The rapid development of iron and steel metallurgy technology has promoted the continuous innovation and iteration of carbon-containing refractories for clean steel smelting.To meet the high-quality requirements for c...The rapid development of iron and steel metallurgy technology has promoted the continuous innovation and iteration of carbon-containing refractories for clean steel smelting.To meet the high-quality requirements for clean steel production and full exploit the performance advantages of carbon-containing refractories in dynamic smelting environment,it is necessary to explore the role of graphite and modified graphite in carbon-containing refractories.Based on this,graphite surface modification methods,including surfactants,surface oxidation,and surface coating,and their applications in carbon-containing refractories are reviewed.The advantages and disadvantages of each method are analyzed for practical use.Furthermore,combined with the existing problems,the application prospect of improved graphite in carbon-containing refractories is discussed.展开更多
To avoid the nonuniform phenomena of heat and mass transfer of metallurgical powdery materials caused by conventional heating method,the temperature rise characteristics of carbon-containing chromite ore fines in the ...To avoid the nonuniform phenomena of heat and mass transfer of metallurgical powdery materials caused by conventional heating method,the temperature rise characteristics of carbon-containing chromite ore fines in the microwave field were investigated using microwave heating in a microwave metallurgical furnace.The experimental results show that the carbon-containing chromite ore fines have better temperature rise characteristics in the microwave field at a frequency of 2.45 GHz.After heated in the microwave field of 10 kW,the temperature of 1 kg carbon-containing chromite ore fines rose up to 1 100 ℃ in 7 min,at a temperature rise rate of 157.1（℃·min-1·kg-1）,whereas the temperature of 1 kg carbon-containing magnetite ore fines rose only up to 1 000 ℃ in 10 min,at a temperature rise rate of 100（℃·min-1·kg-1）.With increasing carbon-fitting ratios and by adding calcic lime,their heating effects changed regularly.展开更多
Lithium-sulfur batteries(LSBs)have become promising next-generation energy storage technologies for electric vehicles and portable electronics,due to its excellent theoretical specific energy.However,the low conductiv...Lithium-sulfur batteries(LSBs)have become promising next-generation energy storage technologies for electric vehicles and portable electronics,due to its excellent theoretical specific energy.However,the low conductivity of sulfur species,notorious lithium dendrites,the severe"shuttle effect"of polysulfides(LiPSs)and the inferior kinetic reaction for LiPSs/Li_(2)S conversion during discharge-charge have seriously hindered their practical application,and also pose potential safety hazards.Owing to their superior porous architectures,high specific surface areas,excellent structural designability,functional modifiability,abundant active sites and flexibility of carbon-containing electrospun nanofibers(CENFs),they exhibited the superior characteristics that can simultaneously solve the above issues.In this review,we summarize the recent progress and application of CENFs in LSBs.First,we provide a brief introduction to the structure and composition controlled of carbon nanofibers by electrospinning.We then review progress in recent developments of CENFs for LSBs including cathodes,anodes,separators,and interlayers.We focus on how to solve practical issues that arise when the CENFs are applied to various parts of LSBs,and the relevant working mechanisms are described,from high sulfur loading and Li dendrites suppression to LiPSs’confinement and conversion.Finally,we summarize and propose the existing challenges and future prospects of CENFs,for the design and architecture of electrochemical components in Li-S energy storage systems.展开更多
In this paper, X-ray diffractogram analysis and SEM observation of Al$ C$ formed at high temperature from carbon-containing refractories ivith Al have been carried out. Aluminum added to carbon-containing refractories...In this paper, X-ray diffractogram analysis and SEM observation of Al$ C$ formed at high temperature from carbon-containing refractories ivith Al have been carried out. Aluminum added to carbon-containing refractories reacts with C（s） to form Al^ C^（s） gradually during heating from 600 ’C to 1200^0 . It is considered that the interlocked structure of Al^ C-$ plate crystals promotes the outstanding increase of hot modulus of rupture of carbon-containing refractories with Al. The HMOR of carbon-containing refractories added with Al additive from 0 to 5wt% increases by 2.8 times being from 6.5MPa to 18.2MPa. After a thermochemical calculation for hydration reaction processes ofAl^C^ and H^O （g）, the equilibrium partial pressure chart ofH^O （g） in H^O-A^C^-Al^ OH)} system vs various temperatures has been attained . The H2 0 （g） partial pressure in the air needed for the Al^ C3 hydration reaction is no more than 10;18 atm at the temperature below 120t . It is considered that the burned carbon-containing re展开更多
