Dual Utilization of Medicinal and Aromatic Crops as Bioenergy Feedstocks

Dual production of biofuels and chemicals can increase the economic value of lignocellulosic bioenergy feedstocks. We compared the bioenergy potential of several essential oil (EO) crops with switchgrass (Panicum virgatum L.), a crop chosen to benchmark biomass and lignocellulosic biofuel production. The EO crops of interest were peppermint (Mentha x piperita L.), ‘Scotch’ spearmint (Mentha x gracilis Sole), Japanese cornmint (Mentha canadensis L.), and sweet sagewort (Artemisia annua L.). We also assessed each crop for EO production in a marginal production environment in Wyoming, USA, with irrigation and nitrogen rates using a split-plot experimental design. Oil content ranged from 0.31 to 0.4% for Japanese cornmint, 0.23 to 0.26% for peppermint, 0.38 to 0.5% for spearmint, and the overall mean of sweet sagewort was 0.34%. Oil yields ranged from (in kg ha-1) 34 to 165 in Japanese cornmint, 25 to 108 in peppermint, 29.3 to 126 in spearmint, and 39.7 in sweet sagewort. EO production, but not composition w...