Ethanol and high-value terpene co-production from lignocellulosic biomass of Cymbopogon flexuosus and Cymbopogon martinii

Authors: JOYCE, BLAKE - University Of Tennessee; ZHELJAZKOV, VALTCHO - Oregon State University; SYKES, ROBERT - National Renewable Energy Laboatory; Cantrell, Charles; HAMILTON, CHOO - Oak Ridge National Laboratory; MANN, DAVID - Oak Ridge National Laboratory; RODRIQUEZ, MIGUEL - Oak Ridge National Laboratory; MIELENZ, JONATHAN - Oak Ridge National Laboratory; ASTATKIE, TESSEMA - Dalhousie University; STEWART, JR., C. NEAL - Dalhousie University

Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/10/2015
Publication Date: 10/5/2015
Publication URL: http://handle.nal.usda.gov/10113/62576
Citation: Joyce, B.L., Zheljazkov, V.D., Sykes, R., Cantrell, C.L., Hamilton, C., Mann, D.G., Rodriquez, M., Mielenz, J., Astatkie, T., Stewart, Jr., C. 2015. Ethanol and high-value terpene co-production from lignocellulosic biomass of Cymbopogon flexuosus and Cymbopogon martinii. PLoS One. 10(10):1-17. doi:10.1371/journal.pone.0139195

Interpretive Summary: Replacing petroleum as a natural resource extends beyond producing renewable liquid fuels. Petroleum products shape modern life: plastics, lubricants, asphalt, and petrochemicals for reagents in chemical synthesis, synthetic fibers for textiles, cosmetics, flavoring and food additives, surfactants and cleaning chemicals. Liquid fuels are currently necessary to maintain modern transportation and industrial infrastructure. Coproduction of high-value commodities from lignocellulosic sources has recently become a major focus of research. Lemongrass and 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 switchgrass. These data suggest that dual use crops such as lemongrass and palmarosa may increase the economic viability of lignocellulosic biofuels.

Technical Abstract: Cymbopogon flexuosus and C. martinii 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 Panicum virgatum (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. 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.