Lignin has been proved to be a promising precursor for producing carbon foam.The thermal and chemistry properties of lignin during its thermal conversion make it quite unique comparing with other precursors,and the co...Lignin has been proved to be a promising precursor for producing carbon foam.The thermal and chemistry properties of lignin during its thermal conversion make it quite unique comparing with other precursors,and the conversion parameters can clearly affect the properties of the derived products.Therefore,this study systematically investigated the effects of key carbonization parameters on the properties of the resulting carbon foam materials.The findings demonstrate that the performance of the self-shaping lignin-derived carbon foam is simultaneously influenced by the factors that carbonization temperature,heating rate,and carbonization duration.Specifically,the carbonization temperature and carbonization duration have a significant impact on the mechanical performance,where higher temperatures and long carbonization time improve compressive strength and specific strength.Moreover,the data revealed that elevated temperatures,rapid heating rates,and shortened carbonization periods collectively promoted the development of higher porosities and larger pore diameters within the carbon foam structure.Conversely,lower carbonization temperatures,slower heating rates,and extended carbonization durations facilitated the formation of microporous in the carbon foam.This study provides a scientific foundation for optimizing the production of lignin-derived carbon foam with tailored properties and performance characteristics.展开更多
The calcium-containing rare earth solution is generated during the recovery processes of NdFeB waste,which is treated as wastewater by enterprises.In this paper,the carbon dioxide carbonization method was applied to t...The calcium-containing rare earth solution is generated during the recovery processes of NdFeB waste,which is treated as wastewater by enterprises.In this paper,the carbon dioxide carbonization method was applied to the separation of rare earths and calcium in the solution,as well as the preparation of rare earth oxides with a large specific surface.It is shown that the process of CO_(2)carbonization of solution includes reactions such as the dissolution,diffusion and ionization of CO_(2),the carbonate precipitation of rare earth ions,and the neutralization of hydrogen ions.At a pH of 4.5,the carbonization precipitation rate is effectively controlled,enabling homogeneous precipitation and ensuring both high precipitation yield and rare earth oxides purity.In this way,the crystallization of carbonization products is a process dominated by the oriented attachment theory and coexisting with the Ostwald ripening theory,resulting in abundant pores formed by multiple layers of stacking in the products.With the optimal carbonization conditions,the rare earth precipitation yield solution reaches 99.32%.The obtained carbonization products are crystalline(LaCe)(CO_(3))_(3)·8H_(2)O,and the purity of the rare earth oxides is as high as 99.22 wt%.The specific surface area of the rare earth oxides reaches 94.7 m^(2)/g,and its adsorption efficiency for tetracycline hydrochloride in solution can reach 92.6%in a short time.The rare earth oxides are expected to be used as an adsorption material for wastewater treatment and other adsorption environments.展开更多
Ultrafast reaction kinetics is essential for rapid detection,synthesis,and process monitoring,but the intrinsic energy barrier as a basic material property is challenging to tailor.With the involvement of nanointerfac...Ultrafast reaction kinetics is essential for rapid detection,synthesis,and process monitoring,but the intrinsic energy barrier as a basic material property is challenging to tailor.With the involvement of nanointerfacial chemistry,we propose a carbonization-based strategy for achieving ultrafast chemical reaction.In a case study,ultrafast Griess reaction within 1 min through the carbonization of N-(1-naphthalene)ethylenediamine(NETH)was realized.The carbonization-mediated ultrafast reaction is attributed to the synergic action of reduced electrostatic repulsion,enriched reactant concentration,and boosted NETH nucleophilicity.The enhanced reaction kinetics in o-phenylenediamine-Cu^(2)+and ophenylenediamine-ascorbic acid systems validate the universality of carbonization-engineered ultrafast chemical reaction strategy.The finding of this work offers a novel and simple tactic for the fabrication of multifunctional nanoparticles as ultrafast and effective nanoreactants and/or reporters in analytical,biological,and material aspects.展开更多
In this context,an enzyme-induced magnesia carbonization(EIMC)method was proposed for practical healing of rock weathering cracks in term of bio-cementing sandstone grains.For this,a series of experiments were conduct...In this context,an enzyme-induced magnesia carbonization(EIMC)method was proposed for practical healing of rock weathering cracks in term of bio-cementing sandstone grains.For this,a series of experiments were conducted on EIMC mortar samples,and the physicomechanical properties were obtained.The effects of urea pre-hydrolysis time,mass ratio of liquid solution to magnesia,and urea concentration were analyzed.Experimental results indicated that the urea pre-hydrolysis based EIMC method had a better cementation ability of sandstone grain and greater crack surface bonding performance of sandstone than the existing microbial-induced magnesia carbonization(MIMC)method.The optimal bio-cementation conditions were of pre-hydrolysis time of 24 h,mass ratio of liquid solution to magnesia of 1.75,and urea concentration of 1 mol/L.Under these conditions,the peak tensile stress of EIMC mortar samples reached up to 948.45 kPa,and interfacial peak tensile stress of EIMC-sandstone samples reached 608.57 kPa.These values were 118.6%(799.97 kPa)and 123.2%(493.19 kPa)of those of samples bio-cemented by the MIMC method,respectively.The improved bio-cementation performance can be attributed to the pre-hydrolysis of urea,ensuring an adequate supply of CO_(3)^(2-) ions and promoting the magnesia hydration and the brucite carbonization.The increased production of hydrated magnesium carbonates,coupled with formation of the amorphous brucite facilitated by biomolecules,established a denser structure,enhancing the physicomechanical properties.Microcrack development near the interfacial zone of mortar and sandstone was an important factor in the reduced biocementation performance of the MIMC method.The EIMC method is a practical bio-healing method for rock weathering cracks due to the availability of urease and its good cementation properties.展开更多
This study investigates the disparities in the deployment of photovoltaic(PV)technology for carbon emissions reduction across different nations,highlighting the mismatch between countries with high economic capacity a...This study investigates the disparities in the deployment of photovoltaic(PV)technology for carbon emissions reduction across different nations,highlighting the mismatch between countries with high economic capacity and those where PV installation would maximize global decarbonization benefits.This mismatch is discussed based on three key factors influencing decarbonization via PV technology:per capita gross domestic product;carbon intensity of the energy system;and solar resource availability.Current PV deployment is predominantly concentrated in economically advanced countries,and does not coincide with regions where the environmental and economic impact of such installations would be most significant.Through a series of thought experiments,it is demonstrated how alternative prioritization strategies could significantly reduce global carbon emissions.Argument is put forward for a globally coordinated approach to PV deployment,particularly targeting high-impact sunbelt regions,to enhance the efficacy of decarbonization efforts and promote equitable energy access.The study underscores the need for international policies that support sustainable energy transitions in economically less developed regions through workforce development and assistance with the activation of capital.展开更多
