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Bakelite, a thermosetting plastic, has limited feasibility for thermal recycling processes such as pyrolysis, unlike thermoplastics, due to its inherent tendency to get charred upon heating and difficulty in being converted into valuable fuel and chemical compounds. In this study, the co‐pyrolysis of bakelite and poly methyl methacrylate is explored to improve the thermal degradation and thus recycling feasibility of bakelite by pyrolysis. The kinetics and thermodynamics of the co‐pyrolysis of blended samples are analyzed using different kinetics models. The thermal degradation experiments of the sample are conducted from ambient to 1000 °C at five various heating rates of 5, 10, 20, 30, and 50 °C/min in an inert N2 gas environment. The results showed that adding poly methyl methacrylate to bakelite changes the pyrolytic degradation temperature and weight loss trend. The kinetic analysis reveals that the thermal degradation at 220–345 °C follows an F2.5 order‐based model with an average activation energy of 181 kJ/mol, while the degradation at 345–475 °C follows an F2 order‐based model with an average activation energy of 318 kJ/mol. The enthalpy changes and free energy change associated with thermal degradation exhibit a positive trend while that of entropy change shows a negative trend. With blending the free energy change and entropy change decreased while enthalpy change increased. During batch pyrolysis at 450 °C, the PMMA‐Bakelite blend generates oil (49.17 %), wax (12.36 %), residue (15.36 %), and gas (23.11 %). According to FTIR and GC‐MS analyses, the pyrolytic oil produced by the co‐pyrolysis of the blended sample at 450 °C comprises 32.23 % saturated hydrocarbons (C9–40), 20.97 % unsaturated hydrocarbons (C6–24), and 46.80 % oxygenated material (C5–19). These findings can assist in the optimization of pyrolysis reactor design for the recycling of thermosetting plastics. [ABSTRACT FROM AUTHOR]

Phosphorus is an essential element of ecosystems, supporting the growth of plants and animals; however, its excessive presence in water can lead to eutrophication. In this study, the phosphate adsorbent SA2:8 Mg/Ca was prepared by loading calcium and magnesium onto sludge and almond shell. Various characterization methods were used to analyze biochar, and the phosphorus removal effect of SA2:8 Mg/Ca under different conditions was evaluated. The results showed that the phosphate removal rate of the adsorbent was more than 70% in the range of pH 4 ~ 12, and the adsorption performance was significantly affected by HCO3− and SO42−, though the removal rate remained over 50%. The adsorption process conforms to the pseudo-second-order model, and the isothermal adsorption model aligns more closely with the Langmuir model. Increased temperature was favorable for phosphate adsorption. The theoretical maximum adsorption capacity of SA2:8 Mg/Ca was 78.27 mg/g. Thermodynamic analysis confirmed that the adsorption process was spontaneous. The main mechanisms of adsorption include electrostatic interaction, ion exchange, Lewis acid–base interaction, and chemical precipitation. Additionally, the P-laden biochar exhibited excellent potential for application: it can be used as a catalyst to improve the efficiency of persulfate catalytic degradation of ofloxacin. The removal rate of OFX in water by the SA2:8 Mg/Ca-PS system was 81.4%. [ABSTRACT FROM AUTHOR]

Pyrolysis of waste furniture wood, mixed plastics and waste tyres was examined separately and in different combinations from the perspective of improved value products and energy production. The effect of different combinations of furniture wood, plastics and tyres on the product distribution during co-pyrolysis was analyzed. The experimental work throughout this study was performed at a temperature of 500 °C. Prior to the pyrolysis experiments, thermogravimetric analysis was done to assess the thermal degradation behavior of all selected feedstocks. During individual pyrolysis, mixed plastic wastes produced 70.6 wt% of pyrolysis liquid, which is 37.9% and 33.4% more than furniture wood and waste tyres. During co-pyrolysis, a binary blend of mixed plastics and waste tyres produced 63.3 wt% of pyrolysis liquid, which is 7.65% more than the logarithmic mean value, indicating a positive synergistic interaction on liquid production. The liquid yield of the ternary blend was observed to be as low as 54.4 wt% due to the lower volatiles present in the blend. The presence of volatiles in the feedstock is correlated with the production of liquids by individual and co-pyrolysis. For feed-flexible, more efficient, and cleaner operating systems, the increased liquid production offers crucial information. With the use of Fourier transform infrared spectroscopy (FT-IR) and gas chromatography/mass spectroscopy (GC–MS), the impact of different combinations on product characterization was investigated. The characterization study of the pyrolysis liquid obtained from mixed plastics showed the presence of different aromatic and aliphatic compounds. The findings offered viable options for efficiently utilizing waste materials, particularly plastics and tyres to improve the quality and substance of products. [ABSTRACT FROM AUTHOR]

