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
The resource utilization of sludge can effectively achieve the regeneration and utilization of resources,and promote sustainable economic development.Sludge carbonization is a sludge treatment and disposal technology ...The resource utilization of sludge can effectively achieve the regeneration and utilization of resources,and promote sustainable economic development.Sludge carbonization is a sludge treatment and disposal technology with broad application prospects,and its products have shown significant resource potential in land use,fuel utilization,and other fields.At present,China still faces some challenges in the resource utilization of sludge carbonization,such as issues related to heavy metal stability and outdated standards.In the future,it is necessary to further strengthen research,improve the standard system,and promote the widespread application of sludge carbonization technology,so as to achieve the goals of sludge reduction,harmlessness,and resource utilization and support the development of circular economy.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
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
To overcome the ever-growing organic pollutions in the water system,abundant efforts have been dedicated to fabricating efficient Fenton-like carbon catalysts.However,the rational design of carbon catalysts with high ...To overcome the ever-growing organic pollutions in the water system,abundant efforts have been dedicated to fabricating efficient Fenton-like carbon catalysts.However,the rational design of carbon catalysts with high intrinsic activity remains a long-term goal.Herein,we report a new N-molecule-assisted self-catalytic carbonization process in augmenting the intrinsic Fenton-like activity of metal-organic-framework-derived carbon hybrids.During carbonization,the N-molecules provide alkane/ammonia gases and the formed iron nanocrystals act as the in situ catalysts,which result in the elaborated formation of carbon nanotubes(in situ chemical vapor deposition from alkane/iron catalysts)and micro-/meso-porous structures(ammonia gas etching).The obtained catalysts exhibited with abundant Fe/Fe-Nx/pyridinic-N active species,micro-/meso-porous structures,and conductive carbon nanotubes.Consequently,the catalysts exhibit high efficiency toward the degradation of different organic pollutions,such as bisphenol A,methylene blue,and tetracycline.This study not only creates a new pathway for achieving highly active Fenton-like carbon catalysts but also takes a step toward the customized production of advanced carbon hybrids for diverse energy and environmental applications.展开更多
The carbonization of magnesium oxide particles by CO2 was investigated using a stirring mill reactor. The effects of the system temperature, stirring rotation speed, influx rate of CO2 and initial diameter of the magn...The carbonization of magnesium oxide particles by CO2 was investigated using a stirring mill reactor. The effects of the system temperature, stirring rotation speed, influx rate of CO2 and initial diameter of the magnesium oxide particles on the carbonization process were determined, The results show that the system temperature and the stirring rotation speed are the most significant influencing factors on the carbonization rate. The determi-nation of critical decomposition temperature (CDT) gives the maximum carbonization rate with other conditions fixed. A theoretical model involving mass transfer and reaction kinetics was presented for the carbonization process. The apparent activation energy was calculated to be 32.8kJ·mol-1. The carbonization process is co-controlled by diffusive mass transfer and chemical reaction. The model fits well with the experimental results.展开更多
Coal due to its relatively large quantities and wide distribution worldwide has generated renewed interest in research and development with the aim of establishing coal conversion technologies that are technically rel...Coal due to its relatively large quantities and wide distribution worldwide has generated renewed interest in research and development with the aim of establishing coal conversion technologies that are technically reliable,envi-ronmentally and economically feasible.It has proved to be a prominent energy source in emerging markets with increasing energy demand by accounting for the largest increase in the demand of energy amongst all other energy sources.Fur-thermore,with its higher mesophase content,coal tar is an appropriate raw material for precursors in the production of carbon fiber.However,whenever a material is put to use,it is important to be able to associate its properties to the behavioral characteristics during a conversion process so as to have a basis for opting for the material in a given process or adjusting the operating conditions in order to optimize the material utilization.Therefore,as with any other material,it is important to be able to relate the properties of coal to its utilization.A review was carried out on the influence of coal properties on four main utilization technologies:gasification,carbonization,liquefaction and carbon fibre production.Among several properties rank,type,mineral matter content,distribution of trace elements,structural composition and pore structure were found to be most influential on the behavior of coal during conversion processes.展开更多
