Background
The world’s largest FCC Unit was scheduled for a major shutdown to further increase its capacity. In order to reduce the duration of the plant turnaround,
the client challenged TerraChem® to engineer and execute a full-system decontamination to encompass all vessels and lines in the unit at once,
including even the unit’s flushing oil circuit and flare systems, with the assurance that any and every line in the unit could be cut without safety risks.
Furthermore, the client wanted a guarantee of zero H2S, zero LEL, no pyrophoric material, and less than 1.0 ppm of benzene in the process lines
and equipment throughout the entire unit. The scope of the decontamination included the FCC Feed System, the Main Fractionator System and all its
associated circuits, the complete Gas Plant, the Absorbers, and the unit’s 3 different Flare Systems.

Application
TerraChem® engineered the job to cover the decontamination of all the FCC systems as listed above, developed step-by- step decontamination procedures
for each system and carried out the training for all operations personnel. All job resource requirements such as manpower support, pump specs,
temporary piping, water and steam flow rates, were assessed and specified by TerraChem®.
TerraChem® utilized its proprietary TC-5000 formulation for the job, a state of the art and new-generation decontamination product. TC-5000 was applied at
a 1.5% concentration in water for the Feed System and FCC Fractionator at 185º F for twelve hours and then the wash emulsion was rinsed away. For the
Gas Plant, the Absorbers, and the Flare Systems, TC-5000 was applied at a lower concentration.

Results
The result of the decontamination exceeded all expectations. The client found no coke or solids in the entire unit, zero LEL, zero H2S, zero benzene and no
pyrophoric material in the piping and process equipment. This allowed the client to issue hot work permits throughout the entire plant without a single fire or
safety related incident, achieving over 500 line cuts on the first day alone. As a result, the client was able to modify and install new spool pieces and piping in
the unit in record time. In addition, finding no solids in the entire plant, including the main column bottom and the Slurry circuit, allowed the client to save a significant amount of time and resources following decontamination with TC5000.

Background:
The world’s largest Delayed Coker Unit was scheduled for a major shutdown in to further increase its capacity. In order to reduce the duration of the plant
turnaround, the client challenged TerraChem® to engineer and execute a full-unit decontamination to encompass all vessels and lines in the unit at once, with the assurance that any and every line in the unit could be cut without risk of explosion and fire. Furthermore, the client wanted a guarantee of finding zero
H2S, zero LEL, no pyrophoric material, and less than 1.0 ppm of benzene in the process lines and equipment throughout the entire unit. Systems to be
decontaminated included the Feed Train, the Main Fractionator System and all its associated loops, the Gas Plant, the Absorbers, and the Blowdown circuit.

Application:
TerraChem® engineered the job to cover the decontamination of all the Coker systems as listed above, developed step-by- step decontamination procedures for
each system and carried out the training for all the operations personnel. All job resource requirements such as manpower support, pump specs, temporary
piping, water & steam rates, etc., were assessed and specified by TerraChem®. TerraChem® utilized its proprietary TC-5000 formulation for the job, a state of the art and new-generation decontamination product. TC-5000 was applied at a 1.5% concentration in water for the main Coker Fractionator and Blowdown
circuits at 185º F for twelve hours and then the wash emulsion was rinsed away. For the gas plant circuit, TC-5000 was applied at a lower concentration.

Results:
All the Coker Unit systems were released for maintenance work only 60 hours after plant feed-out, which exceeded all expectations. The actual duration of the
TC-5000 decontamination lasted only 36 hours. The client found zero LEL, zero H2S, and zero benzene in the process equipment. The client also found 75%
less free coke in the main column bottom than when cleaning it by conventional methods. Even the VR feed exchangers were pulled easily and were found to be
very clean after the decontamination, with no solids and hydrocarbons on both the shell side and the tube side of the exchangers. The client issued hot work
permits throughout the entire plant immediately following the decontamination with TC-5000, without having a single fire or safety related incident, and was able
to bring the plant back online in record time.