Search

• Co-pyrolysis Ea was ∼ 50 % lower than with waste textiles alone. • 3D diffusion explained co-pyrolysis devolatilization stages. • Co-pyrolysis increased hydrocarbon yield, lowered emissions. • Co-pyrolysis enhanced sugar and acid decomposition. • Co-pyrolysis char showed more fatty alkyls and branching. Co-pyrolysis is a promising technology for industrial organic waste to utilize their unique resource and energy properties for efficient conversion into valuable products. This study was the first time to characterize the co-pyrolysis of waste textiles with Ca-rich industrial sludge and Fe-rich industrial sludge on a laboratory-scale fixed bed. The properties, mechanisms, gas, oil and carbon production were investigated as a function of temperature and mixing type. Co-pyrolysis increased the total weight loss from 50.05 % to 69.81 % for Ca-rich industrial sludge mixed with 50 % waste textiles and from 49.13 % to 70.01 % for Fe-rich industrial sludge mixed with 50 % waste textiles. The activation energy of co-pyrolysis was approximately 50 % lower compared to the pyrolysis of waste textiles alone. The optimal reaction model for the different reaction stages for all samples was three diffusion (D3). Co-pyrolysis resulted in lower CO and CO 2 emission temperatures of about 25–110 °C and produced more short-chain organic compounds (C < 10). Co-pyrolysis produced more aldehydes and ketones organics. Moreover, co-pyrolysis char exhibited an elevated level of fatty alkyl side chains and bridge branching, as well as higher degrees of aromatization and stability. This study offers valuable insights into the potential application of pyrolysis for the management of Ca/Fe-rich industrial sludge and waste textiles, thereby serving as a basis for future utilization endeavors. [ABSTRACT FROM AUTHOR]

Low-cost and green preparation of efficient sorbents is critical to the removal of organic contaminants during water treatment. In this study, the co-pyrolysis of macroalgae and oyster shell was designed to synthesize nitrogen-doped porous biochars for sorption removal of atrazine from water. Oyster shell played a significant role in opening pores in macroalgae-derived biochars, resulting in the surface area of the macroalgae (Enteromorpha prolifera and Ulva lactuca) and oyster shell co-pyrolyzed carbonaceous as high as 1501.80 m2 g−1 and 1067.18 m2 g−1, the pore volume reached 1.04 cm3 g−1 and 0.93 cm3 g−1, and O/C decreased to 0.09 and 0.08, respectively. The sorption capacity of atrazine to nitrogen-doped porous biochars (the Enteromorpha prolifera, Ulva lactuca and oyster shell co-pyrolyzed carbonaceous) reached 312.06 mg g−1 and 340.52 mg g−1. Pore-filling, hydrogen bonding, π-π or p-π stacking and electrostatic interaction dominated the multilayer sorption process. Moreover, the nitrogen-doped porous biochars showed great performance in cyclic reusability, and the Enteromorpha prolifera, Ulva lactuca and oyster shell co-pyrolyzed carbonaceous sorption capacity still reached 246.13 mg g−1 and 255.97 mg g−1, respectively. Thus, this study suggested that it is feasible and efficient to remove organic contaminants with the nitrogen-doped porous biochars co-pyrolyzed from macroalgae and oyster shell, providing a potential green resource utilization of aquatic wastes for environmental remediation. Highlights: Nitrogen-doped porous biochars (NPBs) were derived from natural wastes. Oyster shell enhanced the micropore and mesopore structures of NPBs. Physical sorption dominated atrazine sorption onto the NPBs. [ABSTRACT FROM AUTHOR]

The co-pyrolysis of torrefied oiltea camellia shells (OCS) and reused polypropylene (PP) was investigated for pyrolysis oil, pyrolysis gas and carbon nanotubes (CNTs) distribution characters in a two-stage pyrolysis system. Compared with raw OCS/PP, the quality of pyrolysis oil from torrefied OCS and PP was upgraded while yield decreased gradually. In particular, torrefaction pretreatment was beneficial to the formation of aromatic hydrocarbons and the higher selectivity of phenols in pyrolysis oil. And serious N 2 torrefaction (260 N) and slight CO 2 torrefaction (200C) is more conducive to the synthesis of C6–C11 (gasoline component). In addition, torrefaction could contribute to lower volatiles, which resulted in a lower yield of CNTs. For comparison, higher graphitized CNTs was prepared from the co-pyrolysis of torrefied OCS and PP. Appropriate torrefaction temperature and atmosphere have a potential for high value conversion of pyrolysis oil, pyrolysis gas and CNTs from co-pyrolysis of biomass and plastics. [Display omitted] • Aromatic hydrocarbons and phenols were the main content obtained by torrefaction. • CO 2 torrefaction exhibited higher gas and lower bio-oil yield than N 2 torrefaction. • Production of liquid oil, CNTs and gas from torrefied biomass and plastics. • Strategies to facilitate biomass high value on products conversion were provided. [ABSTRACT FROM AUTHOR]

Thermo‐catalytic co‐pyrolysis of paulownia wood and polypropylene mixture were carried out in a fixed bed horizontal reactor system. The biochar obtained from pyrolysis of paulownia wood was activated by steam at 700°C. Activated biochar supported magnesium oxide, nickel oxide and cobalt oxide catalysts were prepared by incipient miosture impregnation and were used to upgrade the bio‐oil. Catalytic pyrolysis reduced the amount of bio‐oil compared with non‐catalytic pyrolysis (59.5% of bio‐oil). The results indicate that the production of aromatic compounds increased from 40.35% to 65.93, 62.12 and 61.56% using Ni, Co and Mg catalysts, respectively. For all three catalysts, the production of furan compounds decreased. It was found that bio‐char based catalysts are suitable for use in the co‐pyrolysis process to improvement the biofuel production. [ABSTRACT FROM AUTHOR]

Co-pyrolysis behaviors of peanut shells (PS) and tea plant branches (TPB) were explored with a focus on the physicochemical properties, thermal degradation behavior, synergistic effect, and thermo-kinetic analyses. The differences between individual biomass and the equivalent blend were also highlighted. Results showed that the blend sample showed an enhancement in fixed carbon content but a reduction in moisture and ash contents, when compared to those of the individual PS. The average activation energies (Ea) of the equivalent blend estimated by three isoconversional methods (i.e., Friedman, KAS, and Starink methods) were 181.65, 166.87, and 167.14 kJ/mol, respectively. The average Ea and ΔH of the blend were quite lower than those of the TPB but slightly higher than those of the PS. During pyrolysis, ΔH and ΔG exhibited positive values which showed the decomposition was endothermic and non-spontaneous. Negative ΔS values were first observed, followed by positive ΔS values at late conversion stage. [ABSTRACT FROM AUTHOR]

