Effects of moisture and pressure on densification process of raw material from Artemisia dubia Wall.

Abstract At present, active scientific research studies are being carried out worldwide on alternative biomass resources that could replace wood. One possibility is to use plants belonging to the group of fast rotation energy crops, which includes Artemisia genus plants such as mugwort ( Artemisia dubia Wall.). These plants easily adapt to the prevailing agricultural-climate conditions in Lithuania and can offer yields from 22 to 27 t ha −1 in dry matter. However, due to the low bulk density of the harvested biomass, extensive use of A. dubia for energy production is not sufficiently effective. This study analyses the effects of the moisture content of A. dubia biomass and comparative pressure on the pellet formation process and pellet characteristics. A study was carried out on milled A. dubia biomass with six different moisture content levels (4.3, 7.8, 10, 12.9, 15.5 and 21.5%). Depending on the raw material press load and moisture content, it was determined that the pellet density was between 912 and 1214 kg m −3 . As a result of plastic deformation and depending on the moisture content of the raw material used, the original pellet density decreased to 583 and 1064 kg m −3 , corresponding to 13.1 and 5.5% respectively The results of the study demonstrate that the optimal moisture content for producing A. dubia pellets is 9.4%.