Pyrolysis Of Algae Research Articles

Influence of different pyrolysis temperatures on chemical composition and graphite-like structure of biochar produced from biomass of green microalgae Chlorella sp

There is a great demand for environmentally friendly carbon materials as an alternative to fossil raw materials in industrial production. Microalgae biomass can be a valuable renewable source for the production of biochar. The study examined the effect of the pyrolysis temperature on the chemical composition, morphological features and the degree of order of the carbon structure of biochar based on green microalgae – Chlorella sp. Thermochemical conversion was carried out at 400÷900 °C in a CO2 atmosphere. The obtained biochar material had a porous structure. It was found that as the temperature increased, the biochar yield decreased from 38.4 to 21.9 wt%, while its aromaticity and stability, determined by the H/C molar ratio, increased. Based on the results of FTIR and Raman spectroscopy, it was evidenced that the biochar produced at 400÷500 °C was distinguished by the presence of functional groups and double bonds (i.e. –NH2, C–O, CC, CN, NO) as well as a high degree of order in the carbon structure (ID/IG=0.2). As the temperature increases, the amorphous nature of biochar began to develop. This study could provide data for the proper selection of temperature for pyrolysis of green algae to obtain biochar with the desired graphite-like structure and properties.

Comparison of Antioxidants to Increase the Oxidation Stability of Pyrolysis Oils of Three Plastics Using Iodine Value

Pyrolysis is an excellent method for recovering mixed and contaminated plastics that are no longer recyclable. Special attention must be paid to the stability of the fuel to avoid the formation of undesirable products. This can be achieved by additives such as antioxidants. In this study, high-density polyethylene, polypropylene, and polystyrene plastic waste are slowly pyrolyzed to a maximum of 470 degrees Celsius. A gasoline fraction (0–190 °C) and a diesel fraction (190–320 °C) are then obtained from these. Three antioxidants are added to these fractions: pyrocatechol, phenol, and freshly produced algal pyrolysis oil; the latter is described in the literature as containing particularly high levels of antioxidants. The oxidation stability of these mixtures and the change in the iodine number over time are measured using a newer method than the commonly used method of Wijs. Phenol improves the oxidation stability best, followed successively by algae pyrolysis oil and pyrocatechol. The oxidation stability of the gasoline fraction of the polypropylene pyrolysis oil with phenol is 49% higher than that of the same fraction without antioxidants.

Fabrication of carbon black nanoparticles from green algae and sugarcane bagasse

There are several industrial uses for carbon black (CB), an extremely fine powdered form of elemental carbon that is made up of coalesced particle aggregates and almost spherical colloidal particles. Most carbon black is produced from petroleum-derived feedstock, so there is a need to find an alternative method to produce CB, which relies on renewable resources such as algae and agricultural waste. A process involving hydrolysis, carbonization, and pyrolysis of green algae and sugarcane bagasse was developed, as the optimal hydrolysis conditions (16N sulfuric acid, 70 °C, 1 h, 1:30 g/ml GA or SC to sulfuric acid ratio), a hydrolysis ratio of 62% for SC and 85% for GA were achieved. The acidic solution was carbonized using a water bath, and the solid carbon was then further pyrolyzed at 900 °C. The obtained carbon black has a high carbon content of about 90% which is confirmed by EDX, XRD, and XPS analysis. By comparison carbon black from sugar cane bagasse (CBB) and carbon black from green algae Ulva lactuca (CBG) with commercial carbon black (CCB) it showed the same morphology which was confirmed by SEM analysis. The BET data, showed the high specific surface area of prepared CB, which was 605 (m2/g) for CBB and 424 (m2/g) for CBG compared with commercial carbon black (CBB) was 50 (m2/g), also the mean pore diameter of CBB, CBG and CCB indicated that CBB and CBG were rich in micropores, but CCB was rich in mesoporous according to IUPAC classification. This study might have created a technique that can be used to make carbon black from different kinds of biomass.