A study was carried out on the volatilization kinetics of Zn in the pellets made of Zn-bearing dusts mixed with coal powder in a nitrogen atmosphere and within the temperature range between 1 100℃and 1 300℃. The stu...A study was carried out on the volatilization kinetics of Zn in the pellets made of Zn-bearing dusts mixed with coal powder in a nitrogen atmosphere and within the temperature range between 1 100℃and 1 300℃. The study shows that the reduction temperature has a significant effect on the volatilization rate of zinc and that either the coal particle size or the excess carbon content has no effect on the volatilization rate. The obtained activation energy for the volatilization of zinc is 79.42 kJ/mol. The volatilization rate of zinc is controlled by the reaction between the zinc oxides and CO.展开更多
Carbon-bearing stratum normally features low resistance and high polarization.If the lithostratigraphy of the exploration area contains large amounts of carbon,the induced polarization anomaly caused by metal sulfide ...Carbon-bearing stratum normally features low resistance and high polarization.If the lithostratigraphy of the exploration area contains large amounts of carbon,the induced polarization anomaly caused by metal sulfide ore bodies will be inundated by the high polarization of carbon-containing wall rock.In this work,we adopted time-domain induced polarization(TDIP)and controlled-source audio-frequency magnetotellurics(CSAMT)on deep prospecting of the carbon-bearing stratum of the Ar Horqin Banner,Inner Mongolia.The underground medium is divided into target geologic bodies according to the geological information within the known exploration line borehole,and the physical properties of various target geologic bodies are calculated using weighted averages to build a geologic-geophysical model that can fit the observation data.Consequently,we can determine the range and morphological characteristics of the electrical properties of the ore-bearing geologic bodies in the inversion results in the study area.Then we can use the characteristics summarized from the known exploration line to interpret unknown exploration line.Results indicated that,when the diff erence in physical properties between the ore body and interference wall rock is not clear,the geologic body can be classifi ed via the paragenetic(associated)assemblage relations of the underground medium.Geological interpretation is guided by the comprehensive physical properties of ore-bearing geologic bodies to avoid interferences.展开更多
Gaseous phases of carbon-containing and metastable oxides will be resulted from the carbonization of phenolic resin binders and the reduced reactions between C and oxides at high temperatures in carbon-containing refr...Gaseous phases of carbon-containing and metastable oxides will be resulted from the carbonization of phenolic resin binders and the reduced reactions between C and oxides at high temperatures in carbon-containing refractories. With the in-situ catalysis technique, these gaseous phases can be transformed to one-or two-dimensional bonding phases by deposition,which is favorable for the improvement on strength and toughness of carboncontaining refractories,especially low carbon refractories. The research results reveal that：（ 1） the amorphous carbon resulted from phenolic resin can be transformed to carbon nanotubes,thus,the oxidation peak temperature is raised from 506 to 664. 6 ℃;（ 2） onedimensional whiskers of MgO or Mg Al2 O4 can be in-situ formed in MgO-C refractories, and their CMOR,CCS,rupture displacement and residual CCS（ two water quenching cycles,1 100 ℃） are increased by 66%,47%,13% and 26%,respectively;（ 3） two-dimensional array structure of flake β-SiAlON can be in-situ formed in Al2 O3-C refractories,which improves the material strength by 60% and decreases the residual strength after thermal shock by only 4. 5 MPa. It is believed that the in-situ formation of one-or two-dimensional bonding phases at high temperatures can improvethe comprehensive thermal physical properties of carboncontaining refractories,and will be the developing trend of the strengthening and toughening of low carbon-containing refractories.展开更多
