生物质热电技术简介（英文版）_26页_1mb

Summary of Biomass Energy Insights for Policy Makers

Core Content

Biomass, defined as organic matter from plants or animals, is a significant renewable energy source used for a variety of applications, including cooking, heating, electricity generation, and biofuels. In 2012, bioenergy accounted for about 10% of global energy demand, equivalent to 51 EJ, making it the largest single renewable energy source. The majority of this energy (27 EJ) was used in traditional woodstoves in developing countries, highlighting the role of biomass in rural and low-income areas. However, modern biomass technologies, such as combined heat and power (CHP) and biofuels, are gaining traction and are associated with higher efficiency and lower emissions.

Main Views and Key Information

• Biomass Utilisation:

  • Biomass is used in both traditional and modern energy systems.
  • Traditional uses are widespread in developing countries but have low efficiency.
  • Modern uses, such as CHP and electricity generation, are more efficient and environmentally friendly.

• Technology Status:

  • Fluidised bed combustion (FBC), co-firing with coal, and CHP are the main technologies for modern biomass utilisation.
  • FBC and CFBC technologies are preferred for large-scale applications due to their high efficiency and low emissions.
  • CHP plants have overall efficiencies ranging from 70% to 90%, making them highly efficient for industrial and district heating.

• Pre-treatment and Upgrading:

  • Pre-treatment methods such as drying, pelletisation, torrefaction, and pyrolysis improve the handling, transportation, and combustion efficiency of biomass.
  • Torrefaction increases the energy density of woody biomass, making it more comparable to coal.
  • Pyrolysis produces bio-oil with twice the energy density of wood pellets, suitable for long-distance transport.

• Economic and Policy Considerations:

  • The cost of biomass feedstock accounts for 40%–50% of total electricity production costs.
  • Investment costs for biomass power generation range from USD 4000/kW to USD 7000/kW, depending on the technology.
  • Economic incentives like Feed-in Tariffs (FITs) and tax credits are essential for initial development, but their levels must be carefully managed to avoid financial burdens.
  • Policy stability is crucial for ensuring the viability of biomass energy projects over their lifetime.

• Challenges and Trade-offs:

  • Biomass availability and supply fluctuations pose challenges due to its biological nature and environmental variability.
  • There is competition between biomass and other uses of agricultural and forestry residues, which can affect market prices.
  • Sustainability and environmental impact must be addressed through proper criteria, indicators, and certifications.

• Biomass Co-firing:

  • Co-firing biomass in coal power plants can reduce greenhouse gas emissions and improve efficiency.
  • It requires boiler retro-fitting and tailored flue gas cleaning equipment.
  • Co-firing efficiency ranges from 36% to 44%, and it is more cost-effective than standalone biomass power plants.

• Anaerobic Digestion:

  • Anaerobic digestion is a key technology for converting wet biomass into biogas, which can then be used for CHP.
  • It is particularly used in the Netherlands, the UK, and Italy.
  • Biogas can be upgraded to biomethane and used in natural gas grids or as compressed natural gas (CNG) for vehicles.

• Sustainability and Policy Mix:

  • A comprehensive and multi-dimensional approach is needed to manage the sustainability of biomass use, considering economic, environmental, and social aspects.
  • Collaboration among governments, research institutions, private sectors, and civil society is essential to establish a common sustainability framework.

Conclusion

Biomass plays a multifaceted role in energy production, offering both traditional and modern applications. Its widespread availability makes it a viable option for many countries, but its low energy density and supply variability require careful management. Modern technologies like CHP, FBC, and anaerobic digestion are increasingly being adopted to improve efficiency and reduce emissions. However, achieving sustainable and economically viable biomass energy systems necessitates a well-designed policy mix, including market targets, financial incentives, and sustainability frameworks.