Preparation of aromatic hydrocarbon (AH)-rich bio-oils through co-pyrolysis of biomass and waste plastics has become a highly promising method of resource utilization. However, the influences of existing different catalytic modes on the co-pyrolysis product distribution still remain unclear and the cycle stability of catalysts has not been fully assessed. To solve these problems, the research used unmodified and (Fe and Zn) bimetal-modified microporous molecular sieve (HZSM-5), mesoporous molecular sieve (MCM-41), and micro-mesoporous composite molecular sieve (HZSM-5/MCM-41) to carry out in-situ and ex-situ catalytic co-pyrolysis experiments on corn stalk (CS) and polystyrene (PS) and assess the cyclic life of catalysts. Results show that for unmodified catalysts: during in-situ catalytic co-pyrolysis, the relative content of AHs in the target product follows the descending order HZSM-5 (99.16%) > HZSM-5/MCM-41 (98.24%) > MCM-41 (96.86%); during ex-situ catalytic co-pyrolysis, the proportion of AHs is as follows: MCM-41 (98.64%) > HZSM-5 (95.92%) > HZSM-5/MCM-41 (95.28%). After introducing metal modification, Fe-Zn-HZSM-5 (FeZnH), Fe-Zn-MCM-41 (FeZnM), and Fe-Zn-HZSM-5/MCM-41 (FeZnHM) all experienced varying degrees of reduction in the relative content of AHs under both in-situ and ex-situ catalytic conditions. The results of the catalyst recycling experiments indicate that bimetallic modification with Fe and Zn can effectively enhance the number of times the catalyst can be reused, in the following order: FeZnHM (18 times) > FeZnM (16 times) > HZSM-5/MCM-41 (11 times) > MCM-41 (8 times) > FeZnH (7 times) > HZSM-5 (5 times). In addition, the thermogravimetric test results also show that the bimetal-modified catalysts have better resistance to carbon deposition. The research provides reference for preparation of high-value chemicals via oriented pyrolysis of biomass and plastics.

This study systematically investigated the effects of torrefaction at 220, 260, and 300 ℃ on the structural evolution, thermal stability, and pyrolysis behavior of kraft lignin (KL), aiming to provide insights for its valorization. KL was pretreated in a fixed-bed reactor and characterized using proximate/ultimate analyses, Fourier Transform Infrared Spectroscopy (FTIR), Carbon-13 Nuclear Magnetic Resonance Spectroscopy (13C NMR), and Thermogravimetric Analysis (TG). Results revealed that increasing torrefaction temperature reduced the solid yield to 58.36%, while significantly enhancing the fixed carbon content, decreasing O/C and H/C ratios to 0.11 and 0.52, and increasing the high heating value (HHV) to 25.26 MJ/kg, indicating pronounced deoxygenation and carbon enrichment. FTIR and 13C NMR analyses showed that the content of unstable ether linkages decreased from 22.22% to 5.51%, and aromatic carbon increased to 42.68%, and Car-Car bond concentration rose continuously, reflecting the combined effects of β-O-4 ether bond cleavage, demethoxylation, dehydration, and aromatization-condensation. TG analysis demonstrated substantially improved thermal stability, with Ti, Tm, and Tt increasing from 259, 358, and 506 ℃ to 374, 532, and 785 ℃, respectively. Pyrolysis experiments further indicated that torrefied KL reduced CO2 yield to 32.83 mL/g while maintaining a solid yield of 37.68%, which successfully enhanced the stability of the lignin carbon framework and improved its carbon sequestration capacity. Overall, torrefaction effectively optimized the chemical structure and bond network of KL, enhancing thermal stability, directing pyrolysis pathways, and improving carbon sequestration potential during energy-oriented biomass utilization, offering an effective approach for carbon mitigation.

This study investigated the kinetics, thermodynamic characteristics, and reaction pathways during the copyrolysis of corn straw (CS) and tar distillation residue (TAR-D). Results showed that incorporating 15% TARD reduced the peak temperature of the system from 358.2 to 346.5 degrees C. The average activation energies of CS, TAR-D, and H-15% calculated by the FWO method were 152.42, 143.77, and 147.01 kJ mol- 1, respectively, indicating that TAR-D addition lowered the reaction energy barrier of CS and promoted pyrolysis. The Delta H values of the three samples were 147.66, 142.22, and 138.56 kJ mol- 1, confirming endothermic reactions. The Delta S of H15% was negative (-4.94 J mol- 1 K- 1), indicating more stable energy release and a more ordered product structure. Co-pyrolysis products showed decreased phenols, alcohols, and ketones, while aromatic hydrocarbons and esters increased significantly. Oxygen-containing radicals from CS cracking underwent hydrogen transfer and coupling with aromatic radicals from TAR-D, facilitating aromatic ring reconstruction, deoxygenation of phenolic hydroxyls, and ester formation. This study elucidates the synergistic conversion of CS and TAR-D during co-pyrolysis, providing a theoretical basis for the efficient thermochemical utilization of all CS components.

