## 3 Results and Discussion
### Results of Calorimetric and Thermogravimetric Tests
[17], examining wood biomass pellets, found the ash content at the level of 0.31 to 0.56% and the calorific value in the range of 17.17 to 19.18 MJ\(\cdot\)kg\({}^{-1}\). The level of total nitrogen in the analyzed samples ranged from 0.42% to 1.70%. Pellets with 50% sawdust were characterized by a lower nitrogen content compared to pellets consisting of 100% biomass of sunflower, Jerusalem artichoke, and tobacco. Total carbon content was not diversified, considering different types of tested materials and different compositions of pellets. The addition of coniferous sawdust did not significantly change the carbon content in the tested pellets. The amount of hydrogen in the tested samples did not differ significantly. The addition of sawdust slightly increased the hydrogen content in the tested biomass of the analyzed pellets (Table 4). The content of nitrogen, carbon and hydrogen, and waste agricultural biomass for the production of pellets is diversified. The bagasse used to make pellets contains 45.05% carbon, 11.8% hydrogen, and 0.2% nitrogen. On the other hand, corn cobs contain 37.35% carbon, 14.4% hydrogen, and 0.2% nitrogen [30]. The chemical composition of pellets produced from sunflower husks was varied. The carbon content ranged from 42.1 to 69.8%, nitrogen ranged from 0.33 to 9.1%, and hydrogen ranged from 5.17-8.80 [31; 32; 33]. Research by scientists has shown that tobacco stem pellets contain 40.54% carbon, 6% hydrogen, and 1.28% nitrogen [29]. In turn, pellets made of hazelnut tree biomass had a carbon content of 45.07%, hydrogen 6.97%, and nitrogen 0.77%. The solid fuel produced from olive tree pruning waste contained 55.02% carbon, 5.42% hydrogen, and 1.24% nitrogen [34]. According to [PERSON] [35], the nitrogen content in biomass (cereal straw, grass, fruit processing waste) above 0.6% indicates that excessive emission of NO\({}_{\mathrm{x}}\) into the atmosphere will occur in the case of biomass combustion. Table 5 presents the average values of gases emitted during the combustion of pellets produced from agricultural waste biomass created during the cultivation of plants for industrial purposes. \begin{table}
\begin{tabular}{c c c c} \hline
**The Type of Pellets** & **Nitrogen [\%]** & **Carbon [\%]** & **Hydrogen [\%]** \\ \hline P1 & 1.70 \({}^{\mathrm{b}}\)\(\pm\) 0.04 & 44.25 \({}^{\mathrm{a}}\)\(\pm\) 0.11 & 6.46 \({}^{\mathrm{a}}\)\(\pm\) 0.16 \\ P2 & 0.47 \({}^{\mathrm{a}}\)\(\pm\) 0.07 & 44.32 \({}^{\mathrm{a}}\)\(\pm\) 0.08 & 6.53 \({}^{\mathrm{a}}\)\(\pm\) 0.28 \\ P3 & 1.62 \({}^{\mathrm{b}}\)\(\pm\) 0.05 & 45.21 \({}^{\mathrm{a}}\)\(\pm\) 0.10 & 6.02 \({}^{\mathrm{a}}\)\(\pm\) 0.18 \\ P4 & 0.42 \({}^{\mathrm{a}}\)\(\pm\) 0.07 & 45.41 \({}^{\mathrm{a}}\)\(\pm\) 0.13 & 6.21 \({}^{\mathrm{a}}\)\(\pm\) 0.22 \\ P5 & 0.99 \({}^{\mathrm{b}}\)\(\pm\) 0.24 & 46.37 \({}^{\mathrm{a}}\)\(\pm\) 0.19 & 5.90 \({}^{\mathrm{a}}\)\(\pm\) 0.14 \\ P6 & 0.51 \({}^{\mathrm{a}}\)\(\pm\) 0.17 & 46.38 \({}^{\mathrm{a}}\)\(\pm\) 0.13 & 6.19 \({}^{\mathrm{a}}\)\(\pm\) 0.17 \\ \end{tabular} Statistically significant differences marked by different letters (\(p\leq\) 0.05). The data were analyzed separately for each type of materials.  
\end{table} 
Table 4: Average values of nitrogen, carbon, and hydrogen for the tested pellets. When analyzing the results of the research, certain dependencies were observed. The addition of coniferous sawdust reduced the amount of carbon monoxide, carbon dioxide, and sulfur oxide emitted, and increased the emission of nitrogen oxides. In the case of carbon monoxide, the lowest emissions were recorded for tobacco stalk pellets and coniferous sawdust (P4). The highest emissions were from pellets made of 100% sunflower stalks (P1). The same dependence was observed when analyzing the results for carbon dioxide. On the other hand, the emission of sulfur dioxide was the highest for pellets made of tobacco stalks (P3), and the lowest for pellets consisting of a mixture of Jerusalem aritchoke stalks and coniferous sawdust (P6).