Hydrogen-enriched blast furnace ironmaking has become an essential route to reduce CO_(2)emissions in the ironmaking process.However,hydrogen-enriched reduction produces large amounts of H_(2)O,which places new demand...Hydrogen-enriched blast furnace ironmaking has become an essential route to reduce CO_(2)emissions in the ironmaking process.However,hydrogen-enriched reduction produces large amounts of H_(2)O,which places new demands on coke quality in a blast furnace.In a hydrogen-rich blast furnace,the presence of H_(2)O promotes the solution loss reaction.This result improves the reactivity of coke,which is 20%-30%higher in a pure H_(2)O atmosphere than in a pure CO_(2)atmosphere.The activation energy range is 110-300 kJ/mol between coke and CO_(2)and 80-170 kJ/mol between coke and H_(2)O.CO_(2)and H_(2)O are shown to have different effects on coke degradation mechanisms.This review provides a comprehensive overview of the effect of H_(2)O on the structure and properties of coke.By exploring the interactions between H_(2)O and coke,several unresolved issues in the field requiring further research were identified.This review aims to provide valuable insights into coke behavior in hydrogen-rich environments and promote the further development of hydrogen-rich blast furnace ironmaking processes.展开更多
In this study,the impact of different reaction times on the preparation of powdered activated carbon(PAC)using a one-step rapid activation method under flue gas atmosphere is investigated,and the underlying reaction m...In this study,the impact of different reaction times on the preparation of powdered activated carbon(PAC)using a one-step rapid activation method under flue gas atmosphere is investigated,and the underlying reaction mechanism is summarized.Results indicate that the reaction process of this method can be divided into three stages:stage I is the rapid release of volatiles and the rapid consumption of O_(2),primarily occurring within a reaction time range of 0-0.5 s;stage II is mainly the continuous release and diffusion of volatiles,which is the carbonization and activation coupling reaction stage,and the carbonization process is the main in this stage.This stage mainly occurs at the reaction time range of 0.5 -2.0 s when SL-coal is used as material,and that is 0.5-3.0 s when JJ-coal is used as material;stage III is mainly the activation stage,during which activated components diffuse to both the surface and interior of particles.This stage mainly involves the reaction stage of CO_(2)and H2O(g)activation,and it mainly occurs at the reaction time range of 2.0-4.0 s when SL-coal is used as material,and that is 3.0-4.0 s when JJ-coal is used as material.Besides,the main function of the first two stages is to provide more diffusion channels and contact surfaces/activation sites for the diffusion and activation of the activated components in the third stage.Mastering the reaction mechanism would serve as a crucial reference and foundation for designing the structure,size of the reactor,and optimal positioning of the activator nozzle in PAC preparation.展开更多
To explore the iron coke application in hydrogen-rich blast furnace,which is an effective method to achieve the purpose of low carbon emissions,the initial gasification temperature of iron coke in CO_(2) and H_(2)O at...To explore the iron coke application in hydrogen-rich blast furnace,which is an effective method to achieve the purpose of low carbon emissions,the initial gasification temperature of iron coke in CO_(2) and H_(2)O atmosphere and its cogasification reaction mechanism with coke were systematically studied.Iron coke was prepared under laboratory conditions,with a 0-7wt%iron ore powder addition.The properties of iron cokes were tested by coke reactivity index(CRI)and coke strength after reaction(CSR),and their phases and morphology were evolution discussed by scanning electron microscopy and X-ray diffraction analysis.The results indicated that the initial gasification temperature of iron coke decreased with the increase in the iron ore powder content under the CO_(2) and H_(2)O_((g))atmosphere.In the 40vol%H_(2)O+60vol%CO_(2) atmosphere,CRI of iron coke with the addition of 3wt%iron ore powder reached 58.7%,and its CSR reached 56.5%.Because of the catalytic action of iron,the reaction capacity of iron coke was greater than that of coke.As iron coke was preferentially gasified,the CRI and CSR of coke were reduced and increased,respectively,when iron coke and coke were cogasified.The results showed that the skeleton function of the coke can be protected by iron coke.展开更多
One factor that limits development of fundamental research on the infuence of coke microstructure on its strength is the difculty in quantifying the way that microstructure is both classifed and distributed in three d...One factor that limits development of fundamental research on the infuence of coke microstructure on its strength is the difculty in quantifying the way that microstructure is both classifed and distributed in three dimensions.To support such fundamental studies,this study evaluated a novel volumetric approach for classifying small(approx.450μm^(3))blocks of coke microstructure from 3D computed tomography scans.An automated process for classifying microstructure blocks was described.It is based on Landmark Multi-Dimensional Scaling and uses the Bhattacharyya metric and k-means clustering.The approach was evaluated using 27 coke samples across a range of coke with diferent properties and reliably identifed 6 ordered class of coke microstructure based on the distribution of voxel intensities associated with structural density.The lower class(1–2)subblocks tend to be dominated by pores and thin walls.Typically,there is an increase in wall thickness and reduced pore sizes in the higher classes.Inert features are also likely to be seen in higher classes(5–6).In general,this approach provides an efcient automated means for identifying the 3D spatial distribution of microstructure in CT scans of coke.展开更多