A special biomass waste, Chinese herb residues (CHR) was considered to be disposed of by the (co-) pyrolysis and the steam gasification with anthracitic coal (AC) through TGA and horizontal tubular furnace reactor (HTFR) coupled with gas chromatography (GC). TGA results showed that the interaction effects between CHR and AC during co-pyrolysis were negligible at the low CHR blending ratio, but there existed an inhibiting effect at the high CHR blending ratio. Co-pyrolysis kinetics results showed that the activation energies rose with the reaction proceeding. The HTFR pyrolysis showed that, with the temperature growing, the contents of CO and H2 increased, but the content of CO2 and CH4 decreased. In the steam gasification tests, the main product in the syngas was H2, and the gasification performances were influenced by the temperature and steam flow rate. FTIR results showed that the absorption peaks of functional groups in the residues from the HTFR pyrolysis reduced with the temperature increasing. For the steam gasification of the 50CHR/50AC blend, the contents of CO and H2 increased obviously as compared to those from the gasification of CHR. The syngas yield of 50CHR/50AC increased with the gasification temperatures increasing, and the value was clearly higher than that from CHR. [ABSTRACT FROM AUTHOR]

In this study, the co-pyrolysis behavior of waste tobacco (WT) and polylactic acid (PLA) from heated tobacco products (HTPs) was investigated by TG, TG-FTIR, and Py-GC/MS in order to reveal the synergistic mechanism during the co-pyrolysis process from the perspective of pyrolytic kinetic parameters and product distribution. The addition of WT during the pyrolysis of PLA reduced the Tmax from 367.5 to 303.8−314.1°C, indicating a notable synergistic effect between PLA and WT during the co-pyrolysis process. Pyrolysis kinetic analysis also indicated the enhanced thermal activity of PLA as reflected by the reduced activation energy, especially when the proportion of WT was wt. 25%, the activation energy was reduced from 166.38 to 111.20 KJ/mol. Meanwhile, the decreased ∆G for the co-pyrolysis of PLA/WT may also indicate an enhanced reaction reactivity. The pyrolytic products detected by TG-FTIR showed that the addition of WT-promoted free radical reactions during the co-pyrolysis process as reflected by the reduction of CO and aldehyde. Py-GC/MS results indicated that for PLA/WT= 1:1, the yield of lactide increased threefold, indicating a significant synergistic effect. In summary, the co-pyrolysis of PLA and WT could effectively tap into residual value from discarded HTPs in resource recovery field and solve potential environmental pollution problems. [ABSTRACT FROM AUTHOR]

Rising concerns over water scarcity, driven by industrialization and urbanization, necessitate the need for innovative solutions for wastewater treatment. This study focuses on developing an eco‐friendly and cost‐effective biochar‐zeolite composite (BZC) adsorbent using waste materials—spent coffee ground biochar (CGB) and steel slag zeolite (SSZ). Initially, the biochar was prepared from spent coffee ground, and zeolite was prepared from steel slag; their co‐pyrolysis resulted in novel adsorbent material. Later, the physicochemical characteristics of the BZC were examined, which showed irregular structure and well‐defined pores. Dye removal studies were conducted, which indicate that BZC adsorption reach equilibrium in 2 h, exhibiting 95% removal efficiency compared to biochar (43.33%) and zeolite (74.58%). Moreover, the removal efficiencies of the novel BZC composite toward dyes methyl orange (MO) and crystal violet (CV) were found to be 97% and 99.53%, respectively. The kinetic studies performed with the dyes and phosphate with an adsorbent dosage of 0.5 g L−1 suggest a pseudo‐second‐order model. Additionally, the reusability study of BZC proves to be effective through multiple adsorption and regeneration cycles. Initially, the phosphate removal remains high but eventually decreases from 92% to 70% in the third regeneration cycle, highlighting the robustness of the BZC. In conclusion, this study introduces a promising, cost‐effective novel BZC adsorbent derived from waste materials as a sustainable solution for wastewater treatment. Emphasizing efficiency, reusability, and potential contributions to environmentally conscious water treatment, the findings highlight the composite's significance in addressing key challenges for the removal of toxic pollutants from the aqueous solutions. Practitioner Points: A novel biochar‐zeolite composite (BZC) material has been synthesized.Excellent removal of dyes by BZC (~95%) was achieved as compared to their counterpartsThe kinetic studies performed suggest a pseudo‐second‐order model.BZC proves to be highly effective for multiple adsorption studies.Excellent reusability showed potential as a robust adsorbent [ABSTRACT FROM AUTHOR]

