The pyrolysis of oak with polyethylene, polypropylene and polystyrene using fixed bed and stirred reactors and TGA instrument

Abbas-Abadi, Mehrdad Seifali; Geem, Kevin Van; Fathi, Maryam; Bazgir, Hossein; Ghadiri, Mohammad

doi:10.1016/j.energy.2021.121085

Cited by 44 publications

(11 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous studies on oak pyrolysis have reported that the addition of PE leads to a decrease in the total content of phenols, aldehydes, ketones, and furans while increasing the percentage of hydrocarbons, which aligns with the findings of this study. However, those studies have not thoroughly elucidated the effects of process operating conditions [ 35 ]. Additionally, incorporating HDPE in the co-pyrolysis of biomass has increased the formation of furans, acids, and methyl or propenyl phenols through dehydration and hydrodeoxygenation reactions.…”

Section: Resultsmentioning

confidence: 99%

Synergistic Effects and Mechanistic Insights into the Co-Hydropyrolysis of Chilean Oak and Polyethylene: Unlocking the Potential of Biomass–Plastic Valorisation

2023

View full text Add to dashboard Cite

This study employed a hydrogen atmosphere in an analytical reactor to investigate the thermochemical transformation of Chilean Oak (ChO) and polyethylene. Thermogravimetric assays and compositional analyses of the evolved gaseous chemicals provided valuable insights regarding the synergistic effects during the co-hydropyrolysis of biomass and plastics. A systematic experimental design approach assessed the contributions of different variables, revealing the significant influence of the biomass/plastic ratio and hydrogen pressure. Analysis of the gas phase composition showed that co-hydropyrolysis with LDPE resulted in lower levels of alcohols, ketones, phenols, and oxygenated compounds. ChO exhibited an average oxygenated compound content of 70.13%, while LDPE and HDPE had 5.9% and 1.4%, respectively. Experimental assays under specific conditions reduced ketones and phenols to 2–3%. Including a hydrogen atmosphere during co-hydropyrolysis contributes to enhanced reaction kinetics and reduced formation of oxygenated compounds, indicating its beneficial role in improving reactions and diminishing the production of undesired by-products. Synergistic effects were observed, with reductions of up to 350% for HDPE and 200% for LDPE compared to the expected values, achieving higher synergistic coefficients with HDPE. The proposed reaction mechanism provides a comprehensive understanding of the simultaneous decomposition of biomass and polyethylene polymer chains, forming valuable bio-oil products and demonstrating the how the hydrogen atmosphere modulates and influences the reaction pathways and product distribution. For this reason, the co-hydropyrolysis of biomass–plastic blends is a technique with great potential to achieve lower levels of oxygenated compounds, which should be further explored in subsequent studies to address scalability and efficiency at pilot and industrial levels.

show abstract

Section: Resultsmentioning

confidence: 99%

Synergistic Effects and Mechanistic Insights into the Co-Hydropyrolysis of Chilean Oak and Polyethylene: Unlocking the Potential of Biomass–Plastic Valorisation

2023

View full text Add to dashboard Cite

show abstract

“…Plastic also can act as a binder, sticking waste or biomass particles together [16,60]. Pyrolysis of polymers in the presence of porous sorbents results in clogging and coking of pores [61]. A melting polymer can fill the macropores in the wood [62], and with a large proportion of plastic, particle encapsulation occurs [63].…”

Section: Organic Matter Melting and Decompositionmentioning

confidence: 99%

Particle Agglomeration of Biomass and Plastic Waste during Their Thermochemical Fixed-Bed Conversion

