In this study, the effect of thermal and acid activation of NZ on the overall product yield of the pyrolysis process was investigated in order to determine how much of an impact each had. The catalytic pyrolysis of individual PS plastic using TA-NZ and AA-NZ catalysts showed the highest liquid oil yields of 70% and 60%, respectively, when compared to all of the other types of individual and combined plastic waste that were researched (2017). This was the case when the individual PS plastic was compared to all of the other types of individual and combined plastic waste. According to Lee (2012), PS degradation occurred via both random-chain scissions and end chain scissions, which resulted in the production of the stable benzene ring structure. Citation neededThis structure makes further cracking more efficient, which could result in an increase in the amount of liquid oil that is produced. In the presence of acid catalysts, the deterioration of PS followed a mechanism involving carbenium. After this mechanism, the inter- and intramolecular transfer of hydrogen occurred, which was followed by -scission (Serrano et al., 2014). In contrast, the production of char during the catalytic pyrolysis machine of PS using an AA-NZ catalyst was significantly higher, coming in at 24.6%, whereas the production of char during the same process using a TA-NZ catalyst was only 15.8%.(2017) found that the catalytic pyrolysis of PS with an acidic zeolite (H) catalyst resulted in a significant amount of char being produced. The high acidity of the catalyst, which favors char production via intense secondary cross-linking reactions (Serrano et al. ), was the cause of the high char production numbers that were observed (Serrano et al.). Citation needed Citation needed Citation needed Citation needed Citation needed Citation needed Citation needed
When PP was put through a catalytic pyrolysis, the AA-NZ catalyst produced a greater amount of liquid oil (54%) than the TA-NZ catalyst did (40%) as a result of the reaction
1. 1%), which may be due to the fact that the TA-NZ catalyst possesses a lower level of catalytic activity
2. According to Kim et al
3. (2002), the initial degradation of PP is aided by catalysts that have low acidity and BET surface areas with microporous structures
4. Additionally, these catalysts should have a relatively large number of pores
5. It's possible that this will result in the greatest amount of gas being produced
6. (2012) discovered that pyrolyzing PP with an alumina-loaded catalyst resulted in the greatest amount of gas being produced
7. Because of this, the amount of gas that was produced was increased to its maximum level
8. Syamsiro et al
9. In spite of this, it was discovered that the production of gases from polyethylene terephthalate (PE) using either AA-NZ or TA-NZ resulted in the greatest quantities (50%) of any of the plastics that were looked into by the researchers
10. The production of char reached its nadir in this particular scenario, clocking in at 7
11. 0% for both AA-NZ and TA-NZ
12. In addition, a number of studies (Xue et al
13. , 2017) reported that the catalytic pyrolysis of PE resulted in a lower overall production of char
14. This was the conclusion reached by the researchers
15. Lopez et al
16. , 2016b, 2017a)
17. Zeaiter (2014) was successful in catalytically pyrolyzing PE with HBeta zeolite and reported a gas production rate of 95
18. 7%
19. This was made possible by the high acidity of the catalyst
20. Batool et al
21. According to Lee (2012) and Williams (2006), PE possesses a lengthy carbon chain structure
22. Its breakdown takes the form of random chain scission, which results in the formation of shorter chain molecules
23. This may stimulate the production of gas
24. Pyrolysis of polyethylene (PE), which only has C-H and C-C bonds, was the first step in the process that led to the production of stable free radicals
25. This step was necessary because PE is the only type of macromolecule that only has these two types of bonds
26. In addition, the steps of hydrogenation occurred, which led to the formation of secondary free radicals (a new stable C-H bond), which in turn caused -scission, which resulted in the production of an unsaturated group (Rizzarelli et al
27. )
28. According to the findings of their study, Rizzarelli et al
When both AA-NZ and TA-NZ were used in the catalytic pyrolysis of PP/PE (in a ratio of 50/50), there was not a discernible difference in the total amount of product that was produced. This was the case even though there was a difference in the ratio of the two catalysts. It's possible that AA-NZ's high acidity is to blame for the slight decrease in the amount of liquid oil it produces, and this theory has been put forward. Syamsiro et al. The overall pyrolysis machine of PP and PE by catalysis produced the greatest amount of gas while only producing small amounts of char. This was due to the fact that gas production was greater than char production. According to Jung et al.'s research, the degradation of PP makes the carbocation process more effective as a result of the presence of tertiary carbon in its carbon chain. Needs additional citationsAdditionally, the breakdown of PE in the presence of a catalyst results in an increase in the production of gas while simultaneously resulting in a decrease in the production of liquid oil.
The yield of liquid oil produced from the catalytic pyrolysis of PS/PP (in a ratio of 50/50) with TA-NZ and AA-NZ catalysts, respectively, resulted in a significant difference. Depending on which catalyst was used, the yield of liquid oil was either 54% or 34%. It was found that the low yield of gases was 3, while the high yield of gases was 35.2%, and it was discovered that. Lopez et al. (2011) and Seo et al. In addition to this, research conducted by Jung et al. found that the presence of PP results in an increase in the production of gas during the carbocation process that occurs during degradation. Kim et al. (2002) found that the process of PP degradation produces the most gas when it is carried out in the presence of acid catalysts. This was one of the findings of their study.
In the presence of a TA-NZ catalyst, the catalytic of PS and PE in a ratio of 50/50 resulted in the production of 44% liquid oil. The ratio of PS to PE was found to be optimal for this reaction. The use of the AA-NZ catalyst, on the other hand, led to the production of liquid oil at a rate of 52%. The findings of Miandad et al., 2016b indicate that the presence of both PS and PE at the same time accelerates the process of degradation. This is due to the fact that PS plays a role in the formation of a benzene ring that is both active and stable. Wu et al. In addition, the deterioration of PE takes place through a free radical chain process and a hydrogenation process, whereas the deterioration of PS takes place through a radical chain process that involves a number of steps (Kiran et al.). When the phenomena of degradation were taken into account in the study that McNeill et al. conducted back in 1990, the findings showed that PS resulted in higher degradation compared to PE and produced stable benzene rings. This was demonstrated by the fact that the PS produced these rings. According to Wu and Williams' research, using the TA-NZ catalyst led to an increase in the amount of char that was produced by 29.0 percent. This increase may be attributable to polymerization reactions. When using TA-NZ and AA-NZ catalysts, respectively, with higher fractions of char and gas, the addition of PET along with PS, PE, and PP in a ratio of 20/40/20/20% decreased the overall liquid oil yields to 28 and 30%, respectively. This resulted in lower overall liquid oil yields. Despite the fact that the proportion of PET to PS, PE, and PP remained unchanged, this was still the case. Adnan et al. (2014) used an Al-Al2O3 catalyst with ratios of 80/20% in order to perform catalytic pyrolysis of polystyrene (PS) and polyethylene terephthalate (PET). They only reported 37% liquid oil production. Moreover, Yoshioka et al. In addition, according to Bhaskar and colleagues' research, the production of char was found to be at its highest level when PET catalytic pyrolysis was carried out in conjunction with the pyrolysis of various other types of plastics. The increased production of char from the of PET was caused by the carbonization and condensation reactions that occurred during the of PET at a high temperature, as stated by Yoshioka et al. (2017). These reactions took place during the pyrolysis of PET.(2016) discovered that the production of benzene-free radicals with two different activated carbons was the precursor to the formation of catalytic coke from the degradation of PET.