scholarly journals Increased Aromatics Formation by the Use of High-Density Polyethylene on the Catalytic Pyrolysis of Mandarin Peel over HY and HZSM-5

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 656 ◽  
Author(s):  
Young-Kwon Park ◽  
Muhammad Siddiqui ◽  
Yejin Kang ◽  
Atsushi Watanabe ◽  
Hyung Lee ◽  
...  

High-density polyethylene (HDPE) was co-fed into the catalytic pyrolysis (CP) of mandarin peel (MP) over different microporous catalysts, HY and HZSM-5, with different pore and acid properties. Although the non-catalytic decomposition temperature of MP was not changed during catalytic thermogravimetric analysis over both catalysts, that of HDPE was reduced from 465 °C to 379 °C over HY and to 393 °C over HZSM-5 because of their catalytic effects. When HDPE was co-pyrolyzed with MP over the catalysts, the catalytic decomposition temperatures of HDPE were increased to 402 °C over HY and 408 °C over HZSM-5. The pyrolyzer-gas chromatography/mass spectrometry results showed that the main pyrolyzates of MP and HDPE, which comprised a large amount of oxygenates and aliphatic hydrocarbons with a wide carbon range, were converted efficiently to aromatics using HY and HZSM-5. Although HY can provide easier diffusion of the reactants to the catalyst pore and a larger amount of acid sites than HZSM-5, the CP of MP, HDPE, and their mixture over HZSM-5 revealed higher efficiency on aromatics formation than those over HY due to the strong acidity and more appropriate shape selectivity of HZSM-5. The production of aromatics from the catalytic co-pyrolysis of MP and HDPE was larger than the theoretical amounts, suggesting the synergistic effect of HDPE co-feeding for the increased formation of aromatics during the CP of MP.

2018 ◽  
Vol 10 (11) ◽  
pp. 3979 ◽  
Author(s):  
Azubuike Anene ◽  
Siw Fredriksen ◽  
Kai Sætre ◽  
Lars-Andre Tokheim

Thermal and catalytic pyrolysis of virgin low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP) and mixtures of LDPE/PP were carried out in a 200 mL laboratory scale batch reactor at 460 °C in a nitrogen atmosphere. Thermogravimetric analysis (TGA) was carried out to study the thermal and catalytic degradation of the polymers at a heating rate of 10 °C/min. The amount of PP was varied in the LDPE/PP mixture to explore its effect on the reaction. In thermal degradation (TGA) of LDPE/PP blends, a lower decomposition temperature was observed for LDPE/PP mixtures compared to pure LDPE, indicating interaction between the two polymer types. In the presence of a catalyst (CAT-2), the degradation temperatures for the pure polymers were reduced. The TGA results were validated in a batch reactor using PP and LDPE, respectively. The result from thermal pyrolysis showed that the oil product contained significant amounts of hydrocarbons in the ranges of C7–C12 (gasoline range) and C13–C20 (diesel range). The catalyst enhanced cracking at lower temperatures and narrowed the hydrocarbon distribution in the oil towards the lower molecular weight range (C7–C12). The result suggests that the oil produced from catalytic pyrolysis of waste plastics has a potential as an alternative fuel.


2021 ◽  
Vol 21 (7) ◽  
pp. 3971-3974
Author(s):  
Young-Kwon Park ◽  
Muhammad Zain Siddiqui ◽  
Sangjae Jeong ◽  
Eun-Suk Jang ◽  
Young-Min Kim

The effect of seawater aging on the thermal and catalytic pyrolysis of polypropylene (PP) was investigated using a thermogravimetric analyzer and pyrolyzer-gas chromatography/mass spectrometry. Although the surface properties of PP were of the oxidized form by seawater aging, the decomposition temperature and non-catalytic pyrolysis products of PP were relatively unchanged largely due to seawater aging. The catalytic pyrolysis of seawater-aged PP over all the catalysts produced smaller amounts of aromatic hydrocarbons than that of fresh PP due to catalyst poisoning caused by the residual inorganics. Among the catalysts, microporous HZSM-5 (SiO2/Al2O3:23) produced the largest amount of aromatic hydrocarbons followed in order by microporous HY(30) and nanoporous Al-MCM-41(20) from seawater-aged PP due to the high acidity and appropriate pore size for the generation of aromatic hydrocarbons.