Donskoy

2023

Energies

View full text Add to dashboard Cite

The article provides state-of-the-art research on agglomeration processes during fixed-bed combustion and gasification of low-grade fuels such as biomass and waste (primarily plastic-containing waste). Such fuels demonstrate complex thermal behaviour: their decomposition and combustion are multistage, accompanied by phase transitions, and may lead to fixed-bed mechanical instability and the non-uniformity of air distribution over the cross-section. To clarify the role of physicochemical factors (fuel composition and properties, reactor conditions), data from different sources are compared. The review shows that the fixed-bed agglomeration regimes can, in a rough approximation, be classified by the sintering mechanism (due to the melting of the mineral part or the organic part), with the following search for each mechanism realisation conditions by comparing the fuel properties and characteristic temperatures. Attempts to theoretically describe and numerically simulate the agglomeration phenomenon as a change in the structure of a reacting dispersed medium are also considered: the main directions in which such approaches can be developed are indicated.

show abstract

“…First, many of the available kinetic models for pyrolysis are validated against the experimental data, such as TGA (Thermo Gravimetric Analysis) performed at relatively low temperatures. Usually, the maximum temperature of TGA experiments is 800 • C [29,95,96,[107][108][109]) while gasification is usually done in the range of 700-1000 • C [20]. This obviously decreases the reliability of the model, especially because at high temperatures alternative chemistry can become important for both pyrolysis and gasification [110].…”

Section: Coupling Of Available Kinetic Modelsmentioning

confidence: 99%

Multi-Scale Modeling of Plastic Waste Gasification: Opportunities and Challenges

et al. 2022

Self Cite

View full text Add to dashboard Cite

Among the different thermo-chemical recycling routes for plastic waste valorization, gasification is one of the most promising, converting plastic waste into syngas (H2+CO) and energy in the presence of an oxygen-rich gas. Plastic waste gasification is associated with many different complexities due to the multi-scale nature of the process, the feedstock complexity (mixed polyolefins with different contaminations), intricate reaction mechanisms, plastic properties (melting behavior and molecular weight distribution), and complex transport phenomena in a multi-phase flow system. Hence, creating a reliable model calls for an extensive understanding of the phenomena at all scales, and more advanced modeling approaches than those applied today are required. Indeed, modeling of plastic waste gasification (PWG) is still in its infancy today. Our review paper shows that the thermophysical properties are rarely properly defined. Challenges in this regard together with possible methodologies to decently define these properties have been elaborated. The complexities regarding the kinetic modeling of gasification are numerous, compared to, e.g., plastic waste pyrolysis, or coal and biomass gasification, which are elaborated in this work along with the possible solutions to overcome them. Moreover, transport limitations and phase transformations, which affect the apparent kinetics of the process, are not usually considered, while it is demonstrated in this review that they are crucial in the robust prediction of the outcome. Hence, possible approaches in implementing available models to consider these limitations are suggested. Finally, the reactor-scale phenomena of PWG, which are more intricate than the similar processes—due to the presence of molten plastic—are usually simplified to the gas-solid systems, which can result in unreliable modeling frameworks. In this regard, an opportunity lies in the increased computational power that helps improve the model’s precision and allows us to include those complexities within the multi-scale PWG modeling. Using the more accurate modeling methodologies in combination with multi-scale modeling approaches will, in a decade, allow us to perform a rigorous optimization of the PWG process, improve existing and develop new gasifiers, and avoid fouling issues caused by tar.

show abstract

The pyrolysis of oak with polyethylene, polypropylene and polystyrene using fixed bed and stirred reactors and TGA instrument

Cited by 44 publications

References 52 publications

Synergistic Effects and Mechanistic Insights into the Co-Hydropyrolysis of Chilean Oak and Polyethylene: Unlocking the Potential of Biomass–Plastic Valorisation

Synergistic Effects and Mechanistic Insights into the Co-Hydropyrolysis of Chilean Oak and Polyethylene: Unlocking the Potential of Biomass–Plastic Valorisation

Particle Agglomeration of Biomass and Plastic Waste during Their Thermochemical Fixed-Bed Conversion

Multi-Scale Modeling of Plastic Waste Gasification: Opportunities and Challenges

Contact Info

Product

Resources

About