Challenge

A refinery contacted Envent Corporation to perform tank degassing on a 150,000-barrel internal floating roof (IFR) tank in preparation for inspection. The tank contained gasoline, a product with a high BTU per cubic foot, making it essential to size a thermal oxidizer correctly to avoid unsafe operating conditions. The tank’s vapor composition posed potential hazards due to volatile organic compounds (VOCs), and failure to degas effectively could delay the inspection schedule and result in significant fines.

Solution

Envent’s engineering team evaluated the tank’s vapor space, flow rate, and product BTU content to select the appropriate mobile thermal oxidizer from our industry-leading fleet. The chosen EMTOS unit met EPA BACT standards, capable of operating safely above 1400 °F to ensure >99.9% destruction efficiency (DRE) of high-BTU vapors.

Key actions included:

• Matching pump-out flow rates with vapor destruction capacity to avoid applying excessive vacuum that could collapse the floating roof

• Advising the customer that water washing must not begin until LEL levels are <50%, ensuring safe tank cleaning operations

• Capturing and destroying all vapors using refinery vapor control methods tailored for high-performance tanks

This approach ensured complete control of the emissions, even as the vapor profile changed during the degassing process.

Benefit

With Envent’s expert planning and use of a properly sized thermal oxidizer, the refinery safely completed the tank degassing and conducted the inspection before the regulatory deadline—avoiding costly non-compliance penalties. The client also gained critical operational insight regarding tank vapor management and safe LEL thresholds during water washing.

This project highlights Envent’s leadership in refinery degassing solutions, turnaround vapor control, and high-BTU vapor control systems—delivering safe, fast, and compliant results for complex tank operations.