This study explored the synergistic interaction of sewage sludge (SS) and distillation residue (DR) during co-pyrolysis for the optimized treatment of sewage sludge in cement kiln systems, utilizing thermogravimetric analysis (TGA) and thermogravimetric analysis with mass spectrometry (TGA-MS). The results reveal the coexisting synergistic and antagonistic effects in the co-pyrolysis of SS/DR. The synergistic effect arises from hydrogen free radicals in SS and catalytic components in ash fractions, while the antagonistic effect is mainly due to the melting of DR on the surface of SS particles during pyrolysis and the reaction of SS ash with alkali metals to form inert substances. SS/DR co-pyrolysis reduces the yielding of coke and gas while increasing tar production. This study will promote the reduction, recycling, and harmless treatment of hazardous solid waste. [ABSTRACT FROM AUTHOR]

• 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]

This study focused on investigating thermal degradation behaviors, kinetics, reaction mechanisms, synergistic effects, and thermodynamic parameters of wood sawdust (WSD), linear low-density polyethylene (LLDPE), and their blends (LW1:3, LW1:1, and LW3:1) during co-pyrolysis in a thermogravimetric analyzer (TGA). Thermal behavior exhibited a LW1:3 blend (25 wt.% LLDPE) showing significant mass loss at lower temperatures (150 to 300 °C) compared to the individual feedstocks, such as 150 to 400 °C and 300 to 520 °C for WSD and LLDPE, respectively. The iso-conversional methods (KAS, FWO, and FM) were used to determine the kinetic parameters (Ea and A), and the activation energy drop was highest for the LW1:3 blend. According to the master plots, the third-order reaction (O3), nucleation (P2/3), and diffusional model (D4) were the predominant reaction mechanisms for the co-pyrolysis of the LW1:3, LW1:1, and LW3:1 blend, respectively. The thermodynamic parameters demonstrate that a small amount of plastic addition into WSD can improve the reactivity of the blend, shorten the reaction time, and cause less energy-intensive reactions. The values of ΔH, ΔG, and ΔS also confirmed the co-pyrolysis process's spontaneity and endothermic nature. The Fourier transforms infrared spectrometer (FTIR) spectra of raw feedstock, blends, and their biochar revealed some of the peaks were shifted, the intensity was reduced, and disappearance can happen when the temperature was increased. Using the experimental and theoretical/predicted activation energies, the parity chart illustrates the synergistic effects of co-pyrolysis of different blends, and the LW1:3 blend has a favorable synergistic impact. These results could be helpful in process optimization and designing an effective reactor system for co-pyrolysis. [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]

The pyrolysis reactions of polyvinyl chloride(PVC) and rubber were corulucled in a tube furnace using ZSM-5, HZSM-5, and HY catalysts. Gas chromatography-mass speclrometiy (GC-MS) was employed to analyze the composition of the pyrolysis products. The results demon st rate significant changes in hydrocarbon components during co-py roly sis of PVC and rul)her, depending on their mixing ratio. Willi HZSM-5 catalyst, the yield of aromatics froin PVC-rubber co-pyrolysis reaches its max ini uni al 77. 37%. On the other hand, HY calalysl exhil)its superior conversion efficiency from monocyclic aromatic hydrocarbons to bicyclic aromatic hydrocarbons with a peak value at 56. 64%. Notably, when employing a 1: 1 • 1 ratio of HY calalysl in PVC-rubber co-pyro lysis, the proportion of polycyclic aromatic hydrocarl)ons (PAHs) can reach as high as 23. 43%. [ABSTRACT FROM AUTHOR]

The behavior of wheat straw biomass (WS), woody sawdust biomass (WB), and their blends during catalytic co-pyrolysis are analyzed in the presence of CaO catalyst, which is obtained from the calcination of mussel shells. Synergy analysis of blends and pure materials is measured by studying the difference between theoretical and experimental values of wt.%/min, (RL%), and (WL%), which correspond to maximum weight loss rate, residue left, and weight loss, respectively. The Coats–Redfern method is utilized for evaluating the thermo-kinetic properties. The chemical reaction order model F1 is the best model that describes the Ea of 60.05 kJ/mol and ∆H, ∆G, and ∆S values of 55.03 kJ/mol, 162.26 kJ/mol, and −0.18 kJ/mol.K, respectively, for the optimum blend 80WS−20WB, reducing the thermo-kinetic properties. Model D3 showed better results for the Ea, ∆H, ∆G, and ∆S for the 5% CaO blend, which certified the viability of co-pyrolysis of WS and WB, while DTG indicated that exothermic and endothermic reactions occur together. [ABSTRACT FROM AUTHOR]

