# Environmental Impact of the Natural Gas Liquefaction Process: An Example from China
## 3 Results and Discussion
### Environmental Impact Potential of Natural Gas Liquefaction at Unit Output  
Owing to the different qualities of raw material gas for natural gas liquefaction in China's provinces, the GWP, AP, EP, POCP, and DU results for Xinjiang, Inner Mongolia, Shaanxi, Shanxi, Ningxia, Henan, Sichuan, and Hebei were found to be different for each unit of LNG production. Therefore, this section discusses the results of each indicator under the unit output in the natural gas liquefaction stage. The following six results can be inferred from Figure 5.  
First, as shown in Figure 5a, the difference in the GWP of the eight provinces was not significant. Specifically, Inner Mongolia, Ningxia, and Shaanxi had the largest GWP results, and Sichuan had the smallest GWP result. In particular, the GWP results of Inner Mongolia (the largest GWP result) were found to be nearly 1.76 times higher than those of Sichuan.  
Second, as shown in Figure 5b, the AP results of the eight provinces were found to be quite different. Among them, Xinjiang, Hebei, and Henan had the largest AP results, whereas the remaining five provinces had smaller AP results. In particular, the AP results of Xinjiang (the largest AP result) were nearly 29 times higher than those of Ningxia (the smallest AP result).  
Third, as shown in Figure 5c, the EP results of the eight provinces varied widely. Among them, Xinjiang, Hebei, and Henan had the largest EP results, whereas the remaining five provinces had smaller EP results. In particular, the EP results of Xinjiang (the largest EP result) were found to be nearly 281.5 times higher than those of Sichuan (the smallest EP result).  
Figure 5: Environmental impact potentials of the eight provinces in the nature gas liquefaction process (per unit): (**a**) Global Warming Potential (GWP), (**b**) Acidification Potential (AP), (**c**) Eutrophication Potential (EP), (**d**) Photochemical Ozone Creation Potential (POC), (**e**) Dust Potential (DP), and (**f**) Total Environmental Impact Potential.  
Fourth, as shown in Figure 5d, the POCP results of the eight provinces were found to be uneven. Among them, Shaanxi, Ningxia, and Inner Mongolia had the largest POCP results, whereas Sichuan had the smallest POCP results. In particular, the POCP results of Shaanxi (the largest POCP result) were found to be nearly 6.14 times higher than those of Sichuan.  
Fifth, as shown in Figure 5e, the DP results of the eight provinces were uneven. Among them, Sichuan, Shaanxi, and Inner Mongolia had the largest DP results, whereas Shanxi had the smallest DP results. In particular, the DP results of Sichuan (the largest DP result) were found to be nearly 3.40 times higher than those of Shanxi.  
Sixth, as shown in Figure 5f, the total environmental impact (EI) potential of the eight provinces varied widely. Among them, Shaanxi, Ningxia, and Inner Mongolia had the largest total EI potential, whereas Sichuan had the smallest total EI potential. In particular, the total EI potential of Shaanxi (the largest total EI potential) was found to be nearly 4.96 times higher than that of Sichuan.