 Melted ash, known as slag or clinker, sticks to the bottom of the boiler, and increase maintenance costs.In order to reduce chlorine (and moisture) content, M. x giganteus is usually harvested dry, in early spring, but this late harvest practice is still not enough of a countermeasure to achieve corrosion-free combustion.However, the chlorine amount in miscanthus reduces by approximately 95% when it is torrefied at 350 degrees Celsius.