Hydrogen from the two-stage pyrolysis of bituminous coal/waste plastics mixtures

Kříž, V.; Bičáková, Olga

doi:10.1016/j.ijhydene.2011.03.136

Cited by 34 publications

(9 citation statements)

References 21 publications

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“…Calcium is, next to potassium the most common active metal found in biomass, but is far less effective. Alkali metals, heavy metals and other inorganic components are present in plastic waste, and may serve as catalysts for the degradation of biomass-plastic mixtures, as mentioned, but not yet thoroughly investigated, by different authors [24], [93], [98], [118], [120], [166], [167]. Plastics contain indeed small amounts of various inorganic elements, used as catalysts during polymerization processes.…”

Section: Catalysis In the Thermoconversion Of Plastic/biomass Wastementioning

confidence: 99%

Co-pyrogasification of Plastics and Biomass, a Review

Block¹,

Ephraim

Weiss-Hortala

et al. 2018

Waste Biomass Valor

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Over the past few decades, the sharp rise in post-consumer plastic and biomass waste has resulted in an ever growing challenge to treat such waste sustainably. Co-pyrogasification of plastics and biomass mixtures, as opposed to separately converting these waste streams, offers several advantages including an improvement in syngas quality and composition (H2/CO ratio) in relation to the desired application, and an easier reactor feeding of plastics. Furthermore, many studies have shown that co-pyrogasification promotes the conversion of waste to gas rather than char and tar. However, in order to achieve the desired product distribution or syngas composition, operating parameters such as the reactor temperature, equivalence ratio (air or oxygen), steam/fuel ratio and catalyst, have to be optimized. Thus, this paper aims to review literature studies on the co-pyrogasification of plastics and biomass by considering various aspects including the process principle, reactors, influence of feedstock characteristics and operating parameters on the products, as well as the synergies observed during the thermoconversion of plastics and biomass mixtures with some reference to coal mixtures when necessary.

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Section: Catalysis In the Thermoconversion Of Plastic/biomass Wastementioning

confidence: 99%

Co-pyrogasification of Plastics and Biomass, a Review

Block¹,

Ephraim

Weiss-Hortala

et al. 2018

Waste Biomass Valor

View full text Add to dashboard Cite

show abstract

“…Therefore, chemical interactions between plastics-and coal thermal decomposition intermediates, during pyrolysis, may have a positive impact on the yield and quality of the obtained products. In previous studies, the synergetic effect (increase of experimental yield in relation to theoretical yield) during coal and plastics co-pyrolysis was mainly monitored by the thermogravimetric analysis [37,38] or, on the other hand, investigations were focused on a certain target product (e.g., production of hydrogen [39], or semi-coke [36]). As for coal and hydrocarbon fuels, formulas for the calculation of the calorific value of plastic waste material and biomass plastic fuel were proposed [40,41].…”

Section: Introductionmentioning

confidence: 99%

Study of the Synergetic Effect of Co-Pyrolysis of Lignite and High-Density Polyethylene Aiming to Improve Utilization of Low-Rank Coal

et al. 2021

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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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“…These results differ from previous studies that showed an increase in produced gas from plastics as the pyrolysis temperature increased, , which could be due to the low reactor volume used in this study, limiting the produced volatiles’ exposure to higher temperatures and further cracking. Kříž and Bičáková found that the addition of mixed waste plastics (15 and 20% wt.) clearly increased the condensable product yield but had little effect on the amount of gas produced (between 11 and 13%) when using slow pyrolysis in a tubular reactor.…”

Section: Resultsmentioning

confidence: 99%

Slow Pyrolysis Products Derived from Extrudates Produced from Discard Coal Fines and Recycled Plastics as Binders

Marais,

Bunt,

Leokaoke

et al. 2024

ACS Omega

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The pyrolysis products derived from both coal and plastics have been extensively evaluated in literature; however, their copyrolysis product yields together with the characterization of the generated products have received less attention. Most studies use high heating rates with small particle sizes of the mechanically mixed blends. This study aims to improve the understanding of the slow copyrolysis behavior of extrudates produced from coal fines from the South African Highveld coalfield combined with recycled waste lowdensity polyethylene (LDPE) and polypropylene (PP). The fraction of plastic was varied between 10 and 100 wt % during extrusion. The extrudates (10 mm diameter) underwent slow pyrolysis in a modified Fischer assay setup by increasing the temperature (5 °C/min) under a nitrogen atmosphere to 520, 720, and 920 °C. The pyrolysis products (char, condensable products, water, and gas) were collected and characterized. The coal fines produced up to 83% char, whereas the plastics produced over 90% condensable products. The slow heating rate and the small reactor volume favored the production of condensable products, which increased with plastic concentration. The extrudates produced char and condensable product yields that fit the additive model of the raw materials. Statistical equations were developed to predict the pyrolysis yields and characteristics as functions of coal and plastic composition. The equations accurately predict the char yield, condensable product yield, fixed carbon content, ash content, sulfur content of chars, and carbon and hydrogen contents of chars and condensable products. Gas chromatography−mass spectrometry results indicate that the extrudates' condensable products consist mainly of alkanes and alkenes, similar to the plastics. Furthermore, the condensable products derived from PP and coal extrudates have fewer components with lower boiling points compared with the raw materials.

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Hydrogen from the two-stage pyrolysis of bituminous coal/waste plastics mixtures

Cited by 34 publications

References 21 publications

Co-pyrogasification of Plastics and Biomass, a Review

Co-pyrogasification of Plastics and Biomass, a Review

Study of the Synergetic Effect of Co-Pyrolysis of Lignite and High-Density Polyethylene Aiming to Improve Utilization of Low-Rank Coal

Slow Pyrolysis Products Derived from Extrudates Produced from Discard Coal Fines and Recycled Plastics as Binders

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