Amidst popular renewable options such as solar and wind power, biofuels have emerged as an accessible and cost-effective alternative to traditional fossil fuels. However, although they have the potential for renewable sourcing and carbon-neutrality, there is still debate about whether biofuels can really pave the way for a net-zero future or whether they are just a stopgap in the energy transition.

What are Biofuels and How Are They Made?
Biofuels are produced from organic materials, known as biomass, including plant materials and animal waste. The most commonly used types are bioethanol and biodiesel and are primarily used in transportation sectors to reduce reliance on petroleum products and decrease the overall emissions of vehicles. Biofuels can be broken down into three generations¹:

First-Generation Biofuels: These are derived from food crops by extracting oils or fermenting sugars. While they are effective at reducing emissions, they are often criticised for competing with food supply.

Second-Generation Biofuels: Produced from inedible biomass, such as wood chips or agricultural residues, these biofuels do not compete with food crops and offer a more sustainable alternative. Technologies to convert these materials into fuel are rapidly evolving, enhancing their commercial viability.

Third-Generation Biofuels: This type of biofuel is extracted from algae and microbial sources² and, if scaled correctly, could have the potential to achieve high yields per acre with minimal impact on freshwater resources.

Globally, biofuel production is dominated by a few key players, namely the United States and Brazil for bioethanol, collectively producing 80% of total output³, and Indonesia for biodiesel. However, while production volumes have reached substantial levels, they still fall short of replacing a major portion of fossil fuel use globally.

The Environmental Impact of Biofuels
Biofuels are widely considered and promoted as being carbon neutral, as the CO2 released when they are burned is roughly the same as the CO2 absorbed by the plants used to produce them. However, one of the challenges in labelling biofuels as truly carbon neutral are their lifecycle emissions, which means taking into account all the emissions generated by growth, harvesting, processing and combusting. Additionally, indirect land use changes (ILUC) can affect their carbon neutrality, for instance, if forests are cleared to grow biofuel crops, this not only releases a substantial amount of carbon but also decreases the land’s future carbon-sequestering capabilities.

Generally, however, biofuels emit fewer greenhouse gas emissions than fossil fuels when burned. For example, a study by the U.S. Department of Energy showed that ethanol can reduce emissions by 44-52% compared to gasoline⁴, while advanced biofuels, like those from waste biomass or algae, have an even greater potential, with some estimates suggesting an over 80% reduction in emissions relative to fossil fuels⁵.

Technological Advancements in Biofuel
One of the most promising advancements in biofuel technology is the development of cellulosic ethanol, which is made from the fibrous, inedible parts of plants. Using these agricultural residues instead of food minimises land use changes and reduces competition between food and fuel, thereby enhancing its sustainability.

The use of genetically modified yeast and bacteria to improve biofuel yields is another exciting leap forwards in biofuel technology. These organisms can be engineered to tolerate higher alcohol concentrations and convert sugars into biofuels more efficiently and effectively⁶.

In addition to these advancements, biofuel production can also be combined with other renewable energy sources, i.e. solar or wind power, to power biofuel facilities and decrease the lifecycle emissions of the biofuels produced.

Future Challenges and Prospects for Biofuel
The primary challenge of biofuel is scaling up its production in a way which maintains sustainability and lowers environmental impact. Innovations in feedstock production, biofuel technologies and waste-to-energy processes will be critical in order to reduce land use, water resources and conserve biodiversity.

However, the ongoing research into third and fourth generation biofuels, particularly those derived from non-plant sources or genetically engineered organisms are likely to yield breakthroughs that could dramatically alter the biofuel landscape. In the future, there may be greater integration of biofuels with other renewable technologies, developing hybrid systems that optimise energy output.

Author: Shirley Carruthers - Content Creator at ParkerSteel Limited

References:
1. UNFCCC Biofuel Generations Report
2. Algae and Microbial Biofuels Study
3. Biofuel Production Data
4. Ethanol vs. Petroleum Emissions
5. Biofuels GHG Emissions Facts
6. Advancements in Biofuel Technology