- Government researchers in Indonesia believe oil from the tamanu tree (Calophyllum inophyllum) could serve an alternative feedstock for biofuel to palm oil.
- They say the plant has shown the ability to grow in burned areas and former mining sites, as well as in waterlogged peat soils.
- Oil from the tree, native to tropical Asia, has been used for centuries across the region as a salve for wounds and scars, and in lotions and balms.
- With the Indonesian government’s ambitious biodiesel program requiring the establishment of more oil palm plantations, alternative feedstocks like tamanu could help stave off the associated deforestation.
YOGYAKARTA, Indonesia — Even as a boy, Budi Leksono knew the tamanu tree had many uses.
The small, hard fruit of the tree, about the size of a pingpong ball, made for a convenient plaything. Budi used to pick them from the one growing outside his home in Pekalongan — tamanu trees had been planted all along Java’s northern coast during colonial times — and watch as road repair workers used tamanu wood, which can burn even when wet, to heat the asphalt.
“Since my childhood I have known the tamanu,” said Budi, now 58. “So when I began my research, it was already very familiar to me.”
Today, Budi, a senior researcher at the Indonesian government’s Center for Forest Biotechnology and Tree Improvement, has a different vision for the tamanu tree: that it will serve as a pillar of Indonesia’s biodiesel program.
The program currently relies on palm oil, the ubiquitous edible oil of which Indonesia is the world’s top producer. Palm oil comes from the red, spiky fruit of the oil palm tree (Elaeis guineensis), grown on huge monoculture plantations and smaller farms across Indonesia.
Since its launch in 2008, the biodiesel program has been rolled out in stages, with the government mandating progressively higher concentrations of palm oil-derived biodiesel into conventional diesel.
In its current B30 stage, the diesel sold at the pump contains a 30% blend of biodiesel and 70% diesel fuel. The plan is to reach the B50 stage, a 50:50 blend, by 2025, and eventually B100.
To reach that target, millions more hectares of oil palm estates will need to be established, energy minister Arifin Tasrif has said, fueling concerns that the biodiesel program, meant to reduce Indonesia’s reliance on petroleum imports and, correspondingly, its greenhouse gas emissions, will actually intensify the nation’s environmental woes by ramping up pressure on its rainforests, huge swaths of which have already been cleared to make way for plantations.
Scientists like Budi and his colleagues at the Yogyakarta-based forest biotechnology and tree improvement center, which is part of the Ministry of Environment and Forestry, are examining alternatives.
Among them is tamanu (Calophyllum inophyllum), known as nyamplung in Indonesia. Oil from the tree, which is native to tropical Asia, has been used for centuries across the region as a salve for wounds and scars. Cosmetics companies use it in lotions and balms.
Scientists say the tamanu has shown the ability to grow in burned areas and former mining sites. Experimental plantations already exist in Central and East Kalimantan provinces, on the island of Borneo, and in Wonogiri, Central Java province, where farmers intercrop tamanu with food crops.
Searching for tamanu
Budi joined the forest biotechnology and tree improvement center, known by its Indonesian acronym BPTH, in 1994, where he developed methods for enhancing fast-growing timber species such as acacia, eucalyptus and sengon, commonly used in pulp and paper production.
In the 2000s, as China’s growth and war in the Middle East sent crude oil prices to record highs, Budi began to research various forest plants as potential sources of biofuel. The Ministry of Agriculture had already looked into the jatropha plant (Jatropha curcas), which is used in biodiesel in places like India. Now, Budi turned to tamanu. Part of its appeal, he told Mongabay, was that tamanu oil is non-edible, meaning its use as a biofuel could not be construed as a threat to food security in the same way as palm oil.
“Its features are similar to jatropha,” Budi said of tamanu. “The process in producing biodiesel from tamanu followed the jatropha process.”
In search of high-quality tamanu varieties, Budi traveled across the Indonesian archipelago. In Dompu, West Nusa Tenggara province, not far from a small island chain inhabited by Komodo dragons, he discovered a tamanu tree more than 100 years old. In Java, he found promising specimens in Banyuwangi, Carita and even Ujung Kulon, the only remaining habitat of the Javan rhino.
At a BPTH greenhouse in Yogyakarta, Budi showcases the center’s collection of tamanu plants from around the country. The plants grow well, despite the soil often being waterlogged and relatively infertile, according to Budi.
“Turns out, they do well on peat,” Budi said. “Of the four types of energy plants we tested, only the tamanu could grow the most. The others died, usually rotted.”
The center has received interest from mining firms that want to use the tree for land reclamation, he said.
Budi said he sees the nation’s biofuel development proceeding in four stages. Palm oil is at the center of the first stage. Other oils, like tamanu oil, will serve as the foundation of the second stage, he said. The third and fourth stages will be driven by microalgae, which is also being studied, though it will require major technological advancements and funding.
While acknowledging that the market for tamanu oil remains relatively undeveloped, Budi said he sees the plant as a key to the “plantations of the future.”
“We must prepare the second generation, non-edible oil, so that we are not drawn to use foodstuffs,” he said.
Banner image: Budi Lesksono in a nursery growing tamanu saplings. Image by Nuswantoro/Mongabay Indonesia.
A version of this story was reported by Mongabay’s Indonesia team and first published here on our Indonesian site on Jan. 5, 2022.