of neutralizing amines in multi-phase systems while adapting to the effects of changing operating conditions. We will also discuss how these models for continuous corrosion monitoring and mitigation will enable rapid and cost-effective response and empower operational asset management through digital transformation of this critical unit.

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