Challenge

An Illinois refinery required degassing services for a 169,000-barrel overflow tank that was directly tied to two active process tanks in series. This overflow tank served as a live receptacle for raw gasoline during process upsets, creating an especially challenging vapor control scenario.

Complicating the job was the high concentration of hydrogen sulfide (H₂S) present in the tank vapors, with H₂S levels fluctuating in response to upstream disturbances. Due to Envent’s strong track record managing similar projects—including previous high-H₂S degassing efforts for the same customer on the East Coast—Envent was referred internally to execute the project.

Solution

Envent Corporation engineered a combined vapor control system consisting of a:

• Thermal oxidizer (EMTOS) for high-efficiency VOC destruction

• Recirculating vapor scrubber system, designed to neutralize fluctuating H₂S levels

This dual approach provided robust hydrogen sulfide vapor control while adapting in real-time to changes in vapor composition caused by ongoing refinery process upsets.

Key components included:

• Continuous real-time vapor monitoring

• On-site field operators and engineers for safe, 24/7 operation

• Use of chemical scrubbers pre-treatment to reduce the load on the thermal oxidizer

Despite the complex tank configuration and unpredictable emissions, Envent’s equipment and expert personnel successfully controlled the toxic vapor streams, ensuring safe and compliant degassing.

Benefit

The customer achieved full regulatory compliance without halting operations and is estimated to have saved $250,000 by choosing Envent’s engineered vapor control solution over alternative options.

This project reinforced Envent’s reputation as an industry leader in high-H₂S degassing, refinery vapor control, and mobile emission control systems—delivering safe, cost-effective, and scalable solutions for the most demanding vapor challenges.

Estimated to have saved $250,000 by contracting Envent.