Catalytic pyrolysis of lignocellulosic and algal biomass using NaOH as a catalyst

AbstractIn this work, the pyrolysis of barley straw (BS) and brown algae (BA) mixed with NaOH as a catalyst was compared. Four different catalyst‐to‐biomass mass ratios (i.e., 6:100, 8:100, 10:100, and 12:100) and five pyrolysis heating rates were examined. The kinetic parameters (e.g., the activation energy and pre‐exponential factor) were evaluated using the Friedman method and kinetic models. For noncatalytic pyrolysis, the average activation energies for BS and BA samples were 139.71 and 183.19 kJ mol−1, respectively. However, the addition of catalyst generally increased the average activation energy of BS samples but decreased that of BA samples. The enthalpy change and Gibbs free energy change revealed that both catalytic and noncatalytic pyrolysis processes were nonspontaneous and endothermic, and the inclusion of catalyst increased the average entropy change of the BS samples but decreased that of the BA samples. Char and biochar yields after pyrolysis were also analyzed quantitatively. These observations provide insight into the differences in catalytic pyrolysis between lignocellulosic and algal biomass species.

Algae pyrolysis in alkaline molten salt: Products transformation

Algae pyrolysis in alkaline molten salt is a promising technology for hydrogen production, but the pyrolysis products transformation has not clearly been described up-to-date. Moreover, the complex bio-oil especially heavy bio-oil fraction directly influences the products transformation pathways, while limiting the hydrogen production yield and application. Both the light and heavy bio-oil fractions are investigated in detail and the effect of alkaline molten salt on products transformation is obtained. Molten salt promotes the cyclization and aromatization of linear alkenes, thereby increasing aromatic compound content and hydrogen production. The decarbonation of Na2CO3 and the deoxygenation of NaOH lead to the methane release, in turn reducing hydrogen production. The heavy compounds tend to polymerize at higher temperatures into compounds with higher molecular weights and unsaturation, while generating hydrogen. As the temperature rises, char reacts with molten salt to form hydrogen and disappears at 650 °C, while aromatics in light compounds condense into heavy compounds, which then grow to form soot-like at 600 °C, accompanying hydrogen release. Based on the relationship between products transformation, hydrogen release and alkaline molten salt effect, strategies to improve the hydrogen yield and purity of AMSP process are proposed.

Thermochemical behavior and kinetics study of algae pyrolysis using iron oxide catalyst

AbstractThe shift in emphasis from fossil fuel‐derived energy to waste‐to‐energy technologies has widened the possibility for environmentally sustainable methods such as pyrolysis. Algae collected from local sources that grow in wastewater using atmospheric CO2 is a potential feedstock for pyrolysis. Thus, the work focuses on studying the pyrolysis reaction of macroalgae sourced from regional sources in the presence of Fe2O3 catalyst using the thermogravimetric analysis, followed by kinetic analysis using iso‐conversional methods of Flynn–Wall–Ozawa (FWO), Kissinger–Akahira–Sunose (KAS), and Starink methods, and model free Kissinger method. The kinetic model was developed using master plot method. XRD analysis of the Fe2O3 catalyst confirms the presence of the maghemite and hematite phases in the sample. Based on the conversion profile, DTG trend, and kinetic parameter variation, the overall pyrolysis process can be divided into three different stages of dissociation reactions. The apparent activation energy calculated from different models varies in the range: stage I (∼268 kJ/mol), stage II (∼261 kJ/mol), and stage III (∼328 kJ/mol), respectively. Master plot analysis of the kinetic data confirms the best fit of the nucleation model (A2) to experimental data in stage II. Further, the thermodynamic properties of the reaction, such as change in enthalpy (ΔH), change in Gibbs free energy (ΔG), and change in entropy (ΔS) range between 206 and 405 kJ/mol, 189 and 651 kJ/mol, −450 and 27 J/mol/K, respectively, corroborates the complexity of the reaction. Kinetics and thermodynamic property analysis of complex reactions like pyrolysis is essential for pilot plant design.

Catalytic pyrolysis of algae: kinetics and thermodynamic analysis

Pyrolysis characteristics of the algae biomass collected from local source in the presence of HZSM-5 catalyst was investigated using Thermogravimetric analyzer (TGA) in this study. Multi-components of carbohydrates, proteins, lipids and other component dissociation in algae sample taking place at different stages at varying temperature condition was confirmed as per the multi-step DTG curve. The average activation energy, and pre-exponential factor for the pyrolysis reaction were analyzed using the isoconversional integral methods such as, Flynn–Wall–Ozawa (FWO), Kissinger–Akahira–Sunose (KAS), and Starnik and Coats Redfern (SCR) methods, and differential isoconversional method of the Kissinger method. The stages of multi-component dissociation was evident consistently in the kinetic and thermodynamic properties analyzed in this study. The diffusion kinetic model fits well into the pyrolysis zone based on the master plot method. The thermodynamic properties including, change in enthalpy, Gibbs free energy, and entropy of the pyrolysis reaction confirms the complex nature of the pyrolysis reaction.

