This work investigated the effect of Na_(2)CO_(3)on the char structures of cellulose and lignin,respective-ly,and examined the electrochemi-cal performance of the char by act-ing as an active material for coin cells.T...This work investigated the effect of Na_(2)CO_(3)on the char structures of cellulose and lignin,respective-ly,and examined the electrochemi-cal performance of the char by act-ing as an active material for coin cells.The morphology of char can be significantly steered by the con-centration of Na_(2)CO_(3).Scanning electron microscopy analysis demonstrated that the intro-duction of Na_(2)CO_(3)into cellulose at an appropriate concentration led to the formation of tubular structure on its surface after pyrolysis,whereas the tubular structure was absent in the lignin char with the addition of Na_(2)CO_(3)at any concentrations.X-ray diffraction and Ra-man spectroscopy characterizations revealed that all the obtained chars from both cellulose and lignin,with or without Na_(2)CO_(3),were ascribed to non-crystalline graphite.Nevertheless,the crystal orientation of graphite from cellulose and lignin changed after the catalysis of Na_(2)CO_(3).Further electrochemical tests showed that cellulose char had a higher sodium stor-age capacity than that of lignin char.The excellent electrochemical performance of carbon materials derived from cellulose might hold a prospective application in the field of energy storage.展开更多
The biodegradability of chars derived from pyrolysis and hydrothermal carbonisation(HTC) was studied in short-term dynamic incubation experiments under controlled conditions. Carbon dioxide C(CO2) emissions from soil-...The biodegradability of chars derived from pyrolysis and hydrothermal carbonisation(HTC) was studied in short-term dynamic incubation experiments under controlled conditions. Carbon dioxide C(CO2) emissions from soil-char mixtures in combination with solid digestate or mineral nitrogen(N) fertiliser were measured in dynamic chambers for 10 d. Compared to the original material(maize straw), pyrolysis and HTC chars showed significantly lower CO2 emissions and slower decay dynamics; and compared to the soil control, HTC char increased soil respiration to a significant extent, while pyrolysis char did not. The addition of mineral N resulted in a delayed respiration dynamics for HTC char, while the addition of digestate resulted in an increase in the respired CO2 for pyrolysis char and a decrease for HTC char. For the first time, a peculiar two-stage decay kinetics was observed for HTC char,indicating a highly inhomogeneous substrate consisting at least of two C pools.展开更多
Pyrolysis temperature and feedstock type used to produce biochar influence the physicochemical properties of the obtained product, which in turn display a range of results when used as soil amendment. From soil carbon...Pyrolysis temperature and feedstock type used to produce biochar influence the physicochemical properties of the obtained product, which in turn display a range of results when used as soil amendment. From soil carbon (C) sequestration strategy to nutrient source, biochar is used to enhance soil properties and to improve agricultural production. However, contrasting effects are observed from biochar application to soil results from a wide range of biochar’s properties in combination with specific environmental conditions. Therefore, elucidation on the effect of pyrolysis conditions and feedstock type on biochar properties may provide basic information to the understanding of soil and biochar interactions. In this study, biochar was produced from four different agricultural organic residues: Poultry litter, sugarcane straw, rice hull and sawdust pyrolysed at final temperatures of 350°C, 450°C, 550°C and 650°C. The effect of temperature and feedstock type on the variability of physicochemical properties of biochars was evaluated through measurements of pH, electrical conductivity, cation exchange capacity, macronutrient content, proximate and elemental analyses, Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analyses. Additionally, an incubation trial was carried under controlled conditions to determine the effect of biochar stability on CO2-eq emissions. Results showed that increasing pyrolysis temperature supported biochar stability regardless of feedstock, however, agricultural properties varied widely both as an effect of temperature and feedstock. Animal manure biochar showed higher potential as nutrient source rather than a C sequestration strategy. Improving the knowledge on the influence of pyrolysis temperature and feedstock type on the final properties of biochar will enable the use of better tailored materials that correspond to the expected results while considering its interactions with environmental conditions.展开更多
This study examined an isothermal CO2 gasification of four chars prepared via two different methods,i.e.,conventional and microwave-assisted pyrolysis,by the approach of thermogravimetric analysis.Physical,chemical,an...This study examined an isothermal CO2 gasification of four chars prepared via two different methods,i.e.,conventional and microwave-assisted pyrolysis,by the approach of thermogravimetric analysis.Physical,chemical,and structural behaviours of chars were examined using ultimate analysis,X-ray diffraction,and scanning electronic microscopy.Kinetic parameters were calculated by applying the shrinking unreacted core(SCM)and random pore(RPM)models.Moreover,char-CO2 gasification was further simulated by using Aspen Plus to investigate thermodynamic performances in terms of syngas composition and cold gas efficiency(CGE).The microwave-induced char has the largest C/H mass ratio and most ordered carbon structure,but the smallest gasification reactivity.Kinetic analysis indicates that the RPM is better for describing both gasification conversion and reaction rates of the studied chars,and the activation energies and pre-exponential factors varied in the range of 78.45–194.72 kJ/mol and 3.15–102,231.99 s−1,respectively.In addition,a compensation effect was noted during gasification.Finally,the microwave-derived char exhibits better thermodynamic performances than the conventional chars,with the highest CGE and CO molar concentration of 1.30%and 86.18%,respectively.Increasing the pyrolysis temperature,gasification temperature,and CO2-to-carbon molar ratio improved the CGE.展开更多
