Pre-Shutdown Cleaning Case Study

Therma Chem neutralized the sulphur deposits of a large Refinery in Western Europe.

Home Why Process Heater 1017710710b - Case-Study-Combustion


The APS Furnace of a large Western European Refinery was approaching a planned turnaround. We inspected the unit and found fouling in the convection section.

It was also identified that there were a number of hotspots throughout the radiant section as well as hard deposits adjacent to the sootblowers in the middle bank of the convection section.


The Therma Chem injection programme commenced by spraying chemicals into the convection sector to break down the deposits. This process was introduced to neutralize the sulphur deposits and prevent them from becoming hygroscopic within the heater, preventing downtime corrosion occurring during the 40-day shutdown period.

This process eliminated the sulphate acid deposits, making it safer for the maintenance teams to enter the furnace.


Reduced downtime during shutdown period.

Broke down deposits and prevented them becoming hygroscopic.

Efficient process allowed maintenance engineers to focus on other essential engineering projects.



• Fouling in the convection section
• Hotspots in the radiant section
• Hard deposts in the convection section


• All completed within 40 day programme
• Cost savings

We found the Therma-Chem treatment very good, the tubes looked very clean when we opened the furnace.
The large amounts of scale and deposits that were present before the treatment disappeared from the tubes surfaces.
During the injection period it was noted that there was a reduction in SOx emissions.
Also, during 40 day T/A period the tubes did not go hygroscopic even when exposed to normal wet atmosphere for 40 days, therefore, there was no sulphuric acid corrosion attack issues and the main aim of the injection programme was fulfilled.

Combustion Specialist