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• Transfer the whole tree product to a local processing node with equipment which is optimised
for the task, and undertake a separation process/ initial processing at the node. Value added
product could then be forwarded via optimised transport systems to markets further afield.
Figure 4.3 System in Brazil for separating trash on the harvester and transporting it separately to the
mill.
Figure 4.4 Attachments are available for choppers and forage harvesters to remove a proportion of
the leaf and lighter material.
Aggressive strategies to remove leaf (and twig) by the incorporation of separation systems on the
harvester could be anticipated to be able to reduce leaf levels and thus improve transport efficiency
(by transporting only the most valuable fraction of the biomass), however high levels of leaf
extraction could be anticipated to result in correspondingly high levels of loss of woodchip. Where
the leaf material is considered to be of zero or negative value, this may be an appropriate strategy,
despite the losses, with additional “cleanup” being undertaken at point of delivery.
The limitation on separation performance will clearly apply also to any strategy targeting separation
of harvested material into different product streams on the harvester. High levels of cross
contamination will not be avoidable. Whilst this strategy is interesting in concept, an additional
constraint to this strategy is the logistic issues associated with the dual transport systems.
At nodal processing points, the degree of separation of delivered material into product classes (leaf,
twigs, bark and woodchip) will be dependent on the technology used, with high levels of efficiency in
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