Oilseed halophytes: a potential source of biodiesel using saline degraded lands

Abstract

The financial and technical aspects of using edible plants as a biodiesel source have been studied extensively, but research on the potential use of salt resistant, non-edible plants for this purpose remains relatively underexplored. Data available on salt tolerance range, seed oil content, composition of fatty acid methyl esters (FAME) and engine performance parameters – Iodine Value (IV), Cetane Number (CN) and Saponification Number (SN) – of 20 salt-resistant plants were examined to assess their suitability for use as diesel engine fuel. Most of the test species were perennial from family Amaranthaceae, exhibiting high salt tolerance. The quantity of their seed oil ranged from 10–30% while nine species contained >25% oil. The SN, IV and CN values varied from 130–206, 29–156 and 38–81, respectively. Based on the above mentioned parameters, seven halophytic plant species – Salicornia fruticosa, Cressa cretica, Arthrocnemum macrostachyum, Alhagi maurorum, Halogeton glomeratus, Kosteletzkya virginica and Atriplex rosea – appear to be promising biodiesel candidates. These non-food plants which can grow using saline resources and have an oil composition suitable for engine efficiency are more salt resistant than Jatropha or other glycophytic feedstock to serve in a bioenergy farming system. Cultivation of such plants for biodiesel production has the additional advantage of reclaiming degraded lands with the environmental benefit of carbon sequestration.