conditions, with the ability to form a protective film on metal surfaces even in highly acidic environments (pH as low as 2). This versatility is beneficial for refineries processing var - ying crude oil qualities, where pH fluctuations are common and corrosion risks are high. x Managing high acid and high sulphur crude oils For refineries tackling high acid or high sulphur crude oils, the Predator high-temperature corrosion inhibitor provides a critical line of defence, allowing it to: • Form a uniform, dense protective film at extreme temperatures. • Prevent corrosion from naphthenic acids and active sul- phur compounds. • Maintain effectiveness without interfering with scaling inhibition. Meanwhile, Veolia developed a proprietary evaluation method to assess the actual risks in refineries that process high TAN/sulphur crude oils. This method can accurately locate the highest risk zone in the crude distillation unit (CDU). It can also help formulate strategies for monitoring corrosion and implement protective measures for equip- ment, such as corrosion inhibitor injection, pipeline diameter enlarging, loading adjustment, and crude blends change. Case study spotlight A Chinese refinery, processing high TAN crude oils, such as ≥2.5 mgKOH/g, implemented a comprehensive high-tem - perature corrosion inhibition strategy from its initial start-up phase. The facility’s challenging feedstock characteristics necessitated an exceptionally robust corrosion manage - ment approach. The proprietary Predator corrosion inhibitor technology was selected and implemented as the cornerstone of this protection strategy. Over an impressive period of four and a half years, this solution demonstrated excellent perfor - mance in safeguarding high-temperature zone equipment, enabling extended operational runs between turnarounds. The effectiveness of this corrosion inhibition programme was thoroughly validated through multiple monitoring meth- ods, including corrosion probe measurements, online ultra- sonic testing (UT), offline UT, and ion concentration analysis. The comprehensive data consistently showed that Predator provided superior corrosion protection compared to other solutions previously employed at the refinery, establishing a new benchmark for high-temperature corrosion manage- ment in high-TAN crude processing operations. Real-world success: comprehensive corrosion control The true test of any corrosion control strategy lies in its real- world application. A refinery in China serves as a testament to the effectiveness of the integrated approach when imple- menting three tools: Embreak, LoSALT, and pHilmPLUS. By implementing these tools, the refinery achieved: • Consistent dehydration and desalting efficiency over multiple years of operation. • Consistent low oil content in desalter effluent. • Effective tower top corrosion control, with iron ion con- centrations and corrosion rates well below target levels.
Vapour Phase Corrosion Inhibition @ pH ~2
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Liquid Phase Corrosion Inhibition @ pH ~2
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100 Vapour and Liquid Phase Corrosion Inhibition @ pH ~2
% inhibition Vapour Phase % inhibition Liquid Phase
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Figure 2 Filmers’ inhibition efficiency
• Stable pH control (5.5-6.5) at the tower top. • Significant reduction in maintenance requirements and no unplanned downtime. • The operation turnaround prolonged to six years. Latest evolution In recent years, Veolia has conducted research on nuclea- tion corrosion in the overhead system and developed new products to inhibit this kind of corrosion. Nucleation corro- sion is defined as corrosion that exists in the hydrocarbon flow that is supposed to have no or low potential for aque - ous corrosion. For example, corrosion of the pipelines of the overhead reflux line. The corrosion is caused by the dissolved water that is saturated in the hydrocarbon stream, and the dissolved water is acidised by some organic acids. The lab results and site application indicate that this type of corrosion is con- trollable by the pHilmPLUS product without any thickness reduction.⁴
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PTQ Q4 2025
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