Fast Pyrolysis Research Articles

Biomass fast pyrolysis kinetics using curie-point pyrolysis: Comparison with pyroprobe and thermogravimetric analysis

In this study, the kinetics of fast pyrolysis of pine wood biomass at short timescales is evaluated using analytical Curie-point and Pyroprobe® pyrolyzers. Curie-point pyrolysis was highly effective in ensuring that the biomass was heated to the set temperatures at very high heating rates and precise time scales. This is the first time the mass loss data of lignocellulosic biomass using a Curie-point pyrolyzer is being reported at short timescales of the order of 10−1 s. COMSOL Multiphysics® simulations, employed to determine the time required for the sample to heat-up to the final reaction temperature, proved that it was 0.2 s in the Curie-point pyrolyzer and 6–8 s in the Pyroprobe® reactor. Within a time period of 0.5 s for temperatures greater than 400 °C, complete conversion of the biomass was achieved using a Curie-point pyrolyzer. The conventional reaction kinetic models were not able to explain the pyrolysis behavior of the sample in a Curie-point pyrolyzer, especially at short timescales of 0–0.5 s. However, the kinetics until 0.4 s, corresponding to the release of light volatiles, is shown to follow the sigmoidal Avrami model, while the major devolatilization stage in the range of 0.4–0.5 s could not be described by a standard kinetic model. This showed that the reactions at short time scales are highly complex processes governed by the competing decomposition rates of the biomolecules. The isothermal mass loss experiments using the Pyroprobe® showed that pyrolysis followed first-order kinetics, and the rate of decomposition was slower as it took 10–20 s for the conversion to attain a steady value. The kinetic compensation for the pyrolysis of pinewood was constructed using the fast pyrolysis data and the kinetics of slow pyrolysis using isoconversional models, and it was found to be ln(A) = 0.18*Ea – 3.12.

Biomass source influence on hydrogen production through pyrolysis and in line oxidative steam reforming.

This study evaluates the potential of several biomasses differing in nature and composition for their valorization by pyrolysis and in-line oxidative steam reforming. The first task involved the fast pyrolysis of the biomasses in a conical spouted bed reactor at 500ºC, in which product yields were analyzed in detail. Then, the oxidative steam reforming of pyrolysis volatiles (gases and bio-oil) was approached in a fluidized bed reactor. The reforming experiments were performed at 600 ºC, with an steam/biomass (S/B) ratio of 3 and catalyst (Ni/Al2O3) space times of 7.5 and 20 gcat min gvol-1. Concerning equivalence ratio (ER), a value of 0.12 was selected to ensure autothermal operation. Remarkable differences were observed in H2 production depending on the type of biomass. Thus, pine wood led to a H2 production of 9.3 wt%. The lower productions obtained with rice husk (7.7 wt%) and orange peel (5.5 wt%) are associated with their higher ash and fixed carbon content, respectively, which limit the efficiency of biomass conversion to bio-oil. However, in the case of the microalga, the poor performance observed is due to the lower conversion in the reforming step toward gases due to the composition of its pyrolysis volatile stream.

Co-production of porous N-doped biochar and hydrogen-rich gas production from simultaneous pyrolysis-activation-nitrogen doping of biomass: Synergistic mechanism of KOH and NH3

In this study, a method of simultaneous activation and nitrogen doping during biomass fast pyrolysis for co-production of porous N-doped biochar and H2-rich gas production was proposed. The effect of temperature on chemical interaction mechanism of KOH and NH3 was investigated at 500–800 °C. Results showed that KOH and NH3 had a synergistic effect on pore development and nitrogen doping, and the specific surface area and nitrogen content reached maximum values of 2008.37 m2/g and 5.05 wt%, respectively. It may be due to that NH3 entered pores generating by KOH activation for further activation, and at the same time, excessive NH3 could convert new O-containing groups to N-containing groups for more effective nitrogen doping. What's more, the H2 concentration and yield were up to 56.67 vol% and 517.95 mL/g, respectively. It indicates that the synchronization method of fast pyrolysis-activation-nitrogen doping is a promising approach, which is of great significance for the high-value utilization of biomass.

