Jatropha trees siphoned for biofuel

Issue date: 8/20/07 Section: News

Head researcher Richard Ogoshi looks through a field of jatropha plants at the univerity's research center in Waialua. The plants' seeds contain oils that can be converted into biofuel.

Media Credit: Tiffany Hill

Jatropha plant

An experiment is under way in the heart of the North Shore's onetime sugar country that, if successful, could yield a sweet payoff: a locally grown source of renewable energy that could power anything from automobiles to generating plants.
Researchers with the University of Hawai‘i College of Tropical Agriculture and Human Resources are looking into crops the oil palm in hopes of finding one that can thrive here and be used to produce biofuel.
But it's the jatropha tree - a native of Central America and relative of the poison oak plant - that has grabbed researchers' attention with its fast growth and early harvest.
Seeds from the jatropha tree contain 50 percent seed oil and are already being used to produce biofuel such countries as India and Cape Verde.
The plant has been here for decades, originally brought by an immigrant Filipino family who used the sap as an anti-viral medicine. The question is whether the tree enough seeds to mass produce biofuel and whether it can be done in a way that's economically feasible.
That's what researchers hope to find out through a quarter-acre planting of the trees at the university's Poamoho Experimental Farm in Waialua.
Though a final answer is likely years off, researchers believe the potential is there to help the state reduce its reliance on fossil fuels and reach its goal of producing 20 percent of Hawai‘i's total energy with renewable sources by the year 2020.
Once the seeds of the jatropha tree have been harvested, they are pressed to extract the oil, which is what gets converted into biofuel.
"It's a great way to produce fuel," said Richard Ogoshi, head researcher of the jatropha plants in Waialua. "It less net CO2 than fossil fuels, and it's a way to produce fuel here in the islands."
Jatropha plants can get up to 15 feet tall, each seed pod containing two to three seeds. A successful crop can yield anywhere from half a ton to 12 tons of seeds per hectare, or 2.47 acres. That equals more than 300 gallons of oil per acre.
Researchers at Poamoho planted just 10,000 square feet of jatropha plants, but still hope for a high seed yield. So far a few hundred seeds have been harvested.
"If the experiment works, if we could get a high enough yield, it would be a component of [economic] security for the state," said Robert Paull, a fellow project researcher and professor and chair of the Department of Tropical Plant and Soil Sciences. "There's enough acreage to do it."

Research goals at Poamoho

Ogoshi and his colleagues divided and planted 700 jatropha seeds in January, testing such variables as water and plant density to determine the best growing conditions for growth and high yield.
"We add water to one set of plants and leave the other with just rainwater," Ogoshi said. To study varying yield results due to plant density, half were planted one meter by one meter apart, while the other half were planted one-half meter by one-half meter apart.
Jatropha plants are considered to be drought-tolerant, but Ogoshi said that if they do not get the minimum amount of water needed to survive, all of their leaves shrivel up and drop off and the stalk of the tree remains dormant yet alive.
"Although it's been said that they're drought-tolerant, we want to push the envelope" to determine the smallest amount of water the trees can receive to thrive and produce, Ogoshi said.
Researchers have already learned something about jatropha plant density.
"It depends on the size of the plant, but if they are too close together, they start competing for sunlight and water and nutrients," Ogoshi said. "The leaves and roots overlap and cause problems later in harvesting."

Hawaii‘s first potential biofuel crop

In addition to researching the plant itself, the team is investigating how to economically grow and harvest the seeds.
"We were looking at how we could make this crop economical," Paull said. "Many crops have potential to grow in Hawai‘i, but can they grow [producing a] high yield?"
The oil palm has double the oil yield of jatropha, but because the trees are so large, and expensive and laborious to harvest, jatropha is a better investment, Paull said because it has the potential to produce at least two crops a year, equaling out to the same production per unit as the oil palm.
The jatropha trees are "developing really fast," said Ogoshi, who was surprised that they already blossomed and produced seeds. Ogoshi harvested the plot's first seeds three weeks ago. He did his second harvest just last Wednesday, picking an estimated 100 seeds from five plants.
Ogoshi and Paull said they are looking into ways to mechanically harvest the seeds by chopping off the tops of the plants where the seeds grow. Because they are perennial, the plants will grow back and produce another crop. Ogoshi explained that researchers are hoping to modify a coffee harvester or blueberry picker machinery to use for the jatropha.
The jatropha tree has attracted an interest from others, too.
The Hawai‘i Agriculture Research Center is doing similar research at the old sugar plantation fields in Kunia.
"We are loosely collaborating with the university in our jatropha research," said Mike Poteet, a HARC crop scientist. "We're kind of sharing the initial findings with each other."
Poteet added that soon HARC will be working directly with the university when it conducts crop research on the Big Island through a $150,000 grant from the U.S. Department of Agriculture.
He will also travel in October to meet with scientists and biofuel companies in India, Madagascar and Cape Verde, all countries that have advanced jatropha crops and commercially produce the oil for biofuel.
"What we hope to accomplish is more diversity as far as feed goes," Poteet said. "The other hope is to get first-hand exposure from people who commercially produce jatropha, and thirdly, understand a little more about the plant itself."
Hawaiian Electric Co. is looking to jatropha as part of the solution to comply with a 2004 law requiring electric companies to produce 20 percent renewable energy by 2020.
"The use of electricity keeps rising, so it's really a moving target," said HECO spokesman Peter Rosegg. "Finding the right ... crop to grow is an important part of reaching that goal. Jatropha seems to be the most attractive agricultural plant."
To turn jatropha oil into biodiesel, triglycerides - a pattern of three-chain molecules of fatty acids composed of hydrogen, oxygen and carbon - are extracted from the oil and undergo a process of chemical reactions called transesterification. The jatropha oil is purified and then reacted with ethanol, or alcohol, in conjunction with either a potassium hydroxide or sodium hydroxide catalyst.
The fatty acids are then transformed into esters, which can be removed from the process to make soap - a common use of esters and glycerol. Continuing transesterification, while retaining the esters, results in biodiesel, a specific type of biofuel.
Ogoshi said researchers are also trying to find more uses for ethanol and glycerol in addition to being used to make biodiesel or soap. Hawai‘i currently does not produce ethanol because there are no processing plants.
By 2009, HECO hopes to change that, however. Plans are under way to build a biodiesel facility in Campbell Industrial Park where refined biodiesel will be imported and used in some of O‘ahu's generators.
The company is also partnering with BlueEarth Maui Biodiesel to construct a $61 million refinery that will eventually be capable of producing 120 million gallons of biodiesel per year. Rosegg said that currently 85 percent of Maui's electricity is produced by diesel generators, but that the HECO-BlueEarth contract will ensure that electricity on the island is virtually biodiesel-run.
He said that, overall, these plants will help decrease the use of fossil fuels in the state and "reduce our carbon footprint."
"We hope that by having the plant here in Hawai‘i, it will encourage local farmers to grow biofuel crops," Rosegg said, adding that jatropha is a strong candidate.
Although the research is still in its infancy, biofuel production from the jatropha appears to offer a promising way to make the islands even more green, Ogoshi said.
"We don't have full results yet - that comes way down the line," Ogoshi said. "But I can wait. Delayed gratification is."

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