Forest biomass production in the form of wood chips

This article reviews various harvesting scenarios for the production of wood chips intended as fuel, taking into consideration the types of forest resources and the desirable features of the end product. Two main markets need to be supplied: small collective central heating facilities that require graded chips with a 25% moisture content; and industrial heating facilities that can handle fuel of far more variable size with a moisture content of 35-40%. There is a very broad range of chipping equipment on offer, from three point hitch chippers on tractors to heavy duty equipment that is taken to logging sites or operates from a permanent position on a platform. Reconstruction of costs for all the operations involved - felling, hauling, shredding and transportation - yields very wide ranging cost prices. An analysis of the parameters that influence productivities shows how important it is to rely on production synergies between forest biomass for energy and other product categories (workable timber, industrial timber). (authors)