Moment of truth for pioneering biofuel project
Mbongeni Mguni | Friday February 5, 2016 16:30
Through the fire, through the rain. In its four years, the country’s pioneering hectare of Jatropha plants at Sebele has witnessed frostbite, heatwaves and hailstorms.
Researchers keen to prove the plant’s potential as an alternative energy source for both diesel engines and woodfire have picked up the pieces each time and plodded on.
Biofuels, or fuels produced from agricultural instead of geological processes, were first investigated in Botswana in 2010 by the University of Botswana’s Department of Mechanical Engineering.
The Jatropha project, according to the department’s Clever Ketlogetswe was initially born out of an investigation into several types of indigenous plants whose natural oils could potentially be processed into fuel.
Jatropha flowers all year round, except in winter, producing seeds that contain up to 40 percent oil.
“In 2010, the department started investigations into indigenous plant oils as feedstock for biofuel production,” he said this week.
“These include morula, morama, mongongo and Jatropha.
In November 2011, there was a Memorandum of Understanding between the Botswana and Japan governments for investigations into the use of Jatropha for the same purpose.
“Our investigations therefore became more relevant and we were then invited by the Department of Energy to join a research team with the Japanese.” Japan’s entry into the budding biofuel research arena in Botswana, came as government also ramped up its own forays into alternative fuels, with plans to establish a five million litre per annum biodiesel processing plant that would initially be fed by meat tallow.
As explained at the time by the then energy minister, Ponatshego Kedikilwe, government does not expect biodiesel to replace the regular pump variety. But with the country importing all of its fuel and more than 75 percent of this coming through a single pipeline in Gauteng, fuel supply has been exposed to strikes, demonstrations, supply constraints and the pricing issues associated with single-supply options.
“Government can go ahead with the project for national strategic purposes such as fuel security, as the fuel will be produced locally as currently all supplies are imported,” Kedikilwe said at the time.
Proving the commercial viability of Jatropha would also result in an economic revolution in the country’s farming sector.
Farmers would be able to diversify into growing Jatropha either for on-sale to national processors or to use smaller scale processors to produce oil for home use as an alternative, cleaner burning fuel.
By some estimates, a tonne of Jatropha seeds could sell for well over $1,000 per tonne, presenting an alternative cash crop for farmers with access to the plenty of land needed for its cultivation.
No part of the Jatropha plant goes to waste during or after processing.
Each by-product can either be used as charcoal, pressed again for oil or incorporated into soil improvement materials.
Where wood fires were slowly deforesting villages and spreading desertification, Jatropha presents a carbon neutral alternative for communities outside the power grid.
With assistance from Japanese technical expertise and equipment, Jatropha was planted on a two-hectare field in Sebele in April 2012, with the researchers aiming to determine how to cultivate the optimal variety for drought and frost-prone Botswana.
The project cost was estimated at $3 million and the answers were soon evident.
The project’s chief advisor (cultivation), Yudai Ishimoto witnessed the good, the bad and ugly of local Jatropha production, having been involved in the initiative since 2012.
“Jatropha trees come from Mexico, which has rainfall in abundance and warm winters,” he said this week.
“In Botswana, we have low rainfall and cold winters. In order to grow the plant here, we have to develop cultivation methods suitable for the climate, with suitable varieties.”
In 2014, the realities of Jatropha production came down hard on the research team. Temperatures that winter plummeted to minus seven degrees Celsius on one occasion and wiped out the crop.
“The temperature fell below freezing point and all the leaves fell off. We lost most or all of the plants,” Ishimoto said.
“Last year’s cold damage was not serious and in September, we saw flowers on some of the plants. By October, the leaves had returned.”
As researchers were breathing sighs of relief, two hailstorms struck in November. After the first, 60 percent of the plants lost their leaves and after the second, the figure moved to 80 percent.
A series of heatwaves followed, although the impact of the drought was minimised by the fact that the project uses water tanks and drip irrigation for its supplies.
Discouraged but determined, Ishimoto and his team of researchers, who include Batswana, plucked their nerve and set about learning from the disasters, implementing various initiatives such as wrapping, pruning and even removal of leaves to prevent frostbite.
Affected plants were also revived quickly through foliar fertilisation, a method of applying liquid fertiliser directly to the leaves of plants, allowing them to absorb essential elements directly.
“Right now about 10 percent of trees have fruits,” said Ishimoto.
“Last season, we had our first fruits in March and this season, already about 10 percent have fruits. The progress is much better this year.”
From the one-hectare plot at Sebele, researchers are targeting the production of at least 100 kilogrammes of seeds, which would potentially yield 25 litres of biodiesel. Once the project fine-tunes the right variety for Botswana, researchers expect higher yields per hectare.
Preliminary results from the four-year project, however, are mixed. As another researcher on the project, Charles Mazereku explained, given the experience of the past years, there is no simple, clear answer about the success of the project.
“We have had hailstorms, drought, frost and heatwaves. This project is one that you cannot be certain about anything.
“In the morning, you could wake up and find everything on the ground.
“The seeds flower on the top tip of the branches and if that’s disturbed, you will not get anything.”
Still, the experience over the past four years, has hinted at the potential for successful Jatropha production in Botswana.
“We have seen that it grows much better in compounds where there are fires provided for its warmth,” Mazereku explained.
“It performs very well when grown in the compounds as opposed to the open fields.”
The results have excited the mechanical engineers at the University of Botswana, who are also racing ahead with their own tests into the use of Jatropha biodiesel for motor diesel fuel.
The UB experts have tested the biofuel’s viscosity, its flash point, calorific value, acidity and safety, which are some of the main international criteria for the use of biofuels.
In one of the Department of Mechanical Engineering’s laboratories, a diesel engine has been set up with computerised performance software, to test the quality of Jatropha fuel.
“We have found that it is far more efficient than fuel from the pump. It would potentially travel further per kilometre than the diesel from the pump,” Ketlogetswe said.
“Also, it does not pollute, as compared to the fuel from the pump.”
Plans are underway to move from the laboratory and actually move a vehicle over distance using Jatropha biodiesel produced in Botswana. Already, standards have been developed at the Botswana Bureau of Standards for biodiesel and have been opened up for public input.
“Once they are accepted, then biodiesel can be used anytime. It will not be used in its pure form, but will be blended,” Ketlogetswe explained.
The experts at UB also plan to take generators that have been donated by Japan to remote rural areas and provide electricity for Batswana, using Jatropha biodiesel.
The wonder plant is gaining traction in the country. However, in other countries, such as Zimbabwe, where it has been introduced, uptake has been slow as farmers have been unwilling to allocate space to a strange new crop requiring a massive amount of land, without guaranteed profits.
And with oil prices at 12-year lows, commercial biodiesel production would be unviable.
However, Jatropha’s local proponents are reading positive signs from their interaction with farmers across the country. In areas such as Maun, Kasane, Francistown and Molepolole, Batswana are already familiar with Jatropha.
Many use it for their hedges as the plant’s high toxicity means livestock and other animals naturally stay away from it.
Few are aware, however, that the plant carries a secret so lucrative, it could change their lives forever.