Production of engineered algal biochar through microwave pyrolysis for nutrient recovery from aqueous solution

AbstractBiochar adsorbs contaminants from wastewater. However, biochar's modification, its application in nutrient removal from wastewater, and its mechanism of nutrient removal need to be explored. In this study, nitrate and phosphate were recovered from secondary treated domestic wastewater using microalgal biochar (Spirulina sp.). The biochar was obtained by microwave pyrolysis of algae at 400 W power for 10 min. The biochar was modified using Mg(OH)2 under different conditions. Three pre‐and post‐treated biochars with varied Mg(OH)2 percentages (2%, 4%, and 6% by weight) were produced. All the modifications in biochar improved its specific surface area. Highest specific surface area of the modified biochar reached 33 m2/g compared to 12 m2/g of the unmodified biochar. SEM analysis showed improvement in the porosity of the modified biochars. Modification also introduced ‒OH, ‒C=C‒ and ‒C‒O‒C‒ functional groups on the biochar surface. All these modifications improved the nutrient adsorption capability of the biochar. Adsorption studies indicated that 4% post‐treated biochar (Po4) was the best. The adsorption data fit the pseudo second order kinetic model with R2 being 0.99 and 0.96 for phosphate and nitrate respectively. Among different isotherm models, the Freundlich isotherm model showed the best fit for phosphate and nitrate, with their respective R2 being 0.96 and 0.97, indicating multi‐layer physical‐chemical adsorption, including the intra‐particle diffusion. The equilibrium time for adsorption for nitrate and phosphate was 7 and 6 h, respectively. The optimum pH was 5 and 6 for nitrate and phosphate, respectively, and the optimum dosage was 2 g/L. The maximum adsorption capacity for nitrate and phosphate was 7.9 and 8.9 mg/g, respectively. Po4 showed potential as a fertilizer as it had 5.84 and 3.02 g of extractable phosphate and nitrate per kg of biochar.

Algae Pyrolysis in Molten NaOH-Na2CO3 for Hydrogen Production.

Biomass pyrolysis within the alkaline molten salt is attractive due to its ability to achieve high hydrogen yield under relatively mild conditions. However, poor contact between biomass, especially the biomass pellet, and hydroxide during the slow heating process, as well as low reaction temperatures, become key factors limiting the hydrogen production. To address these challenges, fast pyrolysis of the algae pellet in molten NaOH-Na2CO3 was conducted at 550, 650, and 750 °C. Algae were chosen as feedstock for their high photosynthetic efficiency and growth rate, and the concept of coupling molten salt with concentrated solar energy was proposed to address the issue of high energy consumption at high temperatures. At 750 °C, the pollutant gases containing Cl and S were completely removed, and the HCN removal rate reached 44.92%. During the continuous pyrolysis process, after a slight increase, the hydrogen yield remained stable at 71.48 mmol/g-algae and constituted 86.10% of the gas products, and a minimum theoretical hydrogen production efficiency of algae can reach 84.86%. Most importantly, the evolution of physicochemical properties of molten NaOH-Na2CO3 was revealed for the first time. Combined with the conversion characteristics of feedstock and gas products, this study provides practical guidance for large-scale application of molten salt including feedstock, operation parameters, and post-treatment process.

Solar pyrolysis of algae in molten salt for capacitive carbon preparation

Pyrolysis of algae in molten carbonates driven by concentrated solar energy is proposed as an economical and environmentally friendly method to obtain capacitive carbon for supercapacitors. The effects of molten carbonates on pyrolysis process and electrochemical performance at different temperatures (800, 850 and 900 °C) are investigated. Na2CO3–K2CO3 leads to a relatively high carbon yield and superior microstructure at around 900 °C compared with other molten salts, which is beneficial for capacitive carbon production. The as-prepared carbon possesses a high specific surface area of 2009.26 m2/g and a hierarchical porous structure mainly consisting of micropores and mesopores. Moreover, it contains abundant oxygen- and nitrogen-containing functional groups, such as CO, –OH, pyrrolic–N and quaternary–N. These features play an important multiple synergy for the preparation of desirable capacitive carbon, which has a high specific capacitance of 230.2 F/g at 0.25 A/g and a capacitance retention of 75.54% at 2 A/g. This work provides a green and promising approach for the production of heteroatom-doped capacitive carbon with superior porosity and specific surface area.

