Kinetic modeling of Essential oil extraction from lemongrass acclimatized in Tandjilé in Chad

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.