Camelina Sativa – The Wonder Weed.
Could a weed, used by ancient Europeans to make oil, pave the way for carbon-negative jet fuels and also help revitalise land lost due to overuse and climate change?
Camelina sativa is an unassuming plant. Once popular among ancient Europeans as a
source of oil for cooking and oil lamps, it has fallen out of favour in modern times and
become an overlooked, and sometimes pesky, weed.
However, the plant, which is similar to mustard, may soon experience its renaissance. Its high oil content and ability to grow on the least nutritious of soils, withstand drought and low temperatures and still produce yield, have put it into focus with researchers
looking for replacements for fossil-based aviation fuels.
In fact, researchers think that camelina could help solve not one but two environmental problems at once. While cutting the carbon footprint of aviation in line with international attempts to combat climate change, it could also replenish agricultural soils that have lost their fertility due to intensive farming and degradation caused by erosion and drought. As such, it can be grown during periods of time when agricultural land needs rest to replenish nutrients.
"We think the energy sector can offer something to food and feed production,” - says David Chiaramonti, a professor of Systems for Energy and Environment and Energy Economics at the Polytechnic of Turin in Italy. “They can pay to recover soil and,
through sustainable rotation between food, feed and energy crops, they can maintain or even implement food production where otherwise it would not be economically doable."
Sustainable aviation fuels (SAFs), made from biomass and food waste, are expected to play a dominant role in aviation’s quest for carbon neutrality by 2050.
Yet there are many challenges associated with SAF. Currently, the most advanced and readily available process to make sustainable jet fuels involves hydrogenation of used cooking oil and animal fat to produce Hydrotreated Esters and Fatty Acids (HEFA). Refineries capable of making HEFAs in large quantities of more than 1000 tonnes already exist, and the resulting fuel can be blended with kerosene or used on its own to power existing aircraft.
However, there is nowhere near enough old cooking oil and waste animal fat in the world to meet aviation’s fuel demand. According to estimates, this resource could cover at best about 2% of aviation’s fuel needs.
The BIO4A project, therefore, looked at the undemanding camelina, a plant native to Europe and Central Asia but spread widely today across North America and China too, and investigated its potential to grow on land no longer used by farmers.
The idea to use HEFA jet fuel made from camelina is not new. In 2011, the USAF conducted an experimental test flight at Edwards AFB, in California, using an F-22 Raptor fighter, powered by a 50:50 blend of military-grade kerosene and biofuel made from camelina.
The Dutch airline KLM has also experimented with camelina-based jet fuel since the early 2010s. Nevertheless, growing camelina for jet fuel production has not yet taken off on a large scale, despite the plant’s low requirements and convenience of use.
Camelina doesn’t require much water, it doesn’t require much fertiliser and it doesn’t require very high land quality in terms of nutrients.
Producing jet fuel from camelina is a tested process, which can be performed in retrofitted oil refineries. The cost of this SAF will, ultimately, depend on the scale of production. However, even with the most optimised supply chain, the price of this clean fuel is bound to be higher than the fossil-based kerosene.