Co-pyrolysis of cellulose with urea and chitosan to produce nitrogen-containing compounds and nitrogen-doped biochar: Product distribution characteristics and reaction path analysis

Empirical Correlation between Electrical Conductivity and Nitrogen Content in Biochar as Influenced by Pyrolysis Temperature

“…This effect of different compounds can be observed through the presence of preserved and formed nitrogenous functional groups during pyrolysis, which can conduct electricity due to their electron donation or acceptance capacity in reaction centers. Examples of these groups present in biochar include amines (NH 2 ), imines (NH), nitro groups (NO 2 ), pyridinic, and pyrazinic groups [16,21,27,39,40,44]. The effect of N-rich groups with high EC was evident in our study, especially in CH-derived biochar, which showed lower N loss, i.e., preserved higher N content in the biochar.…”

“…The positive relationship between total N and C contents is explained by the presence of pyrolytic carbon, which has a porous structure capable of adsorbing molecules, including nitrogenous compounds produced during pyrolysis [3,16,21,39,40,43,44]. Furthermore, when N is adsorbed onto pyrolytic C, additional polymerization or condensation reactions occur between N and C atoms, creating favorable conditions for the formation of nitrogenous compounds with closed chains, thus preserving N during pyrolysis [3,16,21,39,40,43,44]. Among these N compounds are the formation of pyrazine and pyridine and the formation of other heterocyclic compounds, such as pyrazole (Figure 5) [39,40,44].…”

“…Furthermore, when N is adsorbed onto pyrolytic C, additional polymerization or condensation reactions occur between N and C atoms, creating favorable conditions for the formation of nitrogenous compounds with closed chains, thus preserving N during pyrolysis [3,16,21,39,40,43,44]. Among these N compounds are the formation of pyrazine and pyridine and the formation of other heterocyclic compounds, such as pyrazole (Figure 5) [39,40,44]. Despite the C and N correlation, obtaining reliable measures of these elements in biochar is expensive and time-consuming.…”

“…All statistical analyses were performed using the R software version 4.3.1 with the following packages: stats; base; tidyverse; agricolae; factoextra; FactoMineR; and corrplot [34][35][36][37][38]. The dataset of the total N content, N loss, and EC value was adjusted to different nonlinear mathematical models to show the relationship between these variables and increasing PT [9,39,40]. The following mathematical models were adjusted to the biochar attributes and N content and loss as a function of pyrolysis temperature: Linear model (Equation ( 4)); Quadratic model (Equation ( 5)); Elovich model (Equation ( 6)); power function (Equation ( 7)); and hyperbolic model (Equation ( 8)).…”