Crambe is the new corn

Camelina sativa and Crambe abyssinica are little known flowering plants that were commonly cultivated in the past but went out of fashion in the 20th century. Both of them are native to Europe, related to mustard and produce seeds with a high oil content. As such, they’re both now staging a dramatic comeback as potential biofuel feedstocks.

The rise of biofuels is increasingly spurring scientists to trawl through the plant kingdom for potential feedstocks, investigating ever more obscure species of plant. These efforts have recently received added impetus from the development of cellulosic biofuel technologies, which allow a much greater range of plants and plant materials to be used as feedstocks.

These novel feedstocks also have much to offer cellulosic biofuels, which tend to be more difficult and expensive to produce than biofuels made from conventional feedstocks like corn starch and soybean oil. A simple way to bring down the high production cost is to use a cheap feedstock, or at least cheaper than corn starch and soybean oil, and this is what these obscure plants potentially offer.

For instance, both camelina and crambe will happily grow on marginal land that is unsuitable for food crops. They also don’t require much water, fertilizer or pesticides. This all means that not only are they cheap to grow, but they also won’t have any impact on food crops, either direct or indirect. Indeed, Great Plains, a US company that is at the forefront of developing camelina as a biofuel feedstock, claims that camelina makes an excellent rotational crop, able to enhance the yield of subsequent food crops like wheat by as much as 15%.

Over the past three years, in conjunction with the UK chemical company INEOS, Great Plains has been converting crambe oil into biodiesel and plans to produce 100 million gallons a year by 2012. In October 2008, Great Plains also entered into an agreement with the University of North Dakota’s Energy & Environmental Research Center (EERC) to produce jet fuel from crambe oil, utilizing EERC’s proprietary thermochemical production technology (see Biofuels get drafted).

At the end of January 2009, EERC announced that it would be using the same technology to produce synthetic versions of diesel and jet fuel from crambe oil. This $1 million project also involves the Texan oil refining company Tesoro, which will produce the crambe-derived biofuels at its oil refinery in Mandan, North Dakota.

But scientists are not just investigating obscure plants, they’re also investigating obscure species of well-known plants. For over the past few hundred years conventional food crops have been bred to enhance their food-related qualities, but these are often different from the qualities required in a biofuel feedstock.

Take sunflowers. Well known for their oil producing abilities, sunflowers are also pretty big, able to grow up to 3m in height. And like camelina and crambe, they can grow on marginal land without needing too much water, making them a potentially very useful cellulosic biofuel feedstock.

However, two wild relatives of the sunflower – silverleaf and Algodones dune sunflower – are potentially even more promising feedstocks. These wild species thrive in desert conditions and grow even taller than normal sunflowers, but don’t produce as much oil.

So the US departments of energy and agriculture are now jointly funding researchers at the University of Georgia and Iowa State University to study the genomes of these two wild sunflowers. The aim is to identify the genes responsible for their biofuel-friendly traits and then create genetically-modified sunflower hybrids that can produce high levels of both oil and cellulosic biomass.

But with hundreds of thousands of species of plant around the world, what’s to stop biofuel researchers from becoming overwhelmed by the choice of potential feedstock. Well one way to cut back on the choice appears to be to concentrate on those plants closest to home.

At this month’s annual meeting of the American Association for the Advancement of Science in Chicago, César Izaurralde of the University of Maryland’s Joint Global Change Research Institute reported preliminary results from his studies into the economic and environmental sustainability of biofuels. These revealed that producing biofuels using native plants can reduce emissions of greenhouse gases, improve water quality and enhance biodiversity.

The views represented here are solely those of the author and do not necessarily represent those of John Wiley and Sons, Ltd. or of the SCI.