Biomass includes a wide variety of fuels depending on the physical supply networks which provide by-products with energy potential. The water content and the homogeneity of the products have a strong influence on the energy content. If one type of biomass runs out, it is often possible to find an alternative, provided the technical challenges can be met.

The use/production of biomass energy offers several advantages:

• It reduces greenhouse gas emissions. Burning biomass releases about the same amount of carbon dioxide as burning fossil fuels. However, fossil fuels release carbon dioxide captured by photosynthesis millions of years ago, while biomass releases carbon dioxide that is largely balanced by the carbon dioxide captured in its own growth.
• The use of biomass can reduce the dependence on foreign oil because biofuels are the only renewable liquid transportation fuels available at present.
• Biomass energy supports the agricultural and forest industries. The main biomass feedstocks for power are paper mill refuse, lumber mill scrap, forest clearance, the debris from tree pruning, etc. Also, cleaning and clearing forest reduces the risk of forest fires.
• Under the framework of the Kyoto Agreement, the generation of electricity from biomass does not compute in terms of emissions, as the process involves the release of carbon previously fixed in the atmosphere by photosynthesis.

Market Drivers

Energy content of the different types of biomass (electrical mwh)

1 ton of coal			= 2.5 MWh
1 ton of wood pellets			= 1.8 to 2 MWh
1 ton of sawdust			= 1.8 MWh
1 ton of wood cuttings			= 0.8 to 1.5 MWh
1 ton of coffee dregs			= 1.6 MWh
1 ton of sewage sludge			= 10 MWh

10 000 Liters of oil = 40 tons of woodchip = 22 tons of pellets

1 ton of oil = 2.5 tons of pellets

Cost advantages of cellulosics feedstock could get down in the coming years, with booming demand from heat, CHP, biofuels, pulps industries

Biomass-energy industry is creating additional competition for the industry's raw material – Ligno-cellulosics feedstock. Competition will hardly take place with pulp & paper industry; for example, CHP plants have the economical and technical ability to buy pulpwood at regular roadside prices. As, biomass is considered easier to phase in than most other renewable energy technologies many countries internationally have developed national targets for biomass energy. In middle and long term analysis show mismatches between supply and demand. Some area like Europe could face significant increase of biomass prices.

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Wood characteristics vs fossil fuels

Forest chips harvesting methods integrated into wood raw material harvesting

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Source: Alakangas, VTT

Possible products from a pulp mill biorefinery

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Developing a biorefinery technology based on wood is imperative to the development of a bio-based energy economy, whether the final intent is the use of forest biomass, woody biomass crops, perennial grasses, or agricultural residues, all of which are beneficial to the rural economy. Many studies have been done on cereal straw pulps, for example. It has been found that a green field wheat straw pulp mill is not economically feasible. On the other hand, if a straw pulp line is added to an existing pulp mill, the feasibility improves significantly, based on the facility requirement alone. When one considers the seasonality effect or fiber security, the integration of an agriculture residual facility with an existing pulp mill becomes more critical. Therefore, developing biorefining technology based on wood is an important step in the industrial implementation of a bio-based technology for many biomass sources.

In addition to the clear advantage of wood as biomass resource, abundant forest resources currently available (North & South America, Russia , Africa …). Through the promotion of wood as a raw material for a biorefinery we can encourage healthy forestry practices as well. Companies are motivated by their economic needs and ability to maintain the forests as healthy and productive and the development of an outlet for lower grade biomass wood can permit timber stand improvement operations that would of otherwise be uneconomic.

Capital costs and efficiencies of principal bioelectricity and competing conversion technologies

* Larger scale systems will be characterised by the lowest cost and higher efficiency in the value ranges
** 15% discount rate; biomass fuel cost between 7,2 and 14,4 EUR/MWh except for digestion and landfill gas plants where fuel cost assumed to be zero; coal cost 5,8 EUR/MWh; natural gas cost between 5,4 and 10,8 EUR/MWh. The cost is calculated for electricity supply only and cogeneration could reduce the electricity cost significantly.
Source: Bauen et. al,2003

Types of Wood Fibre

The wood fibre used for both paper and wood products falls into two categories: softwood and hardwood.

Softwood. Primarily coniferous trees, which tend to have lower densities and longer and stronger fibres. Generally, the colder the climate, the slower trees grow and the stronger the pulp. Rotation times are also longer in cold climates such as Scandinavia and Canada , ranging from 50 to 120 years, versus 7-15 years in hot climates such as Latin America and Africa .

Hardwood. Deciduous tress with broad leaves and high density wood, but lower fibre strength. Rotation times can vary significantly from region to region – for example, harvesting takes 5-7 years in Brazil and Indonesia , but 35-80 years in Canada and Northern Europe . Eucalyptus represents 9mn of the total hardwood production of 20mn tons.

Saving of CO2 emissions by biomass based power plants

Source: XCO2 conisbee