2019 ◽  
Vol 58 (41) ◽  
pp. 19050-19060 ◽  
Author(s):  
Jesús Zavala-Gutiérrez ◽  
Odilia Pérez-Camacho ◽  
Luis Villarreal-Cárdenas ◽  
Enrique Saldívar-Guerra

2020 ◽  
Vol 3 (1) ◽  
pp. 20-30
Author(s):  
Nguamo Surma ◽  
◽  
Godwin Ijuo ◽  
Blessing Ogoh-Orch ◽  
◽  
...  

Holzforschung ◽  
2016 ◽  
Vol 70 (1) ◽  
pp. 31-38 ◽  
Author(s):  
Manuel R. Pelaez-Samaniego ◽  
Vikram Yadama ◽  
Manuel Garcia-Perez ◽  
Eini Lowell ◽  
Rui Zhu ◽  
...  

AbstractHot water extraction (HWE) partially removes hemicelluloses from wood while leaving the majority of the lignin and cellulose; however, the lignin partially migrates to the inner surfaces of the cell wall where it can be deposited as a layer that is sometimes visible as droplets. This lignin-rich material was isolated via Soxhlet extraction with dichloromethane to investigate its rheological behavior in blends with high-density polyethylene (HDPE), a common material in wood plastic composites (WPCs). Pyrolysis gas-chromatography/mass spectrometry (Py-GC/MS) and electrospray ion mass spectrometry (ESI/MS) confirmed that the isolated material is constituted mainly of low-molecular-weight lignin oligomers. The blends of HDPE/isolated lignin, in varying ratios, were tested by means of dynamic rheology. A “shoulder” was found in plots “shear storage moduli (G′) vs. frequency sweep” and a shift of the terminal zone to lower frequencies was observed. Apparently, this shoulder is caused by the elastic contribution of the interfacial tension between the blend components. The rheology of WPCs produced from HWE wood and HDPE shows a similar shoulder in G′ plots, suggesting that the HDPE/lignin blends are in part responsible for the shape of the G′ curves.


Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 759
Author(s):  
Ivan Kojić ◽  
Achim Bechtel ◽  
Nikoleta Aleksić ◽  
Dragana Životić ◽  
Snežana Trifunović ◽  
...  

The mutual impact of low-quality lignite and high-density polyethylene (HDPE) during open system pyrolysis was investigated, aiming to improve utilization of lignite with simultaneous treatment of HDPE waste. Pyrolysis of lignite, HDPE, and their mixture (mass ratio, 1:1) was performed at temperatures 400, 450, 500, 550, and 600 °C. Initial substrates and pyrolysis products were characterized by thermogravimetric analysis (TGA), gas chromatography–mass spectrometry (GC–MS), specific carbon isotope analysis of individual hydrocarbons (δ13C), Rock-Eval pyrolysis, and elemental analysis. The positive synergetic effect during co-pyrolysis of lignite/HDPE mixture was observed at temperatures ≥450 °C, with the greatest being at 500 °C. The highest yield of liquid co-pyrolysis products with a similar composition to that of crude oils is also noticed at 500 °C. The yields of liquid and gaseous products and quality of pyrolytic products obtained by co-pyrolysis of lignite/HDPE mixture are notably improved compared with pyrolysis of lignite alone. On the other hand, data obtained from pyrolysis of HDPE alone indicate that it cannot be concurrent to well-developed catalytic thermal processes for polymer recycling. However, concerning the huge amount of produced HDPE, at least part of this plastic material can be reused for advanced thermal treatment of lignite, particularly in countries where this low-rank coal represents the main source of energy.


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