The co‐pyrolysis behavior of low‐grade coal with two different feedstocks (beeswax and petroleum wax) at different compositions (w/w) [(75:25), (50:50), (25:75)] is investigated by using a thermogravimetric (TG) analyzer under the non‐isothermal condition at a constant heating rate of 20°C/min from an ambient temperature to 900°C under nitrogen atmosphere. The kinetic and thermodynamic analysis for the thermal decomposition of the sample parameters was carried out by applying the model fitting Coats–Redfern method to the thermogravimetry data of different feedstocks. The activation energy of thermal degradation of coal is found to be 55.8 kJ/mole. A decrease in activation energy is observed by the addition of 25% and 50% waxes in the blended sample and the blended sample with 25% wax and 75% coal has the lowest activation energy. The activation energy for coal‐beeswax blend (75:25) is 35.718 KJ/mol, but it is 34.237 KJ/mol for coal‐petroleum wax blend (75:25). The value of ∆H decreases by the addition of waxes and follows the order (Coal: Feedstock) {(75:25) < (50:50) < (25:75)}, while that of value of ∆S increases by the addition of waxes and follows the order {(75:25) > (50:50) > (25:75)}. However, the value of ΔG does not significantly shift as the blend ratio of the feedstocks is altered. The addition of both feedstocks with the coal sample showed some degree of synergy. The result illustrates that the co‐pyrolysis of coal with wax be energy economical than individual pyrolysis and this study would give precious scope to design a more efficient conversion system. [ABSTRACT FROM AUTHOR]

In this study, the co-pyrolysis of sewage sludge (SS), two-component special municipal waste (SMW) and plastic waste (Plastic) was studied using thermogravimetric equipment and a scaled-up tubular reactor. During the experiments, the effects of the raw material composition and pyrolysis temperature on the decomposition processes, the product yields and compositions were investigated. It was found that co-pyrolysis was a series of complex reactions and resulted in more volatile and lower residue yield than the pyrolysis of the individual raw materials. In some cases (e.g., 25%SMW + 75%Plastic, 25%SS + 75%Plastic, 50%SS + 50%Plastic blends), it also caused a higher synthesis gas yield and H2/CO ratio. During the thermogravimetric analysis, the beneficial effects occurred at lower temperatures, but in the scaled-up experiments, these effects only prevailed at 900 °C as a result of the larger amount of raw materials and the worse heat transfer. The produced gases can be characterized by a lower heating value of 17.3–35 MJ/Nm3. Therefore, they can be used for energetic purposes; however, before chemical use, further quality improvement is needed due to the lower H2/CO ratios. [ABSTRACT FROM AUTHOR]

The disposal of municipal sewage sludge (MSS) from wastewater treatment plants poses a major environmental challenge due to the presence of inorganic and organic pollutants. Co-pyrolysis, in which MSS is thermally decomposed in combination with biomass feedstocks, has proven to be a promising method to immobilize inorganic pollutants, reduce the content of organic pollutants, reduce the toxicity of biochar and improve biochar's physical and chemical properties. This part of the review systematically examines the effects of various co-substrates on the physical and chemical properties of MSS biochar. This review also addresses the effects of the pyrolysis conditions (temperature and mixing ratio) on the content and stability of the emerging pollutants in biochar. Finally, this review summarizes the results of recent studies to provide an overview of the current status of the application of MSS biochar from pyrolysis and co-pyrolysis for the remediation of HM-contaminated soils. This includes consideration of the soil and heavy metal types, experimental conditions, and the efficiency of HM immobilization. This review provides a comprehensive analysis of the potential of MSS biochar for environmental sustainability and offers insights into future research directions for optimizing biochar applications in soil remediation. [ABSTRACT FROM AUTHOR]

In this study, the bagasse ash (BA) from biorefinery process was recovered and used as a catalyst in the co-pyrolysis of solid residue from second-generation bioethanol plant with high-density polyethylene (HDPE). The co-pyrolytic behaviors were studied using thermogravimetric analyzer at three heating rates of 10, 20, and 40 K min−1. The synergistic effects between BA and HDPE and their co-pyrolysis kinetics were investigated using two model-free methods: Kissinger–Akahira–Sunose (KAS) and Flynn–Wall–Ozawa (FWO). The pyrolysis products were determined by pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS) as well. The results indicated that the addition of BA could increase the production yield. The average apparent active energy (Ea) of co-pyrolysis was 171.3 kJ mol−1 from KAS and 174 kJ mol−1 from FWO, which were lower than that for catalyst-free pyrolysis (174.8 kJ mol−1 from KAS and 177.3 kJ mol−1 from FWO). The novel co-pyrolysis process showed great potential in improving both the economic and environment sides of the second-generation biorefineries. [ABSTRACT FROM AUTHOR]

Co-pyrolysis technology is considered to be one of the most promising methods for the sustainable utilization of biomass wastes, as it can realize waste reduction and convert wastes into high-value-added products with little impact on the environment. The evaluation of thermal characteristics and product properties is necessary for understanding this technique. In this paper, thermal characteristics and kinetic and thermodynamic analysis during the co-pyrolysis of mushroom residue (MR) with pine sawdust (PS) or wheat straw (WS) were investigated in a TGA. The carbon structure and surface textures of co-pyrolytic char were explored using Raman spectroscopy and a scanning electron microscope. As the PS or WS mass ratio increased, the devolatilization index increased obviously, indicating that volatile release was promoted and concentrated. Weak interactions were observed between 250 and 400 °C during the co-pyrolysis process, which primarily affected the mass transfer, resulting in a change in the thermal decomposition temperatures and rates. The interactions had no prominent influence on the volatiles' yields. The non-additive performance of average activation energies for the blends was observed due to the interactions, and the lowest average activation energy was obtained when the PS or WS mass ratio was 50%. The lower average pre-exponential factor of the blends indicated the reduced complicacy of the pyrolysis reaction. The relatively small deviation between the activation energy and enthalpy change (4.94–5.18 kJ·mol−1) signified the energy sensitivity of product formation. PS promoted the formation of small aromatic rings (<6 fused rings) in co-pyrolytic chars, whereas WS favored the production of larger rings (≥6 fused rings). The surface textures of the co-pyrolytic chars became porous, and the greater fractal dimensions of the surface morphology for the co-pyrolytic chars indicated that the char surface became irregular and rough. [ABSTRACT FROM AUTHOR]

