Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Kinetic modeling of essential oil extraction from lemongrass acclimatized in Tandjilé in Chad.

Abstract

The Cymbopogon flexuosus species introduced in Congo-Brazzaville (equatorial climate) to solve the low production problem of Cymbopogon citratus, a source of citral, was acclimatized in Chad (subtropical climate) for the same reasons. The plant was perfectly adapted with a very high production of biomass. Its low essential oil extraction yield (0.89% DM) compared to the Cymbopogon citratus local species (1.26%) is very largely balanced by its very high biomass productivity. The extraction of essential oil fits Milojevic's pseudo first order model with rate constant k = 0.0087 min-1 (R2 = 0.9816) for Cymbopogon flexuosus vs k = 0.0109 min-1 (R2 = 0.922), for local C. citratus. It also fits Peleg's model with a kinetic constant k1 = 217.94 min %-1 and an extraction capacity constant K2 = 0.6022%-1, which leads to a pseudo first order kinetic constant of hydrodistillation k = k1/K2 = 0.0028 min-1. For local C. citratus, these values are respectively k1 = 108.94 min %-1; K2 = 0.4971%-1 and k = 0.0046 min-1 with R2 = 0.9885. Michael Menton's model, which is also fitted, leads to the kinetic constant Km/Ymax = 237 min %-1 and the yield Ymax = 1.9% with R2 = 0.9862, for C. flexuosus and Km/Ymax = 113.12 min %-1, Ymax = 2.1% (R2 = 0.9952) for C. citratus. These results corroborate those obtained on the same species acclimatized in Congo-Brazzaville.