## 3 Results and Discussion
### Non-Condensable Gas Analysis  
The composition of non-condensable gas, which consists of O\({}_{2}\), H\({}_{2}\), CO\({}_{2}\), CO, CH\({}_{4}\), C\({}_{2}\)H\({}_{4}\), C\({}_{2}\)H\({}_{6}\), C\({}_{3}\)H\({}_{6}\), C\({}_{3}\)H\({}_{8}\), and N\({}_{2}\), was analyzed by GC. The samples collected from the outlet after the ESP or after the spray condensers train mainly consisted of N\({}_{2}\) (the carrier gas), equal to \(\simeq\)92% \(v/v\), and a small portion of pyrogas, around 8% \(v/v\), generated during the pyrolysis reactions.  
Non-condensable gas contains CO, CO\({}_{2}\), H\({}_{2}\), O\({}_{2}\), CH\({}_{4}\), and a small amount of hydrocarbons (C\({}_{2}\)-C\({}_{3}\)). The volume percentages of the main non-condensable gases generated during the biomass pyrolysis reaction while operating the two spray columns are shown  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Bio-chemical composition** & Cellulose & 35 \\
**(wt.\%, dry)** & Hemicellulose & 29 \\  & Lignin & 28 \\ \hline  & C & 46.58 \\  & H & 6.34 \\ Ultimate analysis (wt.\%, daf) & O (by difference) & 46.98 \\  & N & 0.04 \\  & S & 0.06 \\ \hline Alkali metals (mg/kg, dry) & Total Ash & 2600 \\ \hline Higher heating value & & \\ (MJ kg\({}^{-1}\), dry) & HHV & 18.3 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Feedstock composition from [PERSON] et al. (2018).  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Ultimate Analysis** & **d (\%)** & **daf (\%)** & **mole g\({}^{-1}\) Charcoal, w** \\ \hline
**C** & 76.00 & 78.62 & 0.06 \\
**H (excluding moisture H)** & 2.50 & 2.59 & 0.03 \\
**O (excluding moisture O)** & 17.90 & 18.52 & 0.01 \\
**N** & 0.27 & 0.28 & 0.00 \\
**m.m.** & 3.33 & 3.44 & \\
**Moisture (H\({}_{2}\)O)** & 0.00 & 0.00 & 0.00 \\
**Total d** & 100.00 & & \\
**Higher heating value (MJ kg\({}^{-1}\))** & 27.6 & 28.5 & \\ \hline \hline \end{tabular}
\end{table}
Table 5: Elemental Composition of char produced during Fast Pyrosis of pinewood at 500 \({}^{\circ}\)C.  
in Figure 3. Measured values were averaged and normalized to nitrogen-free conditions. Experiment codes FC_ESP AV and FC_SC1 respectively refer to the average values registered to operate the ESP setup and the spray condensers configurations under the same conditions of FC_SC2 (the latter) in order to guarantee high reproducibility. The amount of CO, CO2, CH4, and C2-C3 showed good agreement with the values reported in the literature [56]. The dominant components were CO and CO2, in which concentrations ranged around 81% \(v/v\). The release of CO2 was generated by cracking and reforming of functional groups of carboxyl COO and COOH, while the CO formation was caused by the cracking of carbonyl (C=O) [57]. Nevertheless, the hydrogen and oxygen volume percentages differed from the figures reported in the literature. In our case, the negligible percentage of the former (CO2) was attributed to the quenching of free radicals that favored the charring reactions that led to H2O and char production [58]. The calculated higher heating value of the non-condensable gas-stream (N2 and H2O free) was 12.41 MJ Nm\({}^{-1}\), confirming that the non-condensable gases could be properly reused as fuel gas to self-support the pyrolysis process in a large-scale industrial plant [43].