Pyrolytic synergistic interactions, in which the production of pyrolyzates is enhanced or inhibited, commonly occur during the co-pyrolysis of different polymeric materials, such as plastics and biomass. Although these interactions can increase the yield of desired pyrolysis products under controlled degradation conditions, the desired compounds must be separated from complex pyrolyzates and further purified. To balance these dual effects, this study was aimed at examining pyrolytic synergistic interactions during slow heating co-pyrolysis of biodegradable plastics including polylactic acid (PLA) and poly(3-hydroxybutyrate-co-3-hydroxyhexaoate) (PHBH) and petroleum-based plastics including high-density polyethylene (HDPE), polypropylene (PP), and polystyrene (PS). Comprehensive investigations based on thermogravimetric analysis, pyrolysis–gas chromatography/mass spectrometry, and evolved gas analysis-mass spectrometry revealed that PLA and PHBH decompose at lower temperatures (273–378 °C) than HDPE, PP, and PS (386–499 °C), with each polymer undergoing independent decomposition without any pyrolytic interactions. Thus, the independent pyrolysis of biodegradable plastics, such as PLA and PHBH, with common plastics, such as HDPE, PP, and PS, can theoretically be realized through temperature control, enabling the selective recovery of their pyrolyzates in different temperature ranges. Thus, pyrolytic approaches can facilitate the treatment of mixed biodegradable and common plastics. [ABSTRACT FROM AUTHOR]

With the increasing production of municipal sewage sludge (MSS) worldwide, the development of efficient and sustainable strategies for its management is crucial. Pyrolysis of MSS offers several benefits, including volume reduction, pathogen elimination, and energy recovery through the production of biochar, syngas, and bio-oil. However, the process can be limited by the composition of the MSS, which can affect the quality of the biochar. Co-pyrolysis has emerged as a promising solution for the sustainable management of MSS, reducing the toxicity of biochar and improving its physical and chemical properties to expand its potential applications. This review discusses the status of MSS as a feedstock for biochar production. It describes the types and properties of various co-substrates grouped according to European biochar certification requirements, including those from forestry and wood processing, agriculture, food processing residues, recycling, anaerobic digestion, and other sources. In addition, the review addresses the optimization of co-pyrolysis conditions, including the type of furnace, mixing ratio of MSS and co-substrate, co-pyrolysis temperature, residence time, heating rate, type of inert gas, and flow rate. This overview shows the potential of different biomass types for the upgrading of MSS biochar and provides a basis for research into new co-substrates. This approach not only mitigates the environmental impact of MSS but also contributes to the wider goal of achieving a circular economy in MSS management. [ABSTRACT FROM AUTHOR]

Among carbon-based nanoparticles, graphene has garnered significant attention since its discovery as a carbon allotrope, owing to its unique two-dimensional structure and outstanding characteristics. In this research study, we present an environmentally friendly, cost-effective technique with the potential for mass production of valuable products such as graphene nanosheets. Graphene was derived from a mixture of wood sawdust and polyethylene–terephthalate bottles as the feedstock, along with a combination of sand and plant fertilizer that was modified by oxalic acid acting as a catalyst. The feedstock was successfully converted to graphite using a two-step fluidized-bed co-pyrolysis technology. Firstly, an experiment was conducted under a nitrogen atmosphere, subjecting the mixture to 500 °C for 30 min at a ramping rate of 5 °C/min, resulting in the synthesis of a black-charged residue. In the second step, graphite was obtained by subjecting the residue to 800 °C for 2 h at a ramping rate of 10°C/min, using the acid-modified catalyst in a nitrogen atmosphere. Finally, graphene nanosheets were produced from graphite through microwave-assisted liquid phase exfoliation. Due to the exceptional features of the synthesized graphene, it was used as an adsorbent for the removal of two organic dyes rhodamine B (RB) and malachite green (MG) from an aqueous solution. The effects of various factors on the adsorption capacity were studied in detail. The chemical structure and morphology of the synthesized samples were analyzed using advanced characterization techniques like XRD, FTIR, EDX, TGA, DTGA, and ZETA to determine the structure of graphene nanosheets and the degree of graphitization. The two models (Freundlich and Langmuir) were used to explain the experimental data obtained three different temperatures (298, 318, and 338 K) with a certain amount of graphene concentrate (0.04 g); the result showed the maximum adsorption capacity of RB and MG solution are 6.25 mg/g and 3 mg/g, respectively. The percentage of dye adsorbed for RB and Mg is 62.5 and 30%, respectively, in the optimum temperature 338 K, and optimum concentration for RB and MG is 25 and 12 ppm, respectively; as a result, the graphene considers as an ideal adsorbent (environmentally friendly and cost-effective) for removal of cationic types of dyes. [ABSTRACT FROM AUTHOR]

Sewage sludge has long been perceived as the bottleneck of wastewater treatment plants in China, restraining the healthy development of sewage treatment for decades. In recent years, pyrolysis as a promising multifunctional platform has attracted increasing interest for converting sludge into valuable resources. However, the generation and presence of pyrolysis tar, one of the key by-products during sludge pyrolysis, limit the wide application of pyrolysis product resources. The efficient and selective conversion of tar is complicated by the inherent complexity of sludge and various pollutants (e.g., N-, S-, and Cl-containing organic pollutants, heavy metals) in pyrolysis products, which may either migrate into tar or be released into the environment, complicating the in-depth treatment of tar and posing environmental risks. This review systematically examines the transformation and migration of tar and related secondary pollutants during sludge pyrolysis in order to optimize the pyrolysis process for resource recovery. We provide an overview of the research progress on tar generation, transformation, and secondary pollutants during pyrolysis; discuss potential control strategies for pollution abatement; and highlight the importance of understanding tar transformation during pyrolysis. Additionally, we offer insights into future development trends and research hotpots in this field. This review aims to deliver valuable information on the mechanism of tar formation, the conversion pathways of secondary pollutants, and corresponding control strategies, thus guiding the design and optimization of sludge pyrolysis processes to achieve higher efficiency and selectivity, with minimal environmental pollution. [ABSTRACT FROM AUTHOR]

