Biomass can be defined as ‘the biodegradable fraction of products, waste and residues from agriculture (including vegetal and animal substances), forestry and related industries, including fisheries and aquaculture, as well as the biodegradable fraction of industrial and municipal waste.’ (Renewable Energy Directive - 2009/28/EG)
In other words biomass is any material of organic origin and can be very diverse, e.g. wood, straw, vegetable oil, manure, agro-industrial wastes, organic waste, etc. It is omnipresent and at first sight, one could conclude rather easily available. Biomass always has a natural origin, is biodegradable and if used in a sustainable way, is totally renewable. But at the same time biomass is a very versatile feedstock, with a high diversity in composition and size, and so with a high variability in handling and costs.
Because of the high diversity in biomass it is not surprising that there exists also a high variability in classification of biomass. A possible classification can be done according to the supply sector, as shown in the Table underneath.
Table: Types of biomass resources (adapted from European Biomass Industry Association, EUBIA, www.eubia.org/)
|Forestry||Dedicated forestry||Short rotation plantations (e.g. willow, poplar, eucalyptus)|
|Forestry by-products||Pellets, wood blocks, wood chips form thinnings, branches, stumps|
|Agriculture||Dry lignocellulosic energy crops||Herbaceous crops (e.g. miscanthus, reed canary grass, giant reed, switch grass, hemp, flax, bamboo)|
|Oil, sugar and starch energy crops||Oil seeds for methylesters (e.g. rape seed, sunflower)|
|Sugar crops for ethanol (e.g. sugar cane, sweet sorghum)|
|Starch crops for ethanol (e.g. maize, wheat)|
|Agricultural residues||Straw, leaves, prunings from vineyards and fruit trees|
|Livestock waste||Wet and dry manure|
Industrial waste wood, sawdust from sawmills
Fibrous waste from paper industries
Organic waste from food and agro industry
|Waste||Dry lignocellulosic||Residues from parks and gardens (e.g. prunings, grass)|
|Contaminated waste||Demolition wood|
|Organic fraction of municipal solid waste|
|Biodegradable landfilled waste, landfill grass|
These biomass resources can all be used in a high variety of applications and trough very different conversion technologies: from simple combustion to the use of sophisticated industrial biochemical pathways to produce solid, liquid or gaseous bio-molecules, as is the case in a biorefinery.
Due to limited global land resources, biomass must be used as efficient as possible. This includes the use of all parts of the plant, non-edible crops and agricultural residues in the most efficient way and the implementation of the principle of cascading the use of biomass (ie a mechanism for prioritising its use for socially preferable or higher added value products, such as food/feed, materials and chemicals, before using it as an energy source).
In Flanders, an inventory has been made of all organic side streams available. This inventory is now available for purchase (in Dutch only).