So I was wondering if pre-heating coal will improve the efficiency of a steam boiler. I did find that intake air pre-heater and water pre-heater do increase efficiency, but I could not find anything related to pre-heating coal.

If we were to take the hot exhaust, make a hot iron platform and keep the coal on top of it, it would heat it and maybe reduce the moisture content also?!

Chemistry troll idea or actually feasible?

Note: it is a traditional hand fired boiler


Coal type: Lignite

Application: Industrial/Factory


The update of your question changes everything!

In Germany, around 25% of the base load is generated in lignite-fired power plants. Lignite (brown coal) is awfully wet (50% water) and it is definitely a good idea to apply drying.

In the power plants, powdered lignite is used. Traditionally, the milled lignite is dried using the hot exhaust gas at temperatures up to 1000 °C, but modern plant like the one in Niederaußem operated the fluid bed drying at temperatures as low as 110 °C.

In summary, pre-drying of lignite is a good idea, if not essential, but it open to question how efficient the drying process of stacked lignite is.

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  • $\begingroup$ its not for a house but for a factory. $\endgroup$ – pallavt Feb 26 '15 at 13:05
  • $\begingroup$ and for the heated surface, place it near the boiler and divert some of the fume exhaust to heat the surface. $\endgroup$ – pallavt Feb 26 '15 at 13:09
  • $\begingroup$ what about increasing the temperature of the coal so it absorbs less heat from the already burning coal and less heat is wasted ? $\endgroup$ – pallavt Feb 27 '15 at 4:53

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