Crystallined hybrid carbon was synthesized by the catalytic carbonization of biomass （Pinus kesiya sawdust） at 1100 ℃ and in-situ growth of carbon nanofibers （CNFs） at 750 ℃ from acetylene. The microstructure of...Crystallined hybrid carbon was synthesized by the catalytic carbonization of biomass （Pinus kesiya sawdust） at 1100 ℃ and in-situ growth of carbon nanofibers （CNFs） at 750 ℃ from acetylene. The microstructure of the composite was characterized by scanning electron microscopy （SEM）, X-ray diffraction （XRD）, transmission electron microscopy （TEM） and high-resolution transmission electron microscopy （HRTEM）. It was found that highly crystallined carbon composed of well-aligned graph℃ene layers with interlayer spacing of 0.34 nm can be formed by catalytic carbonization of biomass. However, the structure of the in-situ growing CNFs is lessaligned. Based on the results of the investigation, the formation mechanism of the crystallined hybrid carbon was discussed. Owning to synergistic effect of the highly crystallined carbon and the conductive network formed by CNFs, the crystallined hybrid carbon shows 32.6% lower electrical resistivity than biocarbon. When being used as anode material of lithium-ion batteries （LIBs）, the crystallined hybrid carbon and the biocarbon have nearly the same first coulombic efficiencies （CEs）, however, the former has a discharge capacity of 67% higher than the latter since the second cycle.展开更多
The coal with low moisture during carbonization could not only increase the yield of coke,but also promote the coke quality and reduce the energy consumption.In this paper,the influence of the moisture in the blend co...The coal with low moisture during carbonization could not only increase the yield of coke,but also promote the coke quality and reduce the energy consumption.In this paper,the influence of the moisture in the blend coal(1.8%10.13%)on the product yields and coke quality during coal carbonization were investigated.The results show that the coke yield is increased from 75.90%to 77.16%,and the coke qualities such as coke strength after reaction with CO2(CSR),coke reactivity index(CRI),fragmentation index(M25)and abrasion index(M10))are also improved when the moisture of the blend coal decreases from 10.13%to 1.80%in a bench scale reactor.Due to the secondary reaction,tar become lighter when the moisture is decreased.In order to further prove the above results,the blend coal with 1.8%and 9%10%(common moisture used in coke plant)moisture is carbonized in a coke oven with 6 m height,the results show that CRI are 23.4%and 27.3%,CRS are 67.1%and 62.2%under 1.8%and 9%10%moisture of blend coal.Moreover,the variation of the moisture in blend coal has a limited influence on dust emission at the ascension pipe and the charging car.展开更多
Carbon microspheres were prepared from waste cotton fibers by hydrothermal carbonization(HTC)with the addition of copper sulphate in this work.The important influence factors,temperature,concentration of copper sulpha...Carbon microspheres were prepared from waste cotton fibers by hydrothermal carbonization(HTC)with the addition of copper sulphate in this work.The important influence factors,temperature,concentration of copper sulphate,resident time were explored here.The smooth and regular carbon microspheres could be formed at 330°C with 0.15 wt%copper sulphate after 6 h from waste cotton fibers.The crystal structures of cotton fibers were destructed in a short resident time with 0.15 wt%copper sulphate from SEM images and XRD patterns of solid products.This strategy provides a new,mild and efficient method to prepare carbon microspheres from waste cotton fibers by HTC.FTIR spectra verified that the abundant functional groups existed on the surface of synthesized carbon microspheres.From XPS and element analysis results,the copper sulphate participated in the forming process of carbon microspheres indeed.The presence of copper sulphate in the carbon microspheres provided a possibility for the application in antibacterial field.Besides,the catalytic mechanism of copper sulphate on the hydrolysis and carbonization of waste cotton fibers were also discussed.In conclusion,the copper sulphate is an efficient agent for preparing carbon microspheres by HTC from waste cotton fibers.展开更多
