## 2 Materials, Experimental Setup, and Procedures
The microwave power was 450 and 600 W. In [28], an experimental microwave system Makewave was used for biomass conversion. The output power of the microwaves was about 600 W. The setup consisted of a gas cylinder for purging with argon, a gas meter, a preheating chamber, a microwave oven, a control unit, a gas analyzer, a cooling system, and a gas collection system. In [29], household microwave ovens with a power of 1000 W and 800 W at a frequency of 2.4 GHz were used for the experimental production of pyrolysis gas from palm date seeds. The installation included a thermocouple, a gas analyzer, a gas cylinder, and a water filter. Figure 2 shows the diagram of the experimental setup used in the present study. A microwave reactor (Menumaster Commercial, model DEC21E2) and a gas analyzer (Test-1, Boner-VT) were the base of the experimental rig. Figure 1: Average concentrations of pyrolysis gas components with varying moisture content of wood raw materials (microwave power was 700 W). To place a raw material in the reactor, we used a ceramic crucible (made of red clay). This material is heat-resistant, microwave-neutral, cheap, and readily available. Ceramic crucibles can be used for the pyrolysis of many organic materials. The power (\(P\)) of the magnetron was regulated in the range from 400 to 2200 W. The reactor was hermetically sealed with a door into which a gas sampling hose was built. To determine the composition of the pyrolysis gas, a gas analyzer with the following set of elements was used: a modular probe, a condensate collector, a sample filtration system, a computing unit, a flow meter, a pump, and electrochemical sensors (O\({}_{2}\), CO, SO\({}_{2}\), NO, NO\({}_{2}\), H\({}_{2}\)S, HCl). The gas analyzer also had optical sensors for CO\({}_{2}\) and CH\({}_{4}\) and a polarographic sensor for H\({}_{2}\). The characteristics of the measuring channels are presented in Table 1. The gas analyzer was connected to a computer via the RS232 interface. The auxiliary software displayed real-time measurements and also exported the resulting data to standard text and graphic formats. The experimental procedure included the following steps:  
1. Preparation of biomass. Dry sawdust was crushed using a high-speed rotary mill and then sieved. The average dispersion of woody particles was 2000 \(\upmu\)m. Water was then added to the biomass to obtain a \"60% sawdust-40% water\" mixture. The mass of the pyrolyzed sample was 30 g in each experiment. 2. The fuel sample was evenly distributed in a ceramic heat-resistant crucible, which was then tightly closed with a ground-in ceramic lid to prevent loss of pyrolysis gas. The crucible was placed in the reactor. The door was hermetically sealed. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Component** & **Measurement Range** & **Accuracy** & **Response Time** \\ \hline O\({}_{2}\) & 0–25\% & \(\pm\)0.2 vol\% (absolute) & \(\leq\)15 s \\ H\({}_{2}\) & 0–5\% & \(\pm\)0.2 vol\% (absolute) & \(\leq\)35 s \\ CO\({}_{2}\) & 0–30\% & \(\pm\)2\% (basic percentage error) & \(\leq\)25 s \\ CH\({}_{4}\) & 0–30\% & \(\pm\)5\% (of the indication) & \(\leq\)25 s \\ CO & 0–40,000 ppm & \(\pm\)5\% (of the indication) & \(\leq\)35 s \\ NO & 0–1000 ppm & \(\pm\)5\% (of the indication) & \(\leq\)35 s \\ NO\({}_{2}\) & 0–500 ppm & \(\pm\)7\% (of the indication) & \(\leq\)45 s \\ SO\({}_{2}\) & 0–1000 ppm & \(\pm\)5\% (of the indication) & \(\leq\)45 s \\ H\({}_{2}\)S & 0–500 ppm & \(\pm\)5\% (of the indication) & \(\leq\)45 s \\ HCl & 0–2000 ppm & \(\pm\)5\% (of the indication) & \(\leq\)45 s \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Specifications of the gas analyzer. Figure 2: Experimental setup scheme. * Magnetron and gas analyzer turned on. The gas mixture passed through a condensate collector, where moisture was deposited. The gas mixture purified from moisture was supplied to the sensors.