Degassing & Decontamination


Reducing vessel entry time, providing cleaner systems and operational safety is our goal in decontamination services.

Most elements of refineries and petrochemical plants (columns, vessels, heat exchangers, etc.) build up hydrocarbon deposits over time. The cleaning of these is often less than straightforward requiring decontamination to eliminate hydrogen sulphide, benzene, explosive gases (LEL) and pyrophoric iron sulphides. Whether as part of scheduled maintenance or break fix works, Span Chen Technologies has experience in the chemical cleaning and decontamination of such elements and ensures that maintenance teams are swiftly provided with safe access to the plant for the required maintenance operations.

Span Chem Technologies uses chemical products for decontamination that are highly effective, fast-acting and safe for personnel, plant and the environment.

The chemicals themselves have near neutral pH, are non toxic and biodegradable. They have no VOCs and are not flammable, with an MSDS hazard rating of 0-0-0. The process drastically improves entry time to 12 hours or less and eliminates safety concerns associated with cleaning, degassing and environmental compliance.

We deliver our decontamination chemistry HYDROSOL both in the liquid and the vapor phase into vessels, columns and exchangers of refineries to reduce LELs, Benzene, H2S while emulsifying all oil into solution and finally neutralizing pyrophoric irons using OXONIA. Oil recovery is possible in this process and the chemistry is biodegradable.

Degassing & Decontamination - Vapor phase

The vapor phase (decontamination) is a process that reduces the steam-out time needed prior to entering the equipment during a turnaround. In Vapor Phase Decontamination the HYDROSOL is entrained into the plant steam and onwards into the equipment. The steam ensures that the HYDROSOL reaches all the locations in the vessel or column and as it condenses the HYDROSOL brings the hydrocarbon into solution and carries away the gases in an action similar to stripping.

Vapor Phase Decontamination techniques are appropriate for: fractionation columns in CDU, vacuum units, FCCU, visbreakers, HDS, LC finer, lube units, amine units, heat exchangers, separators drums, etc.

They offer the advantage of low water requirement, lower lead times to set up in comparison to liquid phase decontamination and generate very little effluent while deliver very clean systems and are particularly useful in dense packed columns.

Degassing & Decontamination - Liquid phase

The liquid phase decontamination is performed when vapor phasing alone is not sufficient to remove fouling or deposits. The liquid phase removes organic substances with medium and high molecular weight and muds. It is commonly used in CDU, vacuum units, visbreakers, FCC slurry, storage tanks, etc. and is also preferred in hydrocarbon processing units where the precipitation of asphaltenes, waxes, and coke particles may have caused fouling during the operation.

The liquid phase also removes light hydrocarbons such as benzene, toluene, xylene, light gasoline, etc., from the equipment and can also used for the removal of hydrogen sulphide and inorganic volatile salts (i.e., ammonium salts).

The liquid phase is capable of delivering extremely clean exchangers in the Crude Preheat Trains with no need to do any further hydrojetting, bundle pulling after liquid phase decontamination is a simple affair.


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Spanchem Technologies is capable of providing chemical cleaning services across many industries including Refining, Chemical processing, Offshore Rigs, Pulp & Paper, Sugar, Steel & Power.