CO2-assisted steam gasification of rice straw (RS) offers a promising approach for both the sustainable utilization of rice straw and the reduction of CO2 emissions. This study investigates the transformation of RS during pyrolysis and gasification in a fixed-bed reactor, with structural changes observed through solid-state 13C nuclear magnetic resonance and Fourier-transform infrared (FT-IR) spectroscopy. The gas composition is analyzed by gas GC, and covalent bonds are quantified through carbon structure and elemental analysis. The results demonstrate that steam acts as a key reactant in the gasification process, significantly enhancing the pyrolysis of RS and leading to higher hydrogen yields. CO2 serves as an oxidant above 500°C, oxygenating aromatic rings and initiating ring-opening reactions to form active C(O) intermediates that are crucial for hydrogen production. The hydrogen yield increases similarly to H2O gasification, while methane and carbon monoxide decrease significantly after gasification over 700°C. The H2/CO ratio improves from 0.64 in N2 to 1.46 in H2O, and further to 1.71 in CO2-H2O at 700°C. CO2-assisted steam gasification optimizes the reactive interface activity, promoting the selective formation of hydrogen and improving the efficiency of the gasification process. Furthermore, CO2 plays a pivotal role in enhancing the formation of active C(O) intermediates, which further facilitates the production of high-purity hydrogen. The process also induces the formation of a regular micro-pore structure, improving the overall efficiency and selectivity of directional hydrogen generation.

Preparation of bio-oils rich in aromatic hydrocarbons (AHs) through catalytic co-pyrolysis of biomass and plastics to replace conventional petroleum-based fuels and chemicals has received extensive attention. However, the yield of target products is relatively low and the catalyst evaluation system is still not comprehensive. To solve the problems, the zinc-iron (Zn-Fe) co-modified HZSM-5/MCM-41 at different Zn:Fe mass ratios were prepared. Additionally, the product distribution during the preparation of hydrocarbon-rich bio-oils through copyrolysis of Miscanthus (MT) and polystyrene (PS) under catalysis of these catalysts was explored. Results show that compared with the non-catalytic pyrolysis of MTPS, all catalysts are conducive to increasing the content of AHs in the products; compared with the catalysis of HZSM-5/MCM-41 alone, the Zn-modified, Fe-modified, and Zn-Fe co-modified HZSM-5/MCM-41 catalysts all can enlarge the proportion of monocyclic aromatic hydrocarbons (MAHs) and also inhibit the generation of polycyclic aromatic hydrocarbons (PAHs). Among them, the combination of 2Zn, 2Fe, and HZSM-5/MCM-41 is most beneficial to increases in the content (93.47%) and yield (1.01 & times;109) of AHs. At this ratio, Zn and Fe show a favorable positive synergy. A two-stage pyrolysis-gas chromatography/mass spectrometer (Py-GC/MS) was utilized to carry out cyclic experiments on the 2Zn2FeHZSM-5/MCM-41 catalyst, and the catalyst was comprehensively assessed combining multiple characterization approaches. The research found that the catalyst has been completely deactivated after nine cycles of use, and the catalyst was regenerated by calcining it at 800 degrees C in an air atmosphere for 20 min, the results showed that this deactivation was irreversible. The research provides reference for the preparation of high-value chemicals through co-pyrolysis of biomass and plastics.

