Study of Cocoa Pod Husks Thermal Decomposition

Thermal decomposition of cocoa pod husks under inert and oxidizing atmospheres was studied. Samples from Cotopaxi, Ecuador were used as raw material. Thermogravimetry based experiments were used to obtain decomposition data vs. temperature. A novel strategy to fit the TG and DTG curves was used giving good fit by considering, in the kinetic model, four biomass fractions following independent reactions. Analytical pyrolysis was used to determine the composition of volatile compounds obtained in slow (150-350, 350-500 degrees C) and flash pyrolysis (400 degrees C). The results indicate that in the slow pyrolysis experiments at low temperatures (150-350 degrees C), the highest area percentages correspond to ketones (7.5%), organic acids (12.5%) and phenolic derivatives (10%), while at increased temperatures (350-500 degrees C) the higher percentages are clearly focused on phenolic derivatives (12%) and aromatic compounds (10%). Comparing the results of flash pyrolysis at 400 degrees C (i.e., higher heating rate but lower final temperature), an increase in the yield of ketones and organic acids is observed compared to slow pyrolysis, but the percentage of phenols and aromatics decreases. The results obtained allow deducing the operating conditions to maximize the mass fraction of the different functional groups identified.

Automated summary

The thermal decomposition of cocoa pod husks was studied under inert and oxidizing atmospheres. The results provide insight into the decomposition behavior and optimal operating conditions for maximizing the mass fraction of different functional groups.