For this study, a fixed-bed, down-draft gasifier was designed to investigate the effect of a dolomite catalytic bedon tar removal. Pine pellets and wood chips (cypress) were used to produce syngas from the down-draft ...For this study, a fixed-bed, down-draft gasifier was designed to investigate the effect of a dolomite catalytic bedon tar removal. Pine pellets and wood chips (cypress) were used to produce syngas from the down-draft gasifier. For the gas conditioning, a combination of a heated dolomite (bed temperature at 850?C for catalytic cracking of tars) and a particulate filter (for particulate removal) was used. Investigation of temperature effects on dolomite activity between 650?C and 950 C bed temperatures, showed optimum catalytic efficiency at approximately 850?C. At the optimum conditions, gravimetric tar and particulate concentrations in syngas produced from pine pellets were 0.85 g/Nm3 (±0.16) and 4.75 g/Nm3 (±0.07), respectively before gas conditioning, and 0.09 g/Nm3 (±0.02) and 2.01 g/Nm3 (±0.13), respectively after gas conditioning. Syngas from wood chips contained 1.63 g/Nm3 (±0.45) and 3.84 g/Nm3 (±1.16) of tars and particulates, respectively before gas cleaning and 0.19 g/Nm3 (±0.02) and 2.27 g/Nm3 (±0.27) tars and particulates, respectively after gas conditioning. The combustible portion of the gas constituted carbon monoxide (12% - 14%), hydrogen (11% - 12%), and methane (~2%). These results suggest that syngas produced from gasification of pine pellets and wood chips in a down-draft biomass gasifier can be effectively cleaned using a heated catalyst bed and a particulate filter. However, the benefits of gas conditioning will be offset by the need to maintain a heated catalyst bed for tar cracking.展开更多
A Raoult’s law-based screening-level assessment methodology was developed to calculate the carcinogenic and non-carcinogenic risks from ingestion of coal tar-contaminated water and it was applied to ten coal tars obt...A Raoult’s law-based screening-level assessment methodology was developed to calculate the carcinogenic and non-carcinogenic risks from ingestion of coal tar-contaminated water and it was applied to ten coal tars obtained from sites in the eastern United States. This approach provides a simple risk screening based on the conservative assumptions of Tier 1 in both the ASTM RBCA methodology and the USEPA Soil Screening Guidance. Results across the ten tars exhibited similar patterns, even though the coal tars had significantly different chemical compositions, and in all cases the screening-level risks were above the USEPA thresholds. There was no appreciable difference in the total risks when using either the current USEPA 1993 PAH risk assessment guidance or the proposed 2010 guidance. Benzene, while present at low concentrations within the coal tars, posed the dominant risk and strong correlations were observed with the benzene mole fraction.展开更多
Tars from two Mongolian coals (Tavan Tolgoi and Baganuur) produced by simple distillation have been characterized using size exclusion chromatography (SEC) with elution in both 1-methyl-2-pyrrolidinone (NMP) and a mix...Tars from two Mongolian coals (Tavan Tolgoi and Baganuur) produced by simple distillation have been characterized using size exclusion chromatography (SEC) with elution in both 1-methyl-2-pyrrolidinone (NMP) and a mixed solvent (NMP and chloroform), UV-fluorescence in chloroform and NMP, gas chromatography (GC), mass spectrometry (GC-MS, probe-MS and LD-MS with thin layer chromatography) and infra-red spectroscopy. The SEC chromatograms using NMP and the solvent mixture NMP: chloroform indicates that similar conclusions can be drawn from using either eluent. The synchronous UV-fluorescence spectra were shifted to longer wavelengths in chloroform solution than in NMP and chloroform may be the better solvent for these tars prepared without extensive secondary thermal treatment. Infra-red spectra indicated differences between the two coal tars that reflected their different ranks, with more oxygenate groups in the lower rank Baganuur coal. Mass spectrometry (GC-MS and probe-MS) of both coal tars confirmed the presence of aliphatic components as well as aromatics and the relatively extensive alkylation of aromatics. Molecular mass ranges indicated for Baganuur tar by SEC compared well with the mass range by LD-MS although the LD-MS extended to higher mass values. The high mass fractions of the tars were revealed by fractionation by thin layer chromatography with the relevant sections of the developed plates inserted directly into the mass spectrometer;laser desorption was directly from the surface of the plate. LD-MS of the unfractionated samples failed to detect the high mass components because of mass discrimination effects. The high mass components were carried over in the distillation by mass transfer of vapours into the condenser.展开更多
In order to study the combustion characteristics of tar in biomass gasifier inner wall and gasification gas,“tobacco stem semi-tar inside furnace”,“tobacco stem tar inside furnace”and“tobacco stem tar out-of-furn...In order to study the combustion characteristics of tar in biomass gasifier inner wall and gasification gas,“tobacco stem semi-tar inside furnace”,“tobacco stem tar inside furnace”and“tobacco stem tar out-of-furnace”were subjected to thermogravimetric experiments,and the combustion characteristics and kinetic characteristics were analyzed.The result shows that“tobacco stem semi-tar inside furnace”has the highest value and“tobacco stem tar out-of-furnace”is has the lowest value on ignition characteristics,combustion characteristics and combustible stability;“tobacco stem semi-tar inside furnace”has the lowest value and“tobacco stem tar outside furnace”has the highest value on burnout characteristics;“tobacco stem tar outside furnace”has the highest value and“tobacco stem tar inside furnace”has the lowest value on integrated combustion characteristics.展开更多