Present industrial decarbonization technologies require an active CO_(2)-concentration system,often based on lime reaction or amine binding reactions,which is energy intensive and carries a high CO_(2)-footprint.Here ...Present industrial decarbonization technologies require an active CO_(2)-concentration system,often based on lime reaction or amine binding reactions,which is energy intensive and carries a high CO_(2)-footprint.Here instead,an effective process without active CO_(2)concentration is demonstrated in a new process-termed IC2CNT(Insulationdiffusion facilitated CO_(2) to Carbon Nanomaterial Technology)decarbonization process.Molten carbonates such as Li_(2)CO_(3)(mp 723℃)are highly insoluble to industrial feed gas principal components(N2,O_(2),and H2O).However,CO_(2) can readily dissolve and react in molten carbonates.We have recently characterized high CO_(2) diffusion rates through porous aluminosilicate and calcium-magnesium silicate thermal insulations.Here,the CO_(2) in ambient feed gas passes through these membranes into molten Li_(2)CO_(3).The membrane also concurrently insulates the feed gas from the hot molten carbonate chamber,obviating the need to heat the(non-CO_(2))majority of the feed gas to high temperature.In this insulation facilitated decarbonization process CO_(2)is split by electrolysis in the molten carbonate producing sequestered,high-purity carbon nanomaterials(such as CNTs)and O_(2).展开更多
The recycling of plastics is a significant global concern.Due to the thermosetting properties of melamineformaldehyde(MF)resin plastics,which make heating and melting difficult,their recycling and reuse pose substanti...The recycling of plastics is a significant global concern.Due to the thermosetting properties of melamineformaldehyde(MF)resin plastics,which make heating and melting difficult,their recycling and reuse pose substantial challenges.In this study,we developed nitrogen-doped(N-doped)carbon materials through scalable carbonization of MF resin plastic waste.This metal-free N-doped carbon catalyst achieved a hydrogen peroxide(H_(2)O_(2))production rate of 971.6 mmol gcatalyst^(-1)h^(-1)with a Faradaic efficiency for H_(2)O_(2)(FEH_(2)O_(2))exceeding 90%under acidic conditions.Additionally,a flow cell utilizing this carbon catalyst demonstrated a production rate of 11.3 mol cm^(-2)h^(-1)(22.5 mol g_(catalyst)^(-1)h^(-1))and maintained a record-high current density of approximately 530 mA cm^(-2)over 300 h.In-situ electrochemical surface-enhanced Raman spectroscopy and density functional theory calculations revealed the presence of porphyrin-like carbon defects,which serve as active sites for the continuous and stable generation of^(*)OOH species.The nitrogen-doped carbon materials obtained from large-scale carbonization of MF plastic waste exhibit abundant active sites,making them highly promising electrocatalysts for the two-electron oxygen reduction reaction(2e^(-)ORR).展开更多
Recently great effort s have been focused on designing high-performance microwave absorbers using sustainable biomass resources,but there remains a lack of green and efficient fabrication methods.Herein,inspired by na...Recently great effort s have been focused on designing high-performance microwave absorbers using sustainable biomass resources,but there remains a lack of green and efficient fabrication methods.Herein,inspired by natural porous character of biomass waste,we demonstrated a green one-step route to convert waste coffee grounds into porous C/Fe hybrids,and further explored their potential applications for broadband and high-efficiency microwave absorption.In this design,the WCG-20-750(incorporated 20 wt%Fe(C_(5)H_(7)O_(2))_(3)catalyst and carbonized at 750℃)exhibited porous microstructure with the highest char yield of 55.45 wt%.Furthermore,the as-prepared C/Fe hybrids from WCG-20-750 displayed excellent microwave absorption performances.Typically,the minimum reflection loss(RL_(min))reached to-52.86 dB and the widest effective absorption bandwidth(EAB)was 6.40 GHz at the thickness of 3.0 mm.This work provides an economically viable and environmentally friendly strategy to convert biomass wastes into value-added microwave absorbers,ultimately making contributions to the upcycling of renewable biomass resources and the fostering of sustainable environment.展开更多
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 con...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.展开更多
It is well-established that high carbonization temperature will trigger the enzyme-like activity of carbon-based materials.However,the catalytic mechanism is still ambiguous,which hinders the further rational design o...It is well-established that high carbonization temperature will trigger the enzyme-like activity of carbon-based materials.However,the catalytic mechanism is still ambiguous,which hinders the further rational design of nanomaterials as enzyme mimics.Hereby,N,S-rich carbonized wool nanosheets(CWs)were synthesized at different pyrolysis temperatures.As expected,only CWs treated with high-temperature possess intrinsic oxidase-and peroxidase-like activities.Meanwhile,density functional theory(DFT)calculations demonstrate that graphitic nitrogen and the co-existence of nitrogen and sulfur in the carbon matrix serve as the active sites for the enzyme-like process.More importantly,combining theoretical calculations and experimental observations,the high-temperature triggered catalytic mechanism can be ascribed to the fact that an appropriate high-temperature maximizes the graphitization degree to a certain extent,at which most of the catalytic active sites are well retained rather than evaporating.Moreover,coupling with excellent photothermal conversion efficiency and catalytic performance,CWs can be applied to photothermal-catalytic cancer therapy under near-infrared region(NIR)light irradiation.We believe this work will contribute to understanding the catalytic mechanism of carbon-based nanozymes and promote the development of new biomedical and pharmaceutical applications.展开更多
High-density carbon/carbon(C/C)composite plays a critical role in the aerospace industry owing to excellent mechanical properties and resistance to ablation.However,traditional manufacturing relies on pitch precursor ...High-density carbon/carbon(C/C)composite plays a critical role in the aerospace industry owing to excellent mechanical properties and resistance to ablation.However,traditional manufacturing relies on pitch precursor and hot isostatic pressure impregnation and carbonization(HIPIC)technology,which is time-consuming and expensive.In this study,we report an innovative method utilizing polyarylacetylene(PAA)resin and ultra-high pressure impregnation and carbonization(UHPIC)technology.The extremely high char yield of PAA resin(85 wt.%)and high isotropic pressure of UHPIC(over 200 MPa)promote the densification of the composite.As a result,we achieve a high-density(1.90 g/cm^(3))C/C composite with a high degree of graphitization(81%).This composite exhibits impressive properties,including flexural strength of 146 MPa,compressive strength of 187 MPa,and thermal conductivity of 147 W/(m K).When exposed to oxyacetylene flame at 3000 K for 100 s,it displays minimal linear ablation,with a rate of 1.27×10^(-2)mm/s.This study demonstrates the exceptional graphitizable characteristic of PAA resin,setting it apart from conventional resins.Our time-saving and cost-effective approach holds significant promise for aerospace applications,particularly in harsh aerodynamic heating environments.展开更多