Although co-thermal oxidation of biomass and low-rank coal can produce composite humic acid (CHA) rich in oxygen-containing functional groups and with high activity, it cannot achieve the separation of biomass residues and low-rank coal residues, thereby affecting their graded utilization. To address this issue, this study proposes a stepwise hydrothermal method for preparing CHA using walnut shell (WS) and Baoqing lignite (BL) as feedstocks. First, WS were mixed with KOH for preliminary hydrothermal treatment, and the biomass residues were filtered out; then BL was added to the filtrate along with KOH for a second hydrothermal treatment, after which the lignite residues were filtered out; finally, acid precipitation was applied to the filtrate to obtain CHA. By analyzing CHA yield, total acidic group content, and combining with 13C NMR structural characterization, the effects of feedstock addition method, feedstock ratio, reaction temperature, and KOH/feedstock mass ratio on CHA yield and structure were investigated. The results show that: 1) Compared with the one-step co-hydrothermal method, the CHA structure prepared by stepwise hydrothermal method was more stable and contains a richer total amount of acidic groups; 2) When the feedstock ratio was WS:BL = 1:2 (mass ratio), the prepared CHA exhibited the highest yield (51.82%). When the ratio was WS:BL = 2:1, the yield of CHA decreased to 30.14%, but the content of carboxyl, aldehyde, and ketone groups was high; 3) As the reaction temperature increased from 90 degrees C to 150 degrees C, the total content of acidic groups in CHA decreased, but the content of carboxyl carbon and the yield of CHA continued to increase, reaching the highest yield of 69.91% at 150 degrees C; 4) Increasing the KOH/feedstock mass ratio during the hydrothermal process helped to improve the CHA yield and the total acidic group content. When the KOH/feedstock mass ratio was 4.5:14, the CHA yield was the highest (67.57%), and the total acidic group content was the greatest (7.29 mmol & sdot;g-1). This study clarifies the effect of preparation conditions on CHA yield and structure, providing new insights for CHA production and the graded utilization of low-rank coal and agricultural/forestry waste.

Biomass-coal co-combustion represents an energy utilization pattern able to cope with adjustments to the overall energy structure and meet requirements of the carbon trading market. To achieve large-scale application of the biomass-coal co-firing power generation technology, it is necessary to measure the biomass blending ratio (BBR). A co-combustion platform, a CO2 absorption apparatus from flue gas, and a preparation platform of graphite samples were designed and established. On this basis, the accurate determination of the BBR during biomass-coal co-combustion using 14C measurement based on accelerator mass spectrometry (AMS) was experimentally investigated and the technique was optimized. The results show that the relative differences between the combustion residue of blended fuel and the ash content are less than 3% and the absorption rate for CO2 from flue gas exceeds 95%, verifying the sufficient combustion and absorption observed on the established experimental platform. Among all carbon-based BBRs for flue gas from co-combustion, more than 83% have relative errors between the calculated and theoretical values within 11% and the minimum relative error is only -0.17%. This finding further confirms the accuracy of the established calculation model for the carbon-based BBR and the reliability of the technological process based on the AMS-14C method for identifying the BBR during biomass-coal co-combustion. The research provides reference for the industrial applications of biomass-coal co-combustion.

The modified Al-HZSM-5, Zn-HZSM-5, and Fe-HZSM-5 were used to catalyze the co-pyrolysis of microcrystalline cellulose(MC)、xylan(XY), and alkali lignin (AL) with polypropylene (PP) and polystyrene (PS) to explore the reaction mechanism of catalytic co-pyrolysis of biomass components and plastics, as well as the interaction and coupling characteristics of each component during the co-pyrolysis process. Results show that in the co-pyrolysis process of MC with PP and PS, the Al-, Zn-, and Fe-doped HZSM-5 catalysts all can increase the yield of total hydrocarbons (THs) and aromatic hydrocarbons (AHs). In the co-pyrolysis process of XY with PP and PS, Zn/Al-HZSM-5 catalysts are both conducive to the generation of THs and Al-HZSM-5 can increase the yield of AHs. In the co-pyrolysis process of AL and PP, Zn-HZSM-5 can promote the generation of AHs; Al-HZSM-5 can improve the yield of THs and AHs during the co-pyrolysis of AL and PS. Compared with mixed components, a single component is more favorable for the formation of THs and AHs. The coupling of the three biomass components facilitates the generation of alkenes, alkanes, and cycloalkanes, while inhibits the generation of AHs. The distribution of catalytic co-pyrolysis products of biomass does not equate to that of catalytic co-pyrolysis products of three biomass components mechanically mixed according to a certain ratio.

