## 3 Results and Discussion
tration of the wood component (Figure 4) in the mixed fuel leads to an increase in carbon dioxide in the gaseous products of their thermal decomposition. Introduction of up to 50% wood into the fuel mixture intensifies the formation of carbon dioxide by 40% relative to the obtained concentrations during thermal decomposition of homogeneous metalignitous coal. This increase in CO2 concentration is most likely due to more intense carbon oxidation in the fuel. However, carbon dioxide emissions from the thermal decomposition of wood are generally considered to be a carbon-neutral footprint [46]. The experiments also revealed a shift in the carbon dioxide output to the lower temperature zone due to the intensification of coal thermal decomposition due to wood pyrolysis. Figure 4: _Cont._  
The results of recording the concentration of carbon oxide in the gaseous pyrolysis products of mixed fuels based on D-grade coal and wood are shown in Figure 5.  
Analysis of Figure 5 made it possible to establish a significant increase in carbon monoxide with an increase in the proportion of wood in the mixed fuel up to 50%. An increase in the area under the carbon monoxide curve confirms an increase in the yield of carbon dioxide, since most of the released oxide was oxidized to CO\({}_{2}\). Figure 4: Changes in the concentration of carbon dioxide in the gaseous products of thermal decomposition of mixed fuels based on D-grade coal and wood with a change in the proportion of the latter in the mixture from 10% to 50%: (**a**) metalignitous coal 100%; (**b**) metalignitous coal 90%/wood waste 10%; (**c**) metalignitous coal 75%/wood waste 25%; (**d**) metalignitous coal 50%/wood waste 50%. The results of calculating the areas under the gas curves for metalignitous coal are shown in Table 2.  
Analysis of the areas under the gas curves for D-grade coal made it possible to reliably state a significant 96% decrease in sulfur oxides in the thermal decomposition products of mixed fuels with an increase in the biomass fraction in the mixture. The difference between the maximum concentration of sulfur oxides and the area under the curve was no more than 3%. Figure 5: Cont. Figure 2:0 Changes in the concentration of carbon oxide in the gaseous products of thermal decomposition of mixed fuels based on D-grade coal and wood with a change in the proportion of the latter in the mixture from 10% to 50%: (**a**) metalignitous coal 100%; (**b**) metalignitous coal 90%/wood waste 10%; (**c**) metalignitous coal 75%/wood waste 25%; (**d**) metalignitous coal 50%/wood waste 50%. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Element**} & \multicolumn{5}{c}{**The Composition of the Mixture**} \\ \cline{2-5}  & **100\% Coal** & **90\% Coal/10\% Wood** & **75\% Coal/25\% Wood** & **50\% Coal/50\% Wood** \\ \hline SO\({}_{2}\)\% & Delta & –48.36 & –94.06 & –96.12 \\ Meaning & 6514.5 & 3364 & 387 & 252.6 \\ NOx\({}_{2}\)\% & Delta & –1916 & –1.38 & –17.32 \\ Meaning & 34554 & 27934.5 & 34,077 & 28,570.5 \\ CO\({}_{2}\)\% & Delta & -5.01 & +22.77 & +29.85 \\ Meaning & 20,310,000 & 192,91500 & 26,299,500 & 28,954,260 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The results of calculating the areas under the gas curves for metalignitous coal. Figure 6: _Cont._ \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Element**} & \multicolumn{4}{c}{**The Composition of the Mixture**} \\ \cline{2-5}  & **100\% Coal** & **90\% Coal/10\% Wood** & **75\% Coal/25\% Wood** & **50\% Coal/50\% Wood** \\ \hline CO,\% & Delta & –39.29 & +48.56 & +70.70 \\ Meaning & 38,671.00 & 23,478.00 & 75,183.00 & 131,977.00 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: _Cont._The results of determining the sulfur oxides concentration in the pyrolysis products of T-grade coal, wood, and the mixed fuels based on them, shown in Figure 6, allow us to conclude that proportion of sulfur oxides formed during pyrolysis is steadily decreasing with an increase in the proportion of the wood component up to 50% in the fuel mixture.