Jet fuel made from food waste could slash carbon emissions
The aviation industry is continuously looking for new ways to help reduce carbon emissions after it pledged to cut them in half by 2050.
Most food scraps that are used for energy around the world currently are converted into methane gas and contribute to climate change, but researchers in the US have now said they found a way to use the food waste to produce sustainable aviation fuel (SAF).
The new , published in the Proceedings of the National Academy of Sciences, shows that scientists have worked out a way to transform food scraps, used cooking oil, animal manure and wastewater into a type of paraffin that works in jet engines.
From avoiding using fossil fuels and diverting food waste from landfills, this enables saving emissions. This “reduction in lifecycle greenhouse gas emissions would provide a path toward net zero jet fuel,” states the report. The authors of the new study say the fuel cuts greenhouse gas emissions by 165 per cent compared to fossil energy.
Although aviation makes up a relatively small fraction of total global transport emissions - - the industry is at a turning point. The UK government has just announced a £15m to encourage companies to use new technologies to develop jet fuel from household waste products.
Replacing fossil fuels
Researchers were able to produce a SAF made from a combination of renewable isoparaffins and straight-chain paraffins that could be blended with conventional jet fuel in higher concentrations, up to 70 per cent, while still meeting the extremely strict quality criteria that Federal authorities impose on aircraft fuels.
A major advantage of this new fuel is that it produces round 34 per cent less soot than current standards. This is a significant benefit because soot plays a major role in the formation of contrails from airplanes, that adds a warming effect to CO2 coming from the engines.
Southwest Airlines are collaborating with National Renewable Energy Laboratory (NREL) on scaling up SAF from wet waste, also they are providing an insight into how the fuel could be used and supplied across regions in the United States.
"We’re excited to partner with NREL as we continue our journey to make commercially-viable SAF a reality and a part of Southwest’s future,” said , senior director of Fuel Supply Chain Management at Southwest. “It is undeniable that SAF’s role in reducing emissions across the industry and at Southwest will be significant. NREL’s research could provide a game-changing opportunity to make SAF cost-effective, leading to its larger-scale deployment.”
, a NREL scientist and corresponding author of the paper, said: “If our refining pathway is scaled up, it could take as little as a year or two for airlines like Southwest to get the fuel regulatory approvals they need to start using wet waste SAF in commercial flights."
The challenges to SAF production remain scale and volume. In 2019, fewer than 200,000 tons of SAF were produced globally, a tiny fraction of the roughly 300 million tons of jet fuel used by commercial airlines, according to McKinsey. If announced SAF projects are completed in the next few years, capacity will scale to at least four million tons - but that would equate to about 1 percent of global jet fuel demand in 2030.
"There is no silver bullet, however - no single feedstock or production pathway will be practical in every geography or yield enough SAF to meet all demand. Even as costs fall, SAF will almost certainly remain more expensive to produce than fossil fuel."
- Waste Knot Energy has developed a new range of pellets made from non-recyclable waste, designed specifically for high-energy-use industries looking to reduce their carbon footprint. These include producers of cement and steel, as well as power stations.
Carbon dioxide removal revenues worth £2bn a year by 2030
Carbon dioxide removal revenues could reach £2bn a year by 2030 in the UK with costs per megatonne totalling up to £400 million, according to the National Infrastructure Commission.
Engineered greenhouse gas removals will become "a major new infrastructure sector" in the coming decades - although costs are uncertain given removal technologies are in their infancy - and revenues could match that of the UK’s water sector by 2050. The Commission’s analysis suggests engineered removals technologies need to have capacity to remove five to ten megatonnes of carbon dioxide no later than 2030, and between 40 and 100 megatonnes by 2050.
The Commission states technologies fit into two categories: extracting carbon dioxide directly out of the air; and bioenergy with carbon capture technology – processing biomass to recapture carbon dioxide absorbed as the fuel grew. In both cases, the captured CO2 is then stored permanently out of the atmosphere, typically under the seabed.