A co-pyrolysis of woodchips and oil shale was conducted in a continuous reactor at 520 °C in a CO2 atmosphere. Experimental product yields were derived and an analysis of the liquid products was conducted, using gas chromatography, infrared spectroscopy, and physicochemical analysis. A maximum yield of liquids and gases was obtained as the share of biomass increased (43.9 and 35.1 wt%, respectively). Product characterization confirmed additive behavior in co-pyrolysis. The liquid products from copyrolysis blends exhibited fewer oxygenated compounds, derived from biomass, and fewer aromatic compounds, derived from oil shale. Co-pyrolysis liquids contained abundant aliphatic hydrocarbons (C6 to C11). [ABSTRACT FROM AUTHOR]

This work aimed to deeper insight into the interaction processes between lignin and holocellulose in lignocellulosic biomass. As a result, apricot shell lignin (ASL) and apricot shell holocellulose (ASH) were prepared. Subsequently, the thermal behaviors of apricot shell (AS), ASL, ASH, and ASL/ASH blends were determined by thermogravimetric analysis (TGA) using mass changes as a monitoring parameter. The activation energy was calculated by employing the model-free integral methodology, and the reaction models were estimated using Criado mater plots (hereinafter referred to as mater plots). Additionally, using the resulting activation energies, the changes of pre-exponential factor (A), enthalpy (ΔH), Gibbs free energy (ΔG), and entropy (ΔS) were determined. When the weight ratio of ASL to ASH was below ~ 1.1, the degradation of ASL and ASH begins to show synergistic effects. Extractives and volatiles in ASH endow a significant effect on improving the reaction dynamics in co-pyrolysis processes, which was evidenced through an increase in decomposition intensity. Samples differ in their primary reaction mechanisms upon small (α ≤ 0.5) and large (α ≥ 0.5) conversion rates. Furthermore, there was a linear positive correlation between the A value and activation energy. Thermal decomposition of AS, ASL, ASH, and ASL/ASH mixtures afforded positive ΔG and ΔH. [ABSTRACT FROM AUTHOR]

This study investigated the effects of different proportions of waste polyethylene (WP) and waste cooking oil (WCO) on the chemical and physical properties of the resulting co‐pyrolysis oil produced in an indigenously developed laboratory‐scale fixed bed batch‐type reactor. The proportion of WCO was altered in increments of 10% from 10% to 90%, and correspondingly, the proportion of WP was adjusted from 90% to 10% (by weight). The highest liquid fuel yield, reaching 70.9% by weight, was achieved using a 40:60 ratio of WCO to WP (W40P60) at a constant heating rate of 12°C and a temperature of 500°C. The obtained fuel exhibits promising properties, including a high calorific value (max HHV around 45.63 MJ/kg) and other advantageous properties such as low viscosity, low oxygen and nitrogen content, and absence of sulfur. Fourier‐transform infrared spectroscopy (FTIR) and gas chromatography–mass spectroscopy (GCMS) were examined on the resulting liquid fuel. The GC–MS spectra predominantly display alkanes, constituting approximately 41% by weight, and alkenes, making up roughly 20% by weight. These analyses revealed properties akin to commercial diesel, emphasizing the potential of waste cooking oil and waste polyethylene proportions in liquid diesel like fuel production. [ABSTRACT FROM AUTHOR]

A co-pyrolysis of woodchips and oil shale was conducted in a continuous reactor at 520 °C in a CO2 atmosphere. Experimental product yields were derived and an analysis of the liquid products was conducted, using gas chromatography, infrared spectroscopy, and physicochemical analysis. A maximum yield of liquids and gases was obtained as the share of biomass increased (43.9 and 35.1 wt%, respectively). Product characterization confirmed additive behavior in co-pyrolysis. The liquid products from co-pyrolysis blends exhibited fewer oxygenated compounds, derived from biomass, and fewer aromatic compounds, derived from oil shale. Co-pyrolysis liquids contained abundant aliphatic hydrocarbons (C6 to C11).

Abstract Pyrolytic synergistic interactions, in which the production of pyrolyzates is enhanced or inhibited, commonly occur during the co-pyrolysis of different polymeric materials, such as plastics and biomass. Although these interactions can increase the yield of desired pyrolysis products under controlled degradation conditions, the desired compounds must be separated from complex pyrolyzates and further purified. To balance these dual effects, this study was aimed at examining pyrolytic synergistic interactions during slow heating co-pyrolysis of biodegradable plastics including polylactic acid (PLA) and poly(3-hydroxybutyrate-co-3-hydroxyhexaoate) (PHBH) and petroleum-based plastics including high-density polyethylene (HDPE), polypropylene (PP), and polystyrene (PS). Comprehensive investigations based on thermogravimetric analysis, pyrolysis–gas chromatography/mass spectrometry, and evolved gas analysis-mass spectrometry revealed that PLA and PHBH decompose at lower temperatures (273–378 °C) than HDPE, PP, and PS (386–499 °C), with each polymer undergoing independent decomposition without any pyrolytic interactions. Thus, the independent pyrolysis of biodegradable plastics, such as PLA and PHBH, with common plastics, such as HDPE, PP, and PS, can theoretically be realized through temperature control, enabling the selective recovery of their pyrolyzates in different temperature ranges. Thus, pyrolytic approaches can facilitate the treatment of mixed biodegradable and common plastics.

This study investigated the interaction between the furfural residue and polyvinyl chloride co-pyrolysis using an infrared heating method. Various analytical techniques including production distribution analysis, thermal behavior, pyrolysis kinetic, simulated distillation and gas chromatography-mass spectrography (GCMS), and X-ray photoelectron spectroscopy were utilized to elucidate the pyrolysis characterization and reaction mechanism during the co-pyrolysis. Initially, the yield of co-pyrolysis oil increased from 35.12% at 5 °C·s−1 to 37.70% at 10 °C·s−1, but then decreased to 32.07% at 20 °C·s−1. Kinetic and thermodynamic parameters suggested non-spontaneous and endothermic behaviors. GCMS analysis revealed that aromatic hydrocarbons, especially mono- and bi-cyclic ones, are the predominant compounds in the oil due to the presence of H radicals in polyvinyl chloride, suggesting an enhancement in oil quality. Meanwhile, the fixed chlorine content increased to 65.11% after co-pyrolysis due to the interaction between inorganic salts in furfural residues and chlorine from polyvinyl chloride. [ABSTRACT FROM AUTHOR]