The influence of reduction temperature, size of coal powder and the carbon content on the evaporation rates of Zn and Pb in pellets made of ZnO-PbO-FeO bearing dust has been investigated between 1100-1300℃. The evapo...The influence of reduction temperature, size of coal powder and the carbon content on the evaporation rates of Zn and Pb in pellets made of ZnO-PbO-FeO bearing dust has been investigated between 1100-1300℃. The evaporation rate of Zn and Pb obtained from the experiments has been analyzed with kinetic models. The results show that the control step for evaporation of Zn is reduction reaction of ZnO by CO at the interface，and that the evaporation rate of Pb is controlled by the volatilization of reduction products, i.e. liquid lead. The overall apparent activation energies of Zn and Pb evaporation from the pellet are 79.42kJ/mol and 88.74kJ/mol respectively.展开更多
This study investigated the volatilization kinetics of lead in pellets made of Zn-Pb-bearing dusts mixed with coal powder,in a nitrogen atmosphere and in the temperature range between 1 100 ℃ - 1 300℃ ,and showed th...This study investigated the volatilization kinetics of lead in pellets made of Zn-Pb-bearing dusts mixed with coal powder,in a nitrogen atmosphere and in the temperature range between 1 100 ℃ - 1 300℃ ,and showed that the reduction temperature has a significant effect on the volatilization rate of lead and that neither the particle size of the coal powder nor the extra carbon content has any effect on the volatilization rate. The obtained activation energy for the volatilization of lead is 88.74 kJ/mol. The volatilization rate of lead is controlled by both the lead evaporation reaction and the diffusion of gaseous lead through the gas boundary layer covering the surface of the reduced liquid lead.展开更多
This paper presents an evaluation of the suitability of a mixed absorbent based on peat and carbon-containing ash for treatment of wastewaters, such as wastewater from professional car washes, landfill leachate and st...This paper presents an evaluation of the suitability of a mixed absorbent based on peat and carbon-containing ash for treatment of wastewaters, such as wastewater from professional car washes, landfill leachate and stormwater. This mixture is very attractive, since it is a low-cost material which has a capability to simultaneously remove inorganic as well as organic pollutants. Since any filter material eventually needs to be replaced either due to saturation of pollutants or reduced infiltration capacity, it is important that the residual can be handled at low cost and that the environment will be not impaired. The tested mixture, used in filter beds, showed low leaching values and high simultaneous removal efficiency of metals as Cu, Cd and Pb, non-polar organic compounds such as PCBs. Polar organic compounds as phenols were also efficiently removed by microbial and/or chemical degradation in the studied treatment plants with the filter bed acted as a biofilter. Filter material used for three years in a full-scale plant for leachate treatment and four years in treatment plants for wastewater from car washes, had sufficiently high energy content indicating that energy recovery is a good alternative for handling after its usage. Results show that the presented filter material is excellent for both small scale applications (e.g. treatment systems for car wash wastewater with capacity between 250 - 3000 m3 per year) as well as large-scale applications (e.g. filter systems for landfill leachates with capacity above 30,000 m3 per year).展开更多
The inferior flammability of coal gasification fine slag(CGFS) from entrained-flow gasifiers hampers its resourceful utilization.However,the reasons behind its poor flammability still need to be investigated.This pape...The inferior flammability of coal gasification fine slag(CGFS) from entrained-flow gasifiers hampers its resourceful utilization.However,the reasons behind its poor flammability still need to be investigated.This paper conducted a comparative study on the combustion characteristics of three CGFS samples:CGFS_(GSP),CGFS_(SN),and CGFS_(OMB)(subscripts GSP,SN,and OMB representing different gasification processes),using experimental techniques such as TG/DTG and combustion kinetic model fitting methods.Additionally,a comprehensive investigation into the physicochemical properties of CGFS was conducted.The objective was to elucidate the causes behind the poor flammability of CGFS.The results revealed that CGFS exhibits lower volatile matter content and higher activation energy than their corresponding raw coal(RC),leading to a significantly higher ignition temperature.The ignition temperatures of RC1,RC2,and RC3 are 361.82℃,378.66℃,and 404.99℃,respectively.In contrast,the ignition temperatures of CGFS_(GSP) CGFS_(SN),and CGFS_(OMB)are 549.08℃,566.58℃,and 532.67℃,respectively.During the combustion reaction,the temperature(T_(max)) at which CGFS reaches its maximum weight loss rate is significantly higher than the temperature(T_(maxⅢ)) at which fixed carbon in raw coal