The pyrolysis properties of five different pyrolysis tars, which the tars from 1# to 5# are obtained by pyrolyzing the sewage sludges of anaerobic digestion and indigestion from the A2/O wastewater treatment process, ...The pyrolysis properties of five different pyrolysis tars, which the tars from 1# to 5# are obtained by pyrolyzing the sewage sludges of anaerobic digestion and indigestion from the A2/O wastewater treatment process, those from the activated sludge process and the indigested sludge from the continuous SBR process respectively, were studied by thermal gravimetric analysis at a heating rate of 10 ℃/min in the nitrogen atmosphere. The results show that the pyrolysis processes of the pyrolysis tars of 1#, 2#, 3# and 5# all can be divided into four stages: the stages of light organic compounds releasing, heavy polar organic compounds decomposition, heavy organic compounds decomposition and the residual organic compounds decomposition. However, the process of 4# pyrolysis tar is only divided into three stages: the stages of light organic compounds releasing, decomposition of heavy polar organic compounds and the residual heavy organic compounds respectively. Both the sludge anaerobic digestion and the "anaerobic" process in wastewater treatment processes make the content of light organic compounds in tars decrease, but make that of heavy organic compounds with complex structure increase. Besides, both make the pyrolysis properties of the tars become worse. The pyrolysis reaction mechanisms of the five pyrolysis tars have been studied with Coats-Redfern equation. It shows that there are the same mechanism functions in the first stage for the five tars and in the second and third stage for the tars of 1#, 2#, 3# and 5#, which is different with the function in the second stage for 4# tar. The five tars are easy to volatile.展开更多
Gasification experiments were carried out in a pilot scale fluid bed reactor operated under allothermal mode and low fluidisation regime with iron-doped olivine and char as catalyst for in-situ tar abatement.The catal...Gasification experiments were carried out in a pilot scale fluid bed reactor operated under allothermal mode and low fluidisation regime with iron-doped olivine and char as catalyst for in-situ tar abatement.The catalyst combination resulted in a reduction of 50%in the overall tar yield with respect to the reference values.Furthermore,the integration of an oxidative Hot Gas Filtration unit downstream the gasification reactor led to a further reduction in overall tar yield and relatively clean gas was obtained(approx.1 g/Nm3,benzene-free).The tar dew point of the resulting producer gas was estimated to 80℃,only 40℃ above the threshold value recommended for its valorisation in standard internal combustion engines.Moreover,catalyst elutriation and char hold-up took place to a large extent inside the reactor.The analysis of catalyst samples at different Time-On-Stream(TOS)revealed:(i)a considerable loss of iron oxides during the first hour of test because of the interparticle mechanical attrition(mostly surface abrasion)and partial reduction of hematite to magnetite and wustite but,stable composition at higher TOS,(ii)the loss of the iron oxide coverage of Fe/olivine particles and the formation of agglomerates with increasing TOS and,(iii)the amount of carbon deposited in the surface of the Fe/olivine particles increased with TOS,but in any case,these carbon deposits can be completely oxidized above 650℃.展开更多
Amyotrophic lateral sclerosis is a devastating neurodegenerative disease for which the current treatment approaches remain severely limited.The principal pathological alterations of the disease include the selective d...Amyotrophic lateral sclerosis is a devastating neurodegenerative disease for which the current treatment approaches remain severely limited.The principal pathological alterations of the disease include the selective degeneration of motor neurons in the brain,brainstem,and spinal cord,as well as abnormal protein deposition in the cytoplasm of neurons and glial cells.The biological markers under extensive scrutiny are predominantly located in the cerebrospinal fluid,blood,and even urine.Among these biomarke rs,neurofilament proteins and glial fibrillary acidic protein most accurately reflect the pathologic changes in the central nervous system,while creatinine and creatine kinase mainly indicate pathological alterations in the peripheral nerves and muscles.Neurofilament light chain levels serve as an indicator of neuronal axonal injury that remain stable throughout disease progression and are a promising diagnostic and prognostic biomarker with high specificity and sensitivity.However,there are challenges in using neurofilament light chain to diffe rentiate amyotrophic lateral sclerosis from other central nervous system diseases with axonal injury.Glial fibrillary acidic protein predominantly reflects the degree of neuronal demyelination and is linked to non-motor symptoms of amyotrophic lateral sclerosis such as cognitive impairment,oxygen saturation,and the glomerular filtration rate.TAR DNA-binding protein 43,a pathological protein associated with amyotrophic lateral sclerosis,is emerging as a promising biomarker,particularly with advancements in exosome-related research.Evidence is currently lacking for the value of creatinine and creatine kinase as diagnostic markers;however,they show potential in predicting disease prognosis.Despite the vigorous progress made in the identification of amyotrophic lateral sclerosis biomarkers in recent years,the quest for definitive diagnostic and prognostic biomarke rs remains a formidable challenge.This review summarizes the latest research achievements concerning blood biomarkers in amyotrophic lateral sclerosis that can provide a more direct basis for the differential diagnosis and prognostic assessment of the disease beyond a reliance on clinical manifestations and electromyography findings.展开更多
