## 3 Results
### Air Gasification Analysis of CPHs
\begin{table}
\begin{tabular}{l l l l l l l l} \hline \hline \multicolumn{1}{c}{\multirow{2}{*}{\(\mathbf{T_{r}}\)}} & \multicolumn{1}{c}{\multirow{2}{*}{**Solid Yield, \%**}} & \multicolumn{1}{c}{\multirow{2}{*}{**Immediate Analysis, \%**}} & \multicolumn{1}{c}{\multirow{2}{*}{**HHV Dry**}} & \multicolumn{1}{c}{\multirow{2}{*}{**HHV Wet**}} \\ \cline{2-3} \cline{5-5} \multicolumn{1}{c}{\({}^{\circ}\)**C**} & & & & & & **C** & **C** \\ \hline
500 & 39.60 & 22.56 & 5.4 & 10.89 & 62.82 & 21.52 & 20.00 \\
600 & 35.07 & 22.78 & 4.18 & 10.96 & 62.08 & 22.80 & 21.83 \\
700 & 33.82 & 22.34 & 3.99 & 11.15 & 62.52 & 21.48 & 20.21 \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Effect of gasification temperature on the yield, immediate analysis, and dry and wet PCS of the coal obtained. Figure 7 shows the accumulated moles of H\({}_{2}\), CO, CH\({}_{4}\), and CO\({}_{2}\) over time, respectively. These figures can be discussed in line with previous observations, considering that two of the gases have a pyrolytic origin and may also react with the gasifying agent, leading to the formation of other gases and potential secondary reactions that can modify the resulting gas composition. To further understand this, the predominant reactions in the air gasification process will be examined to analyze the gas generated in each experiment. Figure 6: Effect of temperature on the evolution of H\({}_{2}\), CO, CH\({}_{4}\), and CO\({}_{2}\) over time in the gasification analysis of CPHs. Figure 7: Effect of temperature on the evolution of cumulative moles of H\({}_{2}\), CO, CH\({}_{4}\), and CO\({}_{2}\) over time in the gasification of CPHs. It is generally accepted that the biomass gasification process occurs in three stages [54]. The first stage, devolatilization or pyrolysis, produces volatile matter and a residue. Subsequently, secondary reactions take place, involving the volatile products. Finally, the gasification of the remaining char occurs with water vapor and CO\({}_{2}\). The volatiles and char can participate in the following reactions:  
\[\text{Oxidation C}+\text{O}_{2}\rightarrow\text{CO}_{2} \tag{1}\]  
\[\text{C}+\text{\textbackslash{}}\text{\textbackslash{}}\text{O}_{2} \rightarrow\text{CO} \tag{2}\]  
\[\text{Boudouard C}+\text{CO}_{2}\rightarrow\text{2 CO} \tag{3}\]  
\[\text{Water-gas: Primary C}+\text{H}_{2}\text{O}\rightarrow\text{CO}+\text{H}_{2} \tag{4}\]  
\[\text{Secondary C}+\text{2 H}_{2}\text{O}\rightarrow\text{CO}_{2}+\text{2 H}_{2} \tag{5}\]  
\[\text{Hydrogasification C}+\text{2 H}_{2}\rightarrow\text{CH}_{4} \tag{6}\]  
\[\text{Water-gas shift CO}+\text{H}_{2}\text{O}\rightarrow\text{CO}_{2}+\text{H}_{2} \tag{7}\]  
Figure 6:0  
Increasing the temperature typically decreases solid yields due to the removal of volatiles and carbon reaction with oxygen. The liquid fraction yield decreases due to cracking reactions, while the gaseous fraction yield increases. This increase is also driven by oxidation reactions producing more CO and CO\({}_{2}\) in the generated gas. Previous work on the pyrolysis of other lignocellulosic residues [50; 51; 52; 53; 18; 53] and other studies [56] have observed the cracking effect. In this study, temperature increases lead to higher H\({}_{2}\) and CO production, while CH\({}_{4}\) and CO\({}_{2}\) peak at 600 \({}^{\circ}\)C and decrease at 700 \({}^{\circ}\)C. Table 8 illustrates the effect of temperature on molar fractions and PCS of the gases. While the CH\({}_{4}\) percentage decreases, the increase in other gases results in an overall higher PCS and gas flow rate due to the higher temperature. Additionally, Table 8 compares these results with previous studies on the air gasification of almond shells [53] and rice husks [57], showing slightly lower results compared to those reported. Figure 8 shows the evolution of CO/CO\({}_{2}\), H\({}_{2}\)/CO, H\({}_{2}\)/CO\({}_{2}\), and H\({}_{2}\)/CH\({}_{4}\) ratios over time.