## 3 Results
### Analysis of the Syngas Produced
Olive seed gasification provides a gas with a high energy density (5.3 MJ/m\({}^{3}\)) and similar properties than  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Parameters**} & \multirow{2}{*}{**Units**} & \multicolumn{4}{c}{**Tests**} \\ \cline{3-5}  & & **100\% Olive** & **10\% Plastic \& 90\% Olive** & **20\% Plastic \& 80\% Olive** \\ \hline
**Olive** & \% & 100 & 90 & 80 \\ \hline
**Plastic** & \% & 0 & 10 & 20 \\ \hline
**T\({}_{\text{max}}\)**oxi** & \({}^{\text{o}}\)C & 720 & 708 & 758 \\ \hline
**T\({}_{\text{max}}\)**red** & \({}^{\text{o}}\)C & 515 & 547 & 526 \\ \hline
**Fuel Feeding** & Kg/h & 5.2 & 6.9 & 5.0 \\ \hline
**Air Inlet** & m\({}^{3}\)/h & 11.21 & 14.17 & 12.04 \\ \hline ER & - & 0.27 & 0.26 & 0.28 \\ \hline
**V\({}_{\text{Tars}}\)** & ml/h & 146.8 & 127.96 & 11.54 \\ \hline
**Chars** & Kg/h & 0.161 & 0.123 & 0.133 \\ \hline
**CO\({}_{\text{2}}\)** & \% & 9.914 & 9.775 & 10.839 \\ \hline
**C\({}_{\text{2}}\)H\({}_{4}\)** & \% & 0.479 & 0.618 & 0.427 \\ \hline
**C\({}_{\text{2}}\)H\({}_{6}\)** & \% & 0.122 & 0.138 & 0.042 \\ \hline
**N\({}_{\text{2}}\)** & \% & 55.99 & 56 wood gas. However, our obtained values on LHV are lower than those found by [PERSON] et al. [78], but higher than those reported by [PERSON] et al. [79]. An interesting aspect of the presented results is that the addition of 10% plastic to the olive seeds leads to an increase in the calorific value of the syngas regarding the experiences of 100% olive seed and 20% plastic, because of the capitalization in the production of hydrocarbons and mainly the methane [80]. The increase in the temperature, namely the gasification temperature, is the responsibility of the greater presence of volatiles that the plastic bring fuel [81]. However, the temperature in the 10% experiment (708 \({}^{\circ}\)C) is not so high compared with the additional experiments; this aspect is related to the literature and indicates that, as the gasification temperature increases, the concentration of the resulting hydrogen and carbon conversion efficiency increases [25]. Meanwhile, the content of CH\({}_{4}\) increased slightly with the decrease in temperature. The main reason for the decrease in CH\({}_{4}\) content in the product gas is the increasing proportion of gasification gas and the decreasing proportion of pyrolysis gas [82]. Another reason was attributed to the thermal decomposition of methane at a temperature greater than 700 \({}^{\circ}\)C [83]. On the one hand, the produced tars were further cracked into gas at the higher temperature. The increase in temperature can rapidly activate the carbon atom and breakdown the carbon chain in the aromatic ring, reacting with the CO\({}_{2}\) to produce gas [84]. This aspect can be observed in the 20% plastic experiment, which has a smaller amount of hydrocarbons in gas produced and also a smaller amount of tars, compared to the 10% plastic experiment. The H\({}_{2}\) concentration is similar in all the experiments performed, and the above result indicates that the concentration of H\({}_{2}\) is not only dependent on the temperature but also on the type of feedstock and gasifying media. The main reason for the increment of H\({}_{2}\) concentration is supposed to be the result of the chemical breakdown (thermal cracking) of heavy hydrocarbons, which favors molar fraction of the permanent gases, such as H\({}_{2}\) and CO, at an elevated temperature. What happens with the experiments with 20% plastic agrees with the experiments conducted by [PERSON] et al., [PERSON] et al. and [PERSON] et al. [85; 86; 87]. The increase in polymeric residue favors an increase in temperature. As the reactor temperature increased, concentrations of H\({}_{2}\) and CO increased. The reason for the increase in the concentrations of H\({}_{2}\) and CO can be mainly explained by [PERSON]'s principle. According to this principle, the increase in temperature favors not only the reactants in exothermic reactions, but also the products in endothermic reactions [88].