## 3 Results and Discussion
A decrease in the peak concentration of sulfur oxides in fuels based on T-grade coal was  
Figure 6: Changes in the concentration of sulfur oxides in the gaseous products of thermal decomposition of mixed fuels based on T-grade coal and wood with a change in the proportion of the latter in the mixture from 10% to 50%: (**a**) lean coal 100%; (**b**) lean coal 90%/wood waste 10%; (**c**) lean coal 75%/wood waste 25%; (**d**) lean coal 50%/wood waste 50%. 90.2% in relation to the concentration of these gases during pyrolysis of homogeneous lean coal. The scale of the maximum concentration reduction in sulfur oxides is comparable to that obtained by pyrolysis of mixed fuels based on metalignitous coal and wood. The results obtained suggest that wood biomass intensifies the processes of reducing the concentration of sulfur oxides in mixed fuels based on these two different, but at the same time quite typical, energy coals, as a result of the calcium and aluminum salts forming in the ash of such fuels [54]. Figure 7: \(Cont.\)  
The analysis results of the nitrogen oxides formation during pyrolysis of T-grade coal, wood, and the mixtures based on them in an inert medium are shown in Figure 7.  
According to the results of the experimental studies (Figure 7), it was found that the greatest decrease in the peak concentration of nitrogen oxides in mixed fuels based on T-grade coal and wood occurs with an increase in the share of the latter by 25% and is 57.7%  
Figure 7: Changes in the concentration of nitrogen oxides in the gaseous products of the thermal decomposition of mixed fuels based on T-grade coal and wood with a change in the proportion of the latter in the mixture from 10% to 50%: (**a**) lean coal 100%; (**b**) lean coal 90%/wood waste 10%; (**c**) lean coal 75%/wood waste 25%; (**d**) lean coal 50%/wood waste 50%. relative to homogeneous T-grade coal. There is a decrease in the concentration of nitrogen oxides by 49.0% with the share of wood in the mixture up to 50%. The results obtained allow us to conclude that wood biomass has a significantly greater effect on reducing the yield of nitrogen oxides during thermal decomposition of mixtures based on lean coal compared to mixed fuels based on metalignitous coal. Figure 8: _Cont._  
Figure 8 shows the analysis results of carbon dioxide formation during pyrolysis of T-grade coal, wood, and the mixtures based on them with an increase in the proportion of the wood component in the mixture from 10% to 50%. Figure 8 shows that an increase in the wood component proportion in the mixture with T-grade coal to 50% leads to a decrease in the maximum concentration of carbon dioxide  
Figure 8: Changes in the concentration of carbon dioxide in the gaseous products of the thermal decomposition of mixed fuels based on T-grade coal and wood with a change in the proportion of the latter in the mixture from 10% to 50%: (**a**) lean coal 100%; (**b**) lean coal 90%/wood waste 10%; (**c**) lean coal 75%/wood waste 25%; (**d**) lean coal 50%/wood waste 50%. by 53.4%, and the most significant decrease in the proportion of this gas occurs during the pyrolysis of a mixture of coal and wood in the ratio of components (coal/wood) 75%/25% (decrease of 65.5% relative to the results obtained by pyrolysis of homogeneous lean coal). It is worth noting that the characteristics of the carbon dioxide formation process in mixed fuels based on T-grade coal with wood significantly differs from the characteristics of the processes occurring during the pyrolysis of mixed fuels prepared on the basis of D-grade coal. This difference is manifested in a significant decrease in the concentration of carbon dioxide in the pyrolysis products of mixed fuels based on T-grade coal and the wood component relative to the initial coal. The reason for this may be that lean coal contains more bound carbon (84.30%) than metalignitous coal (74.20%).