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SAPEC fuel treatment was developed in the UK in 1989 as a cost effective solution to fouling problems in coal-fired industrial boilers. SAPEC has been used successfully with a wide variety of fuels including wood, biomass, refuse, clinical waste and heavy fuel oil.

The SAPEC treatment is already established throughout the UK. But as the industrial use of coal declines in the UK, SAPEC has expanded worldwide to countries where coal-fired boilers remain common. South Africa, for example, is a fast growing market for SAPEC fuel treatment and already has over 150 established sites.

South_African_Power_StationA chemical solution to a chemical problem

Flue side fouling causes heat resistant bonded deposits on the heat transfer surfaces of the boiler. The heat transfer rate is reduced and the boiler must operate for a longer period to generate the same output, using extra fuel.

Prevention and control of these deposits using SAPEC fuel treatment achieves a significant fuel saving in addition to the savings resulting from easier and less frequent boiler cleaning.

The SAPEC treatment is injected into the combustion zone only. Unlike some products, the treatment is too heavy to be carried in the flue gases and remains in the combustion zone.

The boiler fouling effect

Thickness of deposit




Reduction in heat transfer coefficient




Increase in fuel consumption




Trials conducted with the assistance of British Coal demonstrated that using SAPEC fuel treatment could produce the following results

  • reduce deposit build up from 2.5mm to 0.5mm
  • reduce carbon deposit content from 19% to 6.8%
  • increase the period between cleaning from 330 hours to 700 hours

Controlled test ash analysis using the SAPEC fuel treatment demonstrated:

  • Existing bonded deposits became detached from flue-side heat transfer surfaces and were easy to remove
  • No bonded deposits were formed on the flue-side heat transfer surfaces subsequent to SAPEC treatment
  • Deposits in the SAPEC boiler were softer and lighter in colour than those in the untreated boiler
  • The carbon content of the deposits were as much as 64% lower in the SAPEC treated boiler than in the control boiler
  • Clinker formations in the ash did not fuse into hard slag and broke up easily
  • SAPEC treated boilers doubled operating periods yet still had a minimum of 50% less deposition on the heat transfer surfaces

In South Africa, SAPEC has helped users achieve grade A performance from grade B coals. This can represent a cost reduction of up to 25% with no difference in calorific output.

In one major UK manufacturer, boiler operating periods were increased by 50% as a direct result of using SAPEC.


 Flueclear - "for a cleaner and a greener burn"

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