Carbon materials are widely recognized as highly promising electrode materials for various energy storage system applications.Coal tar residues(CTR),as a type of carbon-rich solid waste with high value-added utilizati...Carbon materials are widely recognized as highly promising electrode materials for various energy storage system applications.Coal tar residues(CTR),as a type of carbon-rich solid waste with high value-added utilization,are crucially important for the development of a more sustainable world.In this study,we employed a straightforward direct carbonization method within the temperature range of 700-1000℃to convert the worthless solid waste CTR into economically valuable carbon materials as anodes for potassium-ion batteries(PIBs).The effect of carbonization temperature on the microstructure and the potassium ions storage properties of CTR-derived carbons(CTRCs)were systematically explored by structural and morphological characterization,alongside electrochemical performances assessment.Based on the co-regulation between the turbine layers,crystal structure,pore structure,functional groups,and electrical conductivity of CTR-derived carbon carbonized at 900℃(CTRC-900H),the electrode material with high reversible capacity of 265.6m Ah·g^(-1)at 50 m A·g^(-1),a desirable cycling stability with 93.8%capacity retention even after 100 cycles,and the remarkable rate performance for PIBs were obtained.Furthermore,cyclic voltammetry(CV)at different scan rates and galvanostatic intermittent titration technique(GITT)have been employed to explore the potassium ions storage mechanism and electrochemical kinetics of CTRCs.Results indicate that the electrode behavior is predominantly governed by surface-induced capacitive processes,particularly under high current densities,with the potassium storage mechanism characterized by an“adsorption-weak intercalation”mechanism.This work highlights the potential of CTR-based carbon as a promising electrode material category suitable for high-performance PIBs electrodes,while also provides valuable insights into the new avenues for the high value-added utilization of CTR.展开更多
Sodium-ion batteries(SIBs)have emerged as a promising contender for next-gener-ation energy storage systems.Hard carbon is re-garded as the most promising anode for commer-cial SIB,however,the large number of defects ...Sodium-ion batteries(SIBs)have emerged as a promising contender for next-gener-ation energy storage systems.Hard carbon is re-garded as the most promising anode for commer-cial SIB,however,the large number of defects on its surface cause irreversible electrolyte consump-tion and an uneven solid electrolyte interphase film.An advanced molecular engineering strategy to coat hard carbon with polycyclic aromatic mo-lecules is reported.Specifically,polystyrene-based carbon microspheres(CSs)were first synthesized and then coated with polycyclic aromatic mo-lecules derived from coal tar pitch by spray-drying and followed by oxidation.Compared to the traditional CVD coating meth-od,this molecular framework strategy has been shown to reduce the number of defects on the surface of CSs without sacrifi-cing internal storage sites and suppressing transport kinetics in hosting the sodium ions.Besides the lower surface defect con-centration,the synthesized hybrid carbon microspheres(HCSs)have a larger grain size and more abundant closed pores,and have a higher reversible sodium storage capacity.A HCS-P-60%electrode has a capacity of 332.3 mAh g^(-1)with an initial Cou-lombic efficiency of 88.5%.It also has a superior rate performance of 246.6 mAh g^(-1)at 2 C and a 95.2%capacity retention after 100 cycles at 0.2 C.This work offers new insights into designing high-performance hard carbon microsphere anodes,advan-cing the commercialization of sodium-ion batteries.展开更多
Reducing the amount of aluminum chloride needed for the catalytic preparation of high quality mesophase and carbon materials is important and we have found that using terephthalic acid(PTA)as a co-catalyst serves this...Reducing the amount of aluminum chloride needed for the catalytic preparation of high quality mesophase and carbon materials is important and we have found that using terephthalic acid(PTA)as a co-catalyst serves this purpose.By adding 3%(mass fraction)AlCl_(3)and 0.9%(mass fraction)PTA to the coal tar pitch,approximately 90%mesophase was synthesized.The product(M-3-0.9)had a high stacking order(L_(c)=3.1 nm,n=10.14)and aromaticity(0.942).By adding PTA,a larger anisotropy content was produced using a smaller amount of AlCl_(3).The PTA participated in the polycondensation reaction through its own benzene ring structure to increase the catalytic activity.However,when its content was higher than 1.5%,the number of oxygen-containing groups in the product increased which was unfavorable for the aromatic lamellar stacking and gave rise to more isotropic structures.The work opens up a new way to prepare mesophase by a catalytic method.展开更多
