Modular Solution for Benzene Removal in Ethylene Plant Wastewater

Gulf Coast, TX
A client operating an ethylene plant required a solution to reduce benzene concentrations in wastewater effluent to meet strict environmental regulations. Achieving ultra-low benzene levels was a critical requirement for compliance.

CHALLENGE

The project posed significant challenges, including the need to prevent system fouling and achieve exceptionally low Benzene concentrations in the stripped effluent. The system was designed to target benzene levels of less than 0.1 ppm while operating at a high flow rate of 200 gallons per minute.

SOLUTION

Koch Modular designed and delivered a modular system to address the client’s requirements efficiently and reliably. The process involved steam stripping the wastewater to remove benzene and other hydrocarbons effectively.

To mitigate fouling risks, fouling-resistant Koch-Glitsch fixed-valve trays were installed in the stripping column to prevent solids accumulation. Spiral plate heat exchangers were used to preheat the feed stream by recovering heat from the boiling effluent, reducing fouling risks and enhancing energy efficiency.

Leveraging experience with the design of multiple Benzene stripping systems, Koch Modular accounted for the precise mass transfer efficiency, resulting from the high relative volatility, low concentration gradient, and high liquid-to-gas ratio. This expertise informed the selection of optimized tray efficiency, ensuring the system could meet the required benzene removal performance.

The entire system was pre-assembled as truckable modules, tested for quality and functionality before delivery. The modular design minimized on-site construction time and costs while ensuring rapid installation and commissioning at the client’s facility.

RESULTS

The modular system was designed to consistently meet stringent regulatory requirements, achieving benzene concentrations well below 0.1 ppm in the stripped effluent. The integration of fouling-resistant trays and spiral plate heat exchangers is expected to ensure continuous, reliable operation with minimal maintenance needs. By combining advanced separation technology with a modular delivery model, Koch Modular provided the client with a cost-effective, efficient solution that facilitated compliance and enhanced operational performance.