Anthracite has become one of the good raw materials for the synthesis of activated carbon because of its low ash content and high fixed carbon. In this study, the effects of alkali-carbon ratio, carbonization temperature, activation temperature, and impregnation time on the properties of anthracite-based activated carbon were studied by a four-factor three-level response surface method. The iodine value and methylene blue value were used as response values and the satisfaction function was used to optimize and verify the two response values. The results show that the optimum process parameters of anthracite-based activated carbon are as follows: the ratio of alkali to carbon is 2: 1, the carbonization temperature is 700 degrees C, the activation temperature is 867 degrees C, and the impregnation time is 18.15 h. Under these conditions, the iodine value and methylene blue value of anthracite-based activated carbon reach 1232.70 mg/g and 382.49 mg/g, respectively. Three verification experiments were carried out on the optimal process. The average values of iodine value and methylene blue value of activated carbon were 1271.65 mg/g and 380.78 mg/g, respectively. The error between the measured value and the predicted value was 3.16 % and 0.44 %, respectively. The actual value of overall satisfaction (0.998) is consistent with the predicted value. At the same time, the metal-modified carbon-based catalyst was prepared by ultrasonic impregnation method. It was found that its catalytic activity was stable in CO2 and CH4 reforming reactions. When the metal nickel loading was 6 %, the conversion of CO2 and CH4 reached 91.36 % and 93.35 % respectively at 900 degrees C. This lays a solid foundation for the further design of the preparation of carbon molecular sieve catalysts and the promotion of the utilization of renewable energy such as biomass energy, and also provides a theoretical reference for the industrial preparation of anthracite-based activated carbon.

The catalytic co-pyrolysis processes of biomass components (microcrystalline cellulose (MC), xylan (XY), and alkali lignin (AL)) and plastics (polypropylene (PP) and polystyrene (PS)) were studied using HZSM-5, MCM-41, and HZSM-5/MCM-41. For non-catalytic pyrolysis, the co-pyrolysis of MC and AL with plastics are beneficial for increasing the yield of hydrocarbons. The presence of MC, XY, and AL does not exert significant influences on the distribution of types of pyrolysis products of PP, and the interaction of the three components with PS is conducive to the generation of styrene. The introduction of catalysts can increase the yield of hydrocarbons in the copyrolysis products of biomass components and plastics. The combination of MC (52.39 %)/XY (35.77 %), PP, and HZSM-5 is most beneficial for increasing the content of aromatic hydrocarbons, mainly due to the synergistic effect between MC/XY-derived oxygenates and PP-derived hydrocarbons through the hydrocarbon pool mechanism, the hydrogen transfer reaction, and the Diels-Alder reaction. For the catalytic co-pyrolysis of biomass components and PS, HZSM-5 shows significantly superior selectivity for mononuclear aromatic hydrocarbons, while HZSM-5/MCM-41 and MCM-41 obviously promote the generation of polycyclic aromatic hydrocarbons. The research provides a reference for the preparation of high-quality bio-oils through oriented co-pyrolysis of biomass and plastics.

The structural parameters of carbon were accurately determined through correction by employing a linear correlation method. Further, the nuclear Overhauser effect (NOE) was reduced in solid 13C-nuclear magnetic resonance spectra using a solid cross-polarization/magic angle spinning (CP/MAS) probe and the total suppression of sidebands sequence (TOSS). The reaction pathway during torrefaction was inferred from analysis of the accurate bond behavior and product distribution. The results show that torrefaction has a significant influence on the structural evolution of biomass. After correction, the relative deviations in the H/C ratio and aromaticity of the carbon structure decreased below 20 %. During torrefaction, the aliphatic carbon bonds were cleaved and aromatic carbon bonds were formed by dehydration, deoxygenation, oligomerization, aromatization, and Diels-Alder reaction. Torrefaction of biomass is divided into three stages. The first stage occurs below 220 degrees C, with disruption of the hydrogen bonds, a decrease in the number of Cal-O bonds, and the release of some CO2, CO, and furaldehyde. The second stage proceeds in the 220-260 degrees C range, where beta-O-alpha bonds and glycoside bonds are broken, with the generation of ketones, furan, phenols, CO, and CO2. In the third stage between 260 and 300 degrees C, Cal-O and Cal-Cal bonds are broken. Bio-coal is composed of monomers of C20H14O3 with two aromatic rings linked by one aromatic ring. This significant, fundamental study enables accurate calculation and simulations for optimizing the industrial utilization of biomass.