Gasification is a highly effective technology for converting biomass into fuel gas or syngas.While various gas-ifiers have been commercialized for fuel gas production,mitigating tar formation in gasifiers remains chal...Gasification is a highly effective technology for converting biomass into fuel gas or syngas.While various gas-ifiers have been commercialized for fuel gas production,mitigating tar formation in gasifiers remains chal-lenging.This review is devoted to summarizing the general strategies adopted in various gasifiers to reduce tar formation for high-efficiency clean gasification.For single-bed and staged-gasification processes,their low-tar strategies are typically different.In the single-bed processes,the low-tar strategies involve in-bed intensifica-tion achieved by controlling flow directions of gas and particles inside the gasifier.During the gasification,these two components often have different temperatures to facilitate thermochemical interactions between them.Meanwhile,the two-stage gasifiers are generally designed to decouple pyrolysis,gasification and tar cracking reactions for maximizing the benefits(such as yield and efficiency)realized from the interactions among these reactions.In addition to minimizing tar formation,the approach of reaction decoupling can also raise the calorific value of product gas,even without use of oxygen,and/or improve the adaptability of gasification technology to the feedstocks with various moisture contents and particle sizes.The reanalysis based on those essential low-tar strategies is expected to gain alternative insights into the reaction principles implicated in most advanced biomass gasification technologies.展开更多
The thermal conversion process known as biomass gasification has the potential to produce environmentally friendly fuels such as hydrogen.However,tar generation during the gasification remains an issue,affecting opera...The thermal conversion process known as biomass gasification has the potential to produce environmentally friendly fuels such as hydrogen.However,tar generation during the gasification remains an issue,affecting operational efficiency and environmental health.Biochar has been confirmed as an inexpensive and efficient catalyst for tar removal.The challenge lies in creating a highly reactive biochar which can be applied for different types of biomass with varying properties.This review discusses the factors that affect biochar’s reactivity as a catalyst for tar reforming.Additionally,incorporating biochar into a gasification scenario with raw biomass offers a practical solution by leveraging the synergistic behavior.However,this synergy could be either positive or negative:the positive synergy enhances tar removal while the negative synergy has the opposite effect.The numerous factors affecting the results of gasification are presented in this review.It is concluded that the positive synergistic effect resulted from the balance between the available reactants from biomass and biochar,the optimal gas flowrate and the active sites on the carbon surface.Understanding these interactions is crucial for optimizing biochar performance for tar removal.Ultimately,this research provides insights into biochar’s role in biomass gasification and suggests improvements for future studies to enhance the feasibility of biomass gasification with the assistance of biochar.展开更多
B-COPNA resin,synthesized from the light fraction of ethylene tar(ETLF),is a superior precursor of the carbon materials.An in-depth understanding of the COPNA resin preparation process and strict control of crosslinki...B-COPNA resin,synthesized from the light fraction of ethylene tar(ETLF),is a superior precursor of the carbon materials.An in-depth understanding of the COPNA resin preparation process and strict control of crosslinking degree are crucial for controlling carbon materials performance.Therefore,the synthesis kinetics of B-COPNA resin prepared from ETLF was investigated using in-situ FTIR in this work.The synthesis kinetic models of B-COPNA resin were established for the first time.To express the kinetic model,the concentration changes of C-H in aromatic rings and O-H in PXG monitored by in-situ FTIR were selected as two indicators to calculate concentration of other compounds and describe the synthesis kinetics.Then confirmatory experiments were conducted,and the ρ^(2)(>0.9900),F-values(>10F_(0.05))and parameter errors(below 3%)of kinetic models verify that concentration changes of C-H and O-H can be used to describe synthesis kinetics of B-COPNA resin.Based on the results of confirmatory experiments,the synthesis kinetic model of B-COPNA resin in the ETLF system is established successfully using concentration changes of O-H as an indicator,whose appropriateness and feasibility are proved by the ρ^(2)(0.9960)and F-values(>10F_(0.05)).These models could accurately describe the synthesis rate of B-COPNA resin.展开更多
