Field pennycress, also known as french
weed, is an invasive plant found alongside many of our roads. According to researchers, it could be a good source of biofuel. Scientists have found that the plant yields copious amounts of seeds whose oil can be used for biofuel production and even as a biological herbicide.
It can be an organic bioherbicide due to its high concentration of glucosinolates, which can be used for suppressing a variety of weeds, such as white cockle, dandelion or redroot pigweed. However, the amount of meal necessary for effective weed control is very high, so the plant has more potential for use in horticultural crops.
Pennycress belongs to the Brassicaceae family, of which other oil-rich plants, such as canola and mustard, are also a part. The oil content of a pennycress seed ranges from 26 to 40 per cent; the oil is also suitable for low temperature lubrication. In order to produce bio-diesel and glycerol, pennycress has to be treated with acid and alcohol in the initial stages of production. Once refined, the biodiesel has the potential to be used as a commercial commodity.
However, further research is needed in order for scientists to be sure that this sort of biodiesel can meet industry standards. The biodiesel has to be of sufficient quality to be used in today’s engines. All diesel-based oil starts to gel when the air is cold enough, so the cloud point, the temperature at which crystals become visible in the fuel, is vital for the production of biodiesel.
Researchers have also found that pennycress biofuel is better for cold rather than hot climates, and better than using soybean oil-derived biodiesel as it produces twice the oil per acre than soybeans. Another advantage is that pennycress does not compete with farmers’ summer soybean production because the plant can be grown in winter and harvested in late spring. Pennycress production also absorbs CO2, a harmful greenhouse gas, and can be grown on any type of wasteland, unlike most biodiesel feedstocks that require fertile soil.
As with everything, there is also a negative side to using an invasive plant for biofuel. In the USA and many European countries, pennycress has a largely negative impact on the ecology and economy. It obstructs river systems, ruins wildlife and livestock habitats, limits access for irrigation, and reduces water quality and quantity. But luckily, if approached in the right way, the weeds can be used for something positive.
(Post by Ivelina Dineva)
(Image by Andrew Curtis [CC-BY-SA-2.0], via Wikimedia Commons)








