Productivity and woodchip quality of different chippers during poplar plantation harvesting

In this work, the productivity and work quality of different types of chipping machines used for biomass comminution produced by dedicated plantations were evaluated. Drum and disc chippers with different powers were compared with feller-chippers and grinders. Machines were tested using only one tree species (poplar) and two different feedstocks: branchwood (seven-year-old treetops and biomass produced by a vSRC) and whole-trees (materials produced by an SRC). This study showed a similar performance for all types of machines tested in terms of working rate using different feeding systems, i.e., automatic and forestry crane. However, different results were obtained for woodchip quality. The whole tree comminution was able to guarantee the best woodchips, and chippers produced better wood chips in comparison to grinders. The results obtained indicate that productivity is linked to engine power and that feedstock size can influence wood chip quality. Furthermore, feller-chippers are able to guarantee the same productivity and wood chip quality as “conventional” chippers.