Herein we study the economic performance of hydrochar and synthetic natural gas coproduction from olive tree pruning.The process entails a combination of hydrothermal carbonization and methanation.In a previous work,w...Herein we study the economic performance of hydrochar and synthetic natural gas coproduction from olive tree pruning.The process entails a combination of hydrothermal carbonization and methanation.In a previous work,we evidenced that standalone hydrochar production via HTC results unprofitable.Hence,we propose a step forward on the process design by implementing a methanation,adding value to the gas effluent in an attempt to boost the overall process techno-economic aspects.Three different plant capacities were analyzed(312.5,625 and 1250 kg/hr).The baseline scenarios showed that,under the current circumstances,our circular economy strategy in unprofitable.An analysis of the revenues shows that hydrochar selling price have a high impact on NPV and subsidies for renewable coal production could help to boost the profitability of the process.On the contrary,the analysis for natural gas prices reveals that prices 8 times higher than the current ones in Spain must be achieved to reach profitability.This seems unlikely even under the presence of a strong subsidy scheme.The costs analysis suggests that a remarkable electricity cost reduction or electricity consumption of the HTC stage could be a potential strategy to reach profitability scenarios.Furthermore,significant reduction of green hydrogen production costs is deemed instrumental to improve the economic performance of the process.These results show the formidable techno-economic challenge that our society faces in the path towards circular economy societies.展开更多
In order to obtain liquefied products with higher yields of aromatic molecules to produce mesophase pitch,a good understanding of the relevant reaction mechanisms is required.Reactive molecular dynamics simulations we...In order to obtain liquefied products with higher yields of aromatic molecules to produce mesophase pitch,a good understanding of the relevant reaction mechanisms is required.Reactive molecular dynamics simulations were used to study the thermal reactions of pyrene,1-methylpyrene,7,8,9,10-tetrahydrobenzopyrene,and mixtures of pyrene with 1-octene,cyclohexene,or styrene.The reactant conversion rates,reaction rates,and product distributions were calculated and compared,and the mechanisms were analyzed and discussed.The results demonstrated that methyl and naphthenic structures in aromatics might improve the conversion rates of reactants in hydrogen transfer processes,but their steric hindrances prohibited the generation of high polymers.The naphthenic structures could generate more free radicals and presented a more obvious inhibition effect on the condensation of polymers compared with the methyl side chains.It was discovered that when different olefins were mixed with pyrene,1-octene primarily underwent pyrolysis reactions,whereas cyclohexene mainly underwent hydrogen transfer reactions with pyrene and styrene,mostly producing superconjugated biradicals through condensation reactions with pyrene.In the mixture systems,the olefins scattered aromatic molecules,hindering the formation of pyrene trimers and higher polymers.According to the reactive molecular dynamics simulations,styrene may enhance the yield of dimer and enable the controlled polycondensation of pyrene.展开更多
Objective:To describe the clinical fea-tures of delayed post-hypoxic leukoencephalopathy after smoke inhalation from dry burning.Methods:We col-lected the clinical history and examination data of a pa-tient who presen...Objective:To describe the clinical fea-tures of delayed post-hypoxic leukoencephalopathy after smoke inhalation from dry burning.Methods:We col-lected the clinical history and examination data of a pa-tient who presented with delayed post-hypoxic leukoen-cephalopathy due to smoke poisoning.Results:Patients exposed to heavy smoke from dry burning carbonization can develop delayed post-hypoxic leukoencephalopathy.Conclusion:Delayed post-hypoxic leukoencephalopa-thy after smoke poisoning during cooking is rare.Fam-ily should bring patients to a hospital as soon as possi-ble when observing abnormal neurologic symptoms after smoke inhalation to prevent irreversible damage to the brain.展开更多
Two-dimensional porous carbon nanosheets(PCNSs)are considered promising anodes for lithium-ion batteries due to their synergetic features arising from both graphene and porous structures.Herein,using naturally abundan...Two-dimensional porous carbon nanosheets(PCNSs)are considered promising anodes for lithium-ion batteries due to their synergetic features arising from both graphene and porous structures.Herein,using naturally abundant and biocompatible sodium humate(SH)as the precursor,PCNSs are prepared from the laboratory scale up to the kilogram scale by a method of a facile ice-templating-induced puzzle coupled with a carbonization strategy.Such obtained SH-derived PCNSs(SH-PCNSs)possess a hierarchical porous structure dominated by mesopores having a specific surface area(~127.192 g^(−1)),pore volume(~0.134 cm3 g^(−1)),sheet-like morphology(~2.18nm in thickness),and nitrogen/oxygen-containing functional groups.Owing to these merits,the SH-PCNSs present impressive Li-ion storage characteristics,including high reversible capacity(1011mAh g^(−1) at 0.1 A g^(−1)),excellent rate capability(465mAh g^(−1) at 5 A g^(−1)),and superior cycle stability(76.8%capacitance retention after 1000 cycles at 5 A g^(−1)).It is noted that the SH-PCNSs prepared from the kilogram-scale production procedure possess comparable electrochemical properties.Furthermore,coupling with a LiNi1/3Co1/3Mn1/3O2 cathode,the full cells deliver a high capacity of 167mAh g^(−1) at 0.2A g^(−1) and exhibit an outstanding energy density of 128.8Whkg^(−1),highlighting the practicability of this porous carbon nanosheets and the potential commercial opportunity of the scalable processing approach.展开更多
It is hypothesized and demonstrated that thermal insulation membranes can provide an effective barrier to heat flow and simultaneously facilitate effective CO_(2)diffusion.Decarbonization technology often requires a C...It is hypothesized and demonstrated that thermal insulation membranes can provide an effective barrier to heat flow and simultaneously facilitate effective CO_(2)diffusion.Decarbonization technology often requires a CO_(2)concentration system,often based on amine binding or lime reaction,which is energy intensive and carries a high carbon footprint.Alternatively,C2CNT electrolytic molten carbonate decarbonization does not require CO_(2)pre-concentration and also provides a useful product(graphene nanocarbons)from the captured CO_(2).Here,a method of effective CO_(2)diffusion is demonstrated that simultaneously thermally insulates the decarbonization source gas from the high-temperature C2CNT system.Open pore,low-density,thermal insulations are implemented as membranes that facilitate effective CO_(2)diffusion for high-temperature decarbonization.Selected,high-temperature,strongly thermal insulating,silica composites are measured with porosities,,exceeding 0.9(>90%porosity),and which display,as measured by SEM,large open channels facilitating CO_(2)diffusion.A derived and experimentally verified estimate for the CO_(2)diffusion constant through these membranes is DM-porous=ε^(3/2)DCO_(2),where DCO_(2)is the diffusion constant in air.DM-porous is applicable to a wide-range of CO_(2)concentrations both in the air and N2.The CO_(2)diffusion constant is translated to the equivalent decarbonization system mole influx of CO_(2)and shown capable of sustaining high rates of CO_(2)removal.Combined with the strong electrolyte affinity for CO_(2)compared to N_(2),O_(2),or H_(2)O,the system comprises a framework for decarbonization without pre-concentration of CO_(2).展开更多
