This is our future’ – Kenya’s croton tree touted as new biofuels crop

all, spindly and grey, croton trees grow everywhere in Kenya. Although they tend to be used for little more than firewood or shade, their nuts turn out to be an excellent source of biofuel. This overlooked plant could be the answer to Africa’s growing demand for cheap, low-carbon energy.

At least that is what Eco Fuels Kenya hopes. Founded in 2012, this small company based in Nanyuki, in the foothills of Mount Kenya, is pioneering the use of croton oil as a replacement for diesel and hopes others will soon follow suit. The startup wants to use the tens of thousands of croton trees already growing wild across the nation to improve livelihoods and protect the environment.

The croton industry is still in its infancy but, if the biofuel performs as promised, this macadamia-sized nut could help Africa meet several sustainable development goals, including clean energy, climate action and poverty reduction.

Biofuel’s troubled legacy

Kenya currently imports all of its oil and, while some rural communities can barely afford to buy diesel for their water pumps, car exhausts in the capital Nairobi are causing dangerous levels of air pollution. “Croton has a lot of potential as a sustainable fuel,” says Michael Jacobson, chair of the forest ecosystem management programme at Penn State University.

This is not the first time Kenya has been promised a biofuel revolution. In 2000, jatropha, a plant native to Central America, was introduced, billed as the next big biofuel crop. The Kenyan government took away farmers’ land to make space for thousands of acres of monoculture.

At the peak of the jatropha hype there were thousands of farmers in Kenya helping to grow the plant. But yields were “dismal” and because 90% of the jatropha plantations were established on former agricultural land, when some of these companies left, they kept their land titles. This meant hundreds of farmers were left with no jobs and no place to grow their crops.

Myles Katz, the managing director of Eco Fuels Kenya, says his team has learned from jatropha’s failure and purposefully pursued a different business model.

“Instead of going the way of monoculture, we have decided to collaborate with small-scale holders and minimise the risk for everyone involved,” says Katz. His company currently buys nuts from 5,000 farmers in the Mount Kenya and Rift Valley regions.

Croton oil generates 78% (pdf) less carbon dioxide emissions than diesel and has one big advantage over other common biofuels: food security. The fact that croton nuts are inedible means they can replace the need to make fuel from ingredients that could otherwise be food for humans. Croton trees are also already growing all over the region so there is (in EFK’s model) no need to create massive mono-cultures that could potentially displace other food crops.

Unlike palm oil, croton trees are native to east Africa, which means that monetising their fruit may also incentivise locals to fight deforestation.

While the oil needs to be processed before it can be used in cars, it can go directly into diesel generators, water pumps or tractor engines. The company sells the oil to safari lodges in the Masai Mara. The price fluctuates but it is usually about 10% cheaper than diesel, which is currently about $0.90 (£0.73) a litre in Kenya.

Eco Fuels Kenya also sells the byproducts of the fuel production. The seedcake paste left from pressing the croton nuts is a protein-rich feed for poultry and the grounded husks are sold as an organic fertiliser for depleted soil. “We are constantly discovering new uses for croton,” says Katz.

A cash crop to replace coffee?

Croton nuts could also help bring many Kenyans out of poverty. The trees don’t require any investment in terms of water or fertiliser and harvest time can last up to six months a year, which makes it a steady source of income. What’s more, sellers get paid on delivery while coffee farmers often have to wait months for their money.

This is why, after years as a coffee grower, Martin Kamai is moving into croton. This young farmer and his wife have planted 500 croton trees on their property in Nyeri County, central Kenya, and plan to add even more next year. “Croton pays better than any other crop,” he says, “this is our future.”

Still, there are many challenges in the way of croton taking over the biofuel industry. The failure of jatropha is likely to make foreign investors, local farmers and Kenyan government officials more reluctant to put their weight behind another experimental biofuel solution.

Lack of marketing awareness and knowledge about best growing methods for croton will also make it hard for the business to scale up. “Investors won’t see much gain in small-scale, local projects, and the low price of oil is probably dampening their interest in energy alternatives,” warns Carol Hunsberger, an assistant professor at Western University who researches biofuels in Africa.

Despite the hurdles, Eco Fuels Kenya continues to grow. In 2016, it processed about 1,000 tonnes of nuts (twice as much as the previous year) and helped local farmers plant 100,000 croton trees in regions where they plan to expand their operations.

Next year, it will open its second processing plant in the lake town of Naivasha. The startup wants to set up five plants in Kenya before branching out to neighbouring Tanzania and Rwanda. The company declined to share any figures on the investment and its profit.

Will croton ever become a global biofuel? It’s doubtful, says Jacobson. But he adds that if local entrepreneurs persevere and oil prices go up again, this unlikely cash crop could make a real dent in east Africa’s energy supply, “which alone is good enough”.

Biofuels: could agave, hemp and saltbush be the fuels of the future?

iofuels have long been touted as a carbon-neutral alternative to fossil fuels, doing for the world’s planes, ships and automobiles what windfarms and solar panels are doing for its electricity grids. With the transport sector accounting for almost one fifth of Australia’s total carbon emissions, green biofuels could be an important ingredient of the zero emissions future envisioned by the Paris climate agreement.

