## 3 Results
### Pyrolysis Behavior  
The thermal behavior of cocoa pod shell biomass was analyzed under inert atmospheric conditions to simulate pyrolysis. The TG-DTG curves and mass spectrometry (MS) data (Figure 2) provide insights into the process.  
Pyrolysis can be divided into three stages:  
Initial Stage (40-170 \({}^{\circ}\)C): Characterized by the release of free water, this phase accounts for approximately 5% of the mass loss. The 12.71% moisture content observed in the biomass led to a slight mass gain below 100 \({}^{\circ}\)C due to water condensation and intermediate compound formation.  
Main Stage (170-450 \({}^{\circ}\)C): Rapid volatile release, including internal water, occurs here. The MS spectrum shows the water peak at ~300 \({}^{\circ}\)C, with this phase resulting in a ~50% mass loss.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Formula** & **Z** & **Concentration** \\ \hline K & 19 & 59.79\%m/m \\ Ca & 20 & 6.28\% m/m \\ Mg & 12 & 3.79\% m/m \\ P & 15 & 1.89\% m/m \\ Si & 14 & 1.62\% m/m \\ S & 16 & 1.43\% m/m \\ Na & 11 & 0.30\% m/m \\ Al & 13 & 0.28\% m/m \\ Fe & 26 & 0.22\% m/m \\ Rb & 37 & 710 ppm \\ Zn & 30 & 703 ppm \\ Sr & 38 & 505 ppm \\ Cl & 17 & 307 ppm \\ Mn & 25 & 264 ppm \\ Cu & 29 & 182 ppm \\ Zr & 40 & 4.29 ppm \\ \hline \hline \end{tabular}
\end{table}
Table 4: Major components in feedstock ash composition.  
Final Stage (450-800 \({}^{\circ}\)C): Gradual volatile release, secondary pyrolysis of condensable volatiles, and carbon-CO\({}_{2}\) reactions characterize this phase, with a -13% mass loss. These findings align with those of [PERSON] et al. (2023) [42], who identified similar pyrolysis stages in various biomasses, including traditional Chinese medicine residues. The stages include free water release (30-170 \({}^{\circ}\)C), active pyrolysis of hemicellulose and cellulose (170-380 \({}^{\circ}\)C), and secondary reactions above 380 \({}^{\circ}\)C. [PERSON] et al. (2022) observed similar mass loss stages in palm kernel shell pyrolysis, with 5-6% mass loss due to moisture removal (23-150 \({}^{\circ}\)C), 56% loss from volatile release (150-400 \({}^{\circ}\)C), and slow decomposition of biochar (above 400 \({}^{\circ}\)C) [43]. Likewise, [PERSON] et al. (2016) reported rapid degradation of hemicellulose and cellulose (150-250 \({}^{\circ}\)C) and lignin above 500 \({}^{\circ}\)C in rice husk pyrolysis [44]. [PERSON] et al. (2018) found that particle size marginally affects thermal degradation patterns, with DTG peaks around 130 \({}^{\circ}\)C (drying) and 350 \({}^{\circ}\)C (hemicellulose and cellulose decomposition) in kenaf biomass was analyzed and the thermal degradation of kenaf biomass  
Figure 2: Cocoa husk TGA/DTG curves and mass spectra of selected emissions for pyrolysis.  
and observed that particle size had a marginal impact on the degradation process. The peaks in the DTG curves were directly linked to the material's composition, particularly hemicellulose, cellulose, and lignin. The initial mass loss (100-180 \({}^{\circ}\)C) likely reflects water removal, both internal and surface-bound, and intensified with smaller particle sizes, suggesting better drying efficiency. A peak around 350 \({}^{\circ}\)C corresponds to the decomposition of volatile compounds, associated with hemicellulose and cellulose degradation [45].  
Mass spectrometry detected gases such as H\({}_{2}\), CO, CO\({}_{2}\), O\({}_{2}\), CH\({}_{4}\), and H\({}_{2}\)O. The majority of gaseous products were released between 200 and 400 \({}^{\circ}\)C, with H\({}_{2}\) showing increased production at higher temperatures (\(\sim\)300 \({}^{\circ}\)C). Lower-temperature peaks (<150 \({}^{\circ}\)C) indicate drying and water release, which peaked at \(\sim\)300 \({}^{\circ}\)C.