Cross-upgrading of biomass hydrothermal carbonization and pyrolysis for high quality blast furnace injection fuel production:Physicochemical characteristics and gasification kinetics analysis

The paper proposes a biomass cross-upgrading process that combines hydrothermal carbonization and pyrolysis to produce high-quality blast furnace injection fuel.The results showed that after upgrading,the volatile content of biochar ranged from 16.19%to 45.35%,and the alkali metal content,ash content,and specific surface area were significantly reduced.The optimal route for biochar pro-duction is hydrothermal carbonization-pyrolysis(P-HC),resulting in biochar with a higher calorific value,C=C structure,and increased graphitization degree.The apparent activation energy(E)of the sample ranges from 199.1 to 324.8 kJ/mol,with P-HC having an E of 277.8 kJ/mol,lower than that of raw biomass,primary biochar,and anthracite.This makes P-HC more suitable for blast furnace injection fuel.Additionally,the paper proposes a path for P-HC injection in blast furnaces and calculates potential environmental benefits.P-HC of-fers the highest potential for carbon emission reduction,capable of reducing emissions by 96.04 kg/t when replacing 40wt%coal injec-tion.

Mechanism and reservoir simulation study of the autothermic pyrolysis in-situ conversion process for oil shale recovery

The autothermic pyrolysis in-situ conversion process (ATS) consumes latent heat of residual organic matter after kerogen pyrolysis by oxidation reaction, and it has the advantages of low development cost and exploitation of deep oil shale resources. However, the heating mechanism and the characteristic of different reaction zones are still unclear. In this study, an ATS numerical simulation model was proposed for the development of oil shale, which considers the pyrolysis of kerogen, high-temperature oxidation, and low-temperature oxidation. Based on the above model, the mechanism of the ATS was analyzed and the effects of preheating temperature, O_(2) content, and injection rate on recovery factor and energy efficiency were studied. The results showed that the ATS in the formation can be divided into five characteristic zones by evolution of the oil and O_(2) distribution, and the solid organic matter, including residue zone, autothermic zone, pyrolysis zone, preheating zone, and original zone. Energy efficiency was much higher for the ATS than for the high-temperature nitrogen injection in-situ conversion process (HNICP). There is a threshold value of the preheating temperature, the oil content, and the injection rate during the ATS, which is 400 °C, 0.18, and 1100 m3/day, respectively, in this study.

A Review of the Life Cycle Analysis for Plastic Waste Pyrolysis

Pyrolysis is a rapidly expanding chemical-based recyclable method that complements physical recycling. It avoids improper disposal of post-consumer polymers and mitigates the ecological problems linked to the production of new plastic. Nevertheless, while there is a consensus that pyrolysis might be a crucial technology in the years to come, more discussions are needed to address the challenges related to scaling up, the long-term sustainability of the process, and additional variables essential to the advancement of the green economy. Herein, it emphasizes knowledge gaps and methodological issues in current Life Cycle Assessment (LCA), underlining the need for standardized techniques and updated data to support robust decision-making for adopting pyrolysis technologies in waste management strategies. For this purpose, this study reviews the LCAs of pyrolytic processes, encompassing the complete life cycle, from feedstock collection to end-product distribution, including elements such as energy consumption, greenhouse gas emissions, and waste creation. Hence, we evaluate diverse pyrolysis processes, including slow, rapid, and catalytic pyrolysis, emphasizing their distinct efficiency and environmental footprints. Furthermore, we evaluate the impact of feedstock composition, process parameters, and scale of operation on the overall sustainability of pyrolysis-based plastic waste treatment by integrating results from current literature and identifying essential research needs. Therefore, this paper argues that existing LCA studies need more coherence and accuracy. It follows a thorough evaluation of previous research and suggests new insights into methodologies and restrictions.

Influence of carbon coating prepared by microwave pyrolysis on properties of LiNi_(1/3) Mn_(1/3) Co_(1/3) O_2

A novel synthesis method of carbon-coated LiNil/3Mnl/3COl/302 cathode material for lithium-ion battery was reported. The carbon coating was produced from a precursor, glucose, by microwave-pyrolysis method. The prepared powders were characterized by scanning electron microscopy （SEM）, X-ray diffraction （XRD）, X-ray fluorescence （XRF） and charge/discharge tests. XRD results indicate that the carbon coating does not change the phase structure of LiNil/3Mnl/3C01/302 material. SEM results show that the surface of spherical carbon-coated material becomes rough. Electrochemical performance results show that the carbon coating can improve the cycling performance of LiNii/3Mnl/3C01/302. The specific discharge capacity retention of the carbon-coated LiNi1/3Mnt/3Col/30z reached 85.0%-96.0% at the 50th cycle at 0.2C rate, and the specific discharge capacity retention is improved at a high rate.

