## 3 Factsage in the Environmental Sector
### Applications in the Field of Air Pollution
Application of Factsage provides a theoretical basis and operational conditions for subsequent CO\({}_{2}\) capture experiments. In addition to studying CO\({}_{2}\) capture \begin{table}
\begin{tabular}{l c c} \hline \hline
**Case Descriptions** & **Related Modules** & **Reference** \\ \hline Simulated the emissions of HCI and SO\({}_{2}\) pollutants during sludge & & \\ incineration and validated the accuracy of the thermodynamic model & Equilib & [101] \\ predictions through experiments. & & \\ \hline Calculated the chemical equilibrium states of H\({}_{2}\)S adsorption on & & \\ different adsorbents and studied the main factors affecting H\({}_{2}\)S & Equilib & [102] \\ adsorption efficiency. & & \\ \hline Established a mathematical model to predict VOC\({}^{*}\) emission rates & & \\ and analyzed the effects of different parameters on VOC\({}^{*}\) emission & Reaction & [103] \\ rates using Factsage. & & \\ \hline Predicted gas pollutants generated during the production of sintered & & \\ bricks using yellow phosphorus slag and determined the reaction & & \\ conditions that minimize pollutant emissions. & & \\ \hline Calculated the thermodynamic properties of wet and dry carbonation & & \\ reactions of steel slag to determine the feasibility of carbon & Reaction & [105] \\ sequestration using steel slag. & & \\ \hline Simulated and analyzed the thermal decomposition of & & \\ phosphogypsum and the process of capturing carbon dioxide with & Equilib & [106] \\ the decomposition residue. Used phase diagrams to analyze the & & \\ reaction mechanism. & & \\ \hline Utilized circulating fluidized bed gasification technology to convert & & \\ solid carbon into CO and H\({}_{2}\), and other reducing gases. Simulated & Equilib & [107] \\ the reduction products of SO\({}_{2}\) in this highly reducing atmosphere. & & \\ \hline Utilized CO and H\({}_{2}\) to elemental sulfur, and analyzed the & & \\ thermodynamic properties of the reaction. & & \\ \hline \hline \end{tabular} \({}^{*}\) In the table ‘VOC’ stands for volatile organic compounds.  
\end{table} 
Table 6: Application study of the field of air pollution of Factsage software. techniques, Factsage can also be used to investigate the adsorption and separation of HCl and H\({}_{2}\)S [102; 114]. Finally, Factsage can be utilized for the treatment and disposal of gas pollution. The simulation function of Factsage can predict the disposal process of hazardous gases, thereby providing a theoretical basis for the large-scale application of this technology. [PERSON] et al. [107] employed the Equilib module to calculate the products of the SO\({}_{2}\) reduction reaction when it reached equilibrium. This approach enabled them to not only identify the various products of SO\({}_{2}\) reduction under the strong reducing atmosphere of coal gasification but also to determine the reaction conditions with the highest yields. These findings provided a theoretical basis for the subsequent production of the actual process. [PERSON] et al. [108] found that CO and H\({}_{2}\) produced by pyrolysis of activated carbon were able to effectively reduce SO\({}_{2}\) through calculations using the Equilib module, while the unpyrolyzed activated carbon also had good catalytic performance for the reduction of SO\({}_{2}\), which verified the practical feasibility of the process. In conclusion, Factsage provides an effective tool and technical support for the management of atmospheric pollutants, but there are still certain shortcomings. Currently, the software is only applied to the study of a few gases such as SO\({}_{2}\) and CO\({}_{2}\) in the atmospheric field and has not been widely used. Nevertheless, with its functions such as computer simulation and thermodynamic calculations of chemical reactions, Factsage can enable rapid evaluation and optimization of control and treatment options for various gas pollutants, thus effectively reducing pollutant emissions and environmental hazards. Therefore, Factsage has a wide range of applications in the atmospheric field.