Challenge:
A refinery faced significant challenges with high benzene emissions from its wastewater, exceeding the Benzene Waste Operations NESHAP (BWON) requirements. Crude desalter process water, typically directed to the refinery’s Wastewater Treatment Unit (WWTU), contained high levels of dissolved benzene and phenols. These contaminants were not fully removed during primary treatment, leading to their release in an open-topped biological system, which created compliance issues. The presence of multiple constituents in crude desalter brine water makes conventional benzene stripping and removal systems difficult or cumbersome to operate effectively. As a result, benzene-laden brine water continued through their system unchecked, leading to downstream emissions.
Solution:
Envent Corporation’s engineering team, in collaboration with the refinery, developed a scalable benzene stripping solution specifically designed to address this issue. The team designed, implemented, and operated an innovative nitrogen stripping system that efficiently removed 93% of the benzene from the desalter brine water at a flow rate up to 1,250 GPM, while allowing other constituents to pass through unaffected. The stripped brine water was seamlessly reintegrated into the refinery’s wastewater treatment system. Additionally, the nitrogen-stripped benzene vapor were safely routed to a hydrogen sulfide scrubbing system and a state-of-the-art thermal oxidizer, achieving an impressive destruction efficiency of 99.9%.
Benefit:
The implemented system brought significant benefits, transforming the refinery’s wastewater treatment process. The system operated flawlessly, eliminating the need to open towers for media replacement, debris clearing, or any internal servicing, which greatly enhanced reliability and minimized operational downtime over conventional benzene stripping systems. This innovative solution also allowed the refinery to conduct extensive parameter testing, enabling fine-tuning for optimal performance. As a result, the refinery achieved a substantial reduction in benzene emissions, demonstrating Envent’s commitment to sustainability and responsible waste management.
By implementing this advanced benzene water treatment and benzene vapor control solution, Envent not only effectively addressed the refinery’s benzene emissions challenge but also reinforced our position as a leader in providing custom-tailored and sustainable environmental solutions. This project highlighted Envent’s expertise in designing and deploying cutting-edge technologies to solve complex environmental problems.