A high-performance biochar produced from bamboo pyrolysis with in-situ nitrogen doping and activation for adsorption of phenol and methylene blue

Nitrogen doping is a promising method for the preparation of functional carbon materials.In this study,a nitrogen-doped porous coral biochar was prepared by using bamboo as raw material,urea as nitrogen source,and KHCO3 as green activator through in-situ pyrolysis.The structure of the obtained biochar was characterized by various techniques including nitrogen adsorption and desorption,Raman spectroscopy,X-ray photoelectron spectrometer,and etc.The adsorption properties of nitrogen-doped biochar were evaluated with phenol and methylene blue probes.The results showed that the nitrogen source ratio had a significant effect on the evolution of pore structure of biochar.Low urea addition ratio was beneficial to the development of pore structures.The optimum specific surface area of nitrogen-doped biochar could be up to 1693 m^2·g^-1.Nitrogen doping can effectively improve the adsorption capacity of biochar to phenol and methylene blue.Biochar prepared at 973.15 K with low urea addition ratio exhibited the highest adsorption capacity for phenol and methylene blue,and the equilibrium adsorption capacity was 169.0 mg·g^-1 and 499.3 mg·g^-1,respectively.By comparing the adsorption capacity of various adsorbents in related fields,it is proved that the nitrogen-doped biochar prepared in this study has a good adsorption effect.

Offgas Analysis and Pyrolysis Mechanism of Activated Carbon from Bamboo Sawdust by Chemical Activation With KOH

Bamboo sawdust was used as the precursor for the multipurpose use of waste. Offgases released during the activation process of bamboo by KOH were investigated quantitatively and qualitatively by a gas analyzer. TG/DTG curves during the pyrolysis process with different impregnation weight ratios （KOH to bamboo） were obtained by a thermogravimetric analyzer. Pyrolysis mechanism of bamboo was proposed. The results showed that the offgases were composed of CO, NO, SO2 and hydrocarbon with the concentration of 1 372, 37, 86, 215 mg/L, respectively. Thermogravimetric analysis indicated that the pyrolytic process mainly experienced two steps. The first was the low temperature activation step （lower than 300 ℃）, which was the pre-activation and induction period. The second was the high temperature activation step（higher than 550 ℃）, which was a radial activation followed by pore production. The second process was the key to control the pore distribution of the final product.

N/S co-doped 3D carbon framework prepared by a facile morphology-controlled solid-state pyrolysis method for oxygen reduction reaction in both acidic and alkaline media

Developing high-performance non-precious metal electrocatalysts for oxygen reduction reaction(ORR)is crucial for the commercialization of fuel cells and metal-air batteries.However,doped carbon-based materials only show good ORR activity in alkaline medium,and become less effective in acidic environment.We believe that an appropriate combination of both ionic and electronic transport path,and well dopant distribution of doped carbon-based materials would help to realize high ORR performance un-der both acidic and alkaline cond让ions.Accordingly,a nitrogen and sulfur co-doped carbon framework with hierarchical through-hole structure is fabricated by morphology-controlled solid-state pyrolysis of poly(aniline-co-2-ami no thiophenol)foam.The uniform high concentrations of nitrogen and sulfur,high intrinsic conductivity,and integrated three dimensional ionic and electronic transfer passageways of the 3D porous structure lead to synergistic effects in catalyzing ORR.As a result,the limiting current density of the carbonized poly(aniline-co-2-aminothiophenol)foam is equivalent to commercial Pt/C in acidic environment,and twice the latter in alkaline medium.

DFT Thermodynamic Research of the Pyrolysis Mechanism of the Carbon Matrix PrecursorTol uene for Carbon Material

Based on the experiments, the standard enthalpy△H■of the possible pyrolysis reactions of the carbon matrix precursor toluene was investigated by means of DFT method UB3LYP/ 3-21G *(based on semi-empirical method UAM1 and ab initio method UHF/3-21G*). The com- putation results with UB3LYP/3-21G* coincide with the experimental values well. Then, the mechanism for all types of the pyrolysis reactions of toluene was studied by UB3LYP/3-21G * The geometries of the reactant and the product radicals were optimized, meanwhile, the standard thermodynamic parameters of the pyrolysis reaction at different temperatures (298, 773, 843, 963 and 1 073 K) were calculated. The thermodynamic computation result shows that when the pyrolysis temperature of toluene is lower than 963 K, the reaction path supported by thermody- namics is that the C-H bond of the methyl on the benzene ring breaks and bitoluene form, while the temperature increases (about 1 073 K), the thermodynamic calculation result turns to support the reaction path producing phenyl radicals and methyl radicals. This mechanism is in accord with the experiments.

