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Degassing and Decontamination Services


Degassing and Decontamination of a Crude Unit

This was the first vapour-phase application where the entire crude unit was to be degassed and decontaminated simultaneously.

Previously, the client had broken down the unit into separate individual stages with each degassing operation taking place over 48-hours. Our process took 24-hours total; saving one day of outage time over an individual stage, and several days on a cumulative basis.

FQE® Solvent-H was injected into the crude column and vacuum tower during the vapour phase as part of the preliminary decontamination in order to target the heavy oils and sludge. Immediately following this initial injection, the remainder of our degassing chemistry was injected as per the engineered procedure.

Twenty-four hours after initial injection, all equipment in the crude unit was successfully degassed using this method with no LEL’s arising from light end hydrocarbons or hydrogen sulfide present on analysis. Furthermore, upon breaking containment there was no iron sulfide scale combustion encountered.

Manpower designated for vessel entry entered without any delays, minimum PPE, and no additional expenses were required for supplied air operations.

Performing this simultaneous decontamination and degassing, saved this client over 5 times the amount of chemistry that would otherwise be required to perform a traditional, liquid circulation decontamination.

The crude unit scope consisted of the following major equipment and all interconnecting piping:

Crude Column
Crude Heater
Crude Column
Kerosene Stripper
Diesel Stripper
Crude Overhead Receiver
Vacuum Column
Vacuum Heater
Vacuum Column
Ejector Vapour Knock-out Drum
Debutanizer & Splitter
Debutanizer Column
Debutanizer Overhead Receiver
Splitter Column
Splitter Overhead Receiver
Crude Overhead Receiver
Kerosene Water Settling Drum
Desalter Water Drum
Debutanizer Charge Drum
Compressor Suction Drum
Skimmed Naphtha Drum


  • 5x less chemistry required compared to traditional decontamination
  • No additional expenses associated with supplied air and associated PPE for manpower vessel entry
  • Reduced schedule over traditional cleaning methods

Removing Solid Asphalt Via Vapour Phase


Video Overview

This experiment was set up to determine the efficiency of asphaltene dissolution using FQE Solvent-H versus two industry alternatives and water. As evidenced in the experiment, the soluble asphaltene was completely dissolved with vapor phase application of FQE Solvent-H. The alternatives tested essentially yielded the same results as using water (steam).

At the end of an hour, when only insoluble coke remained in the FQE beaker, a spatula was used to easily remove particulates from the beaker wall. FQE Solvent-H condensate was then transferred with the spatula to the other three beakers. The powerful active ingredients of FQE Solvent-H, in condensate, was able to solubilize the deposits in the remaining beakers.

In essence, the experiment mimics decontamination of vertical vessels using a vapor phase cleaning technique. The asphalt along the side of the beakers represent heavy fouling of vessels and process equipment, easily addressed by FQE Solvent-H.

Dissolving Crystalline Asphalt


Chemicals Utilized

FQE Solvent-H
FQE Pyrophoric

Industry Insights

Visit our Industry Insights Blog for more articles on our degassing services.


Liquid Circulation vs. Degassing
Each of these methods has preferential applications where it will prevail over the other due to certain design limitations (eg. No steam available, waste disposal, vessels not connected to flare, etc.).

Vapour Phase Cleaning (Degassing)
Improved safety regulations, mandatory vessel inspections, and new environmental requirements are increasing the demand for system decontamination in the oil and gas industry.

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