Transformation of nitrogen during solar pyrolysis of algae in molten salt

Molten salt pyrolysis of N-rich algae driven by concentrated solar energy is considered as an economical and environmentally friendly method to prepare N-doped value-added carbon. The transformation of nitrogen during the carbon production process by algae pyrolysis in molten Na2CO3-K2CO3 is investigated in-depth, which contributes to the utilization or treatment of nitrogen-containing products. Algae-N is mainly converted to gasN, and the gas-N yield increases as temperature rises, reaching 75.7 wt.% at 900 °C. Molten salt reduces the release temperature of all N-containing gas, captures 89.6% of HCN as CN−, and promotes the release of NH3 and NO. The char-N is dominated by pyrrole-N and quaternary-N at 800–900 °C due to the promotion of molten salt and higher temperature. The major contributors to the bio-oil-N yield are pentadecanenitrile, isoamyl cyanide, benzyl nitrile, styryl cyanide, pyrrole and indole. Nitriles and indoles are promising N-containing products in value-added carbon production, while NH3 and NO are primary pollution gas to be controlled.

Thermodynamic assessment of gasification and pyrolysis of marine algae to produce hydrogen-containing gas

The article gives a thermodynamic assessment of modes of gasification and pyrolysis of algae of gross formulation C1H1.66O1.4 with obtaining hydrogen gas. The authors investigate the modes of air gasification and pyrolysis of algae at pressures of 0.1 MPa and 1 MPa with varying the fuel excess ratio and temperatures. In the case of gasification at a pressure of 0.1 MPa the hydrogen and carbon monoxide concentration increases with an increase of the fuel excess ratio (φ) from 2 to 10 and at φ = 10 and T = 1000 K reaches 25.95 mole % and 27.84 mole %, respectively. An increase in temperature from 1000 K to 1300 K leads to a decrease in the amount of hydrogen and an increase in carbon monoxide in the gaseous products. An increase in the operating pressure from 0.1 to 1 MPa at a gasification temperature of 1000 K leads to the formation of a small amount of methane (~ up to 5 mole %), a decrease in the mole content of hydrogen and carbon monoxide in the final products, and also to the formation of coke (at φ≥7), which we can use as a target product. The caloric value of the gases produced is higher in the pyrolysis of algae than in its gasification. The pressure increase at 1300 K has almost no effect on the equilibrium composition of the products in the gaseous products.

Bio-environmental interactions and associated hydrocarbon generation in a saline lake basin: A case study of the Palaeogene interval in the Dongpu Sag, eastern China

• Different hydrocarbon-generating organisms occur in different saline palaeoenvironments. • The palaeoenvironment affects the hydrocarbon-generating organisms and source rock potential. • Source rocks deposited in saline environments have a low oil generation threshold and are characterised by multi-stage oil generation. • Saline environments form source rocks with a good organic matter type and high hydrocarbon generation potential. Saline lake basins are important Cainozoic petroliferous basins in China. There are significant differences in the palaeoenvironments of these basins. Different biological assemblages resulted in varying hydrocarbon generation characteristics and potential. Therefore, the bio-environmental interactions are key to understanding the oil generation from terrestrial organic matter. In this study, we investigated the organic petrology and geochemistry of the Palaeogene Shahejie Formation in the Dongpu Sag, Bohai Bay Basin, China. The depositional palaeoenvironment varied from saline to freshwater. Cyanobacteria and coccolithophores were deposited in the saline environment, and green algae and higher plant debris were deposited in the freshwater to brackish water environments. The algal biomass in the sediments increased with salinity. Thermal and pyrolysis experiments revealed differences in the hydrocarbon generation potential of the source rocks deposited in different sedimentary environments. The source rocks deposited in the saline water environment have a high hydrocarbon generation potential. Two immature to low-mature oil generation peaks were observed, which are mainly due to the pyrolysis of coccolithophores, cyanobacteria, and dinoflagellates. Only one oil generation peak was observed for source rocks deposited in the freshwater environment, which is mainly due to the pyrolysis of dinoflagellates and green algae. The hydrocarbon generation potential and two stages of oil generation of the source rocks deposited in the saline environment may be due to the type of hydrocarbon-generating organisms and the catalytic effect of the high-salinity diagenetic environment. The results show that the sedimentary environment of saline lake basins affects the hydrocarbon-generating organisms and hydrocarbon generation process.

