scholarly journals Kinetic Analysis for the Catalytic Pyrolysis of Polypropylene over Low Cost Mineral Catalysts

2021 ◽  
Vol 13 (23) ◽  
pp. 13386
Author(s):  
Young-Min Kim ◽  
Sumin Pyo ◽  
Hanie Hakimian ◽  
Kyung-Seun Yoo ◽  
Gwang-Hoon Rhee ◽  
...  

A kinetic analysis of non-catalytic pyrolysis (NCP) and catalytic pyrolysis (CP) of polypropylene (PP) with different catalysts was performed using thermogravimetric analysis (TGA) and kinetic models. Three kinds of low-cost natural catalysts were used to maximize the cost-effectiveness of the process: natural zeolite (NZ), bentonite, olivine, and a mesoporous catalyst, Al-MCM-41. The decomposition temperature of PP and apparent activation energy (Ea) were obtained from the TGA results at multiple heating rates, and a model-free kinetic analysis was performed using the Flynn–Wall–Ozawa model. TGA indicated that the maximum decomposition temperature (Tmax) of the PP was shifted from 464 °C to 347 °C with Al-MCM-41 and 348 °C with bentonite, largely due to their strong acidity and large pore size. Although olivine had a large pore size, the Tmax of PP was only shifted to 456 °C, because of its low acidity. The differential TG (DTG) curve of PP over NZ revealed a two-step mechanism. The Tmax of the first peak on the DTG curve of PP with NZ was 376 °C due to the high acidity of NZ. On the other hand, that of the second peak was higher (474 °C) than the non-catalytic reaction. The Ea values at each conversion were also decreased when using the catalysts, except olivine. At <0.5 conversion, the Ea obtained from the CP of PP with NZ was lower than that with the other catalysts: Al-MCM-41, bentonite, and olivine, in that order. The Ea for the CP of PP with NZ increased more rapidly, to 193 kJ/mol at 0.9 conversion, than the other catalysts.

2021 ◽  
Vol 21 (7) ◽  
pp. 3872-3876
Author(s):  
Su-Min Pyo ◽  
Young-Min Kim ◽  
Jung Sul Jung ◽  
Kyung Seun Yoo ◽  
Sang-Chul Jung ◽  
...  

This study examined the catalytic effects of Al-MCM-41 on the pyrolysis of wood plastic composite via the thermogravimetric analysis (TGA) and model-free kinetic analysis. Al-MCM-41 containing nanopores, with a high BET surface area (633 m2/g) and acidity (SiO2/Al2O3:25), reduced the decomposition temperature of wood and plastic mixtures (PE and PP) in a wood-plastic composite. The average activation energy for the catalytic pyrolysis of wood plastic composite, which was calculated via a model-free kinetic analysis method (Ozawa) of TGA, was also lower at all conversions than those of non-catalytic pyrolysis. This suggests that the pores of Al-MCM-41 and its high cracking efficiency allow the effective diffusion of wood plastic composite components.


2014 ◽  
Vol 12 (1) ◽  
pp. 487-496 ◽  
Author(s):  
Mohammad M. Hossain ◽  
Mogahid Osman ◽  
Sulaiman Al-Khattaf

Abstract This communication reports the kinetics analysis of ethylation of ethylbenzene (EB) with ethanol over large pore size mordenite catalysts. In this regard, two different catalyst samples are selected with SiO2/Al2O3 = 180 and 21, respectively. The higher acidic sample (SiO2/Al2O3 = 21) is desilicated to study the effects of desilication on the EB ethylation. The EB ethylation experiments are conducted in a fluidized CREC Riser Simulator using equimolar amount of EB and ethanol as feed. Under the studied reaction conditions, diethylbenzene (DEB) is the main product while a small amount of benzene and lighter gases are also produced. In addition to DEB, the higher acidic mordenite sample also produces benzene via dealkylation of EB. On the other hand, the large pore size mordenite sample gives triethylbenzene (TEB) as a secondary alkylation product. The desilicated sample shows slightly higher DEB selectivity but the EB conversion with this sample is low. Power law–based kinetics evaluation also confirms the above observations by showing low activation energy for DEB formation while high activation energies for benzene and TEB formations.


Nano Letters ◽  
2011 ◽  
Vol 11 (3) ◽  
pp. 998-1001 ◽  
Author(s):  
Justin Bolton ◽  
Travis S. Bailey ◽  
Javid Rzayev

2021 ◽  
Vol 21 (7) ◽  
pp. 4081-4084
Author(s):  
Seul-Bee Lee ◽  
Young-Min Kim ◽  
Ji-Hui Park ◽  
Young-Kwon Park

This study examined the thermal and catalytic pyrolysis of waste Achyranthes Root (AR) using pyrolyzer-gas chromatography/mass spectrometry (Py-GC/MS). The non-catalytic pyrolysis of waste AR produced various kinds of oxygenates, such as acetic acid, hydroxy propanone, furfural, phenol, cresol, guaiacols, syringols, and so on. By applying nanoporous Al-MCM-41 with acidic properties and mesopores to the pyrolysis of waste AR, the levels of furan and aromatic hydrocarbons production increased with a concomitant decrease in the other oxygenates. The formation efficiency of furans was improved further by increasing the amount of Al-MCM-41 applied to the catalytic pyrolysis of waste AR.


2007 ◽  
Vol 57 (11) ◽  
pp. 1020-1023 ◽  
Author(s):  
Y.P. Zhang ◽  
D.S. Li ◽  
X.P. Zhang

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5270
Author(s):  
Sung Soo Park ◽  
Sang-Wook Chu ◽  
Liyi Shi ◽  
Shuai Yuan ◽  
Chang-Sik Ha

Crystalline walled SBA-15 with large pore size were prepared using alkali and alkali earth metal ions (Na+, Li+, K+ and Ca2+). For this work, the ratios of alkali metal ions (Si/metal ion) ranged from 2.1 to 80, while the temperatures tested ranged from 500 to 700 °C. The SBA-15 prepared with Si/Na+ ratios ranging from 2.1 to 40 at 700 °C exhibited both cristobalite and quartz SiO2 structures in pore walls. When the Na+ amount increased (i.e., Si/Na increased from 80 to 40), the pore size was increased remarkably but the surface area and pore volume of the metal ion-based SBA-15 were decreased. When the SBA-15 prepared with Li+, K+ and Ca2+ ions (Si/metal ion = 40) was thermally treated at 700 °C, the crystalline SiO2 of quartz structure with large pore diameter (i.e., 802.5 Å) was observed for Ca+2 ion-based SBA-15, while no crystalline SiO2 structures were observed in pore walls for both the K+ and Li+ ions treated SBA-15. The crystalline SiO2 structures may be formed by the rearrangement of silica matrix when alkali or alkali earth metal ions are inserted into silica matrix at elevated temperature.


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.


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