The silver bullet of biofuels

Paul Boughton
Government subsidies and prospective national fuel targets have sparked a growing commercial interest in biofuels. Add the ongoing focus that surrounds global warming and the market place kudos of green credentials and it becomes obvious why investment in biofuels has steadily gained steam.

ADM, Bayer, BP, and Daimler are the latest big corporate players entering the sector. What sets them apart from other major biofuel players is their narrow focus on a poisonous seed-bearing plant; one that offers answers to the growing questions levelled at competing first generation crops.

BP announced in July 2007 that it was going further Beyond Petroleum when it formed a joint venture with the relatively tiny UK biodiesel business D1 Oils. And then earlier this year a second high profile joint venture was formed, this time between ADM, Bayer's crop science division, and automotive engineering giant Daimler.

Both ventures are interested in plant species Jatropha curcas (Fig. 1) a perennial shrub traditionally used in tropical and sub-tropical regions for natural fencing. Compared to maize-derived bioethanol or palm biodiesel, Jatropha has received scant attention in the popular press. This seems surprising in light of the recent accusations levelled at biofuels. Previously hailed as the solution to sustainable transportation, many now question whether ethanol and palm are the panacea that everyone predicted.

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Biofuel worries

The Royal Society report Sustainable biofuels: prospects and challenges examines questionable elements of biofuel policy. One consequence of the US government’s subsided drive for energy security has been an increase in the prices of staple foods such as bread and tortillas that are derived from wheat and corn. This is a result of less cereal in the market and less arable space for food cultivation. Demand for biodiesel has led to environmental consequences in Southeast Asia, where rainforest is increasingly being cleared to make room for profitable palm.

Forgetting the consequences on the economy and biodiversity, questions have been asked about whether biofuels genuinely realise the net carbon savings that they are incentivised for. The use of fertilisers to increase yield, and the costs of transporting fuels from field to market poses questions of their true sustainability.

This is not the case with Jatropha according to D1 Oils communication director Graham Prince: “Jatropha grows on poorer soil – land that is unsuitable for crop production. You can grow it without replacing food crops or destroying biodiversity.”

As part of the joint venture established between BP and D1 Oils, D1 provides seeds and seedling agronomy services directly and exclusively to the joint venture, D1-BP Fuel Crops, which is responsible for everything else from planting to pre-processing of Jatropha oil prior to refining.

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Planting benefits

Prince says that the environmental benefits of Jatropha are linked to its harvesting methods. It produces a golf ball-sized fruit (Fig. 2) that has to be picked by hand. This is because Jatropha flowers and seeds concurrently making automated harvesting impossible because it would remove the fruit and destroy the flowers, thereby ruining the following season’s crop. The same is true of wild coffee but selective breeding solved the problem and the same is likely to be true for Jatropha. Until then, farmers will continue to harvest by hand, which eliminates certain carbon expenditure and provides more jobs for local people.

D1-BP Fuel Crops has two types of relationship with local producers. It either manages a plantation and both partners take 50 per cent of the final product; or it has a joint venture with another local partner, such as tea company Williamson, which takes 50 per cent, leaving the D1-BP partners to split the remainder.

The key environmental and sociological benefit of Jatropha is that it grows on poorer soil. This enables farmers in developing countries to make use of land that won’t support food. Developing world farmers have found such benefits hard to ignore. D1-BP currently has 200 000 hectares of planted Jatropha spread across India (Fig. 3), Africa, Southeast Asia, and aims to plant an additional 1m hectares by the close of 2012. Planting is contiguous and takes five to six years to reach maturity. Current estimates of global Jatropha volumes are unknown but reports are expected shortly.

Getting the oil

The fruit is left to dry on the tree before it is picked. The outer husk is stripped off revealing three to four Jatropha seeds (Fig. 4), which are referred to as grain and average around 30 per cent oil. The grain is put into a crusher and expeller – technology that is readily available in the developing world according to Prince. This strips the outer grain coat leaving the internal grain core. This is heated and put under pressure to extract the oil.

“The oil is then put through a pre-refining process,” Prince explains. “This strips out some of the fatty acids and some of the gums – and the remaining oil is processed through a transesterification unit.” The resulting product is then refined to the necessary national fuel standards or can be used locally in diesel engines straight from the expeller.

The seed cake by-product is high in protein and can be used as animal feed, or as fuel for co-generated burning, or as a natural fertiliser due to its high NPK values.

Current planting is all done with uncultivated seed – villagers are paid to pick fruit from wild Jatropha growing in hedgerows – so cultivation is currently somewhat of a lottery.  However, a West African Jatropha variety has been selected that has a high oil yield and a good oil profile for biodiesel. Prince says that this variety, once mature, is possible of producing 2.7t of biodiesel per hectare. “We’re looking at a promising first step to the yield curve,” says Prince. “And it is a wild seed variety, so we would expect it to improve after selective breeding.”

So, how does this compare to competitive biofuel crops? Prince says that soya produces around 0.5t/hectare; rape seed: 1.5t/hectare; and palm: 4t/hectare. “And Jatropha biodiesel can be produced sustainably, so it already stacks up well against alternatives.”

Current estimates suggest that anywhere between 0.5 and 4 jobs can be supported per hectare of Jatropha; a conservative estimate would therefore suggest that D1-BP’s 1.2m hectares could support 1.2m jobs in 2012. 

Developing countries are quickly embracing the crop as a route to energy security. It can be processed locally without large capital investment in equipment, and it doesn't impinge on other key needs for developing nations, such as food and water demands.

Competition

The presence of the second joint venture indicates just how much potential the plant has and Prince welcomes the competition. “This isn't a zero sum game; it’s a new crop, so there's lots of room for lots of different players. Also, there's a lot we don’t know.”

The latest joint venture project aims to develop production and quality standards for Jatropha-based biofuels. Specifically, Bayer CropScience will develop and register herbicides, soil insecticides and fungicides for disease and pest control. Daimler provides the automotive stance; it has just completed a five-year research study, which the company says demonstrates that Jatropha can be used and cultivated to obtain high-quality biodiesel for vehicles; it will continue to investigate interactions between fuels and vehicle engines and mixtures of Jatropha-based biodiesel with other fuels.

With such major players entering the mix and the EU calling for a reappraisal of its biofuel legislation and a possible certification system to measure the true sustainability of biofuel sources, it seems possible that Jatropha will become the plant of choice for responsible biofuel production.

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