The AquaCritox® SCWO continuous pilot unit was commissioned in November of 2023 on a petrochemical manufacturing site in Spain. The waste treated by the system is propylene oxide and styrene monomer (POSM) waste. Initial trials were conducted with waste material having a COD of 230 g/L at moderate operating temperatures. Initial tests at moderate temperature gave COD destructions >90%, higher than what was observed in the bench scale trials used for initial idea screening.
The Application
Wastewater from POSM facilities contains high concentrations of recalcitrant organic matter. For this reason, this wastewater cannot be treated by conventional wet air oxidation. Supercritical Water Oxidation (SCWO) holds the key to meeting increasingly stringent discharge limits from these facilities.
Site Operations
The AquaCritox® SCWO continuous pilot unit was deployed to site in October of 2023, commissioned in November 2023 and the first operating results were obtained in December 2023. At the time overnight, operations were not permitted, limiting the start-up time and subsequently the operating temperature. The unit was operated at moderate operating temperatures (435°C), processing waste with a COD of 230 g/L.
The process is fully automated and was remotely monitored by SCFI’s specialist team in Cork, Ireland. A contracted SCFI operator is responsible for operating and maintaining the unit on site in Spain. Treated effluent samples were collected and submitted for analysis by a third-party laboratory servicing the site.
The Success
The AquaCritox® SCWO continuous pilot unit has met the expected COD destruction efficiencies, outperforming the results achieved in the initial bench-scale idea screening trials. A COD destruction efficiency of 90% was achieved.
What’s Next
April 2024 will see the second operating campaign of SCWO testing on the site, with the aim at running at the full operating temperature of 550°C, where destruction efficiencies >99% are expected. The technology is being qualified on site before scale-up to the next phase of the project.