Enhancement of selective monoaromatic hydrocarbon and syngas products from fast pyrolysis of cassava stalks over Co, Mo promoted Ni catalysts

Catalytic fast pyrolysis of cassava stalks has been intriguing as a promising, feasible chemical refinery method in terms of waste-to-energy conversion from cassava cultivation. This study aims to determine the synergetic influence of Mo and Co on Ni catalysts (Ni, Ni–Mo, and Ni–Co) prepared via ultrasonic-assisted incipient wetness impregnation method for catalytic pyrolysis vapor upgrading. The results indicated that Co and Mo enhance the reducibility of NiO and promote weak-to-medium acidity, thereby enhancing Ni's performance. Mono-Ni favors cracking deoxygenation, whereas oxophilicity promoters particularly enhance the oxygen absorbability efficiency to selective deoxygenated production. A fine Ni dispersion on CoNi/SiO2 catalyst was observed to positively affect the production of monoaromatic hydrocarbons (46.10 %), in contrast to those without promoters (21.63 %). This is attributed to an optimal Ni-metallic distribution with a small crystal size of 7.01 nm and a high surface area of 342.6 m2 g−1, highlighting the effectiveness of the promoter-assisted Ni catalyst. Additionally, a high yield of H2 (66.9 %) in non-condensable gas was recorded at 550 °C. The study suggests that a simplified approach to developing Ni-based catalysts could enhance the eco-friendliness of commercial catalysts, thereby facilitating the scale-up of biomass pyrolysis applications.

Microwave Effect in Hydrolysis of Levoglucosan with a Solid Acid Catalyst for Pyrolysis-Based Cellulose Saccharification.

Pyrolysis-based saccharification consisting of fast pyrolysis followed by hydrolysis of the resulting anhydrosugars such as levoglucosan is a promising method for converting cellulosic biomass into glucose that can be used for producing biofuels and biochemicals. In the present study, hydrolysis of levoglucosan was evaluated in water with a polystyrene sulfonic acid resin (a solid acid catalyst) by heating under microwave irradiation or in an oil bath at 95 °C-120 °C. When the equilibrium temperature of the solution was the same, the conversion rate of levoglucosan was greater under microwave irradiation than in an oil bath. Model experiments indicate that the sulfonyl groups of the solid acid catalyst were selectively heated by microwave irradiation. The temperature of the reaction solution in the vicinity of the catalyst was locally higher than the equilibrium temperature of the solution, which enabled hydrolysis to proceed efficiently.

Mechanism of phenols evolution during pyrolysis of Shendong coal macerals swelled with oxygen-containing organic solvents: Experimental and DFT study

Phenols are the important high value-added chemical product of coal tar, and exploring the release behavior of phenols is crucial for clarifying the coal pyrolysis mechanism and regulating the product distribution. The aim of this paper is to investigate the effects of swelling on the pyrolytic properties of de-ashed vitrinite (VD) and de-ashed inertinite (ID). VD and ID prepared by Shendong coal were characterized by 13C NMR, XPS and FTIR to explore physicochemical properties. Acetic acid (AA), ethanol (EA) and acetone (AT) were employed to prepare the swelled VD (VD-AA, VD-EA and VD-AT) and swelled ID (ID-AA, ID-EA and ID-AT). Kinetic analysis was carried out using thermogravimetry, the pyrolysis characteristics and distribution of pyrolysis products were analyzed by fast pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS) and fast pyrolysis fixed bed. Combining with density functional theory (DFT), the possible pyrolysis pathways of phenols generation were proposed. As a result, the macromolecular structures of VD and ID are constructed. TG and kinetic analysis exhibit that swelling promotes the pyrolysis of VD and ID, and the activation energy of the second stage is VD > VD-EA > VD-AT > VD-AA and ID > ID-EA > ID-AT > ID-AA, respectively. Py-GC/MS analysis exhibits that the selectivity of phenol, cresol, xylenol and catechol decreases to 17.53 % (VD-AA) and 12.18 % (ID-AT). By analyzing and comparing the distribution of the full component of Py-GC/MS, seven possible pathways of cresol generation are proposed. DFT calculation exhibits that Path 3 of VD-AT, which produces cresol via sequential decarboxylation, ether bond cleavage, decarbonylation, aliphatic side chain removal and dehydroxylation, demonstrates the lowest reaction energy of −148.38 kJ/mol.

