Co-pyrolysis Of Polystyrene Research Articles

Optimization and prediction of thermodynamic parameters in co-pyrolysis of banana peel and waste plastics using AIC model and ANN modeling

The optimization and prediction of thermodynamic parameters including synergistic effects, and kinetic analysis in co-pyrolysis of banana peel (BP) and waste polystyrene (PS) plastic at different heating rates using ANN and AIC models has been performed. Thermogravimetric analysis was performed to determine the initial, maximum, and final degradation temperatures. The synergistic effect was studied using additive formula to determine the theoretical thermal behavior and compared with experimental TGA data. Kinetic parameters were determined by using the advanced isoconversional (AIC) model for estimation of activation energy (Eα), Criado master plot for reaction mechanism (f(α)), and compensation method for frequency factor (Aα). The analysis showed that the average activation energy values were 182.5, 140.6, and 161.8 kJ mol−1 for PS, BP, and PS+BP, respectively. It also clearly shows positive synergy in co-pyrolysis of PS and BP by reducing 11.3 % activation energy compared to that of PS alone. The frequency factor was found to be 1.0 × 1014, 1.0 × 1015, and 1.0 × 1023 s−1 for PS, BP, and PS+BP, respectively. The reaction mechanism was identified as R3, D4, and D4+R3 for PS, BP, and PS+BP, respectively. Further, the obtained kinetic parameters were used to determine the thermodynamic parameters such as enthalpy (ΔH), Gibbs energy (ΔG), and Entropy (ΔS). Finally, ANN was designed to address the co-pyrolysis behavior subjected to various heating rates. Subsequently, the trained ANN model (5 × 4×4 × 4) was employed to forecast thermal degradation behavior. Impressively, the model yielded highly accurate results with a correlation coefficient R2 > 0.998 in each case. The optimized model was further used to predict TGA data and activation energy for unknown mixtures of PS and BP. The suggested ANN model showed a great advantage in optimizing to avoid extensive experiments at various heating rates to achieve the goal.

Exploring sustainable fuel production through thermal behavior analysis using TGA and artificial neural network in the co-pyrolysis of polystyrene and coconut sawmill residue

This study employs Thermogravimetric Analysis (TGA) to explore co-pyrolysis potential using polystyrene (PS) and coconut sawmill residue (CSR) for liquid fuel production. Two distinct degradation stages are observed in CSR-PS blends, mirroring pure CSR samples: the initial phase (200-400°C) decomposes biomass components, while the second stage (400-550°C) targets the synthetic polymer PS within CSR-PS blends. Analyzing thermal degradation parameters reveals insights. 100% PS exhibits the highest weight loss and activation energy, highlighting PS's formidable decomposition. Conversely, 100% CSR shows the lowest weight loss and activation energy due to its organic composition. Artificial Neural Network (ANN) modeling indicates varying correlation accuracies for different blend compositions. Surprisingly, 100% PS exhibits lower correlation accuracy in predicting weight loss compared to the 80% PS blend, which achieves a perfect correlation. Conversely, 100% CSR, with simpler decomposition, has the lowest correlation accuracy. These findings illuminate the complex thermal behavior of CSR-PS blends, emphasizing the distinct degradation characteristics of PS and CSR. Implications extend to material applications and disposal strategies, emphasizing tailored approaches based on blend compositions and thermal profiles. This research advances co-pyrolysis as a sustainable avenue for liquid fuel production, providing insights for future research and practical applications.

Improving the Quality of Bio-oil Using the Interaction of Plastics and Biomass through Copyrolysis Coupled with Nonthermal Plasma Processing.

Bio-oil produced from the pyrolysis of biomass is chemically complex, viscous, highly acidic, and highly oxygenated. Copyrolysis of biomass and plastics can enhance oil quality by raising the H/C ratio, leading to improved biofuel properties. In this work, copyrolysis of polystyrene and biomass was passed to a second-stage dielectric barrier discharge nonthermal plasma reactor with the aim to further improve the product bio-oil. Pyrolysis of the polystyrene and biomass produces volatiles that pass to the second stage to undergo cracking and autohydrogenation reactions under nonthermal plasma conditions. There was a synergistic interaction between biomass and polystyrene in terms of overall oil and gas yield and composition even in the absence of the nonthermal plasma. However, the introduction of the nonthermal plasma produced a marked increase in monocyclic aromatic hydrocarbons (e.g., ethylbenzene), whereas polycyclic aromatic compounds decreased in concentration. Most notably, the influence of the plasma markedly reduced the quantity of oxygenated compounds in the product oil. It is suggested that the unique reactive environment produced by the plasma involving high-energy electrons, excited radicals, ions, and intermediates increases the interaction of the polystyrene and biomass pyrolysis volatiles. Increasing input plasma power from 50 to 70 W further enhanced the effects of the nonthermal plasma.

