In mid April 2016 a Northern California Refinery discovered a seal leak on a 145 ft. diameter x 75 ft. tall above ground external floating roof storage tank that was in Sour Naptha service. Due to the sour nature of the product in the tank, this seal leak presented substantial safety and environmental hazards to any personnel working at the refinery as well as to the surrounding community.
Envent responded quickly to the Northern California Refinery’s emergency and provided a BAAQMD permitted dual column packed bed recirculating H2S scrubber along with our EMTOS-2000. Initial concentrations of H2S during the degas were ~600ppm at the inlet of the H2S scrubber and 0 at the inlet to the EMTOS 2000, thermal oxidizer. Envent simultaneously managed N2 flow keeping O2 less than 12% eliminating pyrophoric hazards.
Our engineered solutions and expedited deployment allowed us to safely degas this Sour Naptha tank. Once the concentrations of H2S dropped to below zero ppm we were able to utilize a bypass around the scrubber to enable a higher flow rate from the tank. This allowed us to finish the tank five days faster than expected. Ultimately with the fast turnaround, Envent was able to save this Northern California refinery ~$30,000 on the project and protected the community from hazardous H2S vapors.