Fast pyrolysis of biomass with diverse properties to produce liquid hydrogen storage molecules

Liquid organic hydrogen carriers (LOHCs), such as methanol and formic acid, offer a reliable solution for the challenges associated with transporting and storing gaseous hydrogen. However, the current industrial LOHCs are costly and in limited supply due to complex synthesis methods involving gasification and Fischer-Tropsch synthesis. An alternative approach utilizing efficient pyrolysis methods can convert biomass into substances that mimic LOHCs, making them a promising avenue for hydrogen storage. Compounds with a high hydrogen content, including glycolaldehyde, acetic acid, and acetol, hold potential as effective LOHCs. This study seeks to assess how the specific properties of biomass impact the resulting products and target molecules, focusing on identifying the primary sources of LOHC compounds. The experimental results indicate that glycolaldehyde primarily originates from cellulose, while acetic acid is mainly derived from hemicellulose. Acetol is produced from both cellulose and hemicellulose. At a pyrolysis temperature of 500 °C and a particle size of 0.38–0.83 mm, corn cob yields a higher quantity of glycolaldehyde, acetic acid, and acetol (107 mg/g) compared to rice husk (85.6 mg/g) and pine (68.9 mg/g) due to its significant cellulose and hemicellulose content. Notably, the primary sources of these hydrogen storage molecules during pyrolysis are the initial biomass pyrolysis products rather than secondary reactions.

Catalytic pyrolysis of lignin to aromatic hydrocarbons over Nb/Al oxide catalyst

Catalytic fast pyrolysis (CFP) of lignin aiming monocyclic aromatic hydrocarbons (MAHs) is attractive. Five metal oxide catalysts (named c-Nb3Alx) with different Nb/Al ratios, c-Nb, c-Al, c-Nb3Al1, c-Nb3Al2 and c-Nb3Al3 were synthesized and applied to CFP of lignin. Among these catalysts, c-Nb3Al2 exhibits excellent deoxygenation ability and the highest selectivity for MAHs (77.0 %). The selectivity and deoxygenation capacity of c-Nb3Al2 for MAHs were higher than H-ZSM-5 (25) as a control. It was attributed to the large external surface area (90 m2g-1), mesoporous structure (16.15 nm) and high acid amount (2.00 mmolNH3/gcat) of c-Nb3Al2. The c-Nb3Al2 has good stability and can be regenerated by simple calcination. The selectivity of the regenerated c-Nb3Al2 for MAHs was still high at 70.1 %. Guaiacol was used to compare the difference in the deoxygenation capacity of c-Nb3Al2 and H-ZSM-5.

Efficient production of activated carbon with well-developed pore structure based on fast pyrolysis-physical activation

As the most commonly used method for industrial activated carbon preparation, physical activation is usually accompanied by significant loss of raw materials, especially when the pore structure of activated carbon is well developed. This not only reduces yields, but also increases costs. To enhance both yield and pore structure of activated carbon, we proposed a facile and scalable method called "fast pyrolysis-physical activation". After fast pyrolysis, although the initial pore volume of the semi-coke decreases, the rapid release of volatiles promotes the increase of mesopore and macropore volumes and the development of micron-scale cracks, which is beneficial for CO2 mass transfer and reduces diffusion resistance. Therefore, compared to slow pyrolysis, the activated carbon produced through this method has a higher pore volume (increased by 25.9 %–30.0 %) and a larger SBET (increased by 26.7 %–38.3 %), while the yield remains almost unchanged. Consequently, due to the increase in pore volume and high yield of the activated carbon, the CO2 adsorption capacity (25 °C, 1 bar) of ACB-K700 increases from 2.02 mmol/g to 2.37 mmol/g compared to ACB-M700, and the total CO2 adsorption capacity of activated carbon prepared from the same mass of raw coal (1 g) increases from 1.07 mmol to 1.16 mmol. Due to the pre-formed pores inside the semi-coke, the gas activator molecules are able to penetrate deep into the particles, which not only reduces the ineffective etching that occurs on the surface, but also promotes the development of pore structure. In conclusion, this study provides a new pore development model for physical activation, and also provides a new method to produce activated carbon rapidly and massively, while the pore structure is well developed.

