Biofuels are a diverse group of fuels made from predominantly plant-based energy sources. Although sometimes used interchangeably, biofuel is both the overarching term and the specific one for liquids or gases like biodiesel or bioethanol, while biomass refers specifically to solid fuels like wood and peat or the source material (feedstock) that biofuels are made from (like sugar- and oil-yielding crops). In the process of energy transition, they are widely considered a bridging alternative energy source between fossil fuels and renewable energy.
Why is biofuel considered a renewable source?
A renewable resource is a supply of a substance that can be naturally replenished faster than it is used. In the strictest sense, this means fuels or power sources that will never be fully used up because their supply is de facto endless, like geothermal, solar, wind and water power. Biomass and biofuel production takes somewhat longer, but can be replenished with a reasonable amount of effort. Although the resources, land and growth periods involved in producing the trees and plants required to make biofuels have to be taken into account, it is fair to call them renewable.
How sustainability has evolved with every generation of biofuels
Other aspects that increase the sustainability of advanced biofuels have been improved through continuous research and development:
- First generation biofuels were made from food crops. High-sugar plants like sugarcane or corn can be converted into ethanol, while vegetable oils from rapeseed, soybean and others are used to make biodiesel. The production requires dedicated land mass, water, fertilization and farming, using resources that can fully negate the benefits of the alternative fuel produced.
- Second generation biofuels are made from waste biomass, for example, from farming and food production (non-edible cellulose from corn husks, sugarcane fibers, etc. resulting in cellulosic ethanol), or waste vegetable oil (used cooking oil, for example, resulting in biodiesel). As no additional land mass, water, fertilization and farming are used to create these by-products, they are more cost-effective and the environmental impact is significantly smaller.
- Third generation biofuels are largely algae-based, an energy source that has been researched for over 50 years, but has yet to see commercial-scale application.
- Fourth generation biofuels take into account the carbon capture and storage potential of the crops used to produce the required biomass, as well as the energy efficiency of the processing technology that generates the resulting fuel.
Biofuel’s role in hybrid systems
MAN Energy Solutions provides optimized hybrid power solutions that enable utilities, municipalities, industrial customers, and independent power producers to reduce their greenhouse gas (GHG) emissions without sacrificing security of supply. In these tailor-made plants, fluctuating renewable energies like wind and solar are supplemented by always available and instantly deployable natural gas or biofuel engines.
From fossil fuel to biodiesel
In 2015, MAN Energy Solutions contributed to the successful conversion of a French refinery from fossil to plant-derived biofuel. Energy company Total uses a sustainable supply mix containing 30% to 40% used and residue oils as feedstock in the new biorefinery. The GHG emissions of the resulting biodiesel are 50% lower than those of the fossil fuels previously produced at the site.
Biofuels are fully renewable and an immediately available solution to cut carbon emissions from ground and air transportation. When produced from sustainable raw materials […] they emit at least 50% less carbon than fossil fuels.