On paper, biofuels seem the ideal replacement for fossil fuels, which drive global warming by spewing tons of carbon dioxide into the atmosphere that would otherwise be locked away in geological deposits. With biofuels, the plants and algae used to produce the raw material inhale carbon as they grow, offsetting the carbon released when they are burned.

But the past decade has seen the biofuel industry face tough economic conditions and niggling questions over its green credentials. The fledgling industry is now turning to a raft of innovative crop and processing technologies to overcome its challenges.

One of the biggest criticisms of the early generation of bioethanol crops, such as corn and sugarcane, was their propensity to mess with food markets and alter land use. Direct impacts – felling forests to make way for a biofuel crop, say – are usually obvious, says Prof Bill Laurance, director of the Centre for Tropical Environmental and Sustainability Science at James Cook University. But indirect impacts can be no less devastating for the environment and are far harder to predict. “The devil is really in the details,” he says.

As an example, when farmers in the US opted out of soy in favour of corn for bioethanol, soy prices soared, suddenly making it an attractive crop for Brazilian farmers, which in turn drove demand for freshly deforested cropland. One analysis of these knock-on effects estimated that instead of cutting emissions, corn-based bioethanol would double emissions over a 30-year period.

This is without even considering loss to biodiversity, pollution from pesticide and fertiliser use, changes to water catchments and decreased food security for marginalised populations. The latest IPCC assessment report, released in 2014, acknowledged some of these risks and trade-offs.

Prof Rachel Burton, leader of the ARC Centre of Excellence for Plant Cell Walls at University of Adelaide, thinks that there is a smarter way forward for biofuels and it starts with selecting the right crop. Instead of growing food crops such as corn and sugarcane on prime agricultural land, Burton and others are looking to more hardy plants that grow on land too dry or saline for conventional crops. Australia could turn to crops like agave (of tequila fame), hemp, or the native saltbush and wild-growing sorghum for biofuels of the future, she says.

The once popular idea of generating biofuels from microscopic algae grown in ponds or tanks – which avoids land use altogether – has largely been abandoned due to the high production costs compared to fossil fuels. But economic considerations are also a factor for crop-based biofuels. Plant oils can be extracted and turned into biodiesel for vehicles and machinery, and aviation fuel that has already been used in commercial airline flights.

However, food oils from palm and soy hover at roughly twice the price of crude oil. “It really is fundamentally an economic problem rather than a technological problem,” says Dr Allan Green, innovation leader for biobased products at CSIRO Agriculture and Food. His solution is to make plants oilier. With more oil being produced on a given parcel of land, harvesting and production costs will inevitably fall. He and his colleagues have patented a way of tinkering with the genetic levers that control oil production in plants, so that a plant produces oil in its leaves, not just its fruit or seeds.

The technology, which has so far only been tested in tobacco, shows that oil production can be boosted to a third or more of the leaf’s weight, more than occurs naturally in any plant. If used in a crop that already produces oil in its seeds or fruit, the hope is that oil output could be doubled, though that theory is yet to be put to the test.

Changes to processing technologies are also influencing the direction that the biofuel industry is taking. Traditional approaches use plant sugars for fermentation to bioethanol, or oils that can be chemically transesterified for biodiesel production. A great deal of attention has gone into finding the perfect crops for these applications: plants dense in sugar-laden cellulose, minus lignins that make extraction more difficult; or crops that pump out high oil volumes. But the industry is also turning to methods that are less finicky about what plants are used.

Hydrothermal liquefaction uses heat and pressure to rip apart the long-chain molecules in whole plants into bio-crude oil, essentially compressing eons of geological time into a matter of hours. This can then be refined as you would petroleum-based crude oil, producing a catalogue of different fuels as well as plastics and other products.

“I think it has a huge future,” Burton says.

Similarly, torrefaction, a process adapted from coffee roasting, can turn essentially any plant matter into easily transportable bio-coal pellets. While both of these processes are energy intensive, combining them with renewables – say, solar panels or wind turbines – or co-locating them with power stations to harvest excess heat, could make the operations more environmentally sustainable, Burton says.

The advantage of a “crop agnostic” approach is that producers won’t be limited to crops designed to be biofuel-only crops but can instead choose species that deliver added benefits or income streams. Agave could be used to produce a high-value tipple, for instance, or hemp farmers could harvest seed for food or fibre for lightweight soundproofing like that used in BMW cars. Meanwhile, work by Kirsten Heimann, associate professor at the College of Science and Engineering at James Cook University, has shown that microalgae can simultaneously be used to produce biofuels and scrub mining tailings of contaminants.

“It’s much more sophisticated thinking,” Burton says, and could change the calculus for biofuels. “Biofuels maybe don’t need to be as cheap as we think they do, because you can make money out of the other things.”

The biofuel industry could well shape up to be a very diverse one, with no one crop or process surging ahead to claim the market, according to Green. “The amount of fuel we need to move away from petroleum is massive, so there’s plenty of space for all technologies,” he says.


United Airlines is flying on biofuels

On Friday, United Airlines will launch a new initiative that uses biofuel to help power flights running between Los Angeles and San Francisco, with eventual plans to expand to all flights operating out of LAX. It’s the first time an American airline will begin using renewable fuel for regular commercial operations, and the occasion is part of a bigger movement when it comes to clean transportation in the U.S.   Continue reading