In this paper, the non-isothermal co-pyrolysis of walnut shell (WS), Enteromorpha clathrata (EN), and their blends (WEB) was studied using a thermogravimetric analyzer (TGA). For all the samples, three different decomposition stages were identified by the thermogravimetric analysis. At the same temperature, the mass loss of WEB was always stable between the values of WS and EN. In addition, different heating rates resulted in different TG–DTG profiles. The interaction between WS and EN showed a gradual enhancement with temperature increase, and the most significant interaction was generated when the blending proportion of WS and EN was 7:3. The Kissinger–Akahira–Sunose (KAS), Flynn–Wall–Ozawa (FWO), and masterplots methods were used to determine the kinetic triplets. The results show that for different blending ratios, the effective activation energies of WS and EN co-pyrolysis vary from 86.21 to 247.86 kJ mol−1 when the conversion rate is 0.2–0.8. The most appropriate mechanism for the pyrolysis of 70WS30EN is g(α)=[-ln(1-α)]1/2 with kinetic parameters: apparent activation energy 86.21 kJ mol-1 and pre-exponential factor 8.99 × 1016 s−1. The findings in this paper provide a reference for further research on the co-pyrolysis of aquatic and terrestrial biomass. [ABSTRACT FROM AUTHOR]

The aim of present work is to evaluate pyrolysis characteristics of poly(methyl methacrylate) (PMMA) and its blends with sugarcane bagasse (SB) contents of 10 and 20 mass % for the purpose of exploring the effect of SB on pyrolysis of PMMA. Non-isothermal pyrolysis determinations of three PMMA samples were performed thermogravimetrically and the initial pyrolysis temperatures of two PMMA blends are significantly lower than that of pure PMMA while the main pyrolysis shifts to higher temperature range. Using model-free isoconversional methods, pyrolysis activation energies calculated are varying within 71.7 ~ 154.0, 107.8 ~ 192.0 and 121.3 ~ 171.0 kJ·mol−1 for PMMA and its 10 or 20 mass % SB blends, respectively. The added SB turns to increase the activation energy of PMMA and thus make pyrolysis of PMMA become more arduous to accomplish. With the model-fitting method, the order-based F2/3, F3 and F3 chemical reaction models are found to be the most appropriate pyrolysis mechanisms for PMMA and its 10 or 20 mass % SB blends, respectively. Accordingly, their pre-exponential factor values are estimated to separately span in the range of 3.23 × 104 ~ 1.76 × 1011, 3.52 × 108 ~ 7.63 × 1016 and 1.55 × 1010 ~ 1.13 × 1015 min−1. The findings acquired from present work can provide necessary information for performing potential pyrolysis designs of PMMA and its biomass blended wastes. [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]

As a common necessity, masks have been used a lot in recent years, and the comprehensive utilization of waste masks has become a research priority in the post-COVID-19 pandemic era. However, traditional disposal methods suffer from a range of problems, including poor utilization and insecurity. To explore new solution ideas and efficiently utilize waste resources, waste masks and biomass wastes were used as raw materials to prepare mask-based biochar (WMB), bio-oil, and pyrolytic gas via oxygen-limited co-pyrolysis in this study. The obtained solid–liquid–gas product was systematically characterized to analyze the physicochemical properties, and the adsorption properties and mechanisms of WMB on the environmental endocrine bisphenol A (BPA) were investigated. The co-pyrolysis mechanisms were also studied in depth. Furthermore, the strengths and weaknesses of products prepared by co-pyrolysis and co-hydrothermal synthesis were discussed in comparison. The results indicated that the waste masks could shape the microsphere structure, leading to richer surface functional groups and stable mesoporous of WMB. Here, the risk of leaching of secondary pollutants was not detected. The theoretical maximum adsorption of BPA by WMB was 28.73 mg·g−1. The Langmuir and Pseudo-second-order models optimally simulated the isothermal and kinetic adsorption processes, which are a composite of physicochemical adsorption. Simultaneous pyrolysis of mask polymers with biomass polymers produces bio-oil and pyrolytic gas, which is rich in high-quality aliphatic and aromatic compounds. This could have potential as an energy source or chemical feedstock. The co-pyrolysis mechanisms may involve the depolymerization of waste masks to produce hydrocarbons and H radicals, which in turn undergo multi-step cleavage and oligomerization reactions with biomass derivatives. It is recommended to use the co-pyrolysis method to dispose of waste masks, as the products obtained are significantly better than those obtained by the co-hydrothermal method. This work provides a new contribution to the resourcing of waste masks into high-quality products. [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]