Ensuring the timely and precise monitoring of severe liver diseases is crucial for guiding effective therapies and significantly extending overall quality of life.However,this remains a worldwide challenge,given the h...Ensuring the timely and precise monitoring of severe liver diseases is crucial for guiding effective therapies and significantly extending overall quality of life.However,this remains a worldwide challenge,given the high incidence rate and the presence of strong confounding clinical symptoms.Herein,we applied a convenient and high-yield method to prepare the magnetic mesoporous carbon(MMC-Fe),guided by a composite of resol and triblock copolymer.With the combination of MMC-Fe,high-throughput mass spectrometry,and a simple machine learning algorithm,we extracted N-glycan profiles from various serum samples,including healthy controls,liver cirrhosis,and liver cancer,and from which we screened specific N-glycans.Specifically,the selected N-glycans demonstrate exceptional performance with area under the curve(AUC)values ranging from 0.948 to 0.993 for the detection of liver diseases,including alpha fetoprotein(AFP)-negative liver cancer.Among them,five N-glycans holds potential in monitoring distinctions between liver cirrhosis and AFP-negative liver cancer(AUC values of 0.827–0.842).This study is expected to promote the glycan-based precise monitoring of diseases,not limited to liver disease.展开更多
Under the pressure of environmental issues,decarbonization of the entire energy system has emerged as a prevalent strategy worldwide.The evolution of China’s power system will increasingly emphasize the integration o...Under the pressure of environmental issues,decarbonization of the entire energy system has emerged as a prevalent strategy worldwide.The evolution of China’s power system will increasingly emphasize the integration of variable renewable energy(VRE).However,the rapid growth of VRE will pose substantial challenges to the power system,highlighting the importance of power system planning.This letter introduces Grid Optimal Planning Tool(GOPT),a planning tool,and presents the key findings of our research utilizing GOPT to analyze the transition pathway of China’s power system towards dual carbon goals.Furthermore,the letter offers insights into key technologies essential for driving the future transition of China’s power system.展开更多
Porous carbon materials were prepared by hydrothermal carbonization(HTC) and KOH activation of camphor leaves and camellia leaves. The morphology, pore structure, chemical properties and CO2 capture ability of the por...Porous carbon materials were prepared by hydrothermal carbonization(HTC) and KOH activation of camphor leaves and camellia leaves. The morphology, pore structure, chemical properties and CO2 capture ability of the porous carbon prepared from the two leaves were compared. The effect of HTC temperature on the structure and CO2 adsorption properties was especially investigated. It was found that HTC temperature had a major effect on the structure of the product and the ability to capture CO2. The porous carbon materials prepared from camellia leaves at the HTC temperature of 240℃ had the highest proportion of microporous structure, the largest specific surface area(up to 1823.77m^2/g) and the maximum CO2 adsorption capacity of 8.30mmol/g at 25℃ under 0.4 MPa. For all prepared porous carbons, simulation results of isothermal adsorption model showed that Langmuir isotherm model described the adsorption equilibrium data better than Freundlich isotherm model. For porous carbons prepared from camphor leaves, pseudo-first order kinetic model was well fitted with the experimental data. However,for porous carbons prepared from camellia leaves, both pseudo-first and pseudo-second order kinetics model adsorption behaviors were present. The porous carbon materials prepared from tree leaves provided a feasible option for CO2 capture with low cost, environmental friendship and high capture capability.展开更多
Bamboo was carbonized at different temperatures ranging from 200℃to 600℃.The dependence of the change of hemicellulose,cellulose,and lignin on the temperature was investigated by means of elemental analysis and Four...Bamboo was carbonized at different temperatures ranging from 200℃to 600℃.The dependence of the change of hemicellulose,cellulose,and lignin on the temperature was investigated by means of elemental analysis and Fourier Transform Infrared(FTIR)spectra of the residual solid products.The results showed:(1)Below 200℃,hemicellulose in bamboo was de-composed and a large amount of hydroxyl groups are dislocated from hemicellulose and cellulose,accompanied by the evolu-tion of water to escape.(2)200℃-250℃,cellulose in bamboo was drastically decomposed whereas the net structure of lignin keep stable,with the except of the dislocation of methoxyl groups from lignin.(3)250℃~400℃,the net structure of lignin col-lapse,up to 400’℃,followed by that the more position in aryl groups are substituted.(4)For bamboo carbonization,the aroma-tization of residual carbon has approximately completed at the temperature as high as 600℃.But the fusion of aromatic rings possibly does not occur.展开更多
基金funding support from Taishan Scholars Program of Shandong Province(tsqn201909132)National Natural Science Foundation of China(22208183)+1 种基金Startup Foundation from Qingdao Agricultural University(663-1120040,665-1119020)Technology development project from Jinan Shengquan Company(20233702031771)。
文摘Lignin has been proved to be a promising precursor for producing carbon foam.The thermal and chemistry properties of lignin during its thermal conversion make it quite unique comparing with other precursors,and the conversion parameters can clearly affect the properties of the derived products.Therefore,this study systematically investigated the effects of key carbonization parameters on the properties of the resulting carbon foam materials.The findings demonstrate that the performance of the self-shaping lignin-derived carbon foam is simultaneously influenced by the factors that carbonization temperature,heating rate,and carbonization duration.Specifically,the carbonization temperature and carbonization duration have a significant impact on the mechanical performance,where higher temperatures and long carbonization time improve compressive strength and specific strength.Moreover,the data revealed that elevated temperatures,rapid heating rates,and shortened carbonization periods collectively promoted the development of higher porosities and larger pore diameters within the carbon foam structure.Conversely,lower carbonization temperatures,slower heating rates,and extended carbonization durations facilitated the formation of microporous in the carbon foam.This study provides a scientific foundation for optimizing the production of lignin-derived carbon foam with tailored properties and performance characteristics.