The energy properties in bio-coal, such as proximate analysis, element composition, high heat value, colour, thermal behavior are detailed elaborated. The results show bio-coal production processes from biomass can be divided into three stages which is close to coalification through the data in energy properties. The first stage called mild torrefaction (<= 220 degrees C) seen as biomass to peat phase during coalification in the result of unstable oxygenated functional groups in hemicellulose are decomposed and Maillard reaction induces the colour modification. Second stage called moderate torrefaction (220-260 degrees C) seen as lignite formation process during coalification leads to degradation of celluloses. Biomass colour from brown to sepia due to the chromophoric groups. The heating value of maple sawdust (MS) increases to 30.02 MJ/kg of MS-260. Third stage called severe torrefaction (260-300 degrees C) considered as metamorphic episode of lignite to bituminous coal results of covalent bond cleavage, oxygenation of lignin and condensation of aromatic carbons. As functional groups decomposition during bio-coal production, three characteristic temperatures increase with the torrefied temperature increasing read from TG and DTG curves. The MS with the highest cellulose and aliphatic C-C bonds, is effective raw materials for bio-coal production by torrefaction with the close energy properties, thermal behavior to bituminous coals.

This study aimed to analyze a technology of hydrogen-rich gas from full-component oriented pyrolysis (FCOP) of biomass using energy, economic, and environmental life cycle assessment. Firstly, the study taked corn straw (CS) as the research object, the yield of hydrogen-rich gas and char produced by the oriented pyrolysis method are 78.26% and 20.35%, and the yield of biochar produced by activating char with phosphoric acid is 40%. Secondly, the system boundary of FCOP of biomass to produce hydrogen-rich gas and biochar was creatively designed, establishing the energy, environmental, and economic analysis comprehensive model. Various energy, economic, and environmental indicators were computed to facilitate process optimization for hydrogen-rich gas co-production biochar and explored the feasibility of the process. The results show that the stage of hydrogen-rich gas prepared by FCOP of biomass is an important factor affecting energy output and input, and has the highest standard pollutant emissions (92.11%). This process has low carbon emissions and GHG emissions, showing good sustainability and application prospects, which has important guiding significance for realizing cleaner production and solving the energy crisis. Thirdly, taking the large-scale system of producing hydrogen-rich gas co-production biochar, which processes 40,000 t of CS per year, as an example, the economic benefit analysis results were obtained, that is, IRR, NPV, and Pm are 22%, 6.33 million yuan, and 7.3 years, respectively. Meanwhile, the key factors, including the initial investment, expenses of biomass and catalyst, and the sale income of hydrogen and biochar, which are the main factors affecting the economic efficiency of technology, and uncertainties were identified through sensitivity analysis. Finally, we put forward in the background of ecological civilization, the research focus and thinking for the development of hydrogen production technology from pyrolysis/gasification of biomass were proposed. The results obtained can be valuable in practical applications to enhance the sustainability and viability of hydrogen production in biomass conversion and utilization activities. The applied energy, economic, and environmental methodologies appear to be reliable and comprehensive tools for assessing the whole-life sustainability and viability of biofuel.

Co-utilization of waste tires (WT) and agricultural and forestry residues (AFR) provides an effective means to produce energy while simultaneously providing solution for waste treatment and environment protection. In this paper, co-pyrolysis of WT and AFR (cotton stalk, CS, peanut shell, PS, and poplar branch, PB) was performed using thermogravimetric analysis (TGA), Fourier transform infrared spectrometer (FTIR), and pyrolyzer coupled with gas chromatograph/mass spectrometer (Py-GC/MS). The synergistic effects of mass loss rate and hydrocarbon content were quantified from the results of co-pyrolysis of WT with CS, PS, or PB with the weighted average of individual pyrolysis of the feedstocks. The results showed that the mass loss rate of WT with CS, PS, or PB in co-pyrolysis increased by 3.06%, 3.84%, and 0.61%, respectively, compared to the weighted average of individual pyrolysis, while the hydrocarbon content increased by 19.20%, 18.26% and 2.97%, respectively. The addition of AFR to WT made the pyrolysis easier. In co-pyrolysis, the amount of O-compounds decreased while that of hydrocarbons (aromatic hydrocarbons and aliphatic hydrocarbons) increased. Co-pyrolysis of AFR and WT had an effect on reducing aromatic and nitrogen content. These results provide insights into the synergistic effects, from the products distribution and offer potential waste treatment method for these wastes via thermochemical conversion.

