Methods for determination of moisture content in woodchips for power plants—a review

The aim of this article is to show which methods that are suitable for moisture determination according to their usefulness in power plants and their standard error of performance. Moisture content is measured either in a fuel flow or a fuel bulk where the sample has to be specifically representative of the bulk. In order to be able to apply feed forward control, moisture content for chips bulk or flow should be measured automatically and on-line. According to the literature, NIR and RF are today the best-suited methods for measuring moisture content in, respectively, fuel flow and fuel bulks. It shall be pointed out that the conditions during which the SEP has been calculated, differ between the compared methods.