20081130-IEA-From_1st-_to_2nd-Generation_Biofuel_Technologies_124页_2mb

Summary of First- to Second-Generation Biofuel Technologies

Core Content

This report provides an overview of current industry and research, development, and demonstration (RD&D) activities in first- and second-generation biofuel technologies, focusing on their technical challenges, costs, and policy implications. It is a contribution to the Global Bioenergy Partnership (GBEP) and was supported by the Italian Ministry for the Environment, Land and Sea.

Main Goals

• To assess the limitations and potential of first-generation biofuels.
• To evaluate the current status and future prospects of second-generation biofuels.
• To identify technical, economic, and policy barriers to their commercial deployment.
• To recommend strategies for sustainable production and support for future development.

Key Points

First-Generation Biofuels

Current Status

• First-generation biofuels are produced from food crops such as sugarcane, corn, oilseed rape, and palm oil.
• These biofuels have mature commercial markets and well-understood technologies.
• Global demand for liquid biofuels more than tripled between 2000 and 2007.
• They now account for over 1.5% of global transport fuels (around 34 Mtoe in 2007).

Main Drivers

• Energy supply security
• Support for agricultural industries and rural communities
• Reduction of oil imports
• Potential for greenhouse gas (GHG) mitigation

Constraints and Concerns

• Contribute to higher food prices due to competition with food crops
• May be an expensive option for energy security
• Limited GHG reduction benefits (except for sugarcane ethanol)
• Potential negative environmental impacts including deforestation, biodiversity loss, and water resource competition
• Uncertainty around indirect land use change and GHG savings
• Biofuel production may not always be sustainable

Second-Generation Biofuels

Overview

• Second-generation biofuels are produced from non-food biomass such as ligno-cellulosic materials, agricultural and forest residues, and energy crops.
• These biofuels could avoid many of the drawbacks of first-generation biofuels and offer greater long-term cost reduction potential.

Feedstocks

• Ligno-cellulosic feedstocks: crop and forest residues, wood process wastes, organic fraction of municipal solid waste
• Dedicated energy crops: vegetative grasses, short rotation forests
• These feedstocks can be grown on marginal and degraded land without competing with food and fibre production

Conversion Processes

• Biochemical Route: Uses enzymes and micro-organisms to convert cellulose and hemicellulose to sugars, then ferment to ethanol.
• Thermo-chemical Route: Involves pyrolysis/gasification to produce synthesis gas (CO + H₂), which is then used to create long-chain hydrocarbons like synthetic diesel or aviation fuel.
• Other options include dimethyl ether, methanol, and synthetic natural gas (SNG).

Production Costs

• Estimated at USD 0.80–1.00 per litre of gasoline equivalent for ethanol
• At least USD 1 per litre of diesel equivalent for synthetic diesel
• These costs are influenced by feedstock availability and are considered high-risk due to fluctuating oil prices and competition with other alternative fuels

Commercial Investment

• Several demonstration plants are operating or under construction in the US and Europe
• Large multinational companies and investors are involved in second-generation biofuel projects
• The first fully commercial-scale operations may appear as early as 2012, but wide deployment is expected only by 2015 or 2020

Preferred Technology Route

• No clear commercial or technical advantage exists between biochemical and thermo-chemical routes
• Biochemical route offers more potential for cost reduction
• Thermo-chemical route benefits from mature technology and can produce a wider range of fuels

Conversion Efficiency

• Both routes can convert 1 dry tonne of biomass (≈20 GJ/t) to ≈6.5 GJ/t of energy carrier
• Biochemical route yields up to 300 l ethanol per dry tonne of biomass
• Thermo-chemical route yields up to 200 l synthetic diesel per dry tonne of biomass

Policy Support

• Policy recommendations include RD&D investment, demonstration support, and deployment incentives
• Policies may favor second-generation biofuels for their environmental and sustainability benefits
• A transition from first- to second-generation biofuels is expected over the next one to two decades

Key Findings

• Technical Barriers: Remain significant for second-generation biofuels, though progress is ongoing.
• Cost Uncertainty: Production costs are still high and vary depending on feedstock and technology.
• Sustainability: Second-generation biofuels offer a more sustainable alternative, but their environmental impact depends on feedstock and production methods.
• Market Transition: The biofuel industry is expected to continue growing with both first- and second-generation technologies, but second-generation biofuels will likely dominate in the long term.
• Future Prospects: More research, development, and demonstration are needed to ensure the commercial viability and sustainability of second-generation biofuels.

Conclusion

Second-generation biofuels have the potential to significantly reduce the environmental and economic drawbacks of first-generation biofuels. However, they still face major technical and economic challenges. Policy support, along with continued RD&D investment, is essential for their successful deployment. The transition to second-generation biofuels is expected to take several years and will depend on the availability of sustainable feedstocks and the maturity of conversion technologies.