The controversies about the mechanism of sodium storage in hard carbon(HC)hinder its rational structural design.A series of porous HC materials using coal tar pitch show a reversible capacity of 377 mAh g^(−1) and an ...The controversies about the mechanism of sodium storage in hard carbon(HC)hinder its rational structural design.A series of porous HC materials using coal tar pitch show a reversible capacity of 377 mAh g^(−1) and an initial Coulombic efficiency(ICE)of 87%as well as excellent cycling performance.More attention is paid to exploration of the relationships between the sodium status on various storage sites at different sodiation states and the ICE by solidstate^(23)Na nuclear magnetic resonance spectroscopy.The adsorbed Na ions contribute the most to the irreversible capacity.The de-solvated Na ions entering the closed pores are reduced to Na atoms and aggregated to Na clusters.Also,this process contributes the most to the reversible capacity and is characteristic of a long plateau in the voltage profile.Intercalation is partially reversible;it is the main source of capacity for slope-type HCs but plays a minor role in the reversible capacity of plateau-type HCs.Therefore,increasing the content of the closed pores can improve the reversible plateau capacity and reducing the open mesopores of HC increases the ICE.These findings provide insights into the structural design and cost-efficient preparation of high-performance HC anode materials for advanced sodium-ion batteries.展开更多
文摘For this study, a fixed-bed, down-draft gasifier was designed to investigate the effect of a dolomite catalytic bedon tar removal. Pine pellets and wood chips (cypress) were used to produce syngas from the down-draft gasifier. For the gas conditioning, a combination of a heated dolomite (bed temperature at 850?C for catalytic cracking of tars) and a particulate filter (for particulate removal) was used. Investigation of temperature effects on dolomite activity between 650?C and 950 C bed temperatures, showed optimum catalytic efficiency at approximately 850?C. At the optimum conditions, gravimetric tar and particulate concentrations in syngas produced from pine pellets were 0.85 g/Nm3 (±0.16) and 4.75 g/Nm3 (±0.07), respectively before gas conditioning, and 0.09 g/Nm3 (±0.02) and 2.01 g/Nm3 (±0.13), respectively after gas conditioning. Syngas from wood chips contained 1.63 g/Nm3 (±0.45) and 3.84 g/Nm3 (±1.16) of tars and particulates, respectively before gas cleaning and 0.19 g/Nm3 (±0.02) and 2.27 g/Nm3 (±0.27) tars and particulates, respectively after gas conditioning. The combustible portion of the gas constituted carbon monoxide (12% - 14%), hydrogen (11% - 12%), and methane (~2%). These results suggest that syngas produced from gasification of pine pellets and wood chips in a down-draft biomass gasifier can be effectively cleaned using a heated catalyst bed and a particulate filter. However, the benefits of gas conditioning will be offset by the need to maintain a heated catalyst bed for tar cracking.
文摘A Raoult’s law-based screening-level assessment methodology was developed to calculate the carcinogenic and non-carcinogenic risks from ingestion of coal tar-contaminated water and it was applied to ten coal tars obtained from sites in the eastern United States. This approach provides a simple risk screening based on the conservative assumptions of Tier 1 in both the ASTM RBCA methodology and the USEPA Soil Screening Guidance. Results across the ten tars exhibited similar patterns, even though the coal tars had significantly different chemical compositions, and in all cases the screening-level risks were above the USEPA thresholds. There was no appreciable difference in the total risks when using either the current USEPA 1993 PAH risk assessment guidance or the proposed 2010 guidance. Benzene, while present at low concentrations within the coal tars, posed the dominant risk and strong correlations were observed with the benzene mole fraction.
文摘Tars from two Mongolian coals (Tavan Tolgoi and Baganuur) produced by simple distillation have been characterized using size exclusion chromatography (SEC) with elution in both 1-methyl-2-pyrrolidinone (NMP) and a mixed solvent (NMP and chloroform), UV-fluorescence in chloroform and NMP, gas chromatography (GC), mass spectrometry (GC-MS, probe-MS and LD-MS with thin layer chromatography) and infra-red spectroscopy. The SEC chromatograms using NMP and the solvent mixture NMP: chloroform indicates that similar conclusions can be drawn from using either eluent. The synchronous UV-fluorescence spectra were shifted to longer wavelengths in chloroform solution than in NMP and chloroform may be the better solvent for these tars prepared without extensive secondary thermal treatment. Infra-red spectra indicated differences between the two coal tars that reflected their different ranks, with more oxygenate groups in the lower rank Baganuur coal. Mass spectrometry (GC-MS and probe-MS) of both coal tars confirmed the presence of aliphatic components as well as aromatics and the relatively extensive alkylation of aromatics. Molecular mass ranges indicated for Baganuur tar by SEC compared well with the mass range by LD-MS although the LD-MS extended to higher mass values. The high mass fractions of the tars were revealed by fractionation by thin layer chromatography with the relevant sections of the developed plates inserted directly into the mass spectrometer;laser desorption was directly from the surface of the plate. LD-MS of the unfractionated samples failed to detect the high mass components because of mass discrimination effects. The high mass components were carried over in the distillation by mass transfer of vapours into the condenser.
基金the Financial Supported by Hunan Provincial Natural Science Foundation of China(No.2023JJ50224)2021–2022 Hunan Province Enterprise Science and Technology Commissioner Program Project(No.2021GK5046)+1 种基金Hunan Provincial Natural Science Foundation of China(No.2022JJ50013)Hunan Provincial Natural Science Foundation of China(No.2022JJ50041).
