Plastic upgrading via catalytic pyrolysis with combined metal-modified gallium-based HZSM-5 and MCM-41
Huaping Lin , Likai Zhu , Ye Liu , Vasilevich Sergey Vladimirovich , Bilainu Oboirien , Yefeng Zhou
Front. Chem. Sci. Eng. ›› 2024, Vol. 18 ›› Issue (11) : 125
Plastic upgrading via catalytic pyrolysis with combined metal-modified gallium-based HZSM-5 and MCM-41
Currently, the conversion of waste plastics into high-value products via catalytic pyrolysis enables the advancement of plastics’ open-loop recycling. However, enhancing selectivity remains a critical challenge. This study introduces a novel approach to catalytic pyrolysis, utilizing a combination of MCM-41 and modified gallium-based HZSM-5 catalysts, to achieve exceptional selectivity for aromatic liquid-phase products from linear low-density polyethylene. Firstly, to enhance the probability of dehydroaromatization optimization, the type and proportion of metal active sites within the HZSM-5 catalyst are fine-tuned, which would establish equilibrium with acid sites, resulting in a remarkable 15.72% increase in the selectivity of aromatic hydrocarbons. Secondly, to enhance the accessibility of volatiles to active sites, mesoporous MCM-41 with cracking capabilities is introduced. The doping ratio of MCM-41 is meticulously controlled to facilitate the diffusion of cracked volatiles to the active centers of modified gallium-based HZSM-5, enabling efficient reforming reactions. Experimental findings demonstrate that MCM-41 significantly enhances the dehydroaromatization activity of the modified gallium-based HZSM-5 catalyst. Under the influence of MCM-41:Zr2Ga3/HZSM-5 = 1:2 catalyst, the selectivity for aromatic hydrocarbons reaches an impressive 93.11%, with a notable 60.01% selectivity for benzene, toluene, ethylbenzene, and xylene. Lastly, this study proposes a plausible pathway for the generation of high-value aromatic hydrocarbons using the combined catalyst.
polyethylene pyrolysis / aromatic hydrocarbons / bimetal catalyst / HZSM-5 / MCM-41
| [1] |
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| [2] |
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| [3] |
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| [4] |
|
| [5] |
|
| [6] |
|
| [7] |
|
| [8] |
|
| [9] |
|
| [10] |
|
| [11] |
|
| [12] |
|
| [13] |
|
| [14] |
|
| [15] |
|
| [16] |
|
| [17] |
|
| [18] |
|
| [19] |
|
| [20] |
|
| [21] |
|
| [22] |
|
| [23] |
|
| [24] |
|
| [25] |
|
| [26] |
|
| [27] |
|
| [28] |
|
| [29] |
|
| [30] |
|
| [31] |
|
| [32] |
|
| [33] |
|
| [34] |
|
| [35] |
|
| [36] |
|
| [37] |
|
| [38] |
|
| [39] |
|
| [40] |
|
| [41] |
|
| [42] |
|
| [43] |
|
| [44] |
|
| [45] |
|
| [46] |
|
| [47] |
|
| [48] |
|
| [49] |
|
| [50] |
|
| [51] |
|
| [52] |
|
| [53] |
|
Higher Education Press
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