The characteristics and evolution of nitrogen in bio-oil from microalgae pyrolysis in molten salt

Microalgae pyrolysis in molten salt is a promising way to produce high-quality bio-oil. This study provides deep insights into the characteristics of nitrogen-containing compounds (NCCs) during protein-rich spirulina platensis pyrolysis in a ternary eutectic carbonate (Li2CO3-Na2CO3-K2CO3) at different temperatures (450–600 °C). The results indicate that the molten carbonate significantly reduces the NCCs contents in bio-oil and heavy bio-oil by 25.89 % and 62.38 % respectively, which is due to the intensified removal of nitrogenous functional groups (CN, CN of the primary amide, and CN) in NCCs. The molten carbonate also intensifies the direct cleavage of amino acids and the conversion of amides/amines to form nitrile compounds but inhibits the dehydration of hexadecanamide to form hexadecanenitrile in bio-oil light components. Concerning the heavy components in bio-oil, molten carbonate intensifies the depolymerization of NCCs and plays an important role in intensifying the cyclane ring opening, double bond breaking, and cleavage of a benzene ring of NCCs. Finally, the possible pathways for nitrogen evolution in bio-oil are proposed, which can provide guidance for the high-quality bio-oil production by molten salt pyrolysis of algae.

Study on the reaction mechanism of nitrogenous compounds in zeolite-catalyzed pyrolysis of blue-green algae

The ex-situ catalytic fast pyrolysis (CFP) of blue-green algae (BGA) and its nitrogenous model compounds over HZSM-5 was conducted in a microfluidized bed reactor (MFBR) combined with a U-shape fixed bed reactor (U-FBR). A single photoionization mass spectrometer (SPI-MS) was used for on-line studying the dynamics of volatiles formation with the biomass-to-catalyst ratio (BCR). In the CFP of BGA, six different groups of products were differentiated by statistical analysis of SPI mass spectra, which were obtained with the cumulative BCRs. The relative concentration of each group has its own evolution with catalyst deactivation, indicating the different formation pathways of six groups. In combination with results from the CFP of six model compounds, the reaction pathways of nitrogenous compounds in the CFP of BGA over HZSM-5 were proposed. The benzyl nitrile could be fully converted to hydrocarbons while this is hard to achieve N-cyclic compounds (particularly the pyridines). Besides, most of nitrogenous compounds could be interconvertible in the CFP process. Transmethylation is the favorite way for catalytic conversion. In addition, the CFP of BGA and its N-cyclic compounds would lead to the fast coking of HZSM-5, especially the hard coke.

Pyrolysis of marine algae for biochar production for adsorption of Ciprofloxacin from aqueous solutions

Biochars derived from three species of algae was synthesized by impregnating the green algae Ulva Ohnoi, red algae Agardhiella subulata, and brown algae Sargassum hemiphyllum with ZnCl2 chemical activator and employed as a long-term adsorbent for ciprofloxacin (CIP) removal from water. The results revealed that combination of brown algae and ZnCl2 chemical activator (ZBAB) successfully produced mesoporous biochar with excellent physicochemical characteristics and gave the best CIP adsorption capacity. The ZBAB yielded a high CIP adsorption capacity (190–300 mg g−1) under various parameter effects (initial pH, temperature and major ions). Throughought the surface characterization techniques, the proposed adsorption mechanisms were electrostatic interaction, π-π EDA interaction, pore filling and hydrogen bonding. Moreover, not only algal biochars exhibited innovative and potential adsorbent for rapid and effective remediate pollution from water, but combination of algal biomass and ZnCl2 activator also created renewable source of energy from biomass pyrolysis.

Pd–Ni bimetallic nanoparticles supported on TiO2 as an efficient catalyst for catalytic transfer hydrodeoxygenation of guaiacol

