Biofuel is a fuel produced from renewable biomass material. It is commonly used as a cleaner alternative to burning petrochemicals.
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Introduction
Lower carbon intensity means biofuels only account for a fraction of the carbon emissions compared to conventional fuels. Biofuel formulations use waste streams, meaning that biofuels can contribute to a transition from a traditionally linear to a circular economy.
The biofuels sector has grown significantly in the last decade, with 960,000 barrels of oil equivalent produced daily in 2023. In 2000, only 12,000 barrels were produced per day. By 2030, the global biofuels market is projected to reach $200 billion US.
Major biofuel producers include the US, Brazil, the EU, and Indonesia. In 2022, Indonesia alone produced 13.65 billion liters of biodiesel and renewable diesel. More than 500 plants worldwide are estimated to produce biodiesel and renewable diesel.
Types of Biofuels
Ethanol
Ethanol is a flammable and renewable liquid produced by fermenting grain or from waste streams such as agricultural waste, wood chips, and wastepaper. It can also be prepared through gasification, which uses high temperatures or low oxygen conditions to convert biomass into synthesis gas. The synthesis gas can then be converted into ethanol.
Ethanol is combined with gasoline for increasing octane and reducing carbon monoxide emissions. Ethanol releases around 15% less greenhouse gas emissions when burnt than gasoline.
Recent developments in cellulosic ethanol enable ethanol production from waste cellulose, such as food by-products, scrap wood, and non-food plants like switchgrass.
Biodiesel
Biodiesel combines alcohol and recycled cooking grease, animal fat, or vegetable oil. Genetically engineered algae and bacteria strains can also be used to generate biodiesel.
Biodiesel is a highly combustible liquid that burns readily upon mixing with petroleum-based diesel fuel. As a byproduct of its production, highly combustible glycerin is produced.
Biodiesel can be used as a renewable alternative for diesel engines. However, some studies have indicated that it produces more harmful emissions, such as carbon monoxide and particulates.
Biobutanol
Biobutanol is another promising biofuel. This alternative biofuel is produced from biomass feedstocks, such as corn grain, algae, and bacteria.
Biobutanol has lower emissions, lower vapor pressure, and higher energy content than ethanol, but several technical and economic challenges have so far hindered its widespread use in transportation and industry.
How Is Global Production of Biofuels Accelerating?
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Benefits of Biofuels
The following are some of the advantages of biofuels:
- Unlike fossil fuels, biofuels are produced from renewable resources.
- There are less pollutant emissions from biofuels. Ethanol reduces carbon monoxide emissions as it ensures complete combustion.
- Biofuels have less impact on global warming than traditional gas or diesel, as biological feedstocks sequester CO2.
- Biofuels are cost-effective compared to fossil fuels.
- Biofuels have high energy density, which makes them ideal alternatives for transportation.
- Biofuels use agricultural or industrial waste, reducing waste streams from multiple industries.
- Positive economic impacts such as job creation.
Drawbacks of Biofuel
While the environmental benefits of biofuels are well-publicized, there are some drawbacks to their production and use.
In principle, and as stated above, biofuels contribute significantly less to carbon emissions than conventional fuels, as any CO2 produced by burning them is sequestered by any agricultural or biological feedstock used in their manufacture. This makes biofuels carbon neutral. However, this picture is a little more complicated.
In practice, this benefit can be offset by the fossil fuels consumed by the industrial production of biofuels from plant-based biomass and emissions from fertilizer use. Many scientists consider cellulosic biomass to be more beneficial in this regard.
Growing corn, the main source of ethanol, is carbon-intensive, and there are ethical concerns about using agricultural land that could otherwise be used for food production.
Other drawbacks include carbon emissions from farming equipment, transporting corn biomass to biofuel manufacturing plants, and ethanol distillation. Moreover, ethanol from corn produces less net energy gain than cellulosic ethanol or algae biodiesel.
Common biofuel feedstocks, such as corn, soybeans, and oil palms, are low-diversity sources. One solution proposed is to use highly diverse species mixes such as North American Tallgrass. Converting degraded agricultural land to produce this feedstock would have advantages such as increased biodiversity, sequestered CO2 from the atmosphere, and reduced erosion.
Applications of Biofuels
Some of the applications of biofuels are listed below:
- Domestic, commercial, and public road transit
- Engines in mining, agriculture, forestry, and construction industries.
- Biofuel cells have great potential to power implantable medical devices such as glucose biosensors.
- ”Bioheat” for heating buildings
Recent Developments in Biofuels
Biofuels have many advantages for economies trying to meet their net zero goals in line with international agreements.
Aside from the environmental impact of conventional fossil fuel use, concerns over energy security are driving the uptake of biofuels in many nations. Domestic biofuel production could significantly improve energy security in nations traditionally dependent on petrochemical imports.
Emerging economies, such as India, Brazil, and Indonesia, are predicted to account for nearly two-thirds of demand growth. These economies have ample domestic feedstocks and resources, production capacity, and relatively low production costs.
These emerging economies have already announced new biofuel policies. For instance, Indonesia recently released its Ethanol for Energy Security Strategy and mandated increased biodiesel blending to 35% by 2023.
Brazil is considering a 2.5% increase in its mandatory ethanol blending. India has launched the National Policy on Biofuels, with a national target of 20% ethanol blending by 2025.
Renewable diesel growth remains strong in advanced economies, though overall demand expansion is not predicted to notably accelerate. The EU Renewable Energy Directive aims to improve energy security, lower costs, and reduce greenhouse gas emissions, although Sweden has indicated that it wants to reduce their blending obligations.
In Summary
Biofuels like ethanol and biodiesel are more environmentally friendly alternatives to conventional petrochemical-based fuels, offering lower costs and better energy security. However, some challenges persist, such as using fossil fuels in their manufacture and losing agricultural food-producing land.
The biofuel sector has expanded significantly since the turn of the millennium, with strong growth in developing economies projected over the next decade. While technical and economic challenges remain, biofuels will likely become indispensable to the future green energy mix.
Continue Reading: The Role of Biofuels in Decarbonizing Aviation and Shipping
References and Further Reading
Malade, S et al. (2021) Recent advances and viability in biofuel production Energy Conversion and Management: X 10 [online] Available at: https://www.sciencedirect.com/science/article/pii/S2590174520300428 (Accessed on 09 November 2024)
International Energy Agency (2023) Will Energy security Concerns Drive Biofuel Growth in 2023 and 2024? [online] Available at: https://www.iea.org/reports/renewable-energy-market-update-june-2023/will-energy-security-concerns-drive-biofuel-growth-in-2023-and-2024 (Accessed on 09 November 2024)
Encyclopedia Britannica (2024) Biofuel [online] Available at: https://www.britannica.com/technology/biofuel (Accessed on 09 November 2024)
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