Spent Caustic Extraction and BTEX Stripper System

Middle East Client
The client required a solution to remove fouling polymers from a spent caustic stream and strip Benzene, Toluene, Ethylbenzene, and Xylenes (BTEX) to meet strict environmental regulations. Achieving ultra-low BTEX concentrations was essential for compliance with discharge standards.

CHALLENGE

The project involved addressing several critical challenges, including preventing fouling caused by polymer accumulation, selecting materials resistant to corrosion from the caustic salts, and achieving exceptionally low BTEX concentrations in the effluent, targeting levels below 10 ppb.

SOLUTION

Koch Modular implemented a comprehensive, modular solution tailored to the client’s specific needs. The system design began with liquid-liquid extraction to remove fouling polymers from the feed stream. The pretreated stream was then processed in a steam stripping column to remove BTEX. To ensure reliability and efficiency, fouling-resistant Koch-Glitsch fixed-valve trays were installed in the stripping column, and spiral plate heat exchangers were used to preheat the feed while minimizing fouling risks.

Duplex Alloy 2205 was selected for equipment in contact with the salty solution, providing excellent resistance to corrosion in this aggressive environment. Koch Modular’s expertise in mass transfer design enabled the precise selection of tray efficiency to address the low concentration gradient and high liquid-to-gas ratio unique to this system.

The entire system was constructed as pre-assembled, truckable modules. This modular approach will minimize on-site construction time and costs while ensuring quality control during fabrication. Modules were fully tested before delivery, allowing for seamless integration and expedited commissioning at the client’s facility upon arrival.

RESULTS

The modular system was designed to meet stringent EPA requirements, achieving BTEX concentrations well below 10 ppb in the stripped effluent. The incorporation of fouling-resistant technology and corrosion-resistant materials ensured continuous, reliable operation with minimal maintenance. Delivered in a modular format, the system offers the client significant advantages in terms of reduced installation timelines, lower construction costs, and enhanced operational efficiency. Koch Modular’s experience-driven approach ensures a robust, efficient solution that met both environmental and operational goals.