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Tuesday May 7, 2013

Fuel from petai

New fuel source: The shrub Leucaena leucocephala or petai belalang holds great
promise in the production of biofuels. New fuel source: The shrub Leucaena leucocephala or petai belalang holds great promise in the production of biofuels.

A tasty treat has a new use.

AS GEOLOGISTS predict an inexorable decline in oil production, and experts point to a possible near-doubling of oil prices over the coming decade, the search is on for alternative energy sources. In Malaysia, industry has set its sights on a common but hardy weed, the Leucaena leucocephala or petai belalang.

An inconspicuous feature of the Malaysian landscape, chances are you’ve either walked or driven past, or even eaten the seeds, of this shrub. A relentless coloniser, the seeds of its pods, which look and taste like a smaller version of petai, are commonly found in local dishes such as nasi ulam, nasi kerabu and Kelantan laksa.

The tree itself grows wild and almost anywhere – along coastal or riverine habitats and in semi-natural and disturbed sites, often forming dense thickets.

“When I talked to the old people, they told tell me how they climbed the petai belalang tree to pick the seeds and eat them,” says Malaysian Biotechnology Corp (BiotechCorp) chief executive officer Datuk Dr Mohd Nazlee Kamal.

Datuk Dr Mohd Nazlee Kamal. Datuk Dr Mohd Nazlee Kamal.

BiotechCorp started researching the plant, which has been mainly used as livestock fodder, three years ago to address the issues of energy security and environmental sustainability.

“We do have (fossil fuel) reserves but extraction costs are high, so the cost per barrel in the future is going to be very expensive. Plus, there are so many issues that make people reluctant to disturb our remaining oil reserves,” he says.

Speaking from his top-floor office at Menara Atlan, Kuala Lumpur, Mohd Nazlee sits against the panoramic backdrop of a fuel-guzzling city, where products and people constantly shuffle in and out from across thousands of miles. It makes an interesting contrast with the bottle-garden sitting on his coffee table – an entirely self-sufficient ecosystem, a bit like what he has envisioned for Kertih Biopolymer park. The park is also a self-contained industrial “ecosystem” of sorts, expected to take shape in Terengganu within the next five years.

The idea is that it will run on Leucaena, with wood chips from the tree used both as an energy source to produce steam and electricity to run the factories, and as a raw material for processing.

High hopes

Terengganu has allocated 36,000ha of state land for growing Leucaena, which will yield 10.5 million tonnes of wood chips annually. Leucaena has a high content (up to 70%) of cellulose (the long chain of linked sugar molecules that gives wood its remarkable strength). Cellulose can be converted via a fermentation process into sugars, which can be further fermented into a variety of products in the solvent, neutraceutical and biofuel markets.

BiotechCorp is collaborating with food company CJ CheilJedang of Korea and chemical company Arkema of France to produce L-methionine from cellulose-derived sugars. One of the body’s eight essential amino acids, L-methionine has antioxidant properties and has a big market as a nutritional additive in the food supplements industry.

Another partner is renewable chemicals and advanced biofuels company Gevo, which has been at the forefront of a new technology to produce isobutanol, a next-generation biofuel made from sugars that is less evaporative and less corrosive than ethanol. The long-term ambition is for isobutanol to be sold for use as blends with renewable biofuels and jet fuels and perhaps, even as a total replacement for petroleum-based fuels.

Construction of the two L-methionine plants at the Kertih Biopolymer Park has commenced while that of the Gevo factory will start soon.

Another potential product from petai belalang is succinic acid which is used as an acidity regulator in the food and beverage industry as well as in the manufacturing of certain polyesters. BiotechCorp is in the process of identifying investors to exploit this pathway.

Mohd Nazlee says there is even a market for leftover microbes used in the fermentation of cellulose into sugar, and of sugars into the subsequent end products.

“These can amount to a couple of tonnes and can be sold as bio-fertilisers, so as a whole, this is an environmentally friendly, almost zero-waste strategy.”

There are also added advantages for smallholders. Mohd Nazlee encourages anyone with unused patches of land to grow the tree, because its leaves can be harvested every two months, and sold as nutritious livestock fodder.

Second generation biofuel

The tree is native to Central America but its introduction into the Philippines by the Spanish in the early 1800s has seen it become naturalised pan-tropically. The biological features responsible for its widespread success are precisely what makes it such a prospective wonder-crop. It is leguminous, which means it is adapted to harbouring nitrogen-fixing bacteria in its root nodules, and so requires less fertilisation. It also grows fast.

“No replanting exercises are needed because once you cut the stump, it just grows again and you can keep harvesting it for the next 15 years,” says Mohd Nazlee.

In one year, he says the tree can grow up to 10m tall, compared to Acacia mangium, which would take five or six years. First generation biofuels which are created largely from feedstocks traditionally used as food, such as ethanol from corn, have come under criticism for contributing to rising food prices. This has paved the way for second generation biofuels made from non-food feedstocks such as switchgrass, jatropha and of late, Leucaena.

Mohd Nazlee says Malaysia will be one of the first to explore Leucaena for biofuels on a large scale. He says the idea is to set up a biorefinery complex, where raw materials and various factories specialised in each stage of product production are located in proximity.

However, there are challenges. Although fermentation technologies have been tested on other woods, this will be the first time they will be used on Leucaena. Biotechcrop is conducting a seven hectare trial plot within the Merchang Forest Reserve, Terengganu. Some 40,000 Leucaena seedlings, planted in 2012, are growing in a nursery within the reserve.

“We find this a very interesting plant which can potentially be exploited in a very systematic way. It’s not just skilled workers who will benefit from this programme but common people too as they can use this as a new source of livelihood in their villages.”


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