Technical background

Technology

Biomass-to-Liquid plant with wood chips storage area. © CHOREN Industries GmbH

The total annual demand for biomass has increased steadily over recent years and currently accounts for over 10% of global primary energy consumption. Approximately two thirds of this biomass is consumed in developing countries as traditional, non-commercial biomass for domestic cooking and heating.

The current worldwide demand for biomass to provide electricity and heat for buildings and industry is around 8EJ/yr (190 million tonnes of oil equivalent (Mtoe)/yr) and around 1.7 EJ/yr (40 Mtoe/yr) for liquid transport biofuels. In terms of costs, current bio-electricity generation costs are around $62-185 per MWh, heat production costs around $4-19 per GJ and transport biofuels around $10-31 per GJ (Source: IEA, 2008).

In the EU, according to the EurObserv'ER Biofuels Barometer 2008, biofuels represented 7.7 Mtoe in Europe in 2007. After four years of implementation, the European biofuels directive has made it possible to reach biofuel consumption of approximately 2.6% of the energy content of all the fuels used in road transport. This target is nearly half of the target of 5.75% for 2010 set by this directive. As a result, the EU must increase its production and possibly increase its imports. Currently, the amount of land devoted to growing biofuels is only 25 million hectares, or about 0.5% of 1% of the 5 billion hectares of global agricultural land.

In EU27, biomass use accounts approximately for 95.7 Mtoe, of which only a small part is used for biofuels, the rest is divided respectively in 40Mtoe for heat and 48Mtoe for electricity.

Future prospects

If the renewable targets of the EU are to be met, an additional 120Mtoe of biomass need to be produced 2020. These large volumes would have to be created by additional mobilisation of forest resources, energy crops, novel sources such as aquatic biomass and eventually imports taking into account sustainability principles.

The European Biomass Association AEBIOM estimates that the contribution of biomass for energy in the EU can be increased from 72 Mtoe in 2004 to 220 Mtoe in 2020; the biggest potential for growth lies in biomass created from agriculture. In the EU27, 20 to 40 Mha (million hectares) of land can be used for energy production without harming the European food supply.

The European Commission estimated in 2005 that by 2010 it should be feasible to mobilise about 1.5 EJ/yr of the EU's unused wood and agricultural residues. New resources in the form of energy crops (plantations of trees, grasses, oilseed crops and other crops that are optimised for energy production) could provide a further 2 EJ/yr - about 60% as solid biomass for heat and power and 40% as liquid biofuels (source: Biomass - Green energy for Europe DG RTD, 2005).

click to enlarge The indicative technology roadmap of the Industrial Initiative on Bioenergy.

Bioenergy costs are expected to decrease over time, due to better technology and economies of scale in larger commercial plants. According to the International Energy Agency, by 2050 bio-electricity generation costs could reduce to $49 to 123 per MWh, transport biofuels to $7 to 12 per GJ and heat production is expected to remain around the actual price (Source: IEA-2008).

The Industrial Initiative on Bioenergy in the context of the SET-Plan aims to ensure at least 14% bioenergy in the EU energy mix by 2020. At the same time it wants to guarantee GHG emission savings of 60% for bio-fuels and bio-liquids under the sustainability criteria of the new RES directive.

Hurdles to be overcome by research

The successful development of bioenergy is hindered at the moment by a number of obstacles:

  • The biomass resources available in the EU are diverse and dispersed. This leads to a fragmentation of the technological know-how according to the conditions of the feedstock in the specific regions.
  • The low energy content of biomass compared to fossil fuels requires a higher input of feedstock, posing significant logistic and economic challenges. In particular, there is a need to further develop energy crops and aquatic biomass which is a promising approach in disengaging the land-for-fuel issue from biofuels (so called second generation biofuels) and biomass for energy. It is also necessary to further improve the processes related to the recovery of fuels and fibres from municipal solid waste and other industrial waste streams since these can be used for energy conversion and/or as intermediate carriers.
  • Conversion technologies (e.g. waste incineration, anaerobic digestion, gasification, pyrolysis, pellet heating, co-firing) need to be further improved. In particular, development and deployment of new thermo-chemical technologies and improved bio-chemical conversions (e.g. anaerobic digestion and ethanol-fermentation plants) would be necessary in order to reach the large volumes required to meet ambitious EC targets.
  • To make the promising concept of biorefineries a reality, there is a need for extensive research and technological development to test and prove the supply of biomass feedstocks, the extensive range of biorefining technologies, the end uses of the products, etc.

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