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Chemical and Process Engineering Resources

Pyrophoric Iron Fires

Nov 08 2010 01:30 PM | Mukesh Sahdev in Safety and Pressure Relief -----

Solvent/Surfactant Steam Dispersion Methods

There are alternatives to the steam, wash, blind, and wash again technologies.  These include steam dispersion technologies which are sometimes combined with oxidizer washing technologies.   These alternatives may include steam dispersion of organic solvent products and can be very good to excellent de-oiling and degassing compositions (which expose pyrophoric iron sulfide to subsequent oxidizer treatments).

For critical path process units in a turnaround, a very generic procedure may include:

  1. Stop feed and de-inventory the process equipment per normal procedures.  Sometimes this involves steaming and sometimes water displacement.
  2. Establish a steam flow throughout the equipment.  The design of the flow path is critical.
  3. Add chemicals to the incoming steam to promote de-oiling and degassing of the equipment (this may involve numerous injection points).
  4. When the outflow vapors are within safety and environmental specifications, blow down the equipment to the atmosphere for a short time (or continue to flare or condenser as needed).
  5. Perform isolation as needed prior to final washing for oxidation (per pre-designed isolation plan).
  6. Perform a thorough water wash with oxidizer until the oxidation requirement of the fluid path is complete.  Sometimes this must involve total fluid fill of the equipment to obtain positive contact of pyrophoric surfaces.
  7. The unit is then ready for opening, ventilation, and hot work (unless other chemical treatments are required).

This generic procedure may allow for 24-48 hours of savings over the extended steaming, isolation, and washing approaches, and may be safer to perform.  There are several products currently offering this type of service.  Many of them are strong encapsulators and require secondary treatment to break the emulsions.

The oxidizers Zyme-Flow and Zyme-Ox are proprietary products from United Laboratories International, LLC for most refinery and petrochemical decontamination applications.  For more information on Zyme-FlowSM Process Technology, the readers can visit www.zymeflow.com or contact.

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h2s is very poisonous too
found in gas processing processing
s is send to other companies