Sucrose pyrolysis assembling carbon nanotubes on graphite felt using for vanadium redox flow battery positive electrode

In the present paper, multi-walled carbon nanotubes（MWCNTs） are successfully assembled on graphite felt（GF） using sucrose pyrolysis method for the first time. The in situ formed pyrolytic carbon is chosen as the binder because it is essentially carbon materials as well as CNTs and GF which has a natural tendency to achieve high bonding strength and low contact resistance. The MWCNTs/GF electrode is demonstrated to increase surface area, reduce polarization, lower charge transfer resistance and improve energy conversion efficiency comparing with GF. This excellent electrochemical performance is mainly ascribed to the high electro-catalytic activity of MWCNTs and increasing surface area.

Characterization of Carbon Deposits Formed During Plasma Pyrolysis of Xinjiang Candle Coal

Carbon deposits were formed on the reactor wall during plasma pyrolysis of the Xinjiang candle coal in our V-style plasma pyrolysis pilot-plant. The carbon deposits were studied using a scanning electronic microscope （SEM） and the X-ray diffraction （XRD） method. It was found that carbon deposits located at different parts in the reactor exhibited different microscopic patterns. The formation mechanism of the carbon deposits was deduced. The downward increase in the graphitization degree of the carbon deposits was found and interpreted.

A Primary Study on Mechanical Properties of Heat-Treated Wood via in-situ Synthesis of Calcium Carbonate

This study aims to improve the value of fast-growing wood and extend the heat-treated wood utilization using inorganic calcium carbonate(CaCO_(3))crystals via an in-situ synthesis method.CaCl_(2)and Na 2CO_(3)solutions with a concentration ratio of 1:1 were successively introduced into the thermally modified poplar wood obtained by steam heat treatment(HT)at 200℃for 1.5 and 3 h,resulting in the in-situ synthesis of CaCO_(3)crystals inside the heat-treated wood.The filling effect was best at the concentration of 1.2 mol/L.CaCO_(3)was uniformly distributed in the cell cavities of the heat-treated wood,and some of the crystals were embedded in the fissures of the wood cell walls.The morphology of CaCO_(3)crystals was mainly spherical and rhombic polyhedral.Three main types of CaCO_(3)crystals were calcite,vaterite,and aragonite.The HT of poplar wood at 200℃resulted in degrading the chemical components of the wood cell wall.This degradation led to reduced wood mechanical properties,including the surface hardness(HD),modulus of rupture(MOR),and modulus of elasticity(MOE).After CaCO_(3)was in-situ synthesized in the heat-treated wood,the HD increased by 18.36%and 16.35%,and MOR increased by 14.64%and 8.89%,respectively.Because of the CaCO_(3)synthesization,the char residue of the 200℃heat-treated wood samples increased by 9.31%and the maximum weight loss rate decreased by 19.80%,indicating that the filling with CaCO_(3)cannot only improve the mechanical properties of the heat-treated wood but also effectively enhance its thermal stability.

Revealing sodium storage mechanism of hard carbon anodes through in-situ investigation of mechano-electrochemical coupling behavior

Hard carbon(HC)is considered a promising anode material for sodium-ion batteries due to its relatively low price and high specific capacity.However,HC still suffers from unclear reaction mechanisms and unsatisfactory cycling stability.The study of mechano-electrochemical coupling behavior by in-situ measurement techniques is expected to understand the sodium storage and degradation mechanisms.In this paper,the strain and stress evolution of HC anodes at different sodiation/desodiation depths and cycles are investigated by combining electrochemical methods,digital image correlation,and theoretical equations.The observation by monitoring the in-situ strain evolution during the redox process supports the“adsorption-intercalation/filling”mechanism in reduction and the“de-filling/de-intercalation-deso rption”mechanism in oxidation.Further studies have demonstrated that the strain and stress of the electrode show periodic changes accompanied by a continuous accumulation of residual stress during cycles,explaining the capacity degradation mechanism of HC from a mechanical perspective.In addition,when the higher current density is applied,the electrodes experience greater strain and stress associated with the Na+insertion rate.This work clarifies the Na-storage mechanism and the mechano-electrochemical coupling mechanism of HC anodes by in-situ strain measurement,which helps optimize and design the anode materials of sodium-ion batteries from the perspective of interface microstructure and multi-field coupling,such as in situ integrated interface structure design.

