Hydrogen and Carbon Nanotubes from Pyrolysis-Catalysis of Waste Plastics: A Review

Williams, Paul T.

doi:10.1007/s12649-020-01054-w

Cited by 182 publications

(137 citation statements)

References 125 publications

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“…The catalytic bed temperature was kept constant at 850 °C for all the experiments and the steam:biomass ratio was maintained at 2.85. Nickel/Al 2 O 3 catalysts have been used to produce hydrogen from waste plastics since this type of catalyst is commonly used for the commercial production of hydrogen from natural gas [9,19]. In addition, Al 2 O 3 is known to be chemically and physically stable with high mechanical strength properties [24].…”

Section: Effect Of Ni-catalyst Support Materials On the Co-pyrolysis-cmentioning

confidence: 99%

“…The production of hydrogen from renewable resources such as biomass offers a sustainable and renewable source of energy with abundant readily available feedstocks including agricultural residues, forestry residues, and municipal solid waste [2][3][4][5][6]. Waste plastics are also a readily available resource that has been used for the production of hydrogen [7][8][9]. The hydrogen yield from biomass is relatively low compared to waste plastics because of the lower hydrogen content and the presence of high concentrations of oxygen in the biomass; the higher H:C ratio of plastics off-setting the high oxygen content of biomass [10].…”

Section: Introductionmentioning

confidence: 99%

“…The most common catalysts used for hydrogen production from biomass [22] and waste plastics [23] are nickel-based, reflecting the main type of catalyst used for commercial methane catalytic steam reforming [24]. Other transition metals investigated include Co, Fe, Cu, and also noble metal catalysts such as Pt, Pd, Rh, and Ru [9,24]. However, Ni-based catalysts, are preferred due to their lower cost and enhanced activity for breaking C─C, C─H, C─O, and O─H bonds and also for hydrogenation producing H atoms to form H 2 [9].…”

Section: Introductionmentioning

confidence: 99%

“…Other transition metals investigated include Co, Fe, Cu, and also noble metal catalysts such as Pt, Pd, Rh, and Ru [9,24]. However, Ni-based catalysts, are preferred due to their lower cost and enhanced activity for breaking C─C, C─H, C─O, and O─H bonds and also for hydrogenation producing H atoms to form H 2 [9]. The disadvantage of nickel as the active metal lies in its deactivation due to carbonaceous coke deposits on the surface through hydrocarbon decomposition and the Boudouard reaction leading to the covering of the active metal [25,26].…”

Section: Introductionmentioning

confidence: 99%

“…However, in attempts to improve the stability of Ni-based catalysts, different support materials including highly porous zeolites and mesoporous MCM-41 have been investigated for hydrogen production from waste plastics [21,30] and biomass [31]. It has been reported that the pore structure design allows for active metals to be located within the pore structure or nano-metal particles prevent pore-blocking during catalyst coking [9]. Therefore, using MCM-41 as the metal-catalyst support material offers a promising route to higher hydrogen production and is worthy of further investigation.…”

Section: Introductionmentioning

confidence: 99%

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Co-pyrolysis–catalytic steam reforming of cellulose/lignin with polyethylene/polystyrene for the production of hydrogen

Akubo

Nahil

Williams

2020

Waste Dispos. Sustain. Energy

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Co-pyrolysis of biomass biopolymers (lignin and cellulose) with plastic wastes (polyethylene and polystyrene) coupled with downstream catalytic steam reforming of the pyrolysis gases for the production of a hydrogen-rich syngas is reported. The catalyst used was 10 wt.% nickel supported on MCM-41. The influence of the process parameters of temperature and the steam flow rate was examined to optimize hydrogen and syngas production. The cellulose/plastic mixtures produced higher hydrogen yields compared with the lignin/plastic mixtures. However, the impact of raising the catalytic steam reforming temperature from 750 to 850 °C was more marked for lignin addition. For example, the hydrogen yield for cellulose/polyethylene at a catalyst temperature of 750 °C was 50.3 mmol g−1 and increased to 60.0 mmol g−1 at a catalyst temperature of 850 °C. However, for the lignin/polyethylene mixture, the hydrogen yield increased from 25.0 to 50.0 mmol g−1 representing a twofold increase in hydrogen yield. The greater influence on hydrogen and yield for the lignin/plastic mixtures compared to the cellulose/plastic mixtures is suggested to be due to the overlapping thermal degradation profiles of lignin and the polyethylene and polystyrene. The input of steam to the catalyst reactor produced catalytic steam reforming conditions and a marked increase in hydrogen yield. The influence of increased steam input to the process was greater for the lignin/plastic mixtures compared to the cellulose/plastic mixtures, again linked to the overlapping thermal degradation profiles of the lignin and the plastics. A comparison of the Ni/MCM-41 catalyst with Ni/Al2O3 and Ni/Y-zeolite-supported catalysts showed that the Ni/Al2O3 catalyst gave higher yields of hydrogen and syngas. Graphic abstract