Bio-oil is a sustainable energy source, produced from pyrolysis of lignocellulosic materials or algae. It is, however, difficult to directly use the bio-oil for fuels due to several drawbacks, such as its viscosities and high oxygen content. One of the ways to solve this is upgrading of the bio-oil through hydrodeoxygenation (HDO). In this study, guaiacol was used as a bio-oil model compound in HDO reaction via catalytic transfer hydrogenation. The reaction was conducted in the presence of TiO2-supported palladium catalysts, with isopropyl alcohol as a hydrogen source. Nickel and molybdenum were added into the Pd catalyst to investigate their effects on the catalyst activity. The prepared catalysts were characterized using XRD, N2 physisorption, hydrogen temperature-programmed reduction, and transmission electron microscopy. HDO reaction was carried out using a pressurized batch reactor at 250 °C for 1 h with 30 bar of helium. Liquid products were analyzed by GC–MS and GC–FID to identify and quantify the conversions and product yields. The result showed that the presence of nickel on the catalyst could improve the catalytic activity of Pd/TiO2. Guaiacol conversion over Pd–Ni/TiO2 was 32.2%, while the conversion of guaiacol over Pd/TiO2 was only 17.9%. In addition, Pd–Ni/TiO2 showed good selectivity to produce cyclohexanol, while Pd/TiO2 showed good selectivity to produce one oxygenated compound such as 2-methylphenol and phenol.

A Mini Review on Pyrolysis of Natural Algae for Bio-Fuel and Chemicals

The disposal and use of natural algae have recently been the subject of great interest, due to increasing concern for environmental protection and resource utilization. In this paper, a mini review of recent research on the pyrolysis of natural algae, especially the algae from water blooms, is presented. The chemical compositions of the natural algae are summarized, and the pyrolysis properties of different compositions are reviewed. Non-catalytic, catalytic, and integrated catalytic processes are reviewed. Different ideas and methods for the production of bio-fuel or chemicals are discussed. Apparently, deoxygenation and denitrogenation are highly necessary for algae-based bio-fuel and catalysts play an important role in these processes. In addition, the integrated catalytic process, which involves catalysis and other operation conditions aside from the thermal treatment under inert atmosphere, shows potential for the valorization of algae-based bio-oil. Based on the recent concept and progress, the research gaps are discussed, followed by the challenges and proposals to achieve high-value utilization of the natural algae.

Characteristics and Evolution of Nitrogen in the Heavy Components of Algae Pyrolysis Bio-Oil.

Algae pyrolytic bio-oil contains a large quantity of N-containing components (NCCs), which can be processed as valuable chemicals, while the harmful gases can also be released during bio-oil upgrading. However, the characteristics of NCCs in the bio-oil, especially the composition of heavy NCCs (molecular weight ≥200 Da), have not been fully studied due to the limitation of advanced analytical methods. In this study, three kinds of algae rich in lipids, proteins, and carbohydrates were rapidly pyrolyzed (10-25 °C/s) at different temperatures (300-700 °C). The bio-oil was analyzed using a Fourier transform ion cyclotron resonance mass spectrometer equipped with electrospray ionization, and the characteristics and evolution of nitrogen in heavy components were first obtained. The results indicated that the molecular weight of most heavy NCCs was distributed in the 200-400 Da range. N1-3 compounds account for over 60% in lipid and protein-rich samples, while N0 and N4 components are prominent in carbohydrate-rich samples. As temperature increases, most NCCs become more aromatic and contain less O due to the strong Maillard and deoxygenation reactions. Moreover, the heavier NCCs were promoted to form lighter compounds with more nitrogen atoms through decomposition (mainly denitrogenation and deoxygenation). Finally, some strategies to deal with the NCCs for high-quality bio-oil production were proposed.

Comparative study of different algae pyrolysis using photoionization mass spectrometry and gas chromatography/mass spectrometry

Pyrolysis of three algae, i.e. Nannochloropsis, Spirulina, and Sargassum was investigated by the combination of fixed bed pyrolysis with gas chromatography/mass spectrometry and pyrolysis photoionization mass spectrometry (py-PIMS) methods. Lipid, protein, and carbohydrate are the dominant components of the three algae, respectively. Mass spectrum profiles at different temperatures (400 °C, 500 °C, 600 °C, and 700 °C), temperature-programmed and time-evolved profiles of major products were measured. The decomposition reaction of fatty acids led to the formation of alkanes and alkenes. Aromatic compounds came from the nitrogen-containing compounds derived from protein and dehydrogenation of cyclic alkanes and alkenes through the Diels–Alder reaction from unsaturated fatty acids. Polycyclic nitrogenous compounds can be generated by the ring condensation reactions of monocyclic N-heterocyclic compounds. Lipids may interfere with the decomposition of protein. The presence of carbohydrates facilitates the formation of N-heterocyclic compounds. Two formation pathways of 1,4:3,6-dianhydro-α-d-glucopyranose and 2,4-dimethylfuran from hemicellulose and cellulose at different temperatures were observed.