Preparation of CaO-containing carbon pellets from coking coal and calcium oxide:Effects of temperature,pore distribution and carbon structure on compressive strength in pyrolysis furnace

CaO-containing carbon pellets(CCCP)were successfully prepared from well-mixed coking coal(CC)and calcium oxide(CaO)and roasted at different pyrolysis temperatures.The effects of temperature,pore distribution,and carbon structure on the compressive strength of CCCP was investigated in a pyrolysis furnace(350-750℃).The results showed that as the roasting temperature increased,the compressive strength also increased and furthermore,structural defects and imperfections in the carbon crystallites were gradually eliminated to form more organized char structures,thus forming high-ordered CC.Notably,the CCCP preheated at 750℃exhibited the highest compressive strength.A positive relationship between the compressive strength and pore-size homogeneity was established.A linear relationship between the com-pressive strength of the CCCP and the average stack height of CC was observed.Additionally,a four-stage caking mechanism was developed.

In-situ carbonization approach for the binder-free Ir-dispersed ordered mesoporous carbon hydrogen evolution electrode

A binder-free Ir-dispersed ordered mesoporous carbon（Ir-OMC） catalytic electrode has been prepared through a designed in-situ carbonization method, which involves coating resorcinol and formaldehyde mixtures with iridium precursors onto the three-dimensional nickel foam framework, followed by insitu calcination in Natmosphere at 800 ℃ for 3 h. This electrode shows a large surface area, ordered mesoporous structure and homogeneous distribution of metal nanoparticles. It presents good activity and stability towards hydrogen evolution reaction, which is attributed to the efficient mass and electron transport from the intimate contact among Ir nanoparticles, ordered mesoporous carbon matrix and 3 D conductive substrate. We hope that this in-situ carbonization synthetic route can also be applied to design more high-performance catalysts for water splitting, fuel cells and other clean energy devices.

Extraordinary Compatibility to Mass Loading and Rate Capability of Hierarchically Porous Carbon Nanorods Electrode Derived from the Waste Tire Pyrolysis Oil

The conversion of waste tire pyrolysis oil(WTPO)into S-doped porous carbon nanorods(labeled as WPCNs)with hierarchical pore structure is realized by a simple template-directed approach.The specific surface area of as-obtained porous carbon nanorods can reach up to 1448 m^(2) g^(−1) without the addition of any activating agent.As the capacitive electrode,WPCNs possess the extraordinary compatibility to capacitance,different electrolyte systems as well as long-term cycle life even at a commercial-level areal mass loading(10 mg cm^(−2)).Besides,only an extremely small capacitance fluctuation is observed under the extreme circumstance(−40 to 80℃),reflecting the excellent high-and low-temperature performance.The relationship between the pore structure and capacitive behavior is analyzed by comparing WPCNs with mesopores-dominated asphalt-derived porous carbon nanorods(APCNs)and micropores-dominated activated carbon.The molecular dynamics simulation further reveals the ion diffusion and transfer ability of the as-prepared carbon materials under different pore size distribution.The total ion flow(NT)of WPCNs calculated by the simulation is obviously larger than APCNs and the N_(T) ratio between them is similar with the experimental average capacitance ratio.Furthermore,this work also provides a valuable strategy to prepare the electrode material with high capacitive energy storage ability through the high value-added utilization of WTPO.

Development review and the prospect of oil shale in-situ catalysis conversion technology

As an unconventional resource, oil shale possesses abundant reserves and significant potential for industrial applications. The rational and efficient development of oil shale resources holds immense importance in reducing national energy demand. In-situ catalytic technology, characterized by its high efficiency, low pollution, and minimal energy consumption, represents a key direction for future oil shale development. This paper provides a comprehensive review of research progress in in-situ oil shale mining technology, oil shale pyrolysis catalysts, the pyrolysis mechanism of kerogen, and the compatibility of different heating processes and catalysts. Furthermore, the paper proposes future research directions and prospects for oil shale in-situ catalytic technology, including reservoir modification, highefficiency catalyst synthesis, injection processes, and high-efficiency heating technology. These insights serve as valuable technical references for the advancement of oil shale in-situ catalytic technology.

