Guidelines

This Technical Guide provides guidance on the conversion of existing coal fired boilers to wood pellet operation. There are a number of obvious advantages to using wood pellets: they are 100% renewable and relatively clean burning. Of paramount importance in a conversion is the need both to maintain the safety and integrity of the boiler and control systems, and also to improve safety to the level of best practice.

These Guidelines provide a common methodology for classifying, specifying and declaring the quality and properties of wood fuel in New Zealand. The Classification Guidelines have been produced as a voluntary industry standard and have been prepared to meet specific New Zealand requirements. The parameters set out are based on formal international standards that have been modified to meet New Zealand needs.

Forestry and wood processing residues are a potentially significant source of bio-energy fuels. For a variety of reasons storage of these materials prior to utilisation is often necessary. The storage of comminuted (chipped, hogged, shredded or reduced to small particle size by other means (sawing or sanding)) biomass, particularly fresh (green) material such as logging residues can lead to degradation of the fuel due to biological and thermo-chemical processes.

Wood used for energy does not fit well with a payment system that works using non-energy (eg. volume or weight). The energy content of wood is closely related to moisture content, and this can vary substantially, depending on the origin and storage history of the material. This study looks to determine the effects of moving from a weight-based payment system to a specific energy-content-based payment system at a large industrial site, using woody biomass as a fuel source on a large scale.