“Biomass means the biodegradable fraction of products, wastes and residues from biological origin from agriculture (including vegetable 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/EC)
In other words, biomass is any material of organic origin. Wood, straw, vegetable oil, manure, and agro-industrial and organic waste are all biomass and can all be used to produce energy.
Advantages of Biomass
- Widely available in Europe and abroad
- A secure energy supply
- Cheaper than fossil fuels
- On-demand product
- Stable source of employment, especially in rural areas
- Opportunity for EU technology leadership
- Closed carbon cycle, unlike fossil fuels
- Benefits forest management, resulting in carbon credit
- Incentives a balanced growth of agriculture
Forest and wood-based industries produce wood which is the largest resource of solid biomass. The sector covers a wide range of different biomass fuels with different characteristics – wood logs and chips, bark, sawdust and – more recently – pellets. Pellets, due to their high energy density and standardised characteristics, offer great opportunities for developing the bioenergy market worldwide. Biomass procurement logistics from forest to bioenergy plants are currently subject to major improvements – where they have not already been developed to the limits.
Land used for growing conventional crops (rape, wheat, maize, etc.) can be exploited for energy purposes. Agriculture can also provide dedicated energy crops (poplar, willow, miscanthus and others) as well as by-products such as animal manure and straw
Biodegradable waste can cover several forms of waste such as organic fraction of municipal solid waste, wood waste, refused-derived fuels (RDF), sewage sludge, etc.
Each biomass resource has different characteristics in terms of moisture and ash content, calorific value, etc. – which requires appropriate conversion technologies for bioenergy production. These conversion routes use chemical, thermal and/or biological processes.
Biomass for Heating
Combustion of solid biomass (mainly wood) for heat production is the most common process worldwide. Small-scale heating systems for households typically consist in stoves or boilers fueled by firewood or pellets. Medium-scale users’ grate boilers typically burn wood chips while large-scale boilers are able to burn a larger variety of fuels, including wood waste and RDF. Heat can also be produced on a medium or large scale through co-generation which provides heat for industrial processes in the form of steam and can supply district heat networks.
Biomass for Electricity
For the time being, combustion followed by a steam cycle is the main technology around but new technologies exist (ORC-plants, gasification systems, etc.). Biomass is used as the main fuel but can also be co-combusted with coal or peat. Biogas from anaerobic digestion is mainly used on-site for co-generation applications but biogas can also be upgraded into biomethane and injected in the gas grid.
Biomass for Transport
Vegetable oil methyl esters (biodiesel), can be used for transport applications, either in pure form or blended with fossil diesel. Use in blends below 7% does not require any modification of the engine. Pure vegetable oils can also be used but engines have to be adapted. Ethanol can be used in gasoline engines either at low blends (up to 10%), in high blends in Flexible Fuel Vehicles or in pure form in adapted engines. Ethanol can also be processed into ETBE (ethyl tertio butyl ether) and blended in gasoline. Biomethane can also be used by vehicles equipped for natural gas. Advanced biofuels from wood, lignocelluloses and waste, such a BTL, DME or ethanol are subject to intense R&D efforts.