reaches its maximum weight loss rate.The T_(maxⅢ) of RC1,RC2,and RC3 are 450.90℃,457.19℃,and 452.77℃,respectively.In contrast,the T_(max) of CGFS_(GSP),CGFS_(SN),and CGFS_(OMB) are 583.55℃,608.20℃,and 582.18℃,respectively.The maximum weight loss rate of different types of CGFS is also significantly lower than the fixed carbon combustion maximum weight loss rate of their respective raw coal samples.The physicochemical characterization results of CGFS demonstrate that,compared to the corresponding raw coal,there is a significant reduction in the proportion of active sites in CGFS.Simultaneously,the proportion of C-C/C-H on the surface of residual carbon in CGFS decreases.In contrast,the proportion of O=C-O significantly increases,suggesting a shift toward a more stable state of carbon-containing functional groups.This study is expected to offer essential theoretical support for the efficient combustion utilization of CGFS.展开更多
Coal and carbon-containing waste are valuable primary and secondary carbon carriers.In the current dominant linear economy,such carbon resources are generally combusted to produce electricity and heat and as a way to ...Coal and carbon-containing waste are valuable primary and secondary carbon carriers.In the current dominant linear economy,such carbon resources are generally combusted to produce electricity and heat and as a way to resolve a nation’s waste issue.Not only is this a wastage of precious carbon resources,which can be chemically utilized as raw materials for production of other value-added goods,it is also contrary to international efforts to reduce carbon emissions and increase resource efficiency and conservation.This article presents a concept to support the transformation from a linear‘one-way cradle to grave manufacturing model’toward a circular carbon economy.The development of new and sustainable value chains through the utilization of coal and waste as alternative raw materials for the chemical industry via a coupling of the energy,chemical and waste management sectors offers a viable and future-oriented perspective for closing the carbon cycle.Further benefits also include a lowering of the carbon footprint and increasing resource efficiency and conservation of primary carbon resources.In addition,technological innovations and developments that are necessary to support a successful sector coupling will be identified.To illustrate our concept,a case analysis of domestic coal and waste as alternative feedstock to imported crude oil for chemical production in Germany will be presented.Last but not least,challenges posed by path dependency along technological,institutional and human dimensions in the sociotechnical system for a successful transition toward a circular carbon economy will be discussed.展开更多
基金the project supported by the Natural Science Foundation of Hubei Province(Grant No.2023BAB106)the National Natural Science Foundation of China(Grant No.U20A20239).
文摘The rapid development of iron and steel metallurgy technology has promoted the continuous innovation and iteration of carbon-containing refractories for clean steel smelting.To meet the high-quality requirements for clean steel production and full exploit the performance advantages of carbon-containing refractories in dynamic smelting environment,it is necessary to explore the role of graphite and modified graphite in carbon-containing refractories.Based on this,graphite surface modification methods,including surfactants,surface oxidation,and surface coating,and their applications in carbon-containing refractories are reviewed.The advantages and disadvantages of each method are analyzed for practical use.Furthermore,combined with the existing problems,the application prospect of improved graphite in carbon-containing refractories is discussed.
基金Item Sponsored by National Natural Science Foundation of China and Baoshan Iron and Steel Group Co(50474083)
文摘To avoid the nonuniform phenomena of heat and mass transfer of metallurgical powdery materials caused by conventional heating method,the temperature rise characteristics of carbon-containing chromite ore fines in the microwave field were investigated using microwave heating in a microwave metallurgical furnace.The experimental results show that the carbon-containing chromite ore fines have better temperature rise characteristics in the microwave field at a frequency of 2.45 GHz.After heated in the microwave field of 10 kW,the temperature of 1 kg carbon-containing chromite ore fines rose up to 1 100 ℃ in 7 min,at a temperature rise rate of 157.1（℃·min-1·kg-1）,whereas the temperature of 1 kg carbon-containing magnetite ore fines rose only up to 1 000 ℃ in 10 min,at a temperature rise rate of 100（℃·min-1·kg-1）.With increasing carbon-fitting ratios and by adding calcic lime,their heating effects changed regularly.
