The Challenge

The nature of the steam cracking process presents particular challenges when it comes to decontamination in preparation for inspection and maintenance. In the past, a large Gulf States petrochemical plant has had problems cleaning their steam cracker fractionator and associated equipment:

  • The steam cracking process involves a unique combination of intermediate and heavy hydrocarbon, laden with benzene. Achieving a benzenefree environment had been problematic during past shutdowns.
  • The tower circulates heavy quench oil that becomes loaded with coke fines. Ineffective cleaning processes left heavy oil on the lower trays and base of the column.
  • Equipment on the unit is very large, with high volume process circulation loops. Legacy circulation cleaning procedures created massive amounts of effluent.
  • Finally, polymer beads in the rectifier (gasoline) section of the tower contained pyrophoric material that historically was difficult to deactivate.

The Solution

After learning of Refined Technologies’ patented processes for quickly and effectively cleaning oil refinery equipment from its parent company’s best practices program, the plant decided to use Refined Technologies’ Vaporganic® process to solve decontamination problems during an upcoming turnaround. The Vaporganic process is a patented once-through method that removes heavy oil and gasses (H2S, LEL, Benzene) using a vaporized organic solvent. Refined Technologies designed a plan to clean the primary fractionator together with the fuel oil and gasoline strippers, associated piping, and heat exchangers. The plan included MOC-level detailed procedures, a materials list, and drawings to illustrate each step of the procedure. The overview shown here generally illustrates the approach planned for the project. Following the Vaporganic process, a short cascade liquid rinse would be performed on the tower to remove dissolved heavy oil and to treat certain tower sections for pyrophorics. Unfortunately, the unit crashed before reaching the turnaround. When notified of the outage, Refined Technologies immediately mobilized a team of professionals to implement the cleaning plan.

The Results

With a cleaning plan already in place, Refined Technologies was able to remove all measureable quantities of benzene, LEL and H2S despite difficult unit conditions caused by the unexpected shutdown and damaged equipment. During previous turnarounds, the facility had labored 3-5 days in attempts to achieve acceptable levels for benzene readings. The Refined Technologies’ process allowed them to gain entry immediately after chemical cleaning and created only one-tenth the amount of effluent generated during previous cleanings. Refined Technologies also completely deactivated the pyrophoric material. The client stated that the unit was also cleaner than ever before.

The client was impressed with the quality of the cleaning plan, the professionalism of the RTI employees in the field and the results that were achieved despite the unusual circumstances. Future turnarounds will incorporate the plans developed for this turnaround and concepts included in a Lessons Learned document prepared by Refined Technologies after the project. The turnaround team is recommending Refined Technologies to other olefin facilities in their company.

Refined Technologies is committed to serving the chemical cleaning needs of the Petrochemical Industry. For additional information concerning applications such as this, please contact us at (888) 634-3183 or e-mail us at cservice@r-t-i.com.

Steam Cracking Fractionator Cleaning

Steam Cracking Fractionator Cleaning