This section identifies the most important types of biomass residues and waste streams available for bioenergy production globally and provides an overview and introduction to these different sources of feedstock for biomass-to-energy projects.
The availability, amount, and type of biomass will determine the types of technologies appropriate for the specific biomass project. This approach reflects that several generic supply chains will dominate for each type of project based on the availability of biomass and choice of technology.
Typical Biomass Resources and Supply Chains
Figure 2 shows the most suitable biomass types (primary, secondary, and tertiary) and their supply chains. The figure provides a flow chart for biomass waste and residues available for energy production in developing countries and emerging economies across the globe.
For each of the typical biomass types, this section presents the following information:
▪ Industry (agriculture, forestry, food production)
▪ Type (primary, secondary, tertiary)
▪ Feedstock (wood, agricultural)
▪ Characteristics (calorific value, biogas potential, chemical composition, moisture content)
▪ Energy conversion process applicable (boiler, gasification)
Table 2 provides a cross-cutting overview of the different types of biomass available from primary, secondary, and tertiary sources.
Primary sources refer to energy crops harvested for the purpose of energy generation; no other use of the crop is foreseen. These include woody biomass, such as plantation trees (for example, eucalyptus), and herbaceous biomass, such as energy grass or grain (for example, for biofuel production).
Secondary crops refer to byproducts used for energy production. As such, the main crop harvested (for example, grain for food and feed) is not used for energy generation, but any residues (straw, husks, shells) are. Similarly, for woody biomass, the main crop is not used for energy generation (for example, wood is harvested for use as planks or in paper production), while logging byproducts are used for energy generation.
Tertiary sources refer to end-of-life materials, such as discarded wood products or household waste and other biological waste.