Since paraffins catalytic cracking was of significant importance to light olefins and aromatics production,this work was intended to gain insights into the feature and model of coke formation and catalyst deactivation...Since paraffins catalytic cracking was of significant importance to light olefins and aromatics production,this work was intended to gain insights into the feature and model of coke formation and catalyst deactivation in n-heptane catalytic cracking over HZSM-5 zeolites. 18 tests of n-heptane catalytic cracking were designed and carried out over HZSM-5 zeolites in a wide range of operating conditions. A particular attention was paid to the measurement of the conversion, product distribution, coke content, and the porosity and acidity of the fresh and spent HZSM-5 zeolites. It was found that alkene and aromatic promoted coke formation, and it reduced the pore volume and acid site of HZSM-5 zeolites, tailoring its performance in n-heptane catalytic cracking. The specific relationship between HZSM-5 zeolites, n-heptane conversion, product distribution and coke formation was quantitively characterized by the exponential and linear function. Based on the reaction network, the coupled scheme of coke formation and catalyst deactivation were specified for n-heptane catalytic cracking. The dual-model was proposed for the process simulation of n-heptane catalytic cracking over HZSM-5 zeolites. It predicted not only the conversion and product distribution but also coke content with the acceptable errors.展开更多
Objective The study aimed to estimate the benchmark dose(BMD)of coke oven emissions(COEs)exposure based on mitochondrial damage with the mitochondrial DNA copy number(mtDNAcn)as a biomarker.Methods A total of 782 subj...Objective The study aimed to estimate the benchmark dose(BMD)of coke oven emissions(COEs)exposure based on mitochondrial damage with the mitochondrial DNA copy number(mtDNAcn)as a biomarker.Methods A total of 782 subjects were recruited,including 238 controls and 544 exposed workers.The mtDNAcn of peripheral leukocytes was detected through the real-time fluorescence-based quantitative polymerase chain reaction.Three BMD approaches were used to calculate the BMD of COEs exposure based on the mitochondrial damage and its 95%confidence lower limit(BMDL).Results The mtDNAcn of the exposure group was lower than that of the control group(0.60±0.29 vs.1.03±0.31;P<0.001).A dose-response relationship was shown between the mtDNAcn damage and COEs.Using the Benchmark Dose Software,the occupational exposure limits(OELs)for COEs exposure in males was 0.00190 mg/m^(3).The OELs for COEs exposure using the BBMD were 0.00170 mg/m^(3)for the total population,0.00158 mg/m^(3)for males,and 0.00174 mg/m^(3)for females.In possible risk obtained from animal studies(PROAST),the OELs of the total population,males,and females were 0.00184,0.00178,and 0.00192 mg/m^(3),respectively.Conclusion Based on our conservative estimate,the BMDL of mitochondrial damage caused by COEs is0.002 mg/m^(3).This value will provide a benchmark for determining possible OELs.展开更多
The application of high-sulfur petroleum coke after desulfurization in aluminum electrolysis anodes is an important development trend. However, removing sulfur from high-sulfur petroleum coke is still a significant ch...The application of high-sulfur petroleum coke after desulfurization in aluminum electrolysis anodes is an important development trend. However, removing sulfur from high-sulfur petroleum coke is still a significant challenge.This study proposes alkali calcining and reflux washing to examine the impacts of temperature, particle size, the mass ratio of Na_(2)CO_(3) to NaOH, and total sodium addition on the desulfurization efficiency and mechanism. The results show that the desulfurization rate increases with increasing temperature, increasing total sodium content, and decreasing particle size. The addition of alkali can significantly reduce the opening-ring reaction temperature of thiophene and convert organic sulfur into inorganic sulfur(Na_(2)S). Three washing methods were compared, and reflux washing was selected to separate inorganic sulfur(Na_(2)S) from calcined petroleum coke. The sulfur content in petroleum coke decreased from 7.29% to 1.90%, with a desulfurization rate of 80.13% under optimal conditions. The petroleum coke was analyzed before and after desulfurization using X-Ray diffraction(XRD), Scanning Electron Microscopy(SEM), Infrared Spectroscopy(IR), Thermogravimetric Analysis and Differential Scanning Calorimetry(TG-DSC), Gaschromatography-mass Spectrometry(GC-MS). The results show that thiophene and benzothiophene in petroleum coke are decomposed and converted into octane and ethyl cyclohexane. These new observations are expected to provide further understanding and guidance for the utilization of highsulfur petroleum coke.展开更多
Replacing heavy oil with petrol coke can greatly reduce the cost of glass production,but obviously shorten the service life of refractories used in the regenerator checker body of glass tanks.To prolong the service li...Replacing heavy oil with petrol coke can greatly reduce the cost of glass production,but obviously shorten the service life of refractories used in the regenerator checker body of glass tanks.To prolong the service life of the regenerator checker body,the slag chemical composition and alkali-sulfur ratio of glass tanks after using petrol coke and the damage mechanism of the residual magnesia bricks in the regenerator checker body were studied,as well as the corrosion resistance of three magnesia based bricks(direct bonded magnesia chrome bricks,fused rebonded magnesia chrome bricks,and fused rebonded high-purity magnesium aluminate spinel bricks).On this basis,a series of targeted countermeasures were adopted to optimize the configuration of refractories,significantly improving the service life of checker bricks and meeting the requirements of glass industry development.展开更多