基金Project supported by the National Key Research and Development Project of China(2022YFC2905202)Natural Science Foundation of Jiangxi Province(20232ACB204014)Youth Jinggang Scholars Program in Jiangxi Province(QNJG2019056)。
文摘The calcium-containing rare earth solution is generated during the recovery processes of NdFeB waste,which is treated as wastewater by enterprises.In this paper,the carbon dioxide carbonization method was applied to the separation of rare earths and calcium in the solution,as well as the preparation of rare earth oxides with a large specific surface.It is shown that the process of CO_(2)carbonization of solution includes reactions such as the dissolution,diffusion and ionization of CO_(2),the carbonate precipitation of rare earth ions,and the neutralization of hydrogen ions.At a pH of 4.5,the carbonization precipitation rate is effectively controlled,enabling homogeneous precipitation and ensuring both high precipitation yield and rare earth oxides purity.In this way,the crystallization of carbonization products is a process dominated by the oriented attachment theory and coexisting with the Ostwald ripening theory,resulting in abundant pores formed by multiple layers of stacking in the products.With the optimal carbonization conditions,the rare earth precipitation yield solution reaches 99.32%.The obtained carbonization products are crystalline(LaCe)(CO_(3))_(3)·8H_(2)O,and the purity of the rare earth oxides is as high as 99.22 wt%.The specific surface area of the rare earth oxides reaches 94.7 m^(2)/g,and its adsorption efficiency for tetracycline hydrochloride in solution can reach 92.6%in a short time.The rare earth oxides are expected to be used as an adsorption material for wastewater treatment and other adsorption environments.
基金supported by the National Natural Science Foundation of China(Nos.82160153,21505162,22074005,and 22101027)Natural Science Foundation of Hunan Province,China(No.2022SK2102)+1 种基金Hunan Provincial Department of Education Scientific Research Project(No.240994)the Natural Science Foundation of Beijing Municipality(No.2202038).
文摘Ultrafast reaction kinetics is essential for rapid detection,synthesis,and process monitoring,but the intrinsic energy barrier as a basic material property is challenging to tailor.With the involvement of nanointerfacial chemistry,we propose a carbonization-based strategy for achieving ultrafast chemical reaction.In a case study,ultrafast Griess reaction within 1 min through the carbonization of N-(1-naphthalene)ethylenediamine(NETH)was realized.The carbonization-mediated ultrafast reaction is attributed to the synergic action of reduced electrostatic repulsion,enriched reactant concentration,and boosted NETH nucleophilicity.The enhanced reaction kinetics in o-phenylenediamine-Cu^(2)+and ophenylenediamine-ascorbic acid systems validate the universality of carbonization-engineered ultrafast chemical reaction strategy.The finding of this work offers a novel and simple tactic for the fabrication of multifunctional nanoparticles as ultrafast and effective nanoreactants and/or reporters in analytical,biological,and material aspects.
基金supported by the State Key Laboratory for Geo-Mechanics and Deep Underground Engineering,China University of Mining&Technology/China University of Mining&Technology,Beijing(Grant No.SKLGDUEK2214)the National Natural Science Foundation of China(Grant No.42477188)National Key Research and Development Program of China(Grant No.2023YFC3007102).
文摘In this context,an enzyme-induced magnesia carbonization(EIMC)method was proposed for practical healing of rock weathering cracks in term of bio-cementing sandstone grains.For this,a series of experiments were conducted on EIMC mortar samples,and the physicomechanical properties were obtained.The effects of urea pre-hydrolysis time,mass ratio of liquid solution to magnesia,and urea concentration were analyzed.Experimental results indicated that the urea pre-hydrolysis based EIMC method had a better cementation ability of sandstone grain and greater crack surface bonding performance of sandstone than the existing microbial-induced magnesia carbonization(MIMC)method.The optimal bio-cementation conditions were of pre-hydrolysis time of 24 h,mass ratio of liquid solution to magnesia of 1.75,and urea concentration of 1 mol/L.Under these conditions,the peak tensile stress of EIMC mortar samples reached up to 948.45 kPa,and interfacial peak tensile stress of EIMC-sandstone samples reached 608.57 kPa.These values were 118.6%(799.97 kPa)and 123.2%(493.19 kPa)of those of samples bio-cemented by the MIMC method,respectively.The improved bio-cementation performance can be attributed to the pre-hydrolysis of urea,ensuring an adequate supply of CO_(3)^(2-) ions and promoting the magnesia hydration and the brucite carbonization.The increased production of hydrated magnesium carbonates,coupled with formation of the amorphous brucite facilitated by biomolecules,established a denser structure,enhancing the physicomechanical properties.Microcrack development near the interfacial zone of mortar and sandstone was an important factor in the reduced biocementation performance of the MIMC method.The EIMC method is a practical bio-healing method for rock weathering cracks due to the availability of urease and its good cementation properties.
基金supported by the Helmholtz Association within the framework of the innovation platform“Solar TAP”[Az:714-62150-3/1(2023)]co-funded by the European Union(ERC,C2C-PV,project number 101088359)。
文摘This study investigates the disparities in the deployment of photovoltaic(PV)technology for carbon emissions reduction across different nations,highlighting the mismatch between countries with high economic capacity and those where PV installation would maximize global decarbonization benefits.This mismatch is discussed based on three key factors influencing decarbonization via PV technology:per capita gross domestic product;carbon intensity of the energy system;and solar resource availability.Current PV deployment is predominantly concentrated in economically advanced countries,and does not coincide with regions where the environmental and economic impact of such installations would be most significant.Through a series of thought experiments,it is demonstrated how alternative prioritization strategies could significantly reduce global carbon emissions.Argument is put forward for a globally coordinated approach to PV deployment,particularly targeting high-impact sunbelt regions,to enhance the efficacy of decarbonization efforts and promote equitable energy access.The study underscores the need for international policies that support sustainable energy transitions in economically less developed regions through workforce development and assistance with the activation of capital.