A carbon material Cu-corn straw-sludge biochar (Cu-CSBC) was prepared by hydrothermally modifying sewage sludge and corn stover. The composite coupled to ultrasound can effectively catalyze the activation of PS for organic pollutants degradation, and the removal rate of 20 mg/L TC reached 89.15% in 5 min in the presence of 0.5 g/L Cu-CSBC and 3 mM PS. The synergistic effect between the factors in the system, the reaction mechanism, and the efficient removal of TC in the aqueous environment were explored in a Cu-CSBC/US/PS system established for that purpose. Quenching experiments and electron paramagnetic resonance analysis both demonstrated the Cu-CSBC/US/PS system generated •OH, SO4–•, 1O2, and O2- •, which involved in the reaction. The Cu, carboxyl, and hydroxyl groups on the Cu-CSBC surface promoted the generation of radicals and non-radicals for the degradation process, which was dominated by both radical and non-radical pathways. The degradation pathway is proposed by measuring the intermediate products with LC-MS. Finally, the stability of the Cu-CSBC/US/PS system was tested under various reaction conditions. This study not only prepared a novel biochar composite material for the active degradation of organic pollutants by PS but also provided an effective method for the resource utilization of solid waste and sludge treatment. HIGHLIGHTS Cu-CSBC prepared from co-pyrolyzed biomass–sludge to activate PS.; US and Cu-CSBC have a positive synergistic effect on the system.; The TC removal efficiency of the Cu-CSBC/US/PS system exceeded 99%.; The US can promote the production of free radicals in the system.; The main intermediates and pathways of TC degradation were identified.;

Biomass has been suggested as a sustainable alternative to substitute fossil fuels. Based on the pyrolysis method, the biomass would be converted into energy through decomposition by thermal degradation under an inert atmosphere, resulting in charcoal, liquid, and gas products. The quality of oils is effectively enhanced through the pyrolysis of lignocellulosic biomass and plastic due to the facilitation of deoxygenation by plastics. This study investigates the impact of incorporating low-density polyethylene (LDPE) plastic in co-pyrolysis with sago dregs (SDs) waste. Pyrolysis of SDs and LDPE mixtures with ratios of 5:1, 4:2, 3:3, 2:4, and 1:5 at various temperatures of 375°C, 425°C, and 475°C. The maximum oil yield obtained for SDs and LDPE pyrolysis was 44.94%. The calorific value (CV) of all observed compositions is a minimum of 10,579.57 kcal kg-1 and a maximum of 11,545.21 kcal kg-1. The gas chromatography-mass spectroscopy (GC-MS) analysis confirmed the interaction between SDs and LDPE on co-pyrolysis. The addition of LDPE will produce rich aliphatic and aromatic compounds, like the proportions of alkanes (45.53%), alkenes (30.62%), alcohol (0.4%), and benzene (17.68%). Co-pyrolysis of SDs and LDPE promotes enhanced oil production by reducing oxygenated compounds and increasing hydrocarbon compounds.

Abstract Co-pyrolysis of chicken manure with tree bark was investigated to mitigate salinity and potentially toxic element (PTE) concentrations of chicken manure-derived biochar. The effect of tree bark addition (0, 25, 50, 75 and 100 wt%) on the biochar composition, surface functional groups, PTEs and polycyclic aromatic hydrocarbons (PAH) concentration in the biochar was evaluated. Biochar-induced toxicity was assessed using an in-house plant growth assay with Arabidopsis thaliana. This study shows that PTE concentrations can be controlled through co-pyrolysis. More than 50 wt% of tree bark must be added to chicken manure to reduce the concentrations below the European Biochar Certificate-AGRO (EBC-AGRO) threshold. However, the amount of PAH does not show a trend with tree bark addition. Furthermore, co-pyrolysis biochar promotes plant growth at different application concentrations, whereas pure application of 100 wt% tree bark or chicken manure biochar results in decreased growth compared to the reference. In addition, increased plant stress was observed for 100 wt% chicken manure biochar. These data indicate that co-pyrolysis of chicken manure and tree bark produces EBC-AGRO-compliant biochar with the potential to stimulate plant growth. Further studies need to assess the effect of these biochars in long-term growth experiments.

Leucaena leucocephala, an invasive toxic tree species, has threatened the survival of native plants in the Hengchun Peninsula, southern Taiwan. Due to the small-to-medium diameter, the utilization and processing of L. leucocephala is highly restricted, while its discarding accelerates carbon dioxide emission to the atmosphere. Biochar, produced from the pyrolysis of biomass under an inert atmosphere, is considered an effective carbon sequestration technique with high stability, which is important for long-term carbon storage and soil improvement. L. leucocephala biomass and montmorillonite were co-pyrolyzed under inert conditions, aiming to investigate the effects of different pyrolysis temperatures and montmorillonite blending ratios on biochar yield and carbon retention. Results showed improved biochar yield and carbon retention with increasing montmorillonite addition. Thermogravimetric analysis, nuclear magnetic resonance spectroscopy, and Fourier-transform infrared spectroscopy demonstrated enhanced stability of the modified biochars. The production of modified L. leucocephala biochar represents a promising technique for carbon dioxide sequestration and biochar stabilization, enabling the development of L. leucocephala utilization approaches.

The co-pyrolysis (at 300°C and 600°C) of municipal sewage sludge (SS) with zero-valent iron (Fe0: 1.5% and 3%) was investigated to reduce the toxicity of arsenic (As) and zinc (Zn) in SS. The BCR sequential extraction method, desorption kinetic analysis, and material characterization techniques (Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, X-ray diffraction) were used to evaluate the effects of the treatments on Zn and As behavior. The results showed that co-pyrolysis significantly reduced the acid-soluble fraction (18–43% for Zn; 83–95% for As) and mobility factor (45–85% for Zn; 86–96% for As) of Zn and As compared to untreated SS. Desorption experiments indicated a significant reduction in Zn and As release in treated samples, particularly in the co-pyrolysis sample at 600°C and Fe0 3% (67% for Zn; 88% for As) in comparison with untreated SS. Co-pyrolysis of Fe0 and SS led to the formation of new functional groups (Si–O, aromatic), a more porous surface morphology, and highly stable chemical crystals (ferric arsenate, zinc arsenide), which played a crucial role in Zn and As stabilization. The findings of this study suggest that co-pyrolysis is a promising approach for mitigating As and Zn toxicity in SS. However, additional field testing with plant-based systems is necessary for confirmation.