One-pot synthesis of Fe modified lignin biochar for ex-situ catalytic fast pyrolysis of enzymatic hydrolysis lignin to promote the generation of aromatic hydrocarbons

The utilization of waste lignin to produce bio-oil rich in aromatics aromatic hydrocarbons is promising and attractive for a wide range of applications. Fe-modified lignin biochar (xFe/ALC) prepared using a one-step method was utilized as catalysts to investigate their impact on product distribution, aromatic hydrocarbon generation, and pathways during ex-situ catalytic fast pyrolysis of enzymatic hydrolysis lignin. The results revealed that the addition of Fe enhanced the production of gas products such as H2, while decreasing bio-oil yield. The lowest bio-oil yield, at 12.10 wt%, was observed at a Fe loading of 25 wt%, however the relative content of aromatic hydrocarbons reached a maximum value of 16.24 area%. Compared to the pyrolysis of lignin alone, their contents increased by 2.46 times, with the content of monocyclic aromatic hydrocarbons (toluene, ethylbenzene, styrene, xylene) increasing by 1.5–3.8 times. Spent 25Fe/ALC had good stability on the production of aromatic hydrocarbons. Compared with non-catalytic pyrolysis of lignin, the aromatic hydrocarbons content for spent 25Fe/ALC after four cycles increased by 26.70%.

Indentification of coal-origin structural units by multi-step pyrolysis through Py-GC/MS and by DFT calculation

Most of the existing structural models of coal macromolecules are based on indirect characterization, which cannot reflect the real product structure of coal pyrolysis. This study focuses on the construction of the real structural units of de-ashed Shendong coal (RD) and its vitrinite (VD) and inertinite (ID). Two pyrolysis modes of fast pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS), Thermogravimetry (TG), Fourier transform infrared (FTIR) as well as rapid infrared heating (RIH) were used to obtain the pyrolysis properties and product composition distributions of each coal. A strategy for structural unit construction of coal, termed “Molecular Reorganization”, is introduced to ensure that the original structure of the coal can be reproduced. Macromolecules produced by multi-step pyrolysis in the low-temperature region were used to assemble the real structural units of coal. The pyrolysis pathways of the oxygenated compounds in the constructed molecular unit models of RD-C70H50O9N, ID-C101H62O13N2, and VD-C71H43O9N were analyzed by density functional theory (DFT). The results showed that the reaction energy for the pyrolysis of ID fragments to phenol was higher, with fragments 1 and 2 being −4212.98 kJ/mol and −2190.83 kJ/mol, respectively.

Product regulation and kinetics for fast pyrolysis of corncob over niobium oxide modified zeolite

Catalytic fast pyrolysis is considered as a promising technology for converting biomass into biofuels. In the present research, a series of NbOx modified ZSM-5 catalysts were developed and applied for the selective fast pyrolysis of corncob into aromatics. Depolymerization and hydrodeoxygenation of lignin constituents as well as the aromatization of polysaccharide fractions were the major source of aromatics. The introduction of niobium oxide into ZSM-5 remarkably enriched the Lewis acids and improved the porous structures. The presence of synergistic effect between acid sites and porous structure of NbOx modified ZSM-5 contributed to the aromatics formation in a certain degree. Under the catalysis of 3Nb/ZSM-5, the optimum aromatic content was 86.4 % at 450 °C with a heating rate of 104 °C/s. In the meantime, 3Nb/ZSM-5 presented good stability and recyclability in the fast pyrolysis of corncob, and over 75 % aromatics was achieved even after 3 cycles. Kinetical study revealed that the Ea value for corncob pyrolysis could be lowered to ∼ 250 kJ/mol with conversion rate range of 0.4–0.7.

Characteristics performance of adding coconut shell bio-oil to petroleum asphalt

Currently, there is considerable research on modified asphalt using bio-oil prepared by fast pyrolysis and hydrothermal liquefaction methods, but research on modified asphalt using bio-oil prepared by extraction method is scarce. In order to investigate the rationality and applicability of bio-oil produced by extraction method as a modifier added to petroleum asphalt, the coconut shell bio-oil modified asphalt was first prepared by blending the bio-oil at 2%, 3%, 4%, 5%, and 6% with petroleum asphalt. Their conventional performance was evaluated based on penetration, ductility, softening point and viscosity. Their rheological properties were obtained by dynamic shear rheometer, bending beam rheometer and multiple stress creep and recovery. The modification mechanism was analyzed by gel chromatography and Fourier transform infrared reflection. The results show that the bio-oil can significantly improve the low temperature performance and fatigue resistance of the asphalt, but it is not good for the high temperature performance and temperature-sensitive performance. The added bio-oil increases the content of light components and decreases the content of asphaltenes in the asphalt, and the modification of petroleum asphalt by the bio-oil is not only a physical mixing but also a chemical process. The bio-oil has good compatibility with the asphalt binder.

