A client asked Envent to help them to do the vapor control on the fuel gas recovery line at their refinery during their hydrogen plant turnaround event. As the hydrogen plant was being taken offline, the refinery fuel gas consumption would decrease, causing an excess of fuel gas. The excess capacity of the fuel gas line that Envent needed to control was as high as 3 million standard cubic feet per day, while also maintaining compliance with Envent’s Alternative Monitoring Plan from the Environmental Protection Agency.
Extensive engineering efforts were involved to overcome the customer’s challenge. A pressure loss study for two parallel streams of high pressure fuel gas was conducted to size regulator systems. Project-specific upgrades were implemented on the thermal oxidizer control systems. Control and isolation valves were designed into the system during a project PHA to handle unforeseen process conditions. Specialty, auxiliary detonation arrestors were installed to mitigate additional hazards; analyzers were installed to monitor key process conditions.
With this flexible, but thoroughly engineered solution, the fuel gas vapors were treated successfully without any environmental or safety incidents. Knowing that their fuel gas recovery system was in good hands, our customer completed their turnaround faster than it had ever been done before.