Felt base carbon/carbon composites fabricated by super-high pressure impregnation carbonization process (SPIC) were heat treated at high temperature 2773K. The oxidation properties of felt base carbon/carbon composite...Felt base carbon/carbon composites fabricated by super-high pressure impregnation carbonization process (SPIC) were heat treated at high temperature 2773K. The oxidation properties of felt base carbon/carbon composites were investigated at different temperatures (773-1173K), and the microstructures of carbon/carbon composites were studied by SEM and X-ray diffraction. The experimental results showed that the inter-laminar distance of (002) plane (d002) deceased while the microcrystalline stack height (Lc) increased. The oxidation rate of felt base carbon/carbon composites was invari-able at certain temperatures. The oxidation mechanism of carbon/carbon composites changed remarkably at the oxidation temperature 973K. At the initial oxidation stage of carbon/carbon composites, carbon matrix was oxidized much more rapidly than carbon felt.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
Parent coal tar pitch(CTP)was modified with boric acid(BA),cinnamaldehyde(CMA)and the mixture of BA and CMA,respectively.The parent CTP and three modified CTPs were characterized by elemental analysis,thermogravimetri...Parent coal tar pitch(CTP)was modified with boric acid(BA),cinnamaldehyde(CMA)and the mixture of BA and CMA,respectively.The parent CTP and three modified CTPs were characterized by elemental analysis,thermogravimetric analysis,Fourier transform infrared(FT-IR)spectroscopy and scanning electron microscopy.The four samples were carbonized at different temperatures and resultant carbonized products were characterized by FT-IR spectroscopy,X-ray diffraction and polarized-light microscopy.The results show that the morphologies and carbonization behaviors of the parent CTP and modified CTPs are quite different.The carbonization yield of the CTP modified with the mixture of BA and CMA is higher than that of CTP modified with BA or CMA only.In addition,the modification of CTP with 7 g of BA and 10 ml of CMA results in an increase in carbonization yield by5.64%.During the pyrolysis of modified CTPs,the dehydration of BA or the distillation of CMA occurs at the temperature lower than 300°C,and methyl and methylene groups of the modified CTPs disappear gradually as temperature rises.Furthermore,the modification of CTP by the mixture of BA and CMA results in more intensive mesophase spheres than other modified CTPs,and the modified CTP is easier to be carbonized to form graphitic carbon.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 Scientific Research Start-up Project for the Introduction of Senior Talents of Chongqing Three Gorges Vocational College(sxzyzg-202405).
文摘The resource utilization of sludge can effectively achieve the regeneration and utilization of resources,and promote sustainable economic development.Sludge carbonization is a sludge treatment and disposal technology with broad application prospects,and its products have shown significant resource potential in land use,fuel utilization,and other fields.At present,China still faces some challenges in the resource utilization of sludge carbonization,such as issues related to heavy metal stability and outdated standards.In the future,it is necessary to further strengthen research,improve the standard system,and promote the widespread application of sludge carbonization technology,so as to achieve the goals of sludge reduction,harmlessness,and resource utilization and support the development of circular economy.
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.
基金supported by the National Key R&D Program of China(2019YFA0110600 and 2019YFA0110601)National Natural Science Foundation of China(Nos.51603134,51903178,51803134,and 51703141)+1 种基金Sichuan Province’s Science and Technology Planning Project(No.2016GZ0350)the Postgraduate Course Construction Project of Sichuan University(No.2017KCSJ036)and for their financial support.
文摘To overcome the ever-growing organic pollutions in the water system,abundant efforts have been dedicated to fabricating efficient Fenton-like carbon catalysts.However,the rational design of carbon catalysts with high intrinsic activity remains a long-term goal.Herein,we report a new N-molecule-assisted self-catalytic carbonization process in augmenting the intrinsic Fenton-like activity of metal-organic-framework-derived carbon hybrids.During carbonization,the N-molecules provide alkane/ammonia gases and the formed iron nanocrystals act as the in situ catalysts,which result in the elaborated formation of carbon nanotubes(in situ chemical vapor deposition from alkane/iron catalysts)and micro-/meso-porous structures(ammonia gas etching).The obtained catalysts exhibited with abundant Fe/Fe-Nx/pyridinic-N active species,micro-/meso-porous structures,and conductive carbon nanotubes.Consequently,the catalysts exhibit high efficiency toward the degradation of different organic pollutions,such as bisphenol A,methylene blue,and tetracycline.This study not only creates a new pathway for achieving highly active Fenton-like carbon catalysts but also takes a step toward the customized production of advanced carbon hybrids for diverse energy and environmental applications.