Abstract Pyrolysis of waste furniture wood, mixed plastics and waste tyres was examined separately and in different combinations from the perspective of improved value products and energy production. The effect of different combinations of furniture wood, plastics and tyres on the product distribution during co-pyrolysis was analyzed. The experimental work throughout this study was performed at a temperature of 500 °C. Prior to the pyrolysis experiments, thermogravimetric analysis was done to assess the thermal degradation behavior of all selected feedstocks. During individual pyrolysis, mixed plastic wastes produced 70.6 wt% of pyrolysis liquid, which is 37.9% and 33.4% more than furniture wood and waste tyres. During co-pyrolysis, a binary blend of mixed plastics and waste tyres produced 63.3 wt% of pyrolysis liquid, which is 7.65% more than the logarithmic mean value, indicating a positive synergistic interaction on liquid production. The liquid yield of the ternary blend was observed to be as low as 54.4 wt% due to the lower volatiles present in the blend. The presence of volatiles in the feedstock is correlated with the production of liquids by individual and co-pyrolysis. For feed-flexible, more efficient, and cleaner operating systems, the increased liquid production offers crucial information. With the use of Fourier transform infrared spectroscopy (FT-IR) and gas chromatography/mass spectroscopy (GC–MS), the impact of different combinations on product characterization was investigated. The characterization study of the pyrolysis liquid obtained from mixed plastics showed the presence of different aromatic and aliphatic compounds. The findings offered viable options for efficiently utilizing waste materials, particularly plastics and tyres to improve the quality and substance of products.

Abstract 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. Graphical Abstract

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.

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.

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]

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]

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]

In this study, pyrolysis and co-pyrolysis of commonly used plastic materials (polyethylene terephthalate -- PET, high density polyethylene -- HDPE, and polystyrene -- PS) were conducted to analyse the chemical composition of the corresponding pyrolyzates. Different ratios of plastic materials were applied to obtain a composition of aliphatic and aromatic degradation products that closely resemble those of conventional fossil fuels. The systematic chemical variations can act as base for evaluating this approach as a sustainable source of alternative fuels. HDPE revealed an aliphatic composition of degradation products, while PS and PET produced only aromatic compounds. Quantitative analysis of the obtained pyrolyzates revealed a clear correlation of initial proportion with the resulting quantitative product composition. The generation of individual pyrolysis products gave a high reproducibility. However, it became evident that the decomposition products of PS consistently emerged as the most prominent among all tested HDPE/PS mixtures. The ratio of HDPE:PS = 1:3 showed 96 % of the aromatic compounds as PS decomposition products. PET revealed a oxygen containing structure of the products, contributing to 83 % of the HDPE:PET = 1:3 mixture. These results gain insights into the potential of plastic waste as a sustainable source for alternative fuels and valuable chemicals. [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]

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]

Plant available potassium (K) content is very low in K-bearing mineral ores present in Sri Lanka and that restrict their use in crop production as K fertilizer sources. Heating of minerals can increase their plant available forms of nutrients. The objective of this experiment was to study the effect of direct heating of K-bearing minerals at different temperatures and co-pyrolyis with poultry litter (PL) at different rates on their total and available K contents. Poultry litter was co-pyrolyzed with 0, 1 and 5% (w/w) of feldspar and mica at 350, 500, 650 and 900 ℃. K-bearing minerals were also directly heated at these temperatures. With direct heating the mineral, total K contents of feldspar (6.2%) and mica (4.5%) were significantly (p<0.001) increased by 10% and 18%, respectively at 500 ℃ and then decreased by 33 and 65%, respectively at 900 ℃. Available K contents in feldspar (0.05%) and in mica (0.03%) either decreased significantly (feldspar) or did not change (mica) upon direct heating. Increasing pyrolysis temperature up to 650 ℃ increased both total (4.2 to 6.4%), and available K (3.2 to 6.1%) contents in poultry litter biochar (PLB). Co-pyrolysis of PL with feldspar or mica at 1 or 5% rates did not improve the total or available K contents in PLB at these temperatures. We concluded that heat treatment of locally available feldspar and mica or co-pyrolyzing them with PL are not effective technologies to increase their utilization in agriculture. [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]

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]

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.

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.