The coal packing density on coking chamber was tested under different conditions of moisture during coal charging.The result was studied through comparing with the lab research conditions as well as different mixing-r...The coal packing density on coking chamber was tested under different conditions of moisture during coal charging.The result was studied through comparing with the lab research conditions as well as different mixing-ratios of briquette situation,and the effect of CMC process on the coal packing density was also analyzed.The difference of temperature field and coal carbonization in the coking chamber between CMC and briquette was put forward by testing the center temperature of the coke button.With SCO experiment and mass production experiment,the effect of fine coal,CMC and briquette on coke quality was studied contrastively and some conclusion was made.展开更多
This work aimed at investigating the crucial factor in building and maintaining the combustion front during in-situ combustion(ISC),oxidized coke and pyrolyzed coke.The surface morphologies,elemental contents,and non-...This work aimed at investigating the crucial factor in building and maintaining the combustion front during in-situ combustion(ISC),oxidized coke and pyrolyzed coke.The surface morphologies,elemental contents,and non-isothermal mass losses of the oxidized and pyrolyzed cokes were thoroughly examined.The results indicated that the oxidized coke could be combusted at a lower temperature compared to the pyrolyzed coke due primarily to their differences in the molecular polarity and microstructure.Kinetic triplets of coke combustion were determined using iso-conversional models and one advanced integral master plots method.The activation energy values of the oxidized and pyrolyzed cokes varied in the range of 130-153 k J/mol and 95-120 kJ/mol,respectively.The most appropriate reaction model of combustion of the oxidized and pyrolyzed cokes followed three-dimensional diffusion model(D_(3)) and random nucleation and subsequent growth model(F_(1)),respectively.These observations assisted in building the numerical model of these two types of cokes to simulate the ISC process.展开更多
In this study, the effects of particle size distribution (PSD), chemical composition and pore structure of petroleum coke on the slurryability of petroleum coke water slurry (PCWS) were investigated. Four petroleu...In this study, the effects of particle size distribution (PSD), chemical composition and pore structure of petroleum coke on the slurryability of petroleum coke water slurry (PCWS) were investigated. Four petroleum cokes were studied, and they showed completely different slurryability. The solid concentration at fixed viscosity (i.e. apparent viscosity of 1000 mPa) (SCFV) of four PCWSs is different from each other, with the highest value of 70.9%, and lowest of 62.1%. The apparent viscosity of the four PCWSs all increased with an increase of the solid concentration. The results showed that the PSD, inherent moisture content, specific surface area and pore volume of petroleum coke were key factors to affect the slurryability. The slurryability was enhanced with increasing PSD range and particle packing fraction, and with decreasing inherent moisture content, specific surface area and pore volume.展开更多
The mechanism of coke size segregation in the radial direction of pre-chamber in coke dry quenching (CDQ) shaft was investigated by experiment and numerical analysis. The experimental apparatus was a cold three-dime...The mechanism of coke size segregation in the radial direction of pre-chamber in coke dry quenching (CDQ) shaft was investigated by experiment and numerical analysis. The experimental apparatus was a cold three-dimensional semicircle model for bell-type charging, which was used to study the influences of different kinds of bells and different stock line levels on the radial distribution of coke size in the radial direction of a pre-chamber. A mathematical model was used, which is capable of estimating the radial average size distribution as well as the radial deposit distribution of each particle size for multiple size coke with a few fixed parameters. The calculated results agree well with the experimental data, which proves the reliability of both experimental study and numerical analysis.展开更多
In this study, the effects of pH on slurrying properties of petroleum coke water slurry(PCWS) were investigated. The slurrying concentration, rheological characteristics and stability of PCWS were studied with four ...In this study, the effects of pH on slurrying properties of petroleum coke water slurry(PCWS) were investigated. The slurrying concentration, rheological characteristics and stability of PCWS were studied with four different types of additives at pH varying from 5 to 11.The results showed that the slurrying concentration, rheological characteristics and stability of PCWS all increased at first and then decreased with increasing pH from 5 to 11,and a pH of around 9 was found to be the most favorable acid–alkali environment to all these three slurrying properties. It was also indicated that only in a moderate alkaline environment can the additives be active enough to react with particle surfaces sufficiently to obtain good slurrying concentration and form a stable three-dimensional network structure, which can support strong pseudoplastic characteristics and good stability. An acid environment was a very unfavorable factor to the slurrying properties of PCWS.展开更多
The stability of petroleum coke water slurry(PCWS) is currently a hot topic. The inherent relationship between yield stress and stability of bubble-PCWS was studied through orthogonal experiments and range analysis ...The stability of petroleum coke water slurry(PCWS) is currently a hot topic. The inherent relationship between yield stress and stability of bubble-PCWS was studied through orthogonal experiments and range analysis in this work. The results showed that the stability of bubble-PCWS was positively related to the yield stress and that the yield stress could be greatly impacted by the operation conditions during preparation of bubble-PCWS. The main factors affecting the yield stress of bubble-PCWS were solid concentration, aeration time and dosage of frother. However, the effects of aperture size of air distribution plates and type of frother on the yield stress were slight within the experimental range. The optimal conditions for the greatest yield stress were as follows: aeration time of 30 min, solid concentration of 65 wt%, frother dosage of0.030 wt% of the air-dried pulverized petroleum coke, aperture size of air distribution plate of 2-5 lm and AOS frother.The yield stress and the pour rate of bubble-PCWS under this optimum operation condition could reach maxima of more than 0.4 Pa and 96%, respectively.展开更多