Study on the effect of oil shale ash on potassium retention characteristics during pyrolysis of corn stalk

In a multi-station fast pyrolysis reactor, the influence of oil shale ash on the potassium retention characteristics of corn stalk under different pyrolysis conditions was investigated in the study. The influence of oil shale ash on the potassium migration process during the pyrolysis of corn stalk was elucidated by analyzing changes in the composition and concentration of potassium and other minerals in the pyrolysis semi-coke of corn stalk. This analysis was conducted using inductively coupled plasma emission spectroscopy (ICP-AES), X-ray diffraction (XRD), and complemented by thermodynamic simulation. The findings demonstrate that oil shale ash could fix potassium in corn stalk, and the potassium retention rate peaked when the oil shale ash additive amount reached to 10 %. This is because the silica-aluminum compounds in the oil shale ash reacts with potassium salts in a semi-molten state to produce KAl2Si3AlO10(OH)2, KAlSi3O8, and KAlSi2O6.When the amount of oil shale ash added is increased to 15 %, KAlSi3O8 and KAlSi2O6 in the semi-coke would continue to react with Al2O3 and SiO2, converting to KAl2Si3AlO10(OH)2. Thermodynamic simulation results indicate that the alkali metal potassium in corn stalk semi-coke mainly existed in potassium metasilicate, potassium feldspar, and leucogranite. In order to enhance potassium fixation in corn stalk, the addition of oil shale ash would promote the transformation of potassium-solidifying minerals from potassium metasilicate to potassium feldspar and leucite in the semi-coke.

Oxy-hydrogen, solar and wind assisted hydrogen ([formula omitted]) recovery from municipal plastic waste (MPW) and saltwater electrolysis for better environmental systems and ocean cleanup

The pyrolysis of plastic waste and the electrolysis of saltwater is a promising route to carbon neutrality in ocean cleanup and plastic waste management. Therefore, a solar and wind assisted H2-fuelled fast pyrolysis of MPW (municipal plastic waste) and electrolysis of desalinated saline were developed. The combined system uses an oxy-hydrogen furnace for thermal decomposition of MPW feed, CO2 as an inert reaction medium and both solar and wind energy systems to operate the electrical units. The deionised H2O feed to the electrolyser cell was produced from saltwater using the recovered heat from the fast pyrolyser unit. The process CO2 was captured and reused for soil improvement as current waste-to-energy routes of MPW recycling emit 695,850 tonnes of CO2. 2.65 kg/hrH2 fuel in an O2 environment was utilised to meet the decomposer operating temperature and heat duty which is approximately 29 % of the produced H2. Instability associated with bio-oil was prevented by using fast pyrolysis which release more volatiles. Compared to the related studies, this investigated work achieved the highest gas and carbon yields. Thermal NO < 0.1 ppm was recorded. The developed system is expected to reach ≥70 % energy efficiency and a sales price of < $3.89/kgH2.

Upgrading Fast Pyrolysis Oil with Vacuum Gas Oil by Catalytic Hydrodeoxygenation in Supercritical Ethanol

Upgrading Fast Pyrolysis Oil with Vacuum Gas Oil by Catalytic Hydrodeoxygenation in Supercritical Ethanol

THE IMPORTANCE OF BIOETHANOL AS AN ENVIRONMENTALLY CLEAN FUEL

This article is a review based on literature sources. The production technology and areas of application of bioethanol, as well as ways to intensify the production of alcohol obtained from these natural sources, are analyzed. One such method is biomass liquefaction. Modern technologies for converting biomass into valuable biofuels were studied. Common biomass liquefaction technologies are indirect liquefaction and direct liquefaction. Direct biomass liquefaction involves converting biomass into bio-oil, and the main technologies are hydrolytic fermentation and thermodynamic liquefaction. Based on thermodynamic liquefaction, it can be divided into fast pyrolysis and hydrothermal liquefaction. In addition, this review provides an overview of the physicochemical properties of biodiesel and common methods for its processing. Keywords: bioethanol, yeast, natural food waste, purchasing biofuel.

Flame Spray Pyrolysis Synthesis of Ultra-Small High-Entropy Alloy-Supported Oxide Nanoparticles for CO2 Hydrogenation Catalysts.