文摘Present industrial decarbonization technologies require an active CO_(2)-concentration system,often based on lime reaction or amine binding reactions,which is energy intensive and carries a high CO_(2)-footprint.Here instead,an effective process without active CO_(2)concentration is demonstrated in a new process-termed IC2CNT(Insulationdiffusion facilitated CO_(2) to Carbon Nanomaterial Technology)decarbonization process.Molten carbonates such as Li_(2)CO_(3)(mp 723℃)are highly insoluble to industrial feed gas principal components(N2,O_(2),and H2O).However,CO_(2) can readily dissolve and react in molten carbonates.We have recently characterized high CO_(2) diffusion rates through porous aluminosilicate and calcium-magnesium silicate thermal insulations.Here,the CO_(2) in ambient feed gas passes through these membranes into molten Li_(2)CO_(3).The membrane also concurrently insulates the feed gas from the hot molten carbonate chamber,obviating the need to heat the(non-CO_(2))majority of the feed gas to high temperature.In this insulation facilitated decarbonization process CO_(2)is split by electrolysis in the molten carbonate producing sequestered,high-purity carbon nanomaterials(such as CNTs)and O_(2).
基金supported by the National Natural Science Foundation of China(Grant No.22276123,22025505)the Oceanic Interdisciplinary Program of Shanghai Jiao Tong University(SL2022ZD105)State Key Lab of Metal Matrix Composite。
文摘The recycling of plastics is a significant global concern.Due to the thermosetting properties of melamineformaldehyde(MF)resin plastics,which make heating and melting difficult,their recycling and reuse pose substantial challenges.In this study,we developed nitrogen-doped(N-doped)carbon materials through scalable carbonization of MF resin plastic waste.This metal-free N-doped carbon catalyst achieved a hydrogen peroxide(H_(2)O_(2))production rate of 971.6 mmol gcatalyst^(-1)h^(-1)with a Faradaic efficiency for H_(2)O_(2)(FEH_(2)O_(2))exceeding 90%under acidic conditions.Additionally,a flow cell utilizing this carbon catalyst demonstrated a production rate of 11.3 mol cm^(-2)h^(-1)(22.5 mol g_(catalyst)^(-1)h^(-1))and maintained a record-high current density of approximately 530 mA cm^(-2)over 300 h.In-situ electrochemical surface-enhanced Raman spectroscopy and density functional theory calculations revealed the presence of porphyrin-like carbon defects,which serve as active sites for the continuous and stable generation of^(*)OOH species.The nitrogen-doped carbon materials obtained from large-scale carbonization of MF plastic waste exhibit abundant active sites,making them highly promising electrocatalysts for the two-electron oxygen reduction reaction(2e^(-)ORR).
基金supported by Taishan Scholar Constructive Engineering Foundation(No.tsqn202103079)the Talent Start-up Foundation of Qingdao University of Science and Technology(No.202203870).
文摘Recently great effort s have been focused on designing high-performance microwave absorbers using sustainable biomass resources,but there remains a lack of green and efficient fabrication methods.Herein,inspired by natural porous character of biomass waste,we demonstrated a green one-step route to convert waste coffee grounds into porous C/Fe hybrids,and further explored their potential applications for broadband and high-efficiency microwave absorption.In this design,the WCG-20-750(incorporated 20 wt%Fe(C_(5)H_(7)O_(2))_(3)catalyst and carbonized at 750℃)exhibited porous microstructure with the highest char yield of 55.45 wt%.Furthermore,the as-prepared C/Fe hybrids from WCG-20-750 displayed excellent microwave absorption performances.Typically,the minimum reflection loss(RL_(min))reached to-52.86 dB and the widest effective absorption bandwidth(EAB)was 6.40 GHz at the thickness of 3.0 mm.This work provides an economically viable and environmentally friendly strategy to convert biomass wastes into value-added microwave absorbers,ultimately making contributions to the upcycling of renewable biomass resources and the fostering of sustainable environment.
基金the National Key R&D Program of China(No.2022YFE0208100)the National Natural Science Foundation of China(No.5274316)+1 种基金the Key Research and Development Plan of Anhui Province,China(No.202210700037)the Major Science and Technology Project of Xinjiang Uygur Autonomous Region,China(No.2022A01003).
文摘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.
基金funded by the National Natural Science Foundation of China(Nos.12274356,22275081)Key Laboratory of Pharmaceutical Analysis and Laboratory Medicine(Putian University)(No.PALM 202206)+1 种基金Fujian Province University,the Fundamental Research Funds for the Central Universities(No.20720220022)the 111 Project(No.B16029)。
文摘It is well-established that high carbonization temperature will trigger the enzyme-like activity of carbon-based materials.However,the catalytic mechanism is still ambiguous,which hinders the further rational design of nanomaterials as enzyme mimics.Hereby,N,S-rich carbonized wool nanosheets(CWs)were synthesized at different pyrolysis temperatures.As expected,only CWs treated with high-temperature possess intrinsic oxidase-and peroxidase-like activities.Meanwhile,density functional theory(DFT)calculations demonstrate that graphitic nitrogen and the co-existence of nitrogen and sulfur in the carbon matrix serve as the active sites for the enzyme-like process.More importantly,combining theoretical calculations and experimental observations,the high-temperature triggered catalytic mechanism can be ascribed to the fact that an appropriate high-temperature maximizes the graphitization degree to a certain extent,at which most of the catalytic active sites are well retained rather than evaporating.Moreover,coupling with excellent photothermal conversion efficiency and catalytic performance,CWs can be applied to photothermal-catalytic cancer therapy under near-infrared region(NIR)light irradiation.We believe this work will contribute to understanding the catalytic mechanism of carbon-based nanozymes and promote the development of new biomedical and pharmaceutical applications.
基金supported by the Major Program of National Natural Science Foundation of China(No.52293372).