The effects of gas composition, temperature, ore to coke ratio and prereduction rate of ore on coke degradation were studied. The results showed that 1% increment in solution loss of coke reduces coke strength by 0.6%...The effects of gas composition, temperature, ore to coke ratio and prereduction rate of ore on coke degradation were studied. The results showed that 1% increment in solution loss of coke reduces coke strength by 0.6%, and the coke degradation is accelerated with the temperature. The higher the temperature, the more coke surface is involved in reactions, and the less negative effect on coke strength is. Hydrogen exerts stronger effect on coke degradation than CO at high temperature. The coke degradation is decreased with the reduction of ore to coke ratio and increase of ore prereduction rate.展开更多
The coal petrography of 13 different rank single coals and the quality of cokes made on 40 kg pilot coke oven were measured and analyzed in the paper.The results indicated that the relationship between optical texture...The coal petrography of 13 different rank single coals and the quality of cokes made on 40 kg pilot coke oven were measured and analyzed in the paper.The results indicated that the relationship between optical texture index of coke(OTI) and vitrinite mean maximum reflectance of single coal was positive linear correlation.By multiple linear regression analysis,the quantitative relationship between vitrinite reflectance distribution and the component of coke optical texture were determined;The influence of composition of coke optical tissue on crushing strength for coke(M_(40)) and coke reactivity index(CRI) can be summarized:the more mosaics texture proportion of the optical tissue,the better of crushing strength for coke(M_(40)) and its coke reactivity index(CRI).展开更多
To reduce the burning loss and the spalling and to improve energy efficiency,the mullite composite lining plates were used to replace cast steel or alloy lining in rotary coke tanks for coke dry quenching equipment.Th...To reduce the burning loss and the spalling and to improve energy efficiency,the mullite composite lining plates were used to replace cast steel or alloy lining in rotary coke tanks for coke dry quenching equipment.The results show that:the dense mullite composite lining plate in the cone part has the density of 2.20 g·cm^(-3) and the wear test,s volume loss of 4.08 cm^(3),and the light weight mullite composite lining plate in the straight cylinder part has the density of 1.95 g·cm^(-3) and the wear test,s volume loss of 17.6 cm^(3).After using,there is no shrinkage gap,no burn loss or holes in the plates,indicating good sealing of the mullite composite lining plates.The lining plate for the cone part has low burning loss,without spalling for more than half a year.The outer surface temperature of coke tanks adopting the cast steel or the alloy lining is 480 to 570℃,while that of the ones adopting mullite composite lining plates is 120 to 170℃,showing a largely improved insulating property.Adopting mullite composite lining plates on the basis of the current coke tank cage,the lining plates can be timely treated and wholly replaced,improving the service life and reducing the maintenance workload.展开更多
In this article, coke plant wastewater was treated by a simultaneous nitrifying and denitrifying (SND) fixed biofilm hybrid system. The results showed that suitable parameters of the system were important for the pe...In this article, coke plant wastewater was treated by a simultaneous nitrifying and denitrifying (SND) fixed biofilm hybrid system. The results showed that suitable parameters of the system were important for the performance of the bio-degradation system. The chemical oxygen demand (COD) removal efficiency in this system was satisfactory, higher than 94%, and ammonia nitrogen was higher than 95%. The effluent COD concentration could meet the discharge standard, except for very few situations. The results showed that a sufficient carbon source was important for making ammonia nitrogen concentration meet the discharge standard. Then the TiN removal efficiency in this system can be brought higher than 94%. Dissolved oxygen (DO) is very important to the performance of the SND bio-degradation system, and the suitable DO is about 3.5-4.0 mg/L at the forepart of reactor. In addition, the performance of the system was almost not affected by pH value. The results show that the system is feasible to treat coke plant wastewater.展开更多
The oxidation induration and reduction swelling behavior of chromium-bearing vanadium titanomagnetite pellets(CVTP)with Cr2O3 addition were studied,and the reduction swelling index(RSI)and compressive strength(CS)of t...The oxidation induration and reduction swelling behavior of chromium-bearing vanadium titanomagnetite pellets(CVTP)with Cr2O3 addition were studied,and the reduction swelling index(RSI)and compressive strength(CS)of the reduced CVTP with simulated coke oven gas(COG)injection were investigated.The results showed that the CS of the CVTP decreases and the porosity of the CVTP increases with increasing amount of Cr2O3 added.The Cr2O3 mainly exists in the form of(Cr,Fe)2O3 solid solution in the CVTP and as Fe-Cr in the reduced CVTP.The CS of the reduced CVTP increases and the RSI of the reduced CVTP decreases with increasing amount of Cr2O3 added.The limited aggregation and diffusion of metallic iron contribute to the formation of dense lamellar crystals,which leads to the slight decrease for reduction swelling behavior of reduced CVTP.This work provides a theoretical and technical basis for the utilization of CVTP and other Cr-bearing ores such as chromite with COG recycling technology.展开更多