Co-pyrolysis of chicken manure with tree bark was investigated to mitigate salinity and potentially toxic element (PTE) concentrations of chicken manure-derived biochar. The effect of tree bark addition (0, 25, 50, 75 and 100 wt%) on the biochar composition, surface functional groups, PTEs and polycyclic aromatic hydrocarbons (PAH) concentration in the biochar was evaluated. Biochar-induced toxicity was assessed using an in-house plant growth assay with Arabidopsis thaliana. This study shows that PTE concentrations can be controlled through co-pyrolysis. More than 50 wt% of tree bark must be added to chicken manure to reduce the concentrations below the European Biochar Certificate-AGRO (EBC-AGRO) threshold. However, the amount of PAH does not show a trend with tree bark addition. Furthermore, co-pyrolysis biochar promotes plant growth at different application concentrations, whereas pure application of 100 wt% tree bark or chicken manure biochar results in decreased growth compared to the reference. In addition, increased plant stress was observed for 100 wt% chicken manure biochar. These data indicate that co-pyrolysis of chicken manure and tree bark produces EBC-AGRO-compliant biochar with the potential to stimulate plant growth. Further studies need to assess the effect of these biochars in long-term growth experiments. [ABSTRACT FROM AUTHOR]

Co-pyrolysis of palm kernel shell (PKS) with polypropylene (PP) was conducted in a fixed-bed reactor. The effects of pyrolysis temperature (400‒700 °C) and biomass:plastic ratio (0‒100%) on product quantity and quality as well as synergism during co-pyrolysis were investigated. Feedstock characterisation results showed that PKS and PP were able to produce sustainable liquid fuel and chemical. The highest bio-oil yield of 67.65 wt% was obtained at 600 °C and PKS:PP ratio of 25:75. A substantial amount of the desired compounds (60.12%) was obtained consisting of hydrocarbons (37.49%) and alcohols (22.23%). Positive synergistic effects on the production of hydrocarbons and esters, as well as the inhibition of acids and ketones, were prominent at 500 °C and PKS:PP ratio of 75:25. The plausible reaction mechanism for formation of major products was proposed. Co-pyrolysis of PKS and PP has generated bio-oil with a larger hydrogen and carbon content and lower oxygen composition compared to PKS bio-oil. Additionally, the resultant bio-oil has a slightly higher calorific value (47.74 MJ/kg) than the calorific value of commercial diesel fuels (46 MJ/kg), thus, offering an alternative for fuel applications. [ABSTRACT FROM AUTHOR]

In this work, the kinetics, thermodynamics, and mechanism for co-pyrolysis of thermoplastic (PP, HDPE, PS, PMMA) blended bakelite (BL) (1:1 by weight) are explored utilizing different kinetics models like model-fitting and KAS model-free method. The thermal degradation experiments of each sample are conducted from ambient to 1000 °C temperature at 5, 10, 20, 30, and 50 °C/min heating rates in an inert environment. Thermoplastic blended bakelite is degraded in four steps, including two significant weight loss steps. A significant synergetic effect was observed by the addition of thermoplastics, which is reflected in the change in the thermal degradation temperature zone and the weight loss pattern. Among the four thermoplastics blended bakelites, the promotional synergetic effect is more pronounced for PP addition, causing an increase in the degradation of discarded bakelite by 20%, whereas the addition of PS, HDPE, and PMMA enhances the degradation of bakelite by 10%, 8%, and 3% respectively. Again, the activation energy of the thermal degradation of PP blended bakelite is found lowest followed by HDPE blended bakelite, PMMA blended bakelite, and PS blended bakelite. The mechanism of thermal degradation of bakelite changed from F5 to F3, F3, F1, and F2.5 by the addition of PP, HDPE, PS, and PMMA respectively. A significant change in the thermodynamics of the reaction is also found in the addition of thermoplastics. The kinetics, degradation mechanism, and thermodynamics for thermal degradation of the thermoplastic blended bakelite contribute to the optimization of pyrolysis reactor design to increase valuable pyrolytic products. [ABSTRACT FROM AUTHOR]

This study explored the synergistic interaction of sewage sludge (SS) and automotive paint sludge (PS) during co-pyrolysis for the optimized treatment of sewage sludge in cement kiln systems, utilizing thermogravimetric analysis (TGA) and thermogravimetric-mass spectrometry (TGA-MS). The result reveals the coexisting synergistic and antagonistic effects in the co-pyrolysis of SS/PS. The synergistic effect arises from hydrogen free radicals in SS and catalytic components in PS, while the main source of the antagonistic effect is that, during the mechanical mixing process, the SS/PS is converted from the particulate form into a dough-like rubbery which contributes to the film-forming effect, hindering the volatilization of volatile components. SS/PS co-pyrolysis reduces the yielding of tar production while increasing coke and gas. This study will provide some in-depth insights into the co-pyrolysis of SS/PS, and offer theoretical support for the subsequent research on the collaborative disposal processes in cement kilns. [ABSTRACT FROM AUTHOR]

[Display omitted] • The release of Zn and Pb were mitigated by the synergistic effect. • Bioavailable fractions of HMs were reduced by SiO 2 and Al 2 O 3 from the sludge. • Bioavailable phosphorus was increased from 18.79 to 49.69 mg/g by co-pyrolysis. Phosphate tailings (PT) was used to reduce the release of heavy metals (HMs) during pyrolysis and the leachable rate of residual HMs, and simultaneously improve the bioavailability of phosphorus in the sludge-based biochar. The concentration of heavy metals and the fractions determined by BCR method was used to investigate the release and the transformation of Zn, Pb, Mn, Ni and Cu during pyrolysis involved with the effects of temperature and the addition of PT. The respective pyrolysis experiments shows that the release of Zn and Pb increases with temperature for both sewage sludge (SS) and PT, and the bioavailable fractions (F1 + F2) of Mn, Ni, and Cu increases with temperature for PT. During co-pyrolysis, blended samples released lower quantities of Zn and Pb and presented lower bioavailability of HMs than the individual SS or PT. A synergistic effect of co-pyrolysis was evident for volatile Zn and Pb. The decomposition of CaMg (CO 3) 2 from PT produced CaO, by which the volatile ZnCl 2 and PbCl 2 were transformed into ZnO and PbO with less volatility and higher reactivity with SiO 2 and Al 2 O 3 than the chlorides. Then SiO 2 and Al 2 O 3 from SS acted as the final stabilizer to immobilize the oxides. The final product combined with SiO 2 and Al 2 O 3 , such as ZnSiO 4 and ZnAl 2 O 4 , were detected. The addition of PT also introduced more Ca and P into sludge to produce biochar with higher concentration of apatite phosphorus with higher bioavailability. [ABSTRACT FROM AUTHOR]