文摘High-density carbon/carbon(C/C)composite plays a critical role in the aerospace industry owing to excellent mechanical properties and resistance to ablation.However,traditional manufacturing relies on pitch precursor and hot isostatic pressure impregnation and carbonization(HIPIC)technology,which is time-consuming and expensive.In this study,we report an innovative method utilizing polyarylacetylene(PAA)resin and ultra-high pressure impregnation and carbonization(UHPIC)technology.The extremely high char yield of PAA resin(85 wt.%)and high isotropic pressure of UHPIC(over 200 MPa)promote the densification of the composite.As a result,we achieve a high-density(1.90 g/cm^(3))C/C composite with a high degree of graphitization(81%).This composite exhibits impressive properties,including flexural strength of 146 MPa,compressive strength of 187 MPa,and thermal conductivity of 147 W/(m K).When exposed to oxyacetylene flame at 3000 K for 100 s,it displays minimal linear ablation,with a rate of 1.27×10^(-2)mm/s.This study demonstrates the exceptional graphitizable characteristic of PAA resin,setting it apart from conventional resins.Our time-saving and cost-effective approach holds significant promise for aerospace applications,particularly in harsh aerodynamic heating environments.
基金supported by the grants FJC2021–047672-I and FJC2021–048089-Ico-financed by MCIN/AEI/10.13039/501100011033 and the European Union Next Generation EU/PRTR funds+1 种基金sponsored by Spanish Ministry of Science and Innovation through the project PLEC2021–008086 sponsored by MCIN/AEI/10.13039/501100011033 Next Generation Europe and Junta de Andalucía PAIDI program through the project P20_00667MZAMBRANO-2021–19889 excellence grant sponsored by the European Union Next Generation EU program。
文摘Herein we study the economic performance of hydrochar and synthetic natural gas coproduction from olive tree pruning.The process entails a combination of hydrothermal carbonization and methanation.In a previous work,we evidenced that standalone hydrochar production via HTC results unprofitable.Hence,we propose a step forward on the process design by implementing a methanation,adding value to the gas effluent in an attempt to boost the overall process techno-economic aspects.Three different plant capacities were analyzed(312.5,625 and 1250 kg/hr).The baseline scenarios showed that,under the current circumstances,our circular economy strategy in unprofitable.An analysis of the revenues shows that hydrochar selling price have a high impact on NPV and subsidies for renewable coal production could help to boost the profitability of the process.On the contrary,the analysis for natural gas prices reveals that prices 8 times higher than the current ones in Spain must be achieved to reach profitability.This seems unlikely even under the presence of a strong subsidy scheme.The costs analysis suggests that a remarkable electricity cost reduction or electricity consumption of the HTC stage could be a potential strategy to reach profitability scenarios.Furthermore,significant reduction of green hydrogen production costs is deemed instrumental to improve the economic performance of the process.These results show the formidable techno-economic challenge that our society faces in the path towards circular economy societies.
基金financially supported by the National Natural Science Foundation of China(Approval No.42172168).
文摘In order to obtain liquefied products with higher yields of aromatic molecules to produce mesophase pitch,a good understanding of the relevant reaction mechanisms is required.Reactive molecular dynamics simulations were used to study the thermal reactions of pyrene,1-methylpyrene,7,8,9,10-tetrahydrobenzopyrene,and mixtures of pyrene with 1-octene,cyclohexene,or styrene.The reactant conversion rates,reaction rates,and product distributions were calculated and compared,and the mechanisms were analyzed and discussed.The results demonstrated that methyl and naphthenic structures in aromatics might improve the conversion rates of reactants in hydrogen transfer processes,but their steric hindrances prohibited the generation of high polymers.The naphthenic structures could generate more free radicals and presented a more obvious inhibition effect on the condensation of polymers compared with the methyl side chains.It was discovered that when different olefins were mixed with pyrene,1-octene primarily underwent pyrolysis reactions,whereas cyclohexene mainly underwent hydrogen transfer reactions with pyrene and styrene,mostly producing superconjugated biradicals through condensation reactions with pyrene.In the mixture systems,the olefins scattered aromatic molecules,hindering the formation of pyrene trimers and higher polymers.According to the reactive molecular dynamics simulations,styrene may enhance the yield of dimer and enable the controlled polycondensation of pyrene.
文摘Objective:To describe the clinical fea-tures of delayed post-hypoxic leukoencephalopathy after smoke inhalation from dry burning.Methods:We col-lected the clinical history and examination data of a pa-tient who presented with delayed post-hypoxic leukoen-cephalopathy due to smoke poisoning.Results:Patients exposed to heavy smoke from dry burning carbonization can develop delayed post-hypoxic leukoencephalopathy.Conclusion:Delayed post-hypoxic leukoencephalopa-thy after smoke poisoning during cooking is rare.Fam-ily should bring patients to a hospital as soon as possi-ble when observing abnormal neurologic symptoms after smoke inhalation to prevent irreversible damage to the brain.
基金National Natural Science Foundation of China,Grant/Award Numbers:52274261,52074109,52304284Natural Science Foundation of Henan Province,Grant/Award Number:222300420167+4 种基金Research Fund of Henan Key Laboratory of Coal Green Conversion,Grant/Award Number:CGCF202201Program for Science&Technology Innovation Talents in Universities of Henan Province,Grant/Award Number:21HASTIT008Key Scientific Research Project in Colleges and Universities of Henan Province,Grant/Award Numbers:22A430022,24A440003Scientific and Technological Project of Henan Province,Grant/Award Number:212102310564Natural Science Fund from Ningbo Municipal Bureau of Science and Technology,Grant/Award Number:2023J040。
文摘Two-dimensional porous carbon nanosheets(PCNSs)are considered promising anodes for lithium-ion batteries due to their synergetic features arising from both graphene and porous structures.Herein,using naturally abundant and biocompatible sodium humate(SH)as the precursor,PCNSs are prepared from the laboratory scale up to the kilogram scale by a method of a facile ice-templating-induced puzzle coupled with a carbonization strategy.Such obtained SH-derived PCNSs(SH-PCNSs)possess a hierarchical porous structure dominated by mesopores having a specific surface area(~127.192 g^(−1)),pore volume(~0.134 cm3 g^(−1)),sheet-like morphology(~2.18nm in thickness),and nitrogen/oxygen-containing functional groups.Owing to these merits,the SH-PCNSs present impressive Li-ion storage characteristics,including high reversible capacity(1011mAh g^(−1) at 0.1 A g^(−1)),excellent rate capability(465mAh g^(−1) at 5 A g^(−1)),and superior cycle stability(76.8%capacitance retention after 1000 cycles at 5 A g^(−1)).It is noted that the SH-PCNSs prepared from the kilogram-scale production procedure possess comparable electrochemical properties.Furthermore,coupling with a LiNi1/3Co1/3Mn1/3O2 cathode,the full cells deliver a high capacity of 167mAh g^(−1) at 0.2A g^(−1) and exhibit an outstanding energy density of 128.8Whkg^(−1),highlighting the practicability of this porous carbon nanosheets and the potential commercial opportunity of the scalable processing approach.
