8.4.1

Trees and Woodpellets

The most abundant low-tech source of biomass is trees. Woodfuel can be derived from conventional forestry practice such as thinning and trimming as part of sustainable management of woodland to ensure the production of high-quality timber for construction and wood products.

A better way to burn wood is to take the leftovers from saw mills and woodchips, and condense them into woodpellets. You create a sustainable carbon-neutral source of energy, which is renewable as well. This is ideal as feedstock for heating systems. During the drying and compressing of the wood leftovers, the lignin, naturally contained in the biomass, melts and acts as a “binder.” It holds the fibers of the wood together and it gives the pellet a glaze on the outside. Then the lignin cools off and hardens the pellet.

The advantages of woodpellets are:

• No special treatment is needed to cofire them with coal in power plants. They are not a “drop-in fuel,” but a “drop-in biomass.”

• The endless availability of wood waste and sawmill dust makes woodpellets a future large worldwide energy commodity.

• Woodpellet utilization has a low environmental impact — in the production process, during transport (zero environmental damage in the case of spillage), and during combustion.

• Modern pellet combustion equipment produces extremely low amounts of air pollution.

• Woodpellets contain much lower amounts of sulfur or nitrogen than oil or coal.

• Woodpellets are part of a closed carbon cycle. Woodpellets do not increase the overall carbon dioxide emissions in the atmosphere. The carbon dioxide emitted during the combustion of biomass originates from carbon dioxide taken up by the forests.

• The dry agricultural residues of arable crops are not used to produce food, animal feed, or fibers. There is no conflict between food and fuel.

8.4.2