文摘In order to study the combustion characteristics of tar in biomass gasifier inner wall and gasification gas,“tobacco stem semi-tar inside furnace”,“tobacco stem tar inside furnace”and“tobacco stem tar out-of-furnace”were subjected to thermogravimetric experiments,and the combustion characteristics and kinetic characteristics were analyzed.The result shows that“tobacco stem semi-tar inside furnace”has the highest value and“tobacco stem tar out-of-furnace”is has the lowest value on ignition characteristics,combustion characteristics and combustible stability;“tobacco stem semi-tar inside furnace”has the lowest value and“tobacco stem tar outside furnace”has the highest value on burnout characteristics;“tobacco stem tar outside furnace”has the highest value and“tobacco stem tar inside furnace”has the lowest value on integrated combustion characteristics.
基金supported by the project of Tianjin higher education under contract (20060522)the project of Tianjin Polytechnic University (2230004)
文摘The pyrolysis properties of five different pyrolysis tars, which the tars from 1# to 5# are obtained by pyrolyzing the sewage sludges of anaerobic digestion and indigestion from the A2/O wastewater treatment process, those from the activated sludge process and the indigested sludge from the continuous SBR process respectively, were studied by thermal gravimetric analysis at a heating rate of 10 ℃/min in the nitrogen atmosphere. The results show that the pyrolysis processes of the pyrolysis tars of 1#, 2#, 3# and 5# all can be divided into four stages: the stages of light organic compounds releasing, heavy polar organic compounds decomposition, heavy organic compounds decomposition and the residual organic compounds decomposition. However, the process of 4# pyrolysis tar is only divided into three stages: the stages of light organic compounds releasing, decomposition of heavy polar organic compounds and the residual heavy organic compounds respectively. Both the sludge anaerobic digestion and the "anaerobic" process in wastewater treatment processes make the content of light organic compounds in tars decrease, but make that of heavy organic compounds with complex structure increase. Besides, both make the pyrolysis properties of the tars become worse. The pyrolysis reaction mechanisms of the five pyrolysis tars have been studied with Coats-Redfern equation. It shows that there are the same mechanism functions in the first stage for the five tars and in the second and third stage for the tars of 1#, 2#, 3# and 5#, which is different with the function in the second stage for 4# tar. The five tars are easy to volatile.
基金the ADEME,France(Adelither-project N◦1702C0042)the Region Grand-Est,France(Feder Project Hy-C-Green)for the financial support.
文摘Gasification experiments were carried out in a pilot scale fluid bed reactor operated under allothermal mode and low fluidisation regime with iron-doped olivine and char as catalyst for in-situ tar abatement.The catalyst combination resulted in a reduction of 50%in the overall tar yield with respect to the reference values.Furthermore,the integration of an oxidative Hot Gas Filtration unit downstream the gasification reactor led to a further reduction in overall tar yield and relatively clean gas was obtained(approx.1 g/Nm3,benzene-free).The tar dew point of the resulting producer gas was estimated to 80℃,only 40℃ above the threshold value recommended for its valorisation in standard internal combustion engines.Moreover,catalyst elutriation and char hold-up took place to a large extent inside the reactor.The analysis of catalyst samples at different Time-On-Stream(TOS)revealed:(i)a considerable loss of iron oxides during the first hour of test because of the interparticle mechanical attrition(mostly surface abrasion)and partial reduction of hematite to magnetite and wustite but,stable composition at higher TOS,(ii)the loss of the iron oxide coverage of Fe/olivine particles and the formation of agglomerates with increasing TOS and,(iii)the amount of carbon deposited in the surface of the Fe/olivine particles increased with TOS,but in any case,these carbon deposits can be completely oxidized above 650℃.
文摘Amyotrophic lateral sclerosis is a devastating neurodegenerative disease for which the current treatment approaches remain severely limited.The principal pathological alterations of the disease include the selective degeneration of motor neurons in the brain,brainstem,and spinal cord,as well as abnormal protein deposition in the cytoplasm of neurons and glial cells.The biological markers under extensive scrutiny are predominantly located in the cerebrospinal fluid,blood,and even urine.Among these biomarke rs,neurofilament proteins and glial fibrillary acidic protein most accurately reflect the pathologic changes in the central nervous system,while creatinine and creatine kinase mainly indicate pathological alterations in the peripheral nerves and muscles.Neurofilament light chain levels serve as an indicator of neuronal axonal injury that remain stable throughout disease progression and are a promising diagnostic and prognostic biomarker with high specificity and sensitivity.However,there are challenges in using neurofilament light chain to diffe rentiate amyotrophic lateral sclerosis from other central nervous system diseases with axonal injury.Glial fibrillary acidic protein predominantly reflects the degree of neuronal demyelination and is linked to non-motor symptoms of amyotrophic lateral sclerosis such as cognitive impairment,oxygen saturation,and the glomerular filtration rate.TAR DNA-binding protein 43,a pathological protein associated with amyotrophic lateral sclerosis,is emerging as a promising biomarker,particularly with advancements in exosome-related research.Evidence is currently lacking for the value of creatinine and creatine kinase as diagnostic markers;however,they show potential in predicting disease prognosis.Despite the vigorous progress made in the identification of amyotrophic lateral sclerosis biomarkers in recent years,the quest for definitive diagnostic and prognostic biomarke rs remains a formidable challenge.This review summarizes the latest research achievements concerning blood biomarkers in amyotrophic lateral sclerosis that can provide a more direct basis for the differential diagnosis and prognostic assessment of the disease beyond a reliance on clinical manifestations and electromyography findings.