文摘It is hypothesized and demonstrated that thermal insulation membranes can provide an effective barrier to heat flow and simultaneously facilitate effective CO_(2)diffusion.Decarbonization technology often requires a CO_(2)concentration system,often based on amine binding or lime reaction,which is energy intensive and carries a high carbon footprint.Alternatively,C2CNT electrolytic molten carbonate decarbonization does not require CO_(2)pre-concentration and also provides a useful product(graphene nanocarbons)from the captured CO_(2).Here,a method of effective CO_(2)diffusion is demonstrated that simultaneously thermally insulates the decarbonization source gas from the high-temperature C2CNT system.Open pore,low-density,thermal insulations are implemented as membranes that facilitate effective CO_(2)diffusion for high-temperature decarbonization.Selected,high-temperature,strongly thermal insulating,silica composites are measured with porosities,,exceeding 0.9(>90%porosity),and which display,as measured by SEM,large open channels facilitating CO_(2)diffusion.A derived and experimentally verified estimate for the CO_(2)diffusion constant through these membranes is DM-porous=ε^(3/2)DCO_(2),where DCO_(2)is the diffusion constant in air.DM-porous is applicable to a wide-range of CO_(2)concentrations both in the air and N2.The CO_(2)diffusion constant is translated to the equivalent decarbonization system mole influx of CO_(2)and shown capable of sustaining high rates of CO_(2)removal.Combined with the strong electrolyte affinity for CO_(2)compared to N_(2),O_(2),or H_(2)O,the system comprises a framework for decarbonization without pre-concentration of CO_(2).
基金supported by National Key R&D Program of China(No.2018YFA0507501)the National Natural Science Foundation of China(Nos.22074019,21425518,22004017)Shanghai Sailing Program(No.20YF1405300)。
文摘Ensuring the timely and precise monitoring of severe liver diseases is crucial for guiding effective therapies and significantly extending overall quality of life.However,this remains a worldwide challenge,given the high incidence rate and the presence of strong confounding clinical symptoms.Herein,we applied a convenient and high-yield method to prepare the magnetic mesoporous carbon(MMC-Fe),guided by a composite of resol and triblock copolymer.With the combination of MMC-Fe,high-throughput mass spectrometry,and a simple machine learning algorithm,we extracted N-glycan profiles from various serum samples,including healthy controls,liver cirrhosis,and liver cancer,and from which we screened specific N-glycans.Specifically,the selected N-glycans demonstrate exceptional performance with area under the curve(AUC)values ranging from 0.948 to 0.993 for the detection of liver diseases,including alpha fetoprotein(AFP)-negative liver cancer.Among them,five N-glycans holds potential in monitoring distinctions between liver cirrhosis and AFP-negative liver cancer(AUC values of 0.827–0.842).This study is expected to promote the glycan-based precise monitoring of diseases,not limited to liver disease.
基金supported by the National Natural Science Foundation of China(No.52130702,No.52177093)。
文摘Under the pressure of environmental issues,decarbonization of the entire energy system has emerged as a prevalent strategy worldwide.The evolution of China’s power system will increasingly emphasize the integration of variable renewable energy(VRE).However,the rapid growth of VRE will pose substantial challenges to the power system,highlighting the importance of power system planning.This letter introduces Grid Optimal Planning Tool(GOPT),a planning tool,and presents the key findings of our research utilizing GOPT to analyze the transition pathway of China’s power system towards dual carbon goals.Furthermore,the letter offers insights into key technologies essential for driving the future transition of China’s power system.
基金financially supported by the National Natural Science Foundation of China (Nos. U1760119, 51472160 and U1560108)the Shanghai Nature Science Foundation (No. 16ZR1423400)the Science and Technology Commission of Shanghai Municipality (Nos. 15JC1490700 and 16JC1402200)
文摘Porous carbon materials were prepared by hydrothermal carbonization(HTC) and KOH activation of camphor leaves and camellia leaves. The morphology, pore structure, chemical properties and CO2 capture ability of the porous carbon prepared from the two leaves were compared. The effect of HTC temperature on the structure and CO2 adsorption properties was especially investigated. It was found that HTC temperature had a major effect on the structure of the product and the ability to capture CO2. The porous carbon materials prepared from camellia leaves at the HTC temperature of 240℃ had the highest proportion of microporous structure, the largest specific surface area(up to 1823.77m^2/g) and the maximum CO2 adsorption capacity of 8.30mmol/g at 25℃ under 0.4 MPa. For all prepared porous carbons, simulation results of isothermal adsorption model showed that Langmuir isotherm model described the adsorption equilibrium data better than Freundlich isotherm model. For porous carbons prepared from camphor leaves, pseudo-first order kinetic model was well fitted with the experimental data. However,for porous carbons prepared from camellia leaves, both pseudo-first and pseudo-second order kinetics model adsorption behaviors were present. The porous carbon materials prepared from tree leaves provided a feasible option for CO2 capture with low cost, environmental friendship and high capture capability.
基金This paper was supported by the Innovation Project of Nanjing Forestry University.
文摘Bamboo was carbonized at different temperatures ranging from 200℃to 600℃.The dependence of the change of hemicellulose,cellulose,and lignin on the temperature was investigated by means of elemental analysis and Fourier Transform Infrared(FTIR)spectra of the residual solid products.The results showed:(1)Below 200℃,hemicellulose in bamboo was de-composed and a large amount of hydroxyl groups are dislocated from hemicellulose and cellulose,accompanied by the evolu-tion of water to escape.(2)200℃-250℃,cellulose in bamboo was drastically decomposed whereas the net structure of lignin keep stable,with the except of the dislocation of methoxyl groups from lignin.(3)250℃~400℃,the net structure of lignin col-lapse,up to 400’℃,followed by that the more position in aryl groups are substituted.(4)For bamboo carbonization,the aroma-tization of residual carbon has approximately completed at the temperature as high as 600℃.But the fusion of aromatic rings possibly does not occur.
