02/10/2012 (The Star) - Manufacturing biofuel from agricultural and forestry waste is one of the ways Malaysia is hoping to reduce its share of carbon dioxide emissions. Tapping into the huge pool of agricultural waste, broadly categorised as non-food biomass, appears a logical choice given Malaysia’s extensive involvement in oil palm and other agricultural activities.

Many would be familiar with the experimentation with biodiesel (which can also be made from used cooking oil) that started way back in the 1980s. The present national B5 programme – a blend of 5% biodiesel that is derived from palm oil-based feedstock and 95% fossil fuel – currently covers the central region of the Peninsula, namely Putrajaya, Kuala Lumpur, Selangor, Negri Sembilan and Malacca.

Less common is the use of bioethanol here, as its use is not mandatory, even though it is highly popular in Brazil and the European Community. Bioethanol can be produced by the fermentation of sugars derived from wheat, corn, sugar beets, sugar cane, molasses and any sugar or starch that alcoholic beverages can be made from (like potato and fruit waste). In a bioalcohol plant, microorganisms and enzymes are allowed to act on sugars and/or starches found in plant materials, and through the fermentation process, convert them into alcohol.

There are now attempts to turn empty fruit bunches into bioethanol, but the process
is complex, time-consuming and costly.

Bioethanol is a huge industry in Brazil as it has huge tracts of land devoted to sugar cane. For Malaysia, the natural choice of feedstock would be palm oil milling waste, which is estimated to be as high as 40 million tonnes a year. If the haul is narrowed down to just empty fruit bunches (EFBs), then some accounts claim that there are about 20 million tonnes of that produced here.

In the palm oil milling process, one tonne of fresh fruit bunches produces about 220kg of EFBs. This was a problematic waste in the past, with some mills just burning the material. Stricter air pollution standards mean that this practice is no longer acceptable. Some mills still burn EFBs in their boilers to extract the calorific value in the form of heat that is used for the mill’s own processes but many older mills still struggle to meet an acceptable level of smoke discharge at the chimney stacks. EFBs are also not easy to combust as their moisture levels can be as high as 60%, especially when they are fresh out of the mill.

Making bioethanol
EFBs consist primarily of three components, namely cellulose (40% to 50%), hemicellulose (20% to 30%) and lignin (20% to 30%). With the rise in the price of synthetic fertilisers, burning EFBs do not make much sense as they can be used as mulch and compost in the field. Sime Darby Plantation head of plantation sustainability, Tang Men Kon, says his company’s EFBs are mainly used for such purposes.

“Both serve as biofertilisers or organic manure to improve soil fertility by improving soil organic carbon. We do not burn EFBs for biomass power in any of our operating units.”

Still, that has not stopped some parties from attempting to turn EFBs into bioethanol for the export market. Spurred by the intentions spelt out in the National Biofuel Policy which aims to develop biofuels as an alternate energy source to reduce the dependency on depleting petroleum, Lestari Pasifik had declared last year that it would enter the uncharted territory of making ethanol commercially from EFBs. Its optimism stems from the huge demand from China for biofuels.

In many estates, empty fruit bunches are returned to the
soil, as mulching at the base of oil palm seedlings.

Last August, the company announced plans to invest RM2bil for the setting up of 616 biorefinery module lines in the next five years in Malaysia and Indonesia. (None has been completed here to date.)

The most expensive part of making ethanol from lignocellulosic feedstock is pre-treating the raw material to make it accessible to the enzymes that will liberate the sugars from the polymers so that they can be fermented. Pre-treatment includes the mechanical and physical actions to clean and process the biomass, and to subsequently destroy its cell structure so that its contents can be more accessible to further chemical or biological reactions. Ethanol can be used in petrol engines as a part replacement for petrol. It can be mixed with petrol at any percentage, and most existing petrol engines can run on blends of up to 15% bioethanol content. However, ethanol has a smaller energy density than petrol and typically, contains up to 30% less energy.

In other parts of the world, the global production cost for bioethanol fuel ranges from 60 sen to RM2.43, but Lestari Pasifik thinks that Malaysia enjoys the advantage of being a low-cost bioethanol producer, and depending on conditions, the production cost for each litre can be as low as 35 sen.

In December 2010, Sime Darby Plantation had announced its collaboration with Mitsui Engineering and Shipbuilding Co of Japan to construct and operate a bioethanol demonstration plant which will convert EFBs into bioethanol. The collaboration is being undertaken by Sime Darby Research, the company’s research and development arm, and is housed next to the Tennamaram palm oil mill at Bestari Jaya (formerly Batang Berjuntai), Selangor.

The plant can process 1.25 tonnes of EFBs a day using the hydrothermal pre-treatment and enzymatic hydrolysis technology. It is understood that Sime Darby is still collecting operational data to confirm the technical feasibility of commercial-scale production of bioethanol from EFBs.

Multiple uses
Regardless of whether bioethanol production will take off here, plantation owners are already guarding their biomass zealously, given their value and multitude of uses nowadays. It was not too long ago when palm kernel shells were used as road-fill material in estates but now, they command values ranging from RM160 to RM200 per tonne. Likewise, palm oil mills used to pay others to dispose off their EFBs but nowadays, none would give away any form of biomass without some form of payment.

The Felda Global Group, for example, has its own extensive renewable energy programme, consisting of 56 biogas plants, two power plants, six compost plants, two mini-gasifier plants and one fuel pellet plant – all utilising palm waste as feedstock. It foresees that most of the EFBs from its own operations will be fully utilised for its renewable energy programme.

Agriculturalists, however, have their objections to the unfettered removal of biomass for fuel. Common sense dictates that nutrients that are removed from the soil through biomass extraction would have to be replaced. And that would mean added application of fertiliser, whether synthetic or otherwise. As a good proportion of fertilisers are actually fossil-fuel based, it remains to be seen how biofuel production from oil palm waste is an overwhelmingly superior proposition. The question of whether a plantation can afford to have 50% of its waste removed without significantly affecting soil fertility is still subject to research.

“Agronomists are quite reluctant to allow the removal of biomass from the field, even if the intention is to create biofuel out of the biomass,” says Dr Astimar Abdul Aziz, head of the agro product unit under the Malaysian Palm Oil Board’s engineering and processing research division.

With so many people after palm biomass nowadays, the value of the material has appreciated tremendously over the last decade and its alleged “abundance” is beginning to sound like a myth. The level of demand for palm biomass products is now high enough to justify the construction of in-house mills just to extract the long fibre content from EFBs for various value-added products, such as fibre mats and so on.

Increases in fuel prices, coupled with the introduction of feed-in tariff for electricity generated using biomass also mean that many mills are upgrading their boilers so that they can make use of shredded EFBs as fuel instead of fossil fuels.

Alas, current bioethanol prices mean that current processes are not economically viable despite the availability of various technologies. “Lignin hinders the bioconversion into glucose using enzyme, and the delignification process is costly. Most of the technologies are not feasible with current bioethanol prices, and that is why many are now looking at other value-added products like bio-based chemicals like polylactic acid (an ingredient of biodegradable plastic) and so on,” says Dr Astimar.