Maximise throughput and eliminate load restrictions via online cleaning.

Online Cleaning Specialists
Crude and Vacuum Distillation Units can experience a multitude of problems arising from slagging and fouling including the following:
• High bridgewall temperatures
• High flue gas exit temperatures
• Reduced heat transfer
• Finned tube blockages
• Vanadium Pentoxide corrosion
• Sulphur corrosion
All of these issues can be resolved online using Therma-Chem FS12, eliminating the need for load restrictions or costly, unplanned shutdowns.

Metal skin temperatures on a Crude Distillation Unit after Therma-Chem FS12 injection shows a significant reduction in metal skin temperature fluctuations and elimination of hot spots.

How FS12 Benefits Heater Performance
themachem process heater diagram - CDU & VDU


Eliminate slagging and improve
heat transfer.

FS12 removes slagging from the tube walls and converts it to dry, friable powder. This results in increased heat transfer and restored capacity.


Prevent high temperature corrosion


Limit fouling and maintain flue gas velocity


Improve performance and reduce maintenance


Prevent dew point corrosion from sulphuric acid


Improve particulate removal and reduce cleaning time


Reduce NOx, SOx and
Carbon emissions


Improve performance and
prevent corrosion

How Does FS12 Work

Slagging and fouling in the radiant section will result in increasing bridgewall temperatures which can lead to restrictions on throughput. Applied online, Therma-Chem FS12 will remove aged deposits by increasing their melting point, reducing them to soft powdery ash. This results in increased heat transfer and a reduction in the bridgewall temperature.

Therma-Chem FS12 also converts Vanadium Pentoxide into non-corrosive vanadates and vanadites preventing high temperature corrosion in the radiant section. As Vandium Pentoxide is the catalyst for converting SO2 to SO3, this also prevents the formation of sulphuric acid in the cold end of the heater. Nonetheless, should there be any sulphuric acid in the cold end, Therma-Chem FS12 will convert this to non-corrosive sulphates and sulphites. Therefore, Therma-Chem will completely eliminate corrosion throughout the unit.

tc product fs12 - CDU & VDU
Application Methods
FS12 is traditionally applied to process heaters in one of three ways


Applied daily, FS12 keeps units clean and prevents costly drop offs in performance and avoids the possible need for shutdowns during the operating campaign. This is the most common method of application with some customers having used Therma-Chem every day for 15 years across multiple units.


When a unit is load and/or temperature restricted mid-run and there is no window to shut down for maintenance, FS12 is introduced to recover performance. Injected 3-4 times per day over a period of 30-90 days, depending on the severity of the fouling, FS12 can target any part of the unit loosening deposits and restoring performance. We would then recommend switching to Maintenance Dosing to prevent a drop-off in performance recurring.


Utilised in the run up to a shutdown to facilitate a more effective and easier clean of a unit, FS12 can be applied 3-4 times per day for a period between 30 – 90 days.This ensures that during the shutdown, cleaning is more effective, easier, quicker and any vanadium pentoxide and sulphuric deposits are neutralised, dry, and entry into all areas of the unit is safe and comfortable.