Chemical Decontamination

Chemical decontamination is the pre-maintenance activities in Refinery and Petrochemical Industries. It roles has become an integral part of efficient unit turnarounds for safer and faster turnarounds.

Without effective decontamination, there may be delays to vessel entry due to internal conditions, which can lead to additional clean-out operations, delays, personnel and plant-sequence issues, refurbishment and retrofit operations being put on standby, loss of production and escalating costs.

Traditional unit preparation work, including steaming to atmosphere or a flare and hydrocarbon flushing, is time-consuming and can leave hidden pockets of hazardous contaminants.

Decontamination during turnaround (TA) can lead to high exposure to toxic gases, hydrocarbon and chemicals among workers. Turnarounds are time critical, with every minute of downtime costing the operator lost revenue.

Before mechanical works, all hazardous substances must be removed from the plant equipment.

The decontamination process in refinery plants usually comprises two methods, – steaming and circulation.

No matter what method used, continuous monitoring of toxic gases by using the direct reading instrument must be measured at the end of each decontamination cycle, which may be repeated several times until the reading are in acceptable level.

Decontamination can be achieved by circulating chemical solution at low concentration, injecting chemicals with steam or a combination of both.

The exact approach depends on the equipment configuration, fouling mechanism, and deposit analysis.