Final ethanol yield (mg g^-1 biomass) of lemongrass and palmarosa biomass that was (EX) or was not (NE) previously extracted for essential oils in comparison to two lots of BioEnergy Science Center (BESC) control switchgrass.

<p>A) Final ethanol concentration of biomass that was not pretreated in fermentation liquids. B) Final ethanol yield (mg g^-1 biomass) of dilute acid pretreated lemongrass and palmarosa biomass that was (EX) or was not (NE) extracted for essential oils in comparison to lot #1 BESC control switchgrass.</p

Means of lemongrass essential oil content (%) from the different levels of (A) Nitrogen, (B) Sulfur, and (C) Harvest, (<i>E</i>)-citral content (%) from the different levels of (E) sulfur, (<i>E</i>)-citral yield (kg ha^-1) from the different levels of (D) Nitrogen, and (F) Harvest, (<i>Z</i>)-citral yield (kg ha^-1) from the different levels of (G) Nitrogen, and (H) Harvest, and β-caryophyllene yield (kg ha^-1) from the different levels of (I) Nitrogen, and (J) combinations of Sulfur and Harvest.

<p>For each plot, means sharing the same letter are not significantly different.</p

Main and interaction effect plots for dry weight biomass (kg ha^-1) [(A) Crop x Nitrogen Interaction, (C) Nitrogen x Harvest Interaction, and (E) Crop x Harvest Interaction], and essential oil (kg ha^-1) [(B) Nitrogen Main Effect, and (D) Crop x Harvest Interaction].

<p>For each plot means sharing the same letter are not significantly different.</p

Main and interaction effect plots for palmarosa: main effect of Harvest on (A) essential oil content (%), (B) geranylacetate content (%), (D) geraniol yield, and (F) geranylacetate yield (kg ha^-1), and interaction effect of Nitrogen and Sulfur on (C) geraniol content (%), (E) geraniol yield (kg ha^-1), and (G) geranylacetate yield (kg ha^-1).

<p>For each plot means sharing the same letter are not significantly different.</p

Ethanol and High-Value Terpene Co-Production from Lignocellulosic Biomass of <i>Cymbopogon flexuosus</i> and <i>Cymbopogon martinii</i>

<div><p><i>Cymbopogon flexuosus</i>, lemongrass, and <i>C</i>. <i>martinii</i>, palmarosa, are perennial grasses grown to produce essential oils for the fragrance industry. The objectives of this study were (1) to evaluate biomass and oil yields as a function of nitrogen and sulfur fertilization, and (2) to characterize their utility for lignocellulosic ethanol compared to <i>Panicum virgatum</i> (switchgrass). Mean biomass yields were 12.83 Mg lemongrass ha^-1 and 15.11 Mg palmarosa ha^-1 during the second harvest year resulting in theoretical biofuel yields of 2541 and 2569 L ethanol ha^-1 respectively compared to reported 1749–3691 L ethanol ha^-1 for switchgrass. Pretreated lemongrass yielded 198 mL ethanol (g biomass)^-1 and pretreated palmarosa yielded 170 mL ethanol (g biomass)^-1. Additionally, lemongrass yielded 85.7 kg essential oil ha^-1 and palmarosa yielded 67.0 kg ha^-1 with an estimated value of USD $857 and$1005 ha^-1. These data suggest that dual-use crops such as lemongrass and palmarosa may increase the economic viability of lignocellulosic biofuels.</p></div