文摘The carbonization of magnesium oxide particles by CO2 was investigated using a stirring mill reactor. The effects of the system temperature, stirring rotation speed, influx rate of CO2 and initial diameter of the magnesium oxide particles on the carbonization process were determined, The results show that the system temperature and the stirring rotation speed are the most significant influencing factors on the carbonization rate. The determi-nation of critical decomposition temperature (CDT) gives the maximum carbonization rate with other conditions fixed. A theoretical model involving mass transfer and reaction kinetics was presented for the carbonization process. The apparent activation energy was calculated to be 32.8kJ·mol-1. The carbonization process is co-controlled by diffusive mass transfer and chemical reaction. The model fits well with the experimental results.
基金I would like to express my heart felt gratitude to the management,academic and support staff of Botswana International University of Science and Technology for providing access to the resources of the institution during the study carried out for this review.
文摘Coal due to its relatively large quantities and wide distribution worldwide has generated renewed interest in research and development with the aim of establishing coal conversion technologies that are technically reliable,envi-ronmentally and economically feasible.It has proved to be a prominent energy source in emerging markets with increasing energy demand by accounting for the largest increase in the demand of energy amongst all other energy sources.Fur-thermore,with its higher mesophase content,coal tar is an appropriate raw material for precursors in the production of carbon fiber.However,whenever a material is put to use,it is important to be able to associate its properties to the behavioral characteristics during a conversion process so as to have a basis for opting for the material in a given process or adjusting the operating conditions in order to optimize the material utilization.Therefore,as with any other material,it is important to be able to relate the properties of coal to its utilization.A review was carried out on the influence of coal properties on four main utilization technologies:gasification,carbonization,liquefaction and carbon fibre production.Among several properties rank,type,mineral matter content,distribution of trace elements,structural composition and pore structure were found to be most influential on the behavior of coal during conversion processes.
基金supported by the National Natural Science Foundation of China(No.51264016)the Natural Science Foundation of Yunnan Province of China(No.2009ZC006X)+1 种基金the Scientific Research Foundation of Kunming University of Science and Technology,China(No.2009-027)the Analysis and Testing Foundation of Kunming University of Science and Technology,China(No.2011458)
文摘Crystallined hybrid carbon was synthesized by the catalytic carbonization of biomass （Pinus kesiya sawdust） at 1100 ℃ and in-situ growth of carbon nanofibers （CNFs） at 750 ℃ from acetylene. The microstructure of the composite was characterized by scanning electron microscopy （SEM）, X-ray diffraction （XRD）, transmission electron microscopy （TEM） and high-resolution transmission electron microscopy （HRTEM）. It was found that highly crystallined carbon composed of well-aligned graph℃ene layers with interlayer spacing of 0.34 nm can be formed by catalytic carbonization of biomass. However, the structure of the in-situ growing CNFs is lessaligned. Based on the results of the investigation, the formation mechanism of the crystallined hybrid carbon was discussed. Owning to synergistic effect of the highly crystallined carbon and the conductive network formed by CNFs, the crystallined hybrid carbon shows 32.6% lower electrical resistivity than biocarbon. When being used as anode material of lithium-ion batteries （LIBs）, the crystallined hybrid carbon and the biocarbon have nearly the same first coulombic efficiencies （CEs）, however, the former has a discharge capacity of 67% higher than the latter since the second cycle.
基金Project(51706160)supported by the National Natural Science Foundation of ChinaProject(T201906)supported by the Foundation for Outstanding Youth Innovative Research Groups of Higher Education Institution in Hubei Province,China
文摘The coal with low moisture during carbonization could not only increase the yield of coke,but also promote the coke quality and reduce the energy consumption.In this paper,the influence of the moisture in the blend coal(1.8%10.13%)on the product yields and coke quality during coal carbonization were investigated.The results show that the coke yield is increased from 75.90%to 77.16%,and the coke qualities such as coke strength after reaction with CO2(CSR),coke reactivity index(CRI),fragmentation index(M25)and abrasion index(M10))are also improved when the moisture of the blend coal decreases from 10.13%to 1.80%in a bench scale reactor.Due to the secondary reaction,tar become lighter when the moisture is decreased.In order to further prove the above results,the blend coal with 1.8%and 9%10%(common moisture used in coke plant)moisture is carbonized in a coke oven with 6 m height,the results show that CRI are 23.4%and 27.3%,CRS are 67.1%and 62.2%under 1.8%and 9%10%moisture of blend coal.Moreover,the variation of the moisture in blend coal has a limited influence on dust emission at the ascension pipe and the charging car.
基金by the National Nature Science Foundation of the People’s Republic of China(No.51703153).
文摘Carbon microspheres were prepared from waste cotton fibers by hydrothermal carbonization(HTC)with the addition of copper sulphate in this work.The important influence factors,temperature,concentration of copper sulphate,resident time were explored here.The smooth and regular carbon microspheres could be formed at 330°C with 0.15 wt%copper sulphate after 6 h from waste cotton fibers.The crystal structures of cotton fibers were destructed in a short resident time with 0.15 wt%copper sulphate from SEM images and XRD patterns of solid products.This strategy provides a new,mild and efficient method to prepare carbon microspheres from waste cotton fibers by HTC.FTIR spectra verified that the abundant functional groups existed on the surface of synthesized carbon microspheres.From XPS and element analysis results,the copper sulphate participated in the forming process of carbon microspheres indeed.The presence of copper sulphate in the carbon microspheres provided a possibility for the application in antibacterial field.Besides,the catalytic mechanism of copper sulphate on the hydrolysis and carbonization of waste cotton fibers were also discussed.In conclusion,the copper sulphate is an efficient agent for preparing carbon microspheres by HTC from waste cotton fibers.
文摘Felt base carbon/carbon composites fabricated by super-high pressure impregnation carbonization process (SPIC) were heat treated at high temperature 2773K. The oxidation properties of felt base carbon/carbon composites were investigated at different temperatures (773-1173K), and the microstructures of carbon/carbon composites were studied by SEM and X-ray diffraction. The experimental results showed that the inter-laminar distance of (002) plane (d002) deceased while the microcrystalline stack height (Lc) increased. The oxidation rate of felt base carbon/carbon composites was invari-able at certain temperatures. The oxidation mechanism of carbon/carbon composites changed remarkably at the oxidation temperature 973K. At the initial oxidation stage of carbon/carbon composites, carbon matrix was oxidized much more rapidly than carbon felt.
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Supported by the Natural Science Foundation of Shaanxi Province（2009GM6001-1） the Foundation for Fundamental Research of Northwestern Polytechnical University（JC201030）
文摘Parent coal tar pitch(CTP)was modified with boric acid(BA),cinnamaldehyde(CMA)and the mixture of BA and CMA,respectively.The parent CTP and three modified CTPs were characterized by elemental analysis,thermogravimetric analysis,Fourier transform infrared(FT-IR)spectroscopy and scanning electron microscopy.The four samples were carbonized at different temperatures and resultant carbonized products were characterized by FT-IR spectroscopy,X-ray diffraction and polarized-light microscopy.The results show that the morphologies and carbonization behaviors of the parent CTP and modified CTPs are quite different.The carbonization yield of the CTP modified with the mixture of BA and CMA is higher than that of CTP modified with BA or CMA only.In addition,the modification of CTP with 7 g of BA and 10 ml of CMA results in an increase in carbonization yield by5.64%.During the pyrolysis of modified CTPs,the dehydration of BA or the distillation of CMA occurs at the temperature lower than 300°C,and methyl and methylene groups of the modified CTPs disappear gradually as temperature rises.Furthermore,the modification of CTP by the mixture of BA and CMA results in more intensive mesophase spheres than other modified CTPs,and the modified CTP is easier to be carbonized to form graphitic carbon.