The search of sustainable route for biofuel production from renewable biomass have garnered wide interest to seek for various routes without compromising the environment. Co-pyrolysis emerges as a promising thermochemical route that can improve the pyrolysis output from simultaneously processing more than two feedstocks in an inert atmosphere. This paper focuses on the kinetic modeling and neuro-evolution optimization in the application of catalytic co-pyrolysis of microalgae and plastic waste using HZSM-5 supported on limestone (HZSM-5/LS), in which co-pyrolysis of binary mixture of microalgae and plastic wastes (i.e. High-Density Polyethylene and Low-Density Polyethylene) was investigated over different heating rates. The results have shown a positive synergistic effect between the microalgae and polyethylene in which the apparent activation energies values have reduced significantly (-20 kJ/mol) compared to that obtained by pyrolysis of individual microalgae component. The kinetic models reflect that the mixture of microalgae and Low-Density Polyethylene for use as co-pyrolysis feedstock requires activation energy that is 23% and 13% lower compared to that required by pure microalgae and the mixture of microalgae and High-Density Polyethylene, respectively. The Progressive Depth Swarm-Evolution (PDSE) was used for neural architecture search, which subsequently provided optimal reaction condition at 873 K can achieve 99.6 % of degradation rate using a tri-combination of LDPE (0.13 %) + HDPE (0.77 %) + MA (0.11 %) in the presence of HZSM-5/LS catalyst. [ABSTRACT FROM AUTHOR]

Pyrolysis behaviors of polypropylene (PP), low-density polyethylene (LDPE), and their mixtures are investigated by Thermal Gravimetric Analysis (TGA) under varying heating rates to research the co-pyrolysis kinetic and synergistic effect. Model-free methods (Flynn-Wall-Ozawa method, Kissinger-Akahira-Sunose method, and Starink method) and model-fitting techniques (Malek method, Coats-Redfern method) were utilized to determine key kinetic parameters. The average activation energy are 224.69–225.19 kJ/mol for PP, 186–188.5 kJ/mol for LDPE, 195.64–197.48 kJ/mol for PP/LDPE composites. Model-fitting analysis was employed to elucidate the thermal pyrolysis mechanisms. For PP and LDPE, the A3/2 mechanism was found to be the governing pathway, whereas the PP/LDPE blends exhibited the A1 mechanism. Subsequently, compensation effect equations were derived to elucidate the synergistic interactions between PP and LDPE during co-pyrolysis process. The co-pyrolysis of PP and LDPE mixtures exhibit a lower pyrolysis temperature compared to the individual materials. Furthermore, the activation energy and pre-exponential factor results indicate a promotion effect in the early stage and an inhibiting effect in the later stage of the pyrolysis process. [ABSTRACT FROM AUTHOR]

This paper summarizes the utilization status of low-rank coal and biomass resources in China, expounds the synergistic effect mechanism of coal and biomass co-pyrolysis, systematically summarizes the effects of heating rate, pyrolysis temperature, biomass type, mixing ratio, reactor type, carrier gas flow rate and pyrolysis atmosphere on the synergistic effect in the process of coal and biomass co-pyrolysis, and analyzes and looks forward to the development direction and research direction of coal and biomass co-pyrolysis technolog y・ The co-pyrolysis of coal and biomass can combine the advantages of pyrolysis alone and exert a synergistic effect in the pyrolysis process to improve the yield and quality of pyrolysis products・ It can also alleviate the problems of low■:rank coal and biomass burning in large quantities polluting the environment and low energy utilization. Therefore, many scholars at home and abroad have explored the synergistic effect mechanism of co-pyrolysis and the influence of different factors on the synergistic effect from different angles and methods, so as to help the clean utilization of low-rank coal and the efficient utilization of biomass resources. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Science & Biotechnology is the property of Journal of Food Science & Biotechnology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Engineering for Thermal Energy & Power / Reneng Dongli Gongcheng is the property of Journal of Engineering for Thermal Energy & Power and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study utilized a thermogravimetric analyzer to assess the thermal decomposition behaviors and kinetics properties of vacuum residue (VR) and low-density polyethylene (LDPE) polymers. The kinetic parameters were calculated using the Friedman technique. To demonstrate the interactive effects between LDPE and VR during the co-pyrolysis process, the disparity in mass loss and mass loss rate between the experimental and calculated values was computed. The co-pyrolysis curves obtained through estimation and experimentation exhibited significant deviations, which were influenced by temperature and mixing ratio. A negative synergistic interaction was observed between LDPE and VR, although this inhibitory effect could be mitigated or eliminated by reducing the LDPE ratio in the mixture and increasing the co-pyrolysis temperature. The co-pyrolysis process resulted in a reduction in carbon residue, which could be attributed to the interaction between LDPE and the heavy fractions, particularly resin and asphaltene, present in VR. These findings align with the pyrolysis behaviors exhibited by the four VR fractions. Furthermore, it was observed that the co-pyrolysis process exhibited lower activation energy as the VR ratio increased, indicating a continuous enhancement in the reactivity of the mixed samples during co-pyrolysis. [ABSTRACT FROM AUTHOR]

The recycling of plastic packaging wastes helps to alleviate the problems of white pollution and resource shortage. It is very necessary to develop high-value conversion technologies for plastic packaging wastes. To our knowledge, carbon materials with excellent properties have been widely used in energy storage, adsorption, water treatment, aerospace and functional packaging, and so on. Waste plastic packaging and biomass materials are excellent precursor materials of carbon materials due to their rich sources and high carbon content. Thus, the conversion from waste plastic packaging and biomass materials to carbon materials attracts much attention. However, closely related reviews are lacking up to now. In this work, the pyrolysis routes of the pyrolysis of plastic packaging wastes and biomass materials for conversion to high-value carbons and the influence factors were analyzed. Additionally, the applications of these obtained carbons were summarized. Furthermore, the limitations of the current pyrolysis technology are put forward and the research prospects are forecasted. Therefore, this review can provide a useful reference and guide for the research on the pyrolysis of plastic packaging wastes and biomass materials and the conversion to high-value carbon. [ABSTRACT FROM AUTHOR]