To more comprehensively analyze the effect of CO_2 and H_2O on the gasification dissolution reaction and deep reaction of coke, the reactions of coke with CO_2 and H_2O using high temperature gas–solid reaction appar...To more comprehensively analyze the effect of CO_2 and H_2O on the gasification dissolution reaction and deep reaction of coke, the reactions of coke with CO_2 and H_2O using high temperature gas–solid reaction apparatus over the range of 950–1250°C were studied, and the thermodynamic and kinetic analyses were also performed. The results show that the average reaction rate of coke with H_2O is about 1.3–6.5 times that with CO_2 in the experimental temperature range. At the same temperature, the endothermic effect of coke with H_2O is less than that with CO_2. As the pressure increases, the gasification dissolution reaction of coke shifts to the high-temperature zone. The use of hydrogen-rich fuels is conducive to decreasing the energy consumed inside the blast furnace, and a corresponding high-pressure operation will help to suppress the gasification dissolution reaction of coke and reduce its deterioration. The interfacial chemical reaction is the main rate-limiting step over the experimental temperature range. The activation energies of the reaction of coke with CO_2 and H_2O are 169.23 kJ ·mol-1 and 87.13 kJ·mol^(-1), respectively. Additionally, water vapor is more likely to diffuse into the coke interior at a lower temperature and thus aggravates the deterioration of coke in the middle upper part of blast furnace.展开更多
基金financially supported by the Young Elite Scientist Sponsorship Program by CAST(No.YESS20210090)the National Natural Science Foundation of China(No.51974019),Beijing Natural Science Foundation(J210017)China Baowu Low Carbon Metallurgy Innovation Foundation(Nos.BWLCF202119 and BWLCF 202117)。
文摘Hydrogen-enriched blast furnace ironmaking has become an essential route to reduce CO_(2)emissions in the ironmaking process.However,hydrogen-enriched reduction produces large amounts of H_(2)O,which places new demands on coke quality in a blast furnace.In a hydrogen-rich blast furnace,the presence of H_(2)O promotes the solution loss reaction.This result improves the reactivity of coke,which is 20%-30%higher in a pure H_(2)O atmosphere than in a pure CO_(2)atmosphere.The activation energy range is 110-300 kJ/mol between coke and CO_(2)and 80-170 kJ/mol between coke and H_(2)O.CO_(2)and H_(2)O are shown to have different effects on coke degradation mechanisms.This review provides a comprehensive overview of the effect of H_(2)O on the structure and properties of coke.By exploring the interactions between H_(2)O and coke,several unresolved issues in the field requiring further research were identified.This review aims to provide valuable insights into coke behavior in hydrogen-rich environments and promote the further development of hydrogen-rich blast furnace ironmaking processes.
基金supported by the Qingdao Postdoctoral Program Funding(QDBSH20220202045)Shandong provincial Natural Science Foundation(ZR2021ME049,ZR2022ME176)+1 种基金National Natural Science Foundation of China(22078176)Taishan Industrial Experts Program(TSCX202306135).
文摘In this study,the impact of different reaction times on the preparation of powdered activated carbon(PAC)using a one-step rapid activation method under flue gas atmosphere is investigated,and the underlying reaction mechanism is summarized.Results indicate that the reaction process of this method can be divided into three stages:stage I is the rapid release of volatiles and the rapid consumption of O_(2),primarily occurring within a reaction time range of 0-0.5 s;stage II is mainly the continuous release and diffusion of volatiles,which is the carbonization and activation coupling reaction stage,and the carbonization process is the main in this stage.This stage mainly occurs at the reaction time range of 0.5 -2.0 s when SL-coal is used as material,and that is 0.5-3.0 s when JJ-coal is used as material;stage III is mainly the activation stage,during which activated components diffuse to both the surface and interior of particles.This stage mainly involves the reaction stage of CO_(2)and H2O(g)activation,and it mainly occurs at the reaction time range of 2.0-4.0 s when SL-coal is used as material,and that is 3.0-4.0 s when JJ-coal is used as material.Besides,the main function of the first two stages is to provide more diffusion channels and contact surfaces/activation sites for the diffusion and activation of the activated components in the third stage.Mastering the reaction mechanism would serve as a crucial reference and foundation for designing the structure,size of the reactor,and optimal positioning of the activator nozzle in PAC preparation.
基金financially supported by the National Natural Science Foundation of China(No.51576164)the Joint Research Fund of China Bao-Wu Iron and Steel Group Company Limited(Nos.U1860108 and U1860203)Science and Technology Commission of Shanghai Municipality,China(Nos.21DZ1208900 and 19DZ2270200)。
文摘To explore the iron coke application in hydrogen-rich blast furnace,which is an effective method to achieve the purpose of low carbon emissions,the initial gasification temperature of iron coke in CO_(2) and H_(2)O atmosphere and its cogasification reaction mechanism with coke were systematically studied.Iron coke was prepared under laboratory conditions,with a 0-7wt%iron ore powder addition.The properties of iron cokes were tested by coke reactivity index(CRI)and coke strength after reaction(CSR),and their phases and morphology were evolution discussed by scanning electron microscopy and X-ray diffraction analysis.The results indicated that the initial gasification temperature of iron coke decreased with the increase in the iron ore powder content under the CO_(2) and H_(2)O_((g))atmosphere.In the 40vol%H_(2)O+60vol%CO_(2) atmosphere,CRI of iron coke with the addition of 3wt%iron ore powder reached 58.7%,and its CSR reached 56.5%.Because of the catalytic action of iron,the reaction capacity of iron coke was greater than that of coke.As iron coke was preferentially gasified,the CRI and CSR of coke were reduced and increased,respectively,when iron coke and coke were cogasified.The results showed that the skeleton function of the coke can be protected by iron coke.
基金the Australian Coal Industry's Research Program(ACARP)-Grant Number C29073.