基金financially supported by the Research Project Supported by Shanxi Scholarship Council of China(No.2022-049)the Natural Science Foundation of Shanxi Province,China(No.20210302123167)。
文摘Carbon materials are widely recognized as highly promising electrode materials for various energy storage system applications.Coal tar residues(CTR),as a type of carbon-rich solid waste with high value-added utilization,are crucially important for the development of a more sustainable world.In this study,we employed a straightforward direct carbonization method within the temperature range of 700-1000℃to convert the worthless solid waste CTR into economically valuable carbon materials as anodes for potassium-ion batteries(PIBs).The effect of carbonization temperature on the microstructure and the potassium ions storage properties of CTR-derived carbons(CTRCs)were systematically explored by structural and morphological characterization,alongside electrochemical performances assessment.Based on the co-regulation between the turbine layers,crystal structure,pore structure,functional groups,and electrical conductivity of CTR-derived carbon carbonized at 900℃(CTRC-900H),the electrode material with high reversible capacity of 265.6m Ah·g^(-1)at 50 m A·g^(-1),a desirable cycling stability with 93.8%capacity retention even after 100 cycles,and the remarkable rate performance for PIBs were obtained.Furthermore,cyclic voltammetry(CV)at different scan rates and galvanostatic intermittent titration technique(GITT)have been employed to explore the potassium ions storage mechanism and electrochemical kinetics of CTRCs.Results indicate that the electrode behavior is predominantly governed by surface-induced capacitive processes,particularly under high current densities,with the potassium storage mechanism characterized by an“adsorption-weak intercalation”mechanism.This work highlights the potential of CTR-based carbon as a promising electrode material category suitable for high-performance PIBs electrodes,while also provides valuable insights into the new avenues for the high value-added utilization of CTR.
文摘Sodium-ion batteries(SIBs)have emerged as a promising contender for next-gener-ation energy storage systems.Hard carbon is re-garded as the most promising anode for commer-cial SIB,however,the large number of defects on its surface cause irreversible electrolyte consump-tion and an uneven solid electrolyte interphase film.An advanced molecular engineering strategy to coat hard carbon with polycyclic aromatic mo-lecules is reported.Specifically,polystyrene-based carbon microspheres(CSs)were first synthesized and then coated with polycyclic aromatic mo-lecules derived from coal tar pitch by spray-drying and followed by oxidation.Compared to the traditional CVD coating meth-od,this molecular framework strategy has been shown to reduce the number of defects on the surface of CSs without sacrifi-cing internal storage sites and suppressing transport kinetics in hosting the sodium ions.Besides the lower surface defect con-centration,the synthesized hybrid carbon microspheres(HCSs)have a larger grain size and more abundant closed pores,and have a higher reversible sodium storage capacity.A HCS-P-60%electrode has a capacity of 332.3 mAh g^(-1)with an initial Cou-lombic efficiency of 88.5%.It also has a superior rate performance of 246.6 mAh g^(-1)at 2 C and a 95.2%capacity retention after 100 cycles at 0.2 C.This work offers new insights into designing high-performance hard carbon microsphere anodes,advan-cing the commercialization of sodium-ion batteries.
文摘Reducing the amount of aluminum chloride needed for the catalytic preparation of high quality mesophase and carbon materials is important and we have found that using terephthalic acid(PTA)as a co-catalyst serves this purpose.By adding 3%(mass fraction)AlCl_(3)and 0.9%(mass fraction)PTA to the coal tar pitch,approximately 90%mesophase was synthesized.The product(M-3-0.9)had a high stacking order(L_(c)=3.1 nm,n=10.14)and aromaticity(0.942).By adding PTA,a larger anisotropy content was produced using a smaller amount of AlCl_(3).The PTA participated in the polycondensation reaction through its own benzene ring structure to increase the catalytic activity.However,when its content was higher than 1.5%,the number of oxygen-containing groups in the product increased which was unfavorable for the aromatic lamellar stacking and gave rise to more isotropic structures.The work opens up a new way to prepare mesophase by a catalytic method.
基金supported by Youth Fund of National Natural Science Foundation of China(NO.22108175)Basic scientific research Project of colleges and universities of Liaoning Provincial Department of Educa-tion(No.LJKMZ20220798)+1 种基金National Natural Science Foundation of China(No.U1903130)Natural Science Foundation of Liaoning province(No.2021-NLTS-12-09),China,and JST Grant Number JPMJPF2104,Japan.