The synthesis of high-entropy alloys (HEAs) with ultra-small particle sizes has long been a challenging task. The complex and time-consuming synthesis process hinders their practical application and widespread adoption. This study presents the novel synthesis of TiO2 nanoparticles loaded with a quinary high-entropy alloy through flame spray pyrolysis (FSP) for the first time. The extremely fast heating rate of flame combustion makes the precursor fast pyrolysis gasification, high temperature in the flame field promotes the metal vapor mixing uniformly, and the fast quenching process can reduce the particle aggregation sintering, the ultra-small particle size of HEA firmly attached to the TiO2 surface. The catalysts prepared via this gas-to-particle pathway exhibit excellent performance in CO2 hydrogenation, achieving a conversion rate of 62% at 450°C, and maintaining their activity for over 220h without significant particle agglomeration. This finding provides valuable insights for the future design of catalytically active materials with enhanced activity and long-term stability.

Conversion of beechwood organosolv lignin via fast pyrolysis and in situ catalytic upgrading towards aromatic and phenolic-rich bio-oil

Lignin, an abundant renewable biopolymer found in plant cell walls, is enriched in phenolic units within its complex molecular structure. Unlocking its potential as alternative feedstock in (bio)refining has posed a long-standing challenge, even though it holds immense promise for replacing fossil-derived phenolic and aromatic compounds. This study focuses on fast pyrolysis as effective thermochemical depolymerization method of lignin, coupled with the in situ catalytic upgrading aiming to produce valuable bio-oil enriched in dealkoxylated (alkyl)phenolic and aromatic compounds. Lignin was isolated via the organosolv process from beechwood sawdust (hardwood biomass). Various acidic aluminosilicate catalysts (e.g., zeolites, such as ZSM-5, Beta and USY, and amorphous silica alumina) were applied, having different Si/Al ratio, porous and acidic properties. Fast pyrolysis experiments were conducted on a fixed-bed bench-scale reactor at two distinct temperatures (500 and 600 °C), employing different contact times and lignin-to-catalyst ratios. Non-catalytic pyrolysis experiments revealed that higher temperature, significantly influences bio-oil’s composition and yield, resulting in the conversion of initially formed alkoxy-phenols to alkyl-phenolic compounds, reaching a 47% relative concentration at 600 °C, while also yielding high amount of bio-oil up to 43 wt%. Among the catalysts tested, zeolite ZSM-5 (Si/Al=40) proved to be the most efficient, shifting the chemical profile of bio-oil from phenolic to aromatic (mainly BTX) with relative concentration of 57%, owing to its unique microporous structure and acidity. Depending on the catalyst type, a balance between BTX monomer aromatics and naphthalenes was observed. Lignin, as well as the obtained products (bio-oil, non-condensable gases, char/coke-on-catalyst) were thoroughly characterized using various analytical techniques. The catalytic upgrading results were associated with the physicochemical properties of the catalysts, providing valuable insights into the underlying reaction mechanisms.

Product distribution and conversion mechanism of fossil-based biodegradable plastics during rapid pyrolysis

Fast pyrolysis has emerged as a promising technology for converting fossil-based biodegradable plastics (FBBPs) into clean energy and high-value products with rapid volume reduction and efficient utilisation. The degradation mechanism during pyrolysis is crucial, and different chemical structures and reaction processes directly affect the treatment efficiency and economic benefits. In this study, three typical FBBPs, including poly(butylene adipate-co-terephthalate) (PBAT), polybutylene succinate (PBS) and poly(epsilon-caprolactone) (PCL), have been analyzed in rapid pyrolysis experiments and corresponding products. Being pyrolyzed at 550℃, three kinds of FBBPs exhibited distinctly different decomposition behaviors and characteristics. These differences can be attributed to the bond-breaking ways and pyrolysis mechanisms, which enhance the value of products. Specifically, PBS exhibited the highest abundance of bio-oils and particulate matter (total 90.58%) compared to PBAT and PCL, mainly converted to ketones and acids with a homogeneous component distribution, which was likely to help facilitate further utilisation. In addition, the oxygen of PBS remained in the bio-oil fraction while showing high levels of CO in the bio-gas. Moreover, PCL had the highest amount of bio-gas (21.76%) among the three FBBPs, indicating that it was more likely to break into small molecule products. Notably, the broken chains or macro-molecules of PCL were primarily converted into esters, with di(but-2-en-1-yl) adipate accounting for 57.5% of bio-oils. This work elucidated the transformation pathways and mechanism of FBBP pyrolysis, providing guidance for the treatment and resource utilisation of FBBPs.