文摘One factor that limits development of fundamental research on the infuence of coke microstructure on its strength is the difculty in quantifying the way that microstructure is both classifed and distributed in three dimensions.To support such fundamental studies,this study evaluated a novel volumetric approach for classifying small(approx.450μm^(3))blocks of coke microstructure from 3D computed tomography scans.An automated process for classifying microstructure blocks was described.It is based on Landmark Multi-Dimensional Scaling and uses the Bhattacharyya metric and k-means clustering.The approach was evaluated using 27 coke samples across a range of coke with diferent properties and reliably identifed 6 ordered class of coke microstructure based on the distribution of voxel intensities associated with structural density.The lower class(1–2)subblocks tend to be dominated by pores and thin walls.Typically,there is an increase in wall thickness and reduced pore sizes in the higher classes.Inert features are also likely to be seen in higher classes(5–6).In general,this approach provides an efcient automated means for identifying the 3D spatial distribution of microstructure in CT scans of coke.
基金the financial support from the National Natural Science Foundation of China (21908010)the Education Department of Jilin Province (JJKH20220694KJ)。
文摘Since paraffins catalytic cracking was of significant importance to light olefins and aromatics production,this work was intended to gain insights into the feature and model of coke formation and catalyst deactivation in n-heptane catalytic cracking over HZSM-5 zeolites. 18 tests of n-heptane catalytic cracking were designed and carried out over HZSM-5 zeolites in a wide range of operating conditions. A particular attention was paid to the measurement of the conversion, product distribution, coke content, and the porosity and acidity of the fresh and spent HZSM-5 zeolites. It was found that alkene and aromatic promoted coke formation, and it reduced the pore volume and acid site of HZSM-5 zeolites, tailoring its performance in n-heptane catalytic cracking. The specific relationship between HZSM-5 zeolites, n-heptane conversion, product distribution and coke formation was quantitively characterized by the exponential and linear function. Based on the reaction network, the coupled scheme of coke formation and catalyst deactivation were specified for n-heptane catalytic cracking. The dual-model was proposed for the process simulation of n-heptane catalytic cracking over HZSM-5 zeolites. It predicted not only the conversion and product distribution but also coke content with the acceptable errors.
基金supported by the National Natural Science Foundation of China[grant numbers:NSFC81872597,81001239]。
文摘Objective The study aimed to estimate the benchmark dose(BMD)of coke oven emissions(COEs)exposure based on mitochondrial damage with the mitochondrial DNA copy number(mtDNAcn)as a biomarker.Methods A total of 782 subjects were recruited,including 238 controls and 544 exposed workers.The mtDNAcn of peripheral leukocytes was detected through the real-time fluorescence-based quantitative polymerase chain reaction.Three BMD approaches were used to calculate the BMD of COEs exposure based on the mitochondrial damage and its 95%confidence lower limit(BMDL).Results The mtDNAcn of the exposure group was lower than that of the control group(0.60±0.29 vs.1.03±0.31;P<0.001).A dose-response relationship was shown between the mtDNAcn damage and COEs.Using the Benchmark Dose Software,the occupational exposure limits(OELs)for COEs exposure in males was 0.00190 mg/m^(3).The OELs for COEs exposure using the BBMD were 0.00170 mg/m^(3)for the total population,0.00158 mg/m^(3)for males,and 0.00174 mg/m^(3)for females.In possible risk obtained from animal studies(PROAST),the OELs of the total population,males,and females were 0.00184,0.00178,and 0.00192 mg/m^(3),respectively.Conclusion Based on our conservative estimate,the BMDL of mitochondrial damage caused by COEs is0.002 mg/m^(3).This value will provide a benchmark for determining possible OELs.
基金financially supported by the National Natural Science Foundation of China (Grant Nos. 51964031 and 52164039)。
文摘The application of high-sulfur petroleum coke after desulfurization in aluminum electrolysis anodes is an important development trend. However, removing sulfur from high-sulfur petroleum coke is still a significant challenge.This study proposes alkali calcining and reflux washing to examine the impacts of temperature, particle size, the mass ratio of Na_(2)CO_(3) to NaOH, and total sodium addition on the desulfurization efficiency and mechanism. The results show that the desulfurization rate increases with increasing temperature, increasing total sodium content, and decreasing particle size. The addition of alkali can significantly reduce the opening-ring reaction temperature of thiophene and convert organic sulfur into inorganic sulfur(Na_(2)S). Three washing methods were compared, and reflux washing was selected to separate inorganic sulfur(Na_(2)S) from calcined petroleum coke. The sulfur content in petroleum coke decreased from 7.29% to 1.90%, with a desulfurization rate of 80.13% under optimal conditions. The petroleum coke was analyzed before and after desulfurization using X-Ray diffraction(XRD), Scanning Electron Microscopy(SEM), Infrared Spectroscopy(IR), Thermogravimetric Analysis and Differential Scanning Calorimetry(TG-DSC), Gaschromatography-mass Spectrometry(GC-MS). The results show that thiophene and benzothiophene in petroleum coke are decomposed and converted into octane and ethyl cyclohexane. These new observations are expected to provide further understanding and guidance for the utilization of highsulfur petroleum coke.
文摘Replacing heavy oil with petrol coke can greatly reduce the cost of glass production,but obviously shorten the service life of refractories used in the regenerator checker body of glass tanks.To prolong the service life of the regenerator checker body,the slag chemical composition and alkali-sulfur ratio of glass tanks after using petrol coke and the damage mechanism of the residual magnesia bricks in the regenerator checker body were studied,as well as the corrosion resistance of three magnesia based bricks(direct bonded magnesia chrome bricks,fused rebonded magnesia chrome bricks,and fused rebonded high-purity magnesium aluminate spinel bricks).On this basis,a series of targeted countermeasures were adopted to optimize the configuration of refractories,significantly improving the service life of checker bricks and meeting the requirements of glass industry development.