文摘Gasification is a highly effective technology for converting biomass into fuel gas or syngas.While various gas-ifiers have been commercialized for fuel gas production,mitigating tar formation in gasifiers remains chal-lenging.This review is devoted to summarizing the general strategies adopted in various gasifiers to reduce tar formation for high-efficiency clean gasification.For single-bed and staged-gasification processes,their low-tar strategies are typically different.In the single-bed processes,the low-tar strategies involve in-bed intensifica-tion achieved by controlling flow directions of gas and particles inside the gasifier.During the gasification,these two components often have different temperatures to facilitate thermochemical interactions between them.Meanwhile,the two-stage gasifiers are generally designed to decouple pyrolysis,gasification and tar cracking reactions for maximizing the benefits(such as yield and efficiency)realized from the interactions among these reactions.In addition to minimizing tar formation,the approach of reaction decoupling can also raise the calorific value of product gas,even without use of oxygen,and/or improve the adaptability of gasification technology to the feedstocks with various moisture contents and particle sizes.The reanalysis based on those essential low-tar strategies is expected to gain alternative insights into the reaction principles implicated in most advanced biomass gasification technologies.
基金supported by JST Grant Number JPMJPF2104,Japan.Az Zahra and Alahakoon gratefully acknowledge MEXT of Japan for the scholarship.
文摘The thermal conversion process known as biomass gasification has the potential to produce environmentally friendly fuels such as hydrogen.However,tar generation during the gasification remains an issue,affecting operational efficiency and environmental health.Biochar has been confirmed as an inexpensive and efficient catalyst for tar removal.The challenge lies in creating a highly reactive biochar which can be applied for different types of biomass with varying properties.This review discusses the factors that affect biochar’s reactivity as a catalyst for tar reforming.Additionally,incorporating biochar into a gasification scenario with raw biomass offers a practical solution by leveraging the synergistic behavior.However,this synergy could be either positive or negative:the positive synergy enhances tar removal while the negative synergy has the opposite effect.The numerous factors affecting the results of gasification are presented in this review.It is concluded that the positive synergistic effect resulted from the balance between the available reactants from biomass and biochar,the optimal gas flowrate and the active sites on the carbon surface.Understanding these interactions is crucial for optimizing biochar performance for tar removal.Ultimately,this research provides insights into biochar’s role in biomass gasification and suggests improvements for future studies to enhance the feasibility of biomass gasification with the assistance of biochar.
基金financially supported by the National Natural Science Foundation of China(52174023)National Natural Science Foundation of P.R.China(22308104)China Petroleum Engineering Corp.,Ltd.(CPEC)(2021ZYGC-01-01)。
文摘B-COPNA resin,synthesized from the light fraction of ethylene tar(ETLF),is a superior precursor of the carbon materials.An in-depth understanding of the COPNA resin preparation process and strict control of crosslinking degree are crucial for controlling carbon materials performance.Therefore,the synthesis kinetics of B-COPNA resin prepared from ETLF was investigated using in-situ FTIR in this work.The synthesis kinetic models of B-COPNA resin were established for the first time.To express the kinetic model,the concentration changes of C-H in aromatic rings and O-H in PXG monitored by in-situ FTIR were selected as two indicators to calculate concentration of other compounds and describe the synthesis kinetics.Then confirmatory experiments were conducted,and the ρ^(2)(>0.9900),F-values(>10F_(0.05))and parameter errors(below 3%)of kinetic models verify that concentration changes of C-H and O-H can be used to describe synthesis kinetics of B-COPNA resin.Based on the results of confirmatory experiments,the synthesis kinetic model of B-COPNA resin in the ETLF system is established successfully using concentration changes of O-H as an indicator,whose appropriateness and feasibility are proved by the ρ^(2)(0.9960)and F-values(>10F_(0.05)).These models could accurately describe the synthesis rate of B-COPNA resin.
文摘The controversies about the mechanism of sodium storage in hard carbon(HC)hinder its rational structural design.A series of porous HC materials using coal tar pitch show a reversible capacity of 377 mAh g^(−1) and an initial Coulombic efficiency(ICE)of 87%as well as excellent cycling performance.More attention is paid to exploration of the relationships between the sodium status on various storage sites at different sodiation states and the ICE by solidstate^(23)Na nuclear magnetic resonance spectroscopy.The adsorbed Na ions contribute the most to the irreversible capacity.The de-solvated Na ions entering the closed pores are reduced to Na atoms and aggregated to Na clusters.Also,this process contributes the most to the reversible capacity and is characteristic of a long plateau in the voltage profile.Intercalation is partially reversible;it is the main source of capacity for slope-type HCs but plays a minor role in the reversible capacity of plateau-type HCs.Therefore,increasing the content of the closed pores can improve the reversible plateau capacity and reducing the open mesopores of HC increases the ICE.These findings provide insights into the structural design and cost-efficient preparation of high-performance HC anode materials for advanced sodium-ion batteries.
