Challenge

The customer needed to clear their hydrotreater of volatile vapors and product in order to allow manned entry for maintenance activities. During this process, there would be limited availability to use the flare or FGRU to purge vapors from the unit. Additionally, there were high concentrations of hydrogen gas and H2S that needed to be managed to make entry safe. Ultimately, the customer needed a supplemental system that could receive, scrub, and process excess unit vapors to maintain their project timeline.

Solution

Envent provided (2) EMECS thermal oxidizer units to combust process vapors at a 99.9% destruction rate efficiency. Additionally, Envent’s system included (4) ESCRUB recirculating scrubbers that neutralized H2S in the streams, (2) heat exchangers to cool and condense vapors, and a collection system to move condensates back to a designated containment. Lastly, additional safety measures were implemented on the thermal oxidizer to allow for safe combustion of up to 100% hydrogen streams.

Benefit

Envent’s system aided the customer by providing an additional avenue to process unit vapors, thereby allowing the customer to purge their system more quickly. The recirculating scrubbers were able to neutralize all H2S vapors in the vapor stream, eliminating any chance of hazardous SOx emissions from being formed. Additionally, the high thermal capacity of each EMECS allowed Envent to process heavily hydrocarbon-ladened vapors without compromising on flow rates. Nitrogen purge capacity was also increased due to Envent’s presence by providing the customer’s FGRU with additional capacity to manage an inert stream. Overall, the system provided by Envent reduced the customer expected turnaround timeline by ~2 days, thereby saving the end user several million dollars!