Wood powder firing in directly heated grain dryers for increased resource efficiency and lower CO2-emissions

Large amounts of grain are dried each year, corresponding to about 150 000 tons of water in Sweden.

In industrial scale, drying is done with combustion heat in dryers that supply heat directly by contact between the flue gas and the grain, or indirectly via heat exchange to air. Direct heat supply is generally 10-20 % more efficient, has better controllability, and requires lower investments.

So as not to contaminate the grain, it is required that the fuel be natural gas or Lpg, but there is reason to believe that flue gas from firing wood powder could be used without problems.

In the project, grain will be dried with flue gas from wood powder, and the contents of polyaromatic hydrocarbons and metals will be analysed before and after drying to answer the question if the flue gas affects the grain.

The result will be used to adjust the regulation to allow flue gas from more sustainable fuels in drying, whereby a potentially large fraction of fossil fuels and electricity can be replaced.