The accurate measurement of the biomass lower-calorific-value-based blending ratio (BLBR) is the premise and key to scale development of the power generation technology from co-firing of biomass and coal. However, existing determination methods of BLBR are less accurate, which has impeded the scale utilization of the co-firing technology of biomass and coal. To accurately determine the BLBR, this research proposed a flue gas sampling system suitable for determining BLBR through 14C quantitative analysis and established a medium-scale experimental platform for BLBR determination. In addition, predictive models for the lower calorific values of coal and biomass fuels were built and the BLBR calculation model for co-firing power plants was deduced. Furthermore, experimental verification of the BLBR determination was also conducted. The results show that the lower calorific values of coal and biomass fuels are highly linearly positively correlated with the carbon content. The relative errors of the established prediction models for lower calorific values of biomass and coal are separately lower than 5% and 8%. The results indicate that the proposed BLBR determination method is accurate.

Results are presented on the co-pyrolysis of different blends of rapeseed stalk and plastic polypropylene (100:0, 75:25, 50:50, 25:75 and 0:100) using thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy and pyrolyzer-gas chromatography/mass spectrometry (Py-GC/MS), independently. The effect of temperature (450, 550 and 650 °C) on the synergistic effect between rapeseed stalk and polypropylene at different blend ratios as well as on the yield and amounts of alcohols and hydrocarbons produced are presented. The thermogravimetric analysis results showed that at the same temperature, increase of polypropylene in the mixture, gradually increased the intensity and rate of pyrolysis reaction. The weight loss data revealed improved pyrolysis during the process. The Fourier transform infrared spectroscopy results showed that the transmittance of ketones, esters and acids increased while the content of ketones, esters and acids decreased with increased polypropylene in the mixture. The pyrolyzer-gas chromatography/mass spectrometry results showed that temperature and feedstock mixture ratio had an impact on the yield and amounts of alcohols and hydrocarbons. The pyrolysis effect was most favorable at 550 °C temperature and rapeseed stalk/polypropylene mixture ratio of 1:3. These results provide some practical insights on clean energy recovery from mixtures of agricultural residues and waste plastics using thermochemical conversion.

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Developing marginal lands to plant energy crops and then develop biomass-to-liquid fuels is an effective way to ease the energy crisis, promote greenhouse gas emission reduction, and protect the natural ecological environment. Taking Henan Province, China as a research object, the research obtained spatial distributions and areas of marginal lands in the province by processing remote-sensing data for land use using software ArcGIS. Marginal lands in Henan Province were classified into the first-class, second-class, and third-class ones by selecting key natural conditions including the soil thickness, slope, soil texture (sand volume fraction), accumulated temperature above 10 °C, organic matter content, and total annual precipitation as indices. The research showed that the total area of marginal lands in the province is 1.68×10 4 km 2 , including 0.62×10 4 km 2 of first-class marginal lands, 0.83×10 4 km 2 of second-class marginal lands, and 0.23×10 4 km 2 of third-class marginal lands. Taking production of bioethanol with sugar grass as an example, 8.92×10 7 t of sugar grass can be harvested on the marginal lands in Henan Province, which can be converted into 5.80×10 6 t of bioethanol, equivalent to 6.96×10 6 t of standard coal. The research can provide reference for realizing energy structure optimization and consolidating energy security in Henan Province.

Melamine-impregnated paper waste (MIPW) is an unavoidable byproduct of the melamine-impregnated paper production process, and it must be urgently disposed. In this paper, due to its high N content, MIPW was used as a N source to co-pyrolyze with camellia oleifera shell (COS). By changing the proportion of MIPW in the raw materials, the migration path of the N was studied during the co-pyrolysis process. X-ray photoelectron spectroscopy (XPS), elemental analysis (EA), total nitrogen analysis (TN) and ultraviolet spectrophotometry were used to determine the content and the types of N-containing components in raw materials and products. The results showed that during the co-pyrolysis process, the N in MIPW and COS would be converted into different types of N-containing components, and the proportion of MIPW in raw materials directly impacts the product distribution and the N migration path. With the increase in the proportion of MIPW from 10 to 50 wt.% (daf, mass ratio), the proportion of N in raw materials that migrated into the solid phase decreased from 27.58 to 16.31 wt.%, while that which migrated to the gas and liquid phases increased from 24.92 and 47.50 wt.% to 25.97 and 57.72 wt.%, respectively. The proportions of N in the raw materials that changed into pyridinic-N, pyrrolic-N and graphitic-N in the solid phase and N2-N in the gas phase were decreased. The proportions of NH3-N and HCN-N in the gas phase and NH3-N and organic-N in the liquid phase were increased. Moreover, synergies were observed during the co-pyrolysis process, which affected the N migration path in the raw material. This study will provide policy directions and theoretical support for the comprehensive utilization of MIPW and COS.