The essential objective of this work was to co‐pyrolyze a binary mixture of date and cherry seeds in a fixed‐bed reactor. The experimental variables influencing the output of products, such as the pyrolysis temperature, pyrolysis duration, particle size, and heating rate, were optimized. The maximum liquid fraction yield (55.55 % with a bio‐oil yield of 29.70 %) was attained at 500 °C for 60 min at a heating rate of 40 °C min−1 and a particle size of 0.25 mm. The Fourier transform infrared and gas chromatography‐mass spectrometry results revealed that the bio‐oil was predominantly composed of oxygenated hydrocarbons, primarily higher acids (52.05 %), esters (23.67 %), and phenols (13 %). Biochar was converted into activated carbon, which possessed a Brunaer‐Emmett‐Teller surface area of 1055.55 m2g−1. The amorphous structure of this carbon was confirmed by field emission‐scanning electron microscopy and X‐ray diffraction measurements. [ABSTRACT FROM AUTHOR]

The municipal sludge in mountainous cities and the sludge was co-pyrolyzed with agricultural and forestry wastes including rice stalk, rice husk, eucalyptus brand and eucalyptus leaf.The effects of co-pyrolysis on the physicochemical properties and Cu (II) adsorption properties of biochar were investigated, and the synergistic effect of co-pyrolysis on Cu (II) adsorption properties was discussed.The results showed that compared with sludge biochar, the C contents of biochar derived from co-pyrolysis of sludge with rice husk, rice stalk, eucalyptus branch and eucalyptus leaf were increased by 0.64 times, 0.87 times, 1.04 times and 1.22 times, respectively; the O contents were increased by 1.11 times, 1.25 times, 2.01 times and 2.17 times, respectively; the maximum adsorption capacities of Cu (II) were enhanced by 28.4%,60.3%,82.7% and 99.7%,respectively.Co-pyrolysis had a significant synergistic effect on the adsorption capacity of Cu (II) on biochar, and the synergistic value of the maximum Cu (II) adsorption capacity of biochar derived from co-pyrolysis of sludge with eucalyptus leaf was the highest (90.13%). [ABSTRACT FROM AUTHOR]

The disposal of waste generated by the COVID-19 pandemic is still a challenge to the government in most countries. The present study shines its light on the catalytic effect of metal oxide on converting COVID-19 waste i.e. used face masks into valuable products through co-pyrolysis. The co-pyrolysis trial was carried out for a mixture of waste face mask (WFM) and Moringa oleifera (MO) biomass at a constant temperature of 450°C for 15 min of resident time. This investigation focuses on studying the catalytic effect of calcium oxide (CaO) on the by-products of the pyrolysis process. From the FT-IR studies, it is observed that the CaO catalyst assisted to reduce oxygen as well as sulphur and carboxylic acids in the bio-oil due to its strong basic nature. The FE-SEM images suggest the increase in porous structure with catalytic pyrolysis (CP) char compared to non-catalytic pyrolysis (NCP) char. The catalytic activity of CaO increased the alcoholic content with a reduction in aldehydes and ketones in the bio-oil. The addition of WFM to the biomass with CaO catalyst pyrolysis (CP) delivered a higher oil yield of 52% compared to non-catalytic pyrolysis (NCP). [ABSTRACT FROM AUTHOR]

This study investigates the effects of varying temperatures on the co-pyrolysis of wood sawdust (WS) and waste tires (WT) within a stainless steel fixed-bed reactor under a nitrogen atmosphere. The experiments were conducted at three different temperatures: 400 °C, 500 °C, and 600 °C, focusing on the thermal behavior and resultant product yields. At 600 °C, WS produced the highest oil yield (63.6 wt%), suggesting a tendency to generate more aqueous and volatile components. Conversely, WT alone showed an optimal oil yield of 46.4 wt% at 500 °C, while the WS-WT blend achieved 55.6 wt%. Gas chromatography-mass spectrometry (GC-MS) analyses of the pyrolytic oils indicated that WS-heavy mixtures were rich in aliphatic compounds, whereas WT-dominant samples had increased aromatic and phenolic contents, demonstrating the potential for creating valuable chemicals from waste. Additionally, gas analysis highlighted significant variations in syngas composition, with increased methane and decreased CO2 levels at higher temperatures, emphasizing the role of the water-gas shift reaction. These findings underscore the critical importance of temperature control in optimizing the efficiency and quality of products from co-pyrolysis, presenting a viable method for enhancing the value derived from waste materials.

Bakelite, a thermosetting plastic, is harder to recycle as compared to than thermoplastic polymers through thermal method due to its inherent property to harden on application of heat. This study co-pyrolyzes waste bakelite with polypropylene (PP), high-density polyethylene (HDPE), polystyrene (PS), and polymethyl methacrylate (PMMA) in a conventional semi-batch pyrolysis reactor and microwave pyrolysis reactor to determine how the reactor type and thermoplastic blending affect product distribution, yield, and composition of condensable fraction. The blending of thermoplastics and pyrolysis reactor types greatly affects product distribution. Bakelite, on pyrolysis, produces 39.12 wt% condensable product, which increased to 45.42 wt%, 58.76 wt%, 61.53 wt%, and 66.76 wt% in conventional pyrolysis and 49.87 wt%, 61.26 wt%, 66.51 wt%, and 72.88 wt% in microwave pyrolysis by blending HDPE, PP, PMMA, and PS respectively. The composition analysis through Gas chromatography-mass spectrometry and Fourier-transformed infrared spectroscopy confirms the formation of alkanes, cycloalkanes, alkenes, cycloalkenes, aromatics, and oxygenated compounds, from both pyrolysis processes. However, their percentage differ significantly in both processes. Microwave-assisted pyrolysis with activated carbon yields superior oil in both quantity and composition compared to conventional pyrolysis, effectively transforming waste plastics into valuable products.

The present study uncovered the effect of pyrolysis temperature (400, 500, 600, and 700 °C), and biomass-to-plastic ratio (100:0, 25:75, 50:50, 75:25, 0:100) on the product distribution and synergistic effect during co-pyrolysis of palm kernel shell (PKS) and medical bottle (MB). The highest bio-oil yield of 65.93 wt% was attained at 500 °C and PKS:MB ratio of 25:75. To determine the synergistic effect, the product distributions (yield and chemical composition) were compared with those obtained from pyrolysis of individual components. The positive synergistic effect on the production of hydrocarbons and inhibition of acids were most dominant at PKS:MB ratio of 75:25. The presence of PKS-derived oxygen radicals and hydrogen abstraction from MB can accelerate the formation of hydrocarbons via secondary cracking and deoxygenation reaction. The produced oil at PKS:MB ratio of 50:50 showed better characteristics compared to PKS-derived oil which contains higher carbon (45 % higher), and hydrogen content (66 % higher), and lower oxygen content (71 % lower).