文摘The coal packing density on coking chamber was tested under different conditions of moisture during coal charging.The result was studied through comparing with the lab research conditions as well as different mixing-ratios of briquette situation,and the effect of CMC process on the coal packing density was also analyzed.The difference of temperature field and coal carbonization in the coking chamber between CMC and briquette was put forward by testing the center temperature of the coke button.With SCO experiment and mass production experiment,the effect of fine coal,CMC and briquette on coke quality was studied contrastively and some conclusion was made.
基金supported by Chinese Postdoctoral Science Foundation (2021M692696)the National Science and Technology Project (2016ZX05058-003-017)Sichuan Science and Technology Program (2021YFH0081)。
文摘This work aimed at investigating the crucial factor in building and maintaining the combustion front during in-situ combustion(ISC),oxidized coke and pyrolyzed coke.The surface morphologies,elemental contents,and non-isothermal mass losses of the oxidized and pyrolyzed cokes were thoroughly examined.The results indicated that the oxidized coke could be combusted at a lower temperature compared to the pyrolyzed coke due primarily to their differences in the molecular polarity and microstructure.Kinetic triplets of coke combustion were determined using iso-conversional models and one advanced integral master plots method.The activation energy values of the oxidized and pyrolyzed cokes varied in the range of 130-153 k J/mol and 95-120 kJ/mol,respectively.The most appropriate reaction model of combustion of the oxidized and pyrolyzed cokes followed three-dimensional diffusion model(D_(3)) and random nucleation and subsequent growth model(F_(1)),respectively.These observations assisted in building the numerical model of these two types of cokes to simulate the ISC process.
基金the financial support from National Key Basic Research Program Project (No. 2010CB227001)
文摘In this study, the effects of particle size distribution (PSD), chemical composition and pore structure of petroleum coke on the slurryability of petroleum coke water slurry (PCWS) were investigated. Four petroleum cokes were studied, and they showed completely different slurryability. The solid concentration at fixed viscosity (i.e. apparent viscosity of 1000 mPa) (SCFV) of four PCWSs is different from each other, with the highest value of 70.9%, and lowest of 62.1%. The apparent viscosity of the four PCWSs all increased with an increase of the solid concentration. The results showed that the PSD, inherent moisture content, specific surface area and pore volume of petroleum coke were key factors to affect the slurryability. The slurryability was enhanced with increasing PSD range and particle packing fraction, and with decreasing inherent moisture content, specific surface area and pore volume.
文摘The mechanism of coke size segregation in the radial direction of pre-chamber in coke dry quenching (CDQ) shaft was investigated by experiment and numerical analysis. The experimental apparatus was a cold three-dimensional semicircle model for bell-type charging, which was used to study the influences of different kinds of bells and different stock line levels on the radial distribution of coke size in the radial direction of a pre-chamber. A mathematical model was used, which is capable of estimating the radial average size distribution as well as the radial deposit distribution of each particle size for multiple size coke with a few fixed parameters. The calculated results agree well with the experimental data, which proves the reliability of both experimental study and numerical analysis.
基金support from the National Natural Science Foundation of China (No. 51506185)Zhejiang Provincial Natural Science Foundation of China (No. LQ15E060002)
文摘In this study, the effects of pH on slurrying properties of petroleum coke water slurry(PCWS) were investigated. The slurrying concentration, rheological characteristics and stability of PCWS were studied with four different types of additives at pH varying from 5 to 11.The results showed that the slurrying concentration, rheological characteristics and stability of PCWS all increased at first and then decreased with increasing pH from 5 to 11,and a pH of around 9 was found to be the most favorable acid–alkali environment to all these three slurrying properties. It was also indicated that only in a moderate alkaline environment can the additives be active enough to react with particle surfaces sufficiently to obtain good slurrying concentration and form a stable three-dimensional network structure, which can support strong pseudoplastic characteristics and good stability. An acid environment was a very unfavorable factor to the slurrying properties of PCWS.
基金he financial supports from National Natural Science Foundation of China (Grant No. 51506185)Zhejiang Provincial Natural Science Foundation of China (Grant No. LQ15E060002)
文摘The stability of petroleum coke water slurry(PCWS) is currently a hot topic. The inherent relationship between yield stress and stability of bubble-PCWS was studied through orthogonal experiments and range analysis in this work. The results showed that the stability of bubble-PCWS was positively related to the yield stress and that the yield stress could be greatly impacted by the operation conditions during preparation of bubble-PCWS. The main factors affecting the yield stress of bubble-PCWS were solid concentration, aeration time and dosage of frother. However, the effects of aperture size of air distribution plates and type of frother on the yield stress were slight within the experimental range. The optimal conditions for the greatest yield stress were as follows: aeration time of 30 min, solid concentration of 65 wt%, frother dosage of0.030 wt% of the air-dried pulverized petroleum coke, aperture size of air distribution plate of 2-5 lm and AOS frother.The yield stress and the pour rate of bubble-PCWS under this optimum operation condition could reach maxima of more than 0.4 Pa and 96%, respectively.