The report sets out how the engineered removal and storage of carbon dioxide offers the most realistic way to mitigate the final slice of emissions expected to remain by the 2040s from sources that don’t currently have a decarbonisation solution, like aviation and agriculture.
It stresses that the potential of these technologies is “not an excuse to delay necessary action elsewhere” and cannot replace efforts to reduce emissions from sectors like road transport or power, where removals would be a more expensive alternative.
The critical role these technologies will play in meeting climate targets means government must rapidly kick start the sector so that it becomes viable by the 2030s, according to the report, which was commissioned by government in November 2020.
Early movement by the UK to develop the expertise and capacity in greenhouse gas removal technologies could create a comparative advantage, with the prospect of other countries needing to procure the knowledge and skills the UK develops.
The Commission recommends that government should support the development of this new sector in the short term with policies that drive delivery of these technologies and create demand through obligations on polluting industries, which will over time enable a competitive market to develop. Robust independent regulation must also be put in place from the start to help build public and investor confidence.
While the burden of these costs could be shared by different parts of industries required to pay for removals or in part shared with government, the report acknowledges that, over the longer term, the aim should be to have polluting sectors pay for removals they need to reach carbon targets.
Polluting industries are likely to pass a proportion of the costs onto consumers. While those with bigger household expenditures will pay more than those on lower incomes, the report underlines that government will need to identify ways of protecting vulnerable consumers and to decide where in relevant industry supply chains the costs should fall.
Chair of the National Infrastructure Commission, Sir John Armitt, said taking steps to clean our air is something we’re going to have to get used to, just as we already manage our wastewater and household refuse.
"While engineered removals will not be everyone’s favourite device in the toolkit, they are there for the hardest jobs. And in the overall project of mitigating our impact on the planet for the sake of generations to come, we need every tool we can find," he said.
“But to get close to having the sector operating where and when we need it to, the government needs to get ahead of the game now. The adaptive approach to market building we recommend will create the best environment for emerging technologies to develop quickly and show their worth, avoiding the need for government to pick winners. We know from the dramatic fall in the cost of renewables that this approach works and we must apply the lessons learned to this novel, but necessary, technology.”
The Intergovernmental Panel on Climate Change and International Energy Agency estimate a global capacity for engineered removals of 2,000 to 16,000 megatonnes of carbon dioxide each year by 2050 will be needed in order to meet global reduction targets.
Yesterday Summit Carbon Solutions received "a strategic investment" from John Deere to advance a major CCUS project (click here). The project will accelerate decarbonisation efforts across the agriculture industry by enabling the production of low carbon ethanol, resulting in the production of more sustainable food, feed, and fuel. Summit Carbon Solutions has partnered with 31 biorefineries across the Midwest United States to capture and permanently sequester their CO2 emissions.
Cory Reed, President, Agriculture & Turf Division of John Deere, said: "Carbon neutral ethanol would have a positive impact on the environment and bolster the long-term sustainability of the agriculture industry. The work Summit Carbon Solutions is doing will be critical in delivering on these goals."
McKinsey highlights a number of CCUS methods which can drive CO2 to net zero:
- Today’s leader: Enhanced oil recovery Among CO2 uses by industry, enhanced oil recovery leads the field. It accounts for around 90 percent of all CO2 usage today
- Cementing in CO2 for the ages New processes could lock up CO2 permanently in concrete, “storing” CO2 in buildings, sidewalks, or anywhere else concrete is used
- Carbon neutral fuel for jets Technically, CO2 could be used to create virtually any type of fuel. Through a chemical reaction, CO2 captured from industry can be combined with hydrogen to create synthetic gasoline, jet fuel, and diesel
- Capturing CO2 from ambient air - anywhere Direct air capture (DAC) could push CO2 emissions into negative territory in a big way
- The biomass-energy cycle: CO2 neutral or even negative Bioenergy with carbon capture and storage relies on nature to remove CO2 from the atmosphere for use elsewhere