Climate-neutral fuels made from organic waste
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.
Biofuels as alternative shipping fuel
MAN is presently experiencing increased interest from customers for naturally carbon-neutral biofuels which can be burnt in two- and four-stroke engines with minimal engine modifications. If available in sufficient quantities, biofuels could thus make a significant contribution to decarbonization in all engine applications, both a main fuel but also as a pilot fuel to ensure full carbon-neutrality of dual-fuel engines.
Fuel from waste oil
The Volkswagen Group continues to force the pace of climate protection: in future, Volkswagen Group Logistics will be using certified fuel from vegetable residues for certain new car shipments via marine routes. The fuel is produced from materials such as used oil from restaurants and the food industry. The first car freighter was re-fuelled for the first time with this oil in mid-November 2020.
Sustainably produced biofuels, for example those derived from waste woods, can reduce CO2 output by up to 85%.