The gasification reactivity and kinetic parameters of coal chars for non-isothermal steam gasification were investigated.One kind of lignite and three kinds of bituminous coals were used as the samples,and their coal ...The gasification reactivity and kinetic parameters of coal chars for non-isothermal steam gasification were investigated.One kind of lignite and three kinds of bituminous coals were used as the samples,and their coal ranks follow the ascending order:XB<KL<ZJ<GD.As characterized by the comprehensive gasification index,the gasification reactivity of coal chars follows the descending order:XB>KL>ZJ>GD.Through systematically analyzing factors affecting gasification reactivity,it was ascertained that the gasification reactivity is mostly determined by the carbonaceous structure.The gasification reactivity is inversely proportional to the coal rank,and the higher the coal rank,the lower the gasification reactivity.A new kinetic model was proposed to calculate the kinetic parameters,in which the reaction order was considered as an unknown kinetic parameter.The reaction order n follows the ascending order:XB<KL<ZJ<GD,which are n=1.00,n=1.34,n=1.83,and n=2.63,respectively.It is proved that the reaction order is proportional to the coal rank,and the higher the coal rank,the higher the reaction order.展开更多
Sewage sludge(SS)and SS impregnated with activating agents(ZnCl_(2) and KOH)were pyrolyzed in a fixed-bed reactor to produce gaseous fuel and activated char.The effects of heating rate,pyrolysis temperature and activa...Sewage sludge(SS)and SS impregnated with activating agents(ZnCl_(2) and KOH)were pyrolyzed in a fixed-bed reactor to produce gaseous fuel and activated char.The effects of heating rate,pyrolysis temperature and activator type on gas yields,pore structure and adsorption properties of activated char were systematically studied.The results demonstrated that increasing the pyrolysis temperature from 450℃ to 850℃ propo rtionally enhanced H_(2) and CO yields from the rapid pyrolysis of SS,while CH_(4) yield showed minimal variation between 650℃ and 850℃.ZnCl_(2) notably increased the CO yield,reaching71.9 ml·g^(-1)at 850℃,but caused a marked reduction in CH_(4) yield under the tested conditions.Similarly,KOH promoted CO yield at 750℃ and 850℃,with minimal impact on CH_(4) production.Both activators facilitated higher H_(2) yields in the range of 450-550℃,while the maximum H_(2) yield(109.8 ml·g^(-1))was observed at 850℃ in the absence of activator.The activated char derived from ZnCl_(2)-assisted pyrolysis exhibited well-developed micro-and mesopore structures,with specific surface areas ranging from 188.2 to 54.1 m^(2)·g^(-1)across pyrolysis temperatures of 450-850℃.When evaluated as adsorbents for methylene blue removal,activated char with greater specific surface area and total pore volume exhibited superior adsorption capacity.The adsorption process was well-described by the pseudo-second-order kinetic model.展开更多
Ca-based additives have been widely used as a sulfur adsorbent during coal pyrolysis and gasification. The Ca speciation and evolution during the pyrolysis of coal with Ca additives have attracted great attention. In ...Ca-based additives have been widely used as a sulfur adsorbent during coal pyrolysis and gasification. The Ca speciation and evolution during the pyrolysis of coal with Ca additives have attracted great attention. In this paper, Ca species in the coal chars prepared from the pyrolysis of Ca（OH）2 or CaCO3-added coals are studied by using Ca K-edge X-ray absorption near-edge structural spectroscopy. The results demonstrate that Ca（OH）2 , CaSO4 , CaS and CaO coexist in the Ca（OH）2-added chars, while Ca（OH）2 and CaSO4 are the main species in the Ca（OH）2-added chars. Besides, a carboxyl-bound Ca is also formed during both the pyrolysis for the Ca（OH）2-added and the CaCO3-added coals. A detailed discussion about the Ca speciation is given.展开更多
In the current research process of coal rank char gasification reaction in China, it is found that particle size has different influence on the gasification reactivity of coal char of different ranks. Therefore, monod...In the current research process of coal rank char gasification reaction in China, it is found that particle size has different influence on the gasification reactivity of coal char of different ranks. Therefore, monodisperse pulverized coal was prepared from eight kinds of coal chars of different ranks in entrained-flow gasifier. The particle size and gasification temperature of coal char were analyzed for these samples. The degree of influence of carbon dioxide gasification reaction. Through research and analysis, the performance differences of these samples under different carbon conversion rates were compared, and the sample reaction under high carbon conversion rates was discussed. The experimental results show that the orderliness of the microcrystalline structure of coal char is directly proportional to the rank of coal, while the gasification activity of coal char is inversely proportional to the rank of coal. Therefore, for different coal ranks, the influence of coal char particle size on coal char gasification reaction is different. According to the experiments, smaller coal char size and higher gasification temperature can promote the reactivity of higher-order coal gasification. In order to clarify the correlation between particle size and gasification reactivity of coal chars with different ranks, this paper discussed this issue.展开更多
In recent decades,annual urban fire incidents,including those involving ancient wooden buildings burned,transportation,