2nd Generation Cleaner Fuels: From Waste Materials
Biofuels are alternative fuels based on organic feedstock from the Earth’s surface instead of fossil resources. Some emit less greenhouse gases to produce, refine, and burn.
First generation biofuels are produced from edible feedstock, like corn or sugar. But fuel produced from first generation croplands displace the food currently produced there. More land then has to be cleared elsewhere to meet food demands. In 2008 scientists found that transitioning all US food cropland to fuel cropland would result in a greater release of carbon emissions than under the status quo of fossil fuels.
This transition is called indirect land use change and causes harm to ecosystems and economies. So, first generation biofuels are not seen as a sustainable alternative to fossil fuels.
Second generation biofuels are called advanced biofuels because they factor in systems change, like indirect land use and water requirements. They ensure supporting feedstocks are sustainable and equitable and they’re available now.
Second Generation Biofuels
Second generation feedstocks come mainly from biomass, like woody residues or crops grown for alternative energy purposes, known as energy crops. You can burn these to make direct energy, like heating your house with a fire. Or process them to make biofuel.
The best second generation biofuels avoid negative environmental consequences that made first generation ones problematic, like land use change, or high water and fertilizer requirements.
Second generation biofuels are lower impact and have higher energy yields.
Energy crops like switchgrass in the United States or Myscantheus in Southeast Asia are popular second generation feedstocks. They can grow on marginal land and have higher energy yields than corn ethanol. However, switchgrass and Myscantheus require lots of water to grow.
Other potential second generation feedstocks, like Jatropha seeds, camelina, and rapeseed cannot grow on marginal land. This means their energy yields would be cancelled out by land use change, much like first generation biofuels.
Carinata is a seed that can grow on marginal land, like Canada’s prairies, in rotation with wheat and other cereal crops. This flexibility gained it the name of a “drop-in crop”. It can be refined in existing factories and is high in oil making it a natural feedstock solution for biofuels. Carinata is already being processed into cleaner jet fuel and has been approved by the Roundtable of Sustainable Biomaterials (RSB), a global certification body.
These biomasses, grasses, and saplings are high in cellulose. This produces energy that is more efficient than starchy first generation biofuels which relied on food and feed sources. However, the processes of converting woody biomasses into fermentable sugars are longer and costlier than converting grains into energy.
Waste as Second Generation Feedstock
Waste materials are the most promising source for second generation biofuels.
Foody materials, like used cooking oil, are counted as second generation biofuels only if the food has already fulfilled its food purpose. So, used vegetable oil is a secondary biofuel but unused vegetable oil is a first generation biofuel.
Used cooking oil does not pressure land use shift. Vegetable oil is already a product in many commercial kitchens. The leftover oil is sold to be made into energy at such a low cost that there’s no surge in production and no shift of crop land to fuel land.
Used cooking oil was recognized as a source of biodiesel as far back as when Henry Ford dreamt up the Model T.
Municipal solid waste (MSW) like landfill gases and yard clippings are already used in waste-to-energy plants that power electricity and heating. Waste-to-energy plants are a part of municipal city management; they have the dual purpose of helping governments reuse resources that are difficult to get rid of.
Both waste materials avoid the problem of land use and negative life cycle impact.
Second Generation Biofuels as Cleaner Jet Fuels
Aviation is the largest growing sector of greenhouse gas emissions. We must come up with innovative fuel sources to clean it up.
Flightnook coordinates so second generation biofuels from waste used can be used in airplanes.
These cleaner jet fuels cut emissions from extraction, burning, and radiative forcing (source of emissions from contrails that double aviation’s climate impact). On a life cycle assessment they cut up to 80% CO2 compared to fossil fuels.
Second generation biofuels, especially waste materials, are the best option we have today.
True, all commercial and private kitchens around the the world don’t produce enough used cooking oil to power the entirety of a sector like aviation. But upcoming third and fourth generation biofuels will fix the capacity problem, right now we need to create pathways for change.
As we feel the early effects of climate change every metric ton of CO2 matters and we need to shift our reliance away from fossil fuel. Flightnook jumpstarts a transition that will create a network of local fuel providers and energy suppliers to pave the way for the future.
We propose you travel more sustainably. Contribute to us and cover the price difference to choose cleaner jet fuels over fossil fuels.
There’s an argument that waste models have the logistical constraint of needing to collect from several locations then distribute to refining and energy plants. But in Europe they’re already doing this.
SkyNRG, a sustainable biofuel supplier, just announced the construction a dedicated biojet fuel plant in Europe and will annually produce up to 1,000 tons of jet fuel from waste resources.
Flightnook brings awareness of the climate impact of flying and encourages flight-takers to contribute here and support local clean fuel providers. We support local clean fuel providers in Europe, North America, or Asia, because clean jet fuel is a global need.
It promises a quick harvesting cycle, high energy yields, and does not run into issues of land use change, making microalgae more carbon neutral. On an area basis microalgae can produce 15-300 times more oil for biodiesel production than traditional crops.
Flightnook supports such forward-looking development.