Hollow ZIF-67-derived Co@N-doped carbon nanotubes boosting the hydrogenation of phenolic compounds to alcohols

The selective hydrogenation of highly toxic phenolic compounds to generate alcohols with thermal stability,environmental friendliness,and non-toxicity is of great importance.Herein,a series of Co-based catalysts,named Co@NCNTs,were designed and constructed by direct pyrolysis of hollow ZIF-67(HZIF-67)under H_(2)/Ar atmosphere.The evolution of the catalyst surface from the shell layer assembled by ZIF-67-derived particles to the in situ-grown hollow nitrogen-doped carbon nanotubes(NCNTs)with certain length and density is achieved by adjusting the pyrolysis atmosphere and temperature.Due to the synergistic effects of in situ-formed hollow NCNTs,well-dispersed Co nanoparticles,and intact carbon matrix,the as-prepared Co@NCNTs-0.10-450 catalyst exhibits superior catalytic performance in the hydrogenation of phenolic compounds to alcohols.The turnover frequency value of Co@NCNTs-0.10-450is 3.52 h^(-1),5.9 times higher than that of Co@NCNTs-0.40-450 and 4.5 times higher than that of Co@NCNTs-0.10-550,exceeding most previously reported non-noble metal catalysts.Our findings provide new insights into the development of non-precious metal,efficient,and cost-effective metal-organic framework-derived catalysts for the hydrogenation of phenolic compounds to alcohols.

Simple and High-Yield Synthesis of a Thinner Layer of Graphenic Carbon from Coconut Shells

Biomass has become of recent interest as a raw material for‘green’graphenic carbon(GC)since it promotes an environmentally friendly approach.Here,we investigate a single pyrolysis route to synthesize GC from coconut shells which provides a simple method and can produce a high yield,thus being convenient for large-scale pro-duction.The pyrolysis involves a stepped holding process at 350℃ for 1 h and at 650℃ or 900℃ for 3 h.The GC sample resulted at the 900℃ pyrolysis has a thinner sheet,a less porous structure,a higher C/O ratio,and an enhanced electrical conductivity than those pyrolyzed at 650℃.The addition of Na3PO4 catalyst has no signifi-cant effects on the GC structures obtained by this route.The single pyrolysis route generates thinner GC sheets compared to the two-step heat treatment followed by the liquid phase exfoliation(LPE)procedure.Nevertheless,the latter method offers a formation of clean samples with a porous or holey feature which has potential for advanced energy-storage applications.

Basic Properties of Pyrolysis Carbon Black of Waste Tyres and Application of Pyrolysis Carbon Black in Transition Layer Rubber of All Steel Radial Tire

The main chemical composition of pyrolysis carbon black of waste tires is C,O,Cu,Zn and so on.The content of ash and fine powder in pyrolysis carbon black is high,and the 300%elongation stress is high.The difference between pyrolysis carbon black and furnace black N326,which is commonly used in rubber,is obvious compared with chemical property.The pyrolysis carbon black was used to replace furnace black N326 in the transition layer of all steel load Radial tire rubber through experimental study.It was found that the compression heat generation and dynamic loss(Tanδ)of the blend rubber before and after aging were obviously reduced,the elongation at break and resilience increased,while the tensile stress and tear strength decreased by 100%and 300%,but the hardness and tensile strength changed little before and after aging.According to the latest raw material price calculation,15 used tire pyrolysis carbon black instead of furnace carbon black N326 used in all steel Radial tire transition layer rubber application,excluding labor costs,electricity and equipment depreciation,a ton of blended rubber saves about$22.86 in production costs.

Pyrolysis of furfural-acetone resin as matrix precursor for new carbon materials

In order to increase the understanding of the pyrolysis mechanism, Fourier transform infrared spectroscopy (FT-IR) and thermogravimetry-mass spectrometric coupling technique (TG-MS) were used to study the pyrolysis behavior of furfural-acetone resin used for new carbon materials. The curing and carbonization mechanisms of furfural-acetone resin were mainly investigated; structural changes and volatile products evolved during pyrolysis were analyzed. The results indicate that, during pyrolysis of furfural-acetone resin adding 7% (mass fraction) phosphorous acid as curing agent, the rupture of C—O bond in the five-membered heterocycle firstly takes place to release oxygen atoms and then does the C—H bond, which enable the molecular chain to cross-link and condense, then lead to the formation of three dimensional networking structure. With the increase of pyrolyzing temperature, the scission of methyl and the opening of furan ring are generated. As a result, the recomposition of molecular chain structure is generated and a hexatomic fused ring containing double bonds is built. The main volatile products during pyrolysis of furfural- acetone resin are H2O, and a small mount of CO, CO2 and CH4. At elevated temperatures, dehydrogenation takes place and hydrogen gas is evolved.