Activated char from the co-pyrolysis of polystyrene and olive stone mixtures for the adsorption of CO2

Yogurt plastic containers made of polystyrene (PS), olive stone, and mixtures of both have been converted into activated carbon materials transforming them firstly into char via pyrolysis and secondly with activation using either KOH or H2SO4. The pyrolysis of the olive stone gave a higher yield of material than the plastic PS. However, the activation of the PS char with KOH was more effective, reaching surface areas of 508 vs 194 m2 g−1 of the corresponding prepared with olive stone. The prepared materials were tested as CO2 adsorbent in thermobalance and fixed-be column assays. The materials activated with H2SO4 slightly enhanced the adsorption ability of the original char but were far from the performance obtained with KOH activation. The CO2 isotherms showed high synergy of CO2 uptake and selectivity when using activated chars prepared with the char from the mixture of raw materials, specially at a 1:1 mass ratio. The isosteric heat of adsorption values were those expected for a physisorption process. Further experiments in a fixed-bed column were also studied at atmospheric pressure at different inlet CO2 concentrations (10–50%). The CO2 retention increased as the partial CO2 pressure rose. Besides, a very similar performance of the material prepared with plastic and olive stones was obtained at 50%, i.e. 220 and 197 mg g−1 respectively. At low CO2 concentrations, the materials enriched with plastic displayed better performance than those prepared with olive stone. Cycles of adsorption-desorption were carried out in the column to assess the stability of the materials. The curves obtained did not display any substantial change, demonstrating the lack of adsorption retention.

Quantifying the sources of synergistic effects in co-pyrolysis of pinewood and polystyrene

Co-processing of biomass and plastic wastes via pyrolysis and gasification for feed-flexibility revealed the presence of synergistic enhancement of H2 and syngas yield and lowering of char and tar yields. However, an understanding of the source of these interactions and their quantification is lacking. To address this, we investigated the co-pyrolysis of pinewood (PW) and polystyrene (PS) blends at 900 °C using uniquely arranged sample-loading configurations in a fixed-bed reactor with online product gas and energy consumption analysis. Quantification of interactions such as volatiles-volatiles, volatiles-feedstock, and volatiles-char interactions in comparison with weighted results from individual pyrolysis of PW and PS provided deconvoluted information on the synergistic effects. Volatiles-volatiles interaction accounted for a 33% increase in H2, while PS volatiles-PW intermediates interaction accounted for 17% increase, and inhibitive PW volatiles-PS intermediates interaction led to 8% decrease. This deconvolution also revealed another 20% increase associated with the evenly mixed co-pyrolysis of PW and PS that was not accounted for from the volatiles-feedstocks interaction. The co-pyrolysis of PS with PW char also revealed the catalytic activity of PW char on plastics decomposition which was found to be restricted by the capacity of PS melt to block the char’s active sites during their direct contact. Cracking of PS volatiles on these catalytic active sites led to the increased yields of CH4 and H2. These results provide quantified insight into the sources of interaction between biomass and plastics to enhance synergy, develop component compatibility, and gain prediction capability for sustainable and feed-flexible gasifier development.

Catalytic co-pyrolysis of biomass and waste plastics as a route to upgraded bio-oil

A two-stage reactor system consisting of co-pyrolysis of biomass and plastic in the 1st stage and catalytic upgrading (zeolite ZSM-5 catalyst) of the derived pyrolysis gases in the 2nd stage was used to investigate the yield and composition of the product gases and bio-oil. Biomass waste wood and waste plastics in the form of high density polyethylene, low density polyethylene, polypropylene, polystyrene and polyethylene terephthalate were used as feedstock. The addition of the plastics to the biomass with co-pyrolysis-catalysis, produced a higher CnHm gas yield compared with what would be expected by calculation, suggesting some interaction of the biomass and plastic. The presence of waste plastic resulted in a decrease in the relative proportion of oxygenated compounds in the product oil compared to pyrolysis of biomass alone; for example a reduction of >65% for biomass with polyethylene and polypropylene and >95% reduction for biomass with polystyrene. The fuel properties of the co-pyrolysis upgraded oil were improved compared to biomass alone; for example, the co-pyrolysis of polystyrene and biomass showed an improved relative proportion of compounds in the C5 ― C12 fuel range (76%). In terms of the ratio of biomass to plastic, even low quantities of plastic (9:1 biomass:plastic ratio) produced a lower relative proportion of oxygenated bio-oil compounds, for example biomass:polystyrene at a ratio of 9:1 reduced the relative proportion of oxygenated compounds in the product bio-oil by >55%.

Co-pyrolysis of Mixed Plastics and Cellulose: An Interaction Study by Py-GC×GC/MS

Understanding of the interaction between cellulose and various plastics is crucial for designing waste-to-energy processes. In this work, co-pyrolysis of polystyrene (PS) and cellulose was performed in a Py-GC×GC/MS system at 450–600 °C with ratios 70:30, 50:50, and 30:70. Polypropylene (PP), polyethylene (PE), and polyethylene terephthalate (PET) were then added to the mixture with different ratios. It was found that co-pyrolysis of PS and cellulose promotes the formation of aromatic products with a large increase in the yield of ethylbenzene as compared to the calculated value from individual feedstock. This indicates interactions between cellulose and PS pyrolysis products. Observations from experiments including more than one type of plastics indicate that the interactions between different plastics are more pronounced than the interaction between plastics and cellulose.