Japanese company to produce ethanol from oil palm waste

Earlier we referred to a study we're preparing on the technical potential and energy balance of (next-generation) liquid biofuels made from tropical crops and biomass residues under several technology development scenarios. In a small article on the study, we pointed out that the African oil palm - the oils of which are a major biodiesel feedstock - is also the crop that potentially yields more ethanol than any other feedstock. New varieties of the plant yield up to 7000 liters of palm and palm kernel oil. But after the extraction of these oils, a vast amount of biomass remains: palm fronds, empty fruit bunches, fibre, press cake, palm kernel shells and palm trunks (harvested after the useful life of a tree). This biomass - some 50 tonnes per hectare per annum - is currently treated as 'waste' and most often burned in the open air. Some of it (the kernel shells) is being shipped to the EU, where it is co-fired with coal (check out the Database of Biomass Cofiring Initiatives, prepared by the IEA Bioenergy Task 32 on Biomass Combustion and Co-firing, which comprises around 150 initiatives from around the globe where biomass is co-fired in large coal utility boilers. Palm kernels for this purpose are notably exported to the Netherlands.)

However, this 'waste' biomass can be converted into liquid fuels instead of being burned as solid biomass in power plants (or as a feedstock for the production of biogas). Several conversion paths are possible for the production of transport fuels: thermochemical conversion (gasification after which the gas is turned into a 'synthetic' biodiesel via the Fischer-Tropsch process) or biochemical conversion, whereby specially designed enzymes break down the cellulose contained in the biomass to release sugars that can be fermented into ethanol. So besides yielding some 5000 to 7000 liters of biodiesel, the African oil palm's waste stream can be used to produce a vast quantity of ('second generation') ethanol or synfuel.

The reason why we come back to this earlier article is simple: a Japanese company has meanwhile decided to conduct an economic feasibility study on the idea. Interested in utilising the enormous agricultural waste stream generated by the oil palm industry in Malaysia to produce cellulosic ethanol, Mitsui Engineering recently sent an investment team to the country to undertake research scheduled to be completed early next year.

The company's spokesman told a local newspaper: "If found feasible, we will build a pilot plant costing about 3 million US dollars by networking with a local partner from the oil palm sector for the commercial production of bio-ethanol." Mitsui plans to build the pilot in the next two years and commence testing and trial operation by 2010, added the spokesman.

He noted that the development and commercial production of biofuel from oil palm in Malaysia has so far focused on biodiesel only, which is suitable for diesel engines but not applicable to petrol-powered vehicles: "When demand for biodiesel sharply increases, the use of palm oil for biofuel could constitute a competition with its current use mainly in the food industry," he said. The extraction of bioethanol from oil palm wastes can do away with such worries, said the spokesman, adding that the conversion efficiency of turning waste palm trunk fibres into ethanol is around 30%:
ethanol :: biodiesel :: biofuels :: energy :: sustainability :: oil palm :: waste :: biomass :: cellulose :: cellulosic ethanol :: Malaysia ::

In Malaysia, a huge quantity of felled old oil palm trunks are discarded during replanting. An oil palm plant has a productive life of about 25 years, after which it is felled and replaced by new seedlings. Some 4% of the total palm hectarage in Malaysia is replaced this way, each year, amounting to anywhere between 12 and 16 million tonnes of cellulose-rich biomass from trunks alone. Add some 80 million tonnes of biomass from fruit bunches, fronds, press cake and kernels that is generated each year.

The organic constituents of these different types of biomass vary, with some being richer in cellulose than others. But most of them contain more than 50% of easily extractable cellulose and less than 30% of lignin. At an average conversion efficiency of 30% applied to this stream of cellulose-rich biomass, it is not difficult to see that this waste resource holds considerable potential for the production of cellulosic ethanol. The numbers are for Malaysia only. Indonesia, which will surpass Malaysia's palm hectarage next year, has an even larger unused feedstock resource.

The study we are currently preparing deals with the technical potential and energy balance of next-generation liquid biofuels made from tropical and sub-tropical crops and residues only. But the news that a company is already studying the matter from an investment perspective, is an incentive for us to go beyond the technical potential and to study the economic potential as well (in a follow-up). We are looking forward to news on Mitsui's feasibility study, and as soon as it arrives, we will report back on it.

New revenues, less deforestation
The news is important from an environmental perspective as well. The palm oil industry in South East Asia is rightly criticized for driving deforestation. The industry itself is trying to counteract some of the critiques by stressing its investments in crop improvement research and in focusing on getting smallholders to replace old trees with new, high-yielding varieties so that less land and forest has to be converted into plantations.

Now if the biofuel industry in this part of the world were to start utilising the vast amount of unused 'waste' biomass for the production of ethanol, an entirely new revenue stream would emerge, both for smallholders and large estates. This would greatly reduce the stress on forests, which is most often driven by the smaller plantation owners who prefer to convert forest into new land, because they're poor. Unlike large estates who can invest in new palm varieties, in the best plantation management practises and even in downstream sectors, smallholders often only have the single worst option before them: cutting down trees to plant more low-yielding palms.