## 3 Results and Discussion
### Effect on Product Yield and Composition
#### 3.3.3 Effect on Shale Oil Composition
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Sample**} & \multirow{2}{*}{**Temp\(J^{\circ}\)C**} & **N** & **C** & **H** & **S** & **O** & **H/C** & **O/C** \\ \cline{3-8}  & & & & **wt, \%** & & & **Atomic Ratio, \%** \\ \hline \multirow{2}{*}{OS} & 400 & 0.59 & 82.39 & 12.25 & 0.44 & 4.34 & 1.78 & 0.04 \\  & 520 & 0.60 & 81.21 & 11.76 & 0.44 & 6.00 & 1.74 & 0.06 \\ \multirow{2}{*}{DMOS+AlCl3-6H2O} & 400 & 0.54 & 82.65 & 12.27 & 0.43 & 4.12 & 1.78 & 0.04 \\  & 520 & 0.52 & 82.89 & 11.86 & 0.41 & 4.32 & 1.72 & 0.04 \\ \multirow{2}{*}{WMOS+AlCl3-6H2O} & 400 & 0.61 & 82.44 & 12.16 & 0.44 & 4.36 & 1.77 & 0.04 \\  & 520 & 0.58 & 83.11 & 11.87 & 0.40 & 4.04 & 1.71 & 0.04 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Ultimate analysis (N, C, H, S, and O) results of various shale oil samples. Figure 10: _Cont._  
Figure 9: Simulated distillation analysis results of various shale oil samples. The results show that the shale oil obtained from DMOS + AlCl\({}_{3}\cdot\)6H\({}_{2}\)O and WMOS + AlCl\({}_{3}\cdot\)6H\({}_{2}\)O at 400 \({}^{\circ}\)C have different component distributions. Compared to the shale oil from OS, that obtained from DMOS + AlCl\({}_{3}\cdot\)6H\({}_{2}\)O at 400 \({}^{\circ}\)C shows a decrease in short- chain hydrocarbons and an increase in long-chain hydrocarbons. In contrast, shale oil obtained from WMOS + AlCl\({}_{3}\cdot\)6H\({}_{2}\)O at 400 \({}^{\circ}\)C results in an increase in short-chain hydrocarbons and a decrease in long-chain hydrocarbons. These phenomena are similar to the results of the simulated distillation analysis. During the pyrolysis of the DMOS + AlCl\({}_{3}\cdot\)6H\({}_{2}\)O, a significant amount of carbon dioxide escaped, promoting the release of the heavy fraction and reducing the light fraction. However, no significant amount of carbon dioxide was produced in WMOS + AlCl\({}_{3}\cdot\)6H\({}_{2}\)O, which prolonged the conversion of the heavy hydrocarbons and, together with the catalytic effect of AlCl\({}_{3}\cdot\)6H\({}_{2}\)O, resulted in more light fractions. All shale oil samples obtained at 520 \({}^{\circ}\)C then have a similar compositional distribution, with fewer lighter fractions as well as more heavy fractions. This suggests that at high temperatures, AlCl\({}_{3}\cdot\)6H\({}_{2}\)O can facilitate the initial cracking of kerogen and the release of heavy fractions. This is attributed to the catalytic effect of AlCl\({}_{3}\cdot\)6H\({}_{2}\)O and the large amount of pores formed by carbonate removal. Environmental concerns cannot be ignored when using acid chlorates as catalysts. Generally, the injection of acidic chloride salt catalysts into the ground may cause heavy metal contamination, especially Cr, Mo, and Mn, which are less abundant in the soil. In addition, excessive acidic salts may lead to the acidification of soil and groundwater, etc. However, in OS extraction, minerals such as carbonates in the OS strata can effectively neutralize acidic salts and produce more stable metal oxides or salts at high temperatures. This can greatly reduce the environmental impact of the catalyst. Further, AlCl\({}_{3}\) is characterized by low cost and low pollution, and the Al\({}_{2}\)O\({}_{3}\) generated exists in large quantities in the natural environment and has a low environmental impact. This makes it a great potential in OS extraction. Notwithstanding the above, monitoring and treatment of catalyst impacts during the in situ extraction process is essential. Long-term monitoring of the surrounding soil, water, and atmosphere should be carried out during the extraction process to assess the risk of spreading pollution. In addition, if necessary, low concentrations of weakly alkaline solutions should be injected into the ground for neutralization, or adsorbents (activated  
Figure 10: (**a**) GC-MS analysis results, and (**b**) the composition of short- and long-chain normal hydrocarbons of various shale oil samples. carbon) should be used to capture chlorinated organics at the outlet.