文摘The effects of gas composition, temperature, ore to coke ratio and prereduction rate of ore on coke degradation were studied. The results showed that 1% increment in solution loss of coke reduces coke strength by 0.6%, and the coke degradation is accelerated with the temperature. The higher the temperature, the more coke surface is involved in reactions, and the less negative effect on coke strength is. Hydrogen exerts stronger effect on coke degradation than CO at high temperature. The coke degradation is decreased with the reduction of ore to coke ratio and increase of ore prereduction rate.
文摘The coal petrography of 13 different rank single coals and the quality of cokes made on 40 kg pilot coke oven were measured and analyzed in the paper.The results indicated that the relationship between optical texture index of coke(OTI) and vitrinite mean maximum reflectance of single coal was positive linear correlation.By multiple linear regression analysis,the quantitative relationship between vitrinite reflectance distribution and the component of coke optical texture were determined;The influence of composition of coke optical tissue on crushing strength for coke(M_(40)) and coke reactivity index(CRI) can be summarized:the more mosaics texture proportion of the optical tissue,the better of crushing strength for coke(M_(40)) and its coke reactivity index(CRI).
文摘To reduce the burning loss and the spalling and to improve energy efficiency,the mullite composite lining plates were used to replace cast steel or alloy lining in rotary coke tanks for coke dry quenching equipment.The results show that:the dense mullite composite lining plate in the cone part has the density of 2.20 g·cm^(-3) and the wear test,s volume loss of 4.08 cm^(3),and the light weight mullite composite lining plate in the straight cylinder part has the density of 1.95 g·cm^(-3) and the wear test,s volume loss of 17.6 cm^(3).After using,there is no shrinkage gap,no burn loss or holes in the plates,indicating good sealing of the mullite composite lining plates.The lining plate for the cone part has low burning loss,without spalling for more than half a year.The outer surface temperature of coke tanks adopting the cast steel or the alloy lining is 480 to 570℃,while that of the ones adopting mullite composite lining plates is 120 to 170℃,showing a largely improved insulating property.Adopting mullite composite lining plates on the basis of the current coke tank cage,the lining plates can be timely treated and wholly replaced,improving the service life and reducing the maintenance workload.
文摘In this article, coke plant wastewater was treated by a simultaneous nitrifying and denitrifying (SND) fixed biofilm hybrid system. The results showed that suitable parameters of the system were important for the performance of the bio-degradation system. The chemical oxygen demand (COD) removal efficiency in this system was satisfactory, higher than 94%, and ammonia nitrogen was higher than 95%. The effluent COD concentration could meet the discharge standard, except for very few situations. The results showed that a sufficient carbon source was important for making ammonia nitrogen concentration meet the discharge standard. Then the TiN removal efficiency in this system can be brought higher than 94%. Dissolved oxygen (DO) is very important to the performance of the SND bio-degradation system, and the suitable DO is about 3.5-4.0 mg/L at the forepart of reactor. In addition, the performance of the system was almost not affected by pH value. The results show that the system is feasible to treat coke plant wastewater.
基金financially supported by the National Natural Science Foundation of China (Nos.51674084, 51174051, and 51574082)
文摘The oxidation induration and reduction swelling behavior of chromium-bearing vanadium titanomagnetite pellets(CVTP)with Cr2O3 addition were studied,and the reduction swelling index(RSI)and compressive strength(CS)of the reduced CVTP with simulated coke oven gas(COG)injection were investigated.The results showed that the CS of the CVTP decreases and the porosity of the CVTP increases with increasing amount of Cr2O3 added.The Cr2O3 mainly exists in the form of(Cr,Fe)2O3 solid solution in the CVTP and as Fe-Cr in the reduced CVTP.The CS of the reduced CVTP increases and the RSI of the reduced CVTP decreases with increasing amount of Cr2O3 added.The limited aggregation and diffusion of metallic iron contribute to the formation of dense lamellar crystals,which leads to the slight decrease for reduction swelling behavior of reduced CVTP.This work provides a theoretical and technical basis for the utilization of CVTP and other Cr-bearing ores such as chromite with COG recycling technology.
基金financially supported by the National Natural Science Foundation of China (No. 51474002)the National Science Foundation for Young Scientists of China (No. 51304014)the Yong Elite Scientists Sponsorship Program by CAST (No. 2017QNRC001)
文摘To more comprehensively analyze the effect of CO_2 and H_2O on the gasification dissolution reaction and deep reaction of coke, the reactions of coke with CO_2 and H_2O using high temperature gas–solid reaction apparatus over the range of 950–1250°C were studied, and the thermodynamic and kinetic analyses were also performed. The results show that the average reaction rate of coke with H_2O is about 1.3–6.5 times that with CO_2 in the experimental temperature range. At the same temperature, the endothermic effect of coke with H_2O is less than that with CO_2. As the pressure increases, the gasification dissolution reaction of coke shifts to the high-temperature zone. The use of hydrogen-rich fuels is conducive to decreasing the energy consumed inside the blast furnace, and a corresponding high-pressure operation will help to suppress the gasification dissolution reaction of coke and reduce its deterioration. The interfacial chemical reaction is the main rate-limiting step over the experimental temperature range. The activation energies of the reaction of coke with CO_2 and H_2O are 169.23 kJ ·mol-1 and 87.13 kJ·mol^(-1), respectively. Additionally, water vapor is more likely to diffuse into the coke interior at a lower temperature and thus aggravates the deterioration of coke in the middle upper part of blast furnace.