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Section: Effect Of Ni-catalyst Support Materials On the Co-pyrolysis-cmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Co-pyrolysis–catalytic steam reforming of cellulose/lignin with polyethylene/polystyrene for the production of hydrogen

Akubo

Nahil

Williams

2020

Waste Dispos. Sustain. Energy

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Upcycling of Waste Plastic into Hybrid Carbon Nanomaterials

Wyss

Advincula

et al. 2023

Advanced Materials

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these 1D carbon nanomaterials include carbon nanotubes (CNTs), both single-and multi-walled, as well as ribbon-and platelike carbon nanofibers, bamboo-like carbon nanotubes, cup-stacked carbon nanofibers, and many more. [7][8][9][10] 1D materials are used extensively in composites, coatings, sensors, electrochemical energy storage, and electrocatalysts, capitalizing upon their strength, conductivity, low density, broadband electromagnetic absorption, high surface area, and chemical robustness. [11][12][13][14] Due to their broad utility and scientific interest, identifying new methods of synthesizing 1D carbon materials remains critical. The majority of synthetic strategies to form 1D carbon materials, including arcdischarge, laser ablation, chemical vapor deposition, plasma torch, and high partial pressure carbon monoxide involve the mobilization of carbon atoms in feedstocks on the surface of a catalytic metal which then grow into a graphitic 1D morphology. [15] These current methods often result in mixtures of 1D materials and amorphous carbon that require separation, and 1D materials syntheses often suffer from low production rates of <1 g h −1 . [16][17][18] Some recent work has focused on converting waste plastic into higher value carbon nanomaterials, inspired by the low Graphitic 1D and hybrid nanomaterials represent a powerful solution in composite and electronic applications due to exceptional properties, but large-scale synthesis of hybrid materials has yet to be realized. Here, a rapid, scalable method to produce graphitic 1D materials from polymers using flash Joule heating (FJH) is reported. This avoids lengthy chemical vapor deposition and uses no solvent or water. The flash 1D materials (F1DM), synthesized using a variety of earth-abundant catalysts, have controllable diameters and morphologies by parameter tuning. Furthermore, the process can be modified to form hybrid materials, with F1DM bonded to turbostratic graphene. In nanocomposites, F1DM outperform commercially available carbon nanotubes. Compared to current 1D material synthetic strategies using life cycle assessment, FJH synthesis represents an 86-92% decrease in cumulative energy demand and 92-94% decrease in global-warming potential. This work suggests that FJH affords a cost-effective and sustainable route to upcycle waste plastic into valuable 1D and hybrid nanomaterials.

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Effect of the Nature, the Content and the Preparation Method of Zeolite‐Polymer Mixtures on the Pyrolysis of Linear Low‐Density Polyethylene

Arango‐Ponton,

Corjon,

Dhainaut

et al. 2024

Adv Energy and Sustain Res

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The effect of the preparation method of the mixture catalyst/polymer on the linear low‐density polyethylene (LLDPE) pyrolysis is studied by comparing the results obtained when the polymer and the catalyst (Hβ or HZSM‐5) are extruded or simply mixed in powder form. By improving the polymer/catalyst contact through extrusion, the polymer degradation took place at lower temperature. The effect of extrusion is more pronounced with Hβ compared to HZSM‐5 owing to the highest external surface of Hβ. While the yields of gas/liquid/coke do not differ with the preparation method when HZSM‐5 is used as catalyst, more significant amount of liquid phase and high production of paraffins are observed when Hβ/LLDPE mixture is extruded, according to random scission pathway reactions. The subsequent reactions are limited by the size of the pore, which impede hydrogenation reactions, producing high molecular weight molecules. Regardless of zeolite type, the micropores of the zeolite are more affected by deactivation by coke when extrusion method is used, this effect being much more important for HZSM‐5. This result is a consequence of a polymer pre‐degradation during the extrusion process in which the first cracks of the polymer at low temperature and the first pore blockages can be generated.

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Hydrogen and Carbon Nanotubes from Pyrolysis-Catalysis of Waste Plastics: A Review

Cited by 182 publications

References 125 publications

Co-pyrolysis–catalytic steam reforming of cellulose/lignin with polyethylene/polystyrene for the production of hydrogen

Co-pyrolysis–catalytic steam reforming of cellulose/lignin with polyethylene/polystyrene for the production of hydrogen

Upcycling of Waste Plastic into Hybrid Carbon Nanomaterials

Effect of the Nature, the Content and the Preparation Method of Zeolite‐Polymer Mixtures on the Pyrolysis of Linear Low‐Density Polyethylene

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