基金financially supported by the National Natural Science Foundation of China(Grant No.51702241)Key Program of Natural Science Foundation of Hubei Province(Contract No.2017CFA004)+1 种基金the Special Project of Central Government for Local Science and Technology Development of Hubei Province(No.2019ZYYD076)Open Foundation of State Key Laboratory of Advanced Refractories(No.SKLAR202002)。
文摘Lithium-sulfur batteries(LSBs)have become promising next-generation energy storage technologies for electric vehicles and portable electronics,due to its excellent theoretical specific energy.However,the low conductivity of sulfur species,notorious lithium dendrites,the severe"shuttle effect"of polysulfides(LiPSs)and the inferior kinetic reaction for LiPSs/Li_(2)S conversion during discharge-charge have seriously hindered their practical application,and also pose potential safety hazards.Owing to their superior porous architectures,high specific surface areas,excellent structural designability,functional modifiability,abundant active sites and flexibility of carbon-containing electrospun nanofibers(CENFs),they exhibited the superior characteristics that can simultaneously solve the above issues.In this review,we summarize the recent progress and application of CENFs in LSBs.First,we provide a brief introduction to the structure and composition controlled of carbon nanofibers by electrospinning.We then review progress in recent developments of CENFs for LSBs including cathodes,anodes,separators,and interlayers.We focus on how to solve practical issues that arise when the CENFs are applied to various parts of LSBs,and the relevant working mechanisms are described,from high sulfur loading and Li dendrites suppression to LiPSs’confinement and conversion.Finally,we summarize and propose the existing challenges and future prospects of CENFs,for the design and architecture of electrochemical components in Li-S energy storage systems.
文摘In this paper, X-ray diffractogram analysis and SEM observation of Al$ C$ formed at high temperature from carbon-containing refractories ivith Al have been carried out. Aluminum added to carbon-containing refractories reacts with C（s） to form Al^ C^（s） gradually during heating from 600 ’C to 1200^0 . It is considered that the interlocked structure of Al^ C-$ plate crystals promotes the outstanding increase of hot modulus of rupture of carbon-containing refractories with Al. The HMOR of carbon-containing refractories added with Al additive from 0 to 5wt% increases by 2.8 times being from 6.5MPa to 18.2MPa. After a thermochemical calculation for hydration reaction processes ofAl^C^ and H^O （g）, the equilibrium partial pressure chart ofH^O （g） in H^O-A^C^-Al^ OH)} system vs various temperatures has been attained . The H2 0 （g） partial pressure in the air needed for the Al^ C3 hydration reaction is no more than 10;18 atm at the temperature below 120t . It is considered that the burned carbon-containing re
文摘A study was carried out on the volatilization kinetics of Zn in the pellets made of Zn-bearing dusts mixed with coal powder in a nitrogen atmosphere and within the temperature range between 1 100℃and 1 300℃. The study shows that the reduction temperature has a significant effect on the volatilization rate of zinc and that either the coal particle size or the excess carbon content has no effect on the volatilization rate. The obtained activation energy for the volatilization of zinc is 79.42 kJ/mol. The volatilization rate of zinc is controlled by the reaction between the zinc oxides and CO.
基金The Research is funded by Comprehensive Intelligent Mapping System and Application of Geological Survey(DD20190415)Exploration and Development Tracking and Result Integration of Energy and Important Mineral Resources(DD20190457)Resource Assessment and Prediction for Main Tectonic Metallogenetic Domains in the World(DD20190459).
文摘Carbon-bearing stratum normally features low resistance and high polarization.If the lithostratigraphy of the exploration area contains large amounts of carbon,the induced polarization anomaly caused by metal sulfide ore bodies will be inundated by the high polarization of carbon-containing wall rock.In this work,we adopted time-domain induced polarization(TDIP)and controlled-source audio-frequency magnetotellurics(CSAMT)on deep prospecting of the carbon-bearing stratum of the Ar Horqin Banner,Inner Mongolia.The underground medium is divided into target geologic bodies according to the geological information within the known exploration line borehole,and the physical properties of various target geologic bodies are calculated using weighted averages to build a geologic-geophysical model that can fit the observation data.Consequently,we can determine the range and morphological characteristics of the electrical properties of the ore-bearing geologic bodies in the inversion results in the study area.Then we can use the characteristics summarized from the known exploration line to interpret unknown exploration line.Results indicated that,when the diff erence in physical properties between the ore body and interference wall rock is not clear,the geologic body can be classifi ed via the paragenetic(associated)assemblage relations of the underground medium.Geological interpretation is guided by the comprehensive physical properties of ore-bearing geologic bodies to avoid interferences.
文摘Gaseous phases of carbon-containing and metastable oxides will be resulted from the carbonization of phenolic resin binders and the reduced reactions between C and oxides at high temperatures in carbon-containing refractories. With the in-situ catalysis technique, these gaseous phases can be transformed to one-or two-dimensional bonding phases by deposition,which is favorable for the improvement on strength and toughness of carboncontaining refractories,especially low carbon refractories. The research results reveal that：（ 1） the amorphous carbon resulted from phenolic resin can be transformed to carbon nanotubes,thus,the oxidation peak temperature is raised from 506 to 664. 6 ℃;（ 2） onedimensional whiskers of MgO or Mg Al2 O4 can be in-situ formed in MgO-C refractories, and their CMOR,CCS,rupture displacement and residual CCS（ two water quenching cycles,1 100 ℃） are increased by 66%,47%,13% and 26%,respectively;（ 3） two-dimensional array structure of flake β-SiAlON can be in-situ formed in Al2 O3-C refractories,which improves the material strength by 60% and decreases the residual strength after thermal shock by only 4. 5 MPa. It is believed that the in-situ formation of one-or two-dimensional bonding phases at high temperatures can improvethe comprehensive thermal physical properties of carboncontaining refractories,and will be the developing trend of the strengthening and toughening of low carbon-containing refractories.
文摘The influence of reduction temperature, size of coal powder and the carbon content on the evaporation rates of Zn and Pb in pellets made of ZnO-PbO-FeO bearing dust has been investigated between 1100-1300℃. The evaporation rate of Zn and Pb obtained from the experiments has been analyzed with kinetic models. The results show that the control step for evaporation of Zn is reduction reaction of ZnO by CO at the interface，and that the evaporation rate of Pb is controlled by the volatilization of reduction products, i.e. liquid lead. The overall apparent activation energies of Zn and Pb evaporation from the pellet are 79.42kJ/mol and 88.74kJ/mol respectively.
基金financially supported by the "Joint Fund(project number U1260202)for Iron and Steel Research"built by the National Natural Science Foundation of China and Baosteel Group Corporation
文摘This study investigated the volatilization kinetics of lead in pellets made of Zn-Pb-bearing dusts mixed with coal powder,in a nitrogen atmosphere and in the temperature range between 1 100 ℃ - 1 300℃ ,and showed that the reduction temperature has a significant effect on the volatilization rate of lead and that neither the particle size of the coal powder nor the extra carbon content has any effect on the volatilization rate. The obtained activation energy for the volatilization of lead is 88.74 kJ/mol. The volatilization rate of lead is controlled by both the lead evaporation reaction and the diffusion of gaseous lead through the gas boundary layer covering the surface of the reduced liquid lead.
基金the financial support of Stena Recycling AB(Sweden)and the Knowledge Foundation(Sweden).
文摘This paper presents an evaluation of the suitability of a mixed absorbent based on peat and carbon-containing ash for treatment of wastewaters, such as wastewater from professional car washes, landfill leachate and stormwater. This mixture is very attractive, since it is a low-cost material which has a capability to simultaneously remove inorganic as well as organic pollutants. Since any filter material eventually needs to be replaced either due to saturation of pollutants or reduced infiltration capacity, it is important that the residual can be handled at low cost and that the environment will be not impaired. The tested mixture, used in filter beds, showed low leaching values and high simultaneous removal efficiency of metals as Cu, Cd and Pb, non-polar organic compounds such as PCBs. Polar organic compounds as phenols were also efficiently removed by microbial and/or chemical degradation in the studied treatment plants with the filter bed acted as a biofilter. Filter material used for three years in a full-scale plant for leachate treatment and four years in treatment plants for wastewater from car washes, had sufficiently high energy content indicating that energy recovery is a good alternative for handling after its usage. Results show that the presented filter material is excellent for both small scale applications (e.g. treatment systems for car wash wastewater with capacity between 250 - 3000 m3 per year) as well as large-scale applications (e.g. filter systems for landfill leachates with capacity above 30,000 m3 per year).
基金financially supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (No.XDA29020300)。
文摘The inferior flammability of coal gasification fine slag(CGFS) from entrained-flow gasifiers hampers its resourceful utilization.However,the reasons behind its poor flammability still need to be investigated.This paper conducted a comparative study on the combustion characteristics of three CGFS samples:CGFS_(GSP),CGFS_(SN),and CGFS_(OMB)(subscripts GSP,SN,and OMB representing different gasification processes),using experimental techniques such as TG/DTG and combustion kinetic model fitting methods.Additionally,a comprehensive investigation into the physicochemical properties of CGFS was conducted.The objective was to elucidate the causes behind the poor flammability of CGFS.The results revealed that CGFS exhibits lower volatile matter content and higher activation energy than their corresponding raw coal(RC),leading to a significantly higher ignition temperature.The ignition temperatures of RC1,RC2,and RC3 are 361.82℃,378.66℃,and 404.99℃,respectively.In contrast,the ignition temperatures of CGFS_(GSP) CGFS_(SN),and CGFS_(OMB)are 549.08℃,566.58℃,and 532.67℃,respectively.During the combustion reaction,the temperature(T_(max)) at which CGFS reaches its maximum weight loss rate is significantly higher than the temperature(T_(maxⅢ)) at which fixed carbon in raw coal reaches its maximum weight loss rate.The T_(maxⅢ) of RC1,RC2,and RC3 are 450.90℃,457.19℃,and 452.77℃,respectively.In contrast,the T_(max) of CGFS_(GSP),CGFS_(SN),and CGFS_(OMB) are 583.55℃,608.20℃,and 582.18℃,respectively.The maximum weight loss rate of different types of CGFS is also significantly lower than the fixed carbon combustion maximum weight loss rate of their respective raw coal samples.The physicochemical characterization results of CGFS demonstrate that,compared to the corresponding raw coal,there is a significant reduction in the proportion of active sites in CGFS.Simultaneously,the proportion of C-C/C-H on the surface of residual carbon in CGFS decreases.In contrast,the proportion of O=C-O significantly increases,suggesting a shift toward a more stable state of carbon-containing functional groups.This study is expected to offer essential theoretical support for the efficient combustion utilization of CGFS.
基金This research is supported by the German Federal Ministry of Education and Research(BMBF)through the research project grant no.01LN1713A.Any opinions,findings,conclusions and recommendations in the document are those of the authors and do not necessarily reflect the view of the BMBF.
文摘Coal and carbon-containing waste are valuable primary and secondary carbon carriers.In the current dominant linear economy,such carbon resources are generally combusted to produce electricity and heat and as a way to resolve a nation’s waste issue.Not only is this a wastage of precious carbon resources,which can be chemically utilized as raw materials for production of other value-added goods,it is also contrary to international efforts to reduce carbon emissions and increase resource efficiency and conservation.This article presents a concept to support the transformation from a linear‘one-way cradle to grave manufacturing model’toward a circular carbon economy.The development of new and sustainable value chains through the utilization of coal and waste as alternative raw materials for the chemical industry via a coupling of the energy,chemical and waste management sectors offers a viable and future-oriented perspective for closing the carbon cycle.Further benefits also include a lowering of the carbon footprint and increasing resource efficiency and conservation of primary carbon resources.In addition,technological innovations and developments that are necessary to support a successful sector coupling will be identified.To illustrate our concept,a case analysis of domestic coal and waste as alternative feedstock to imported crude oil for chemical production in Germany will be presented.Last but not least,challenges posed by path dependency along technological,institutional and human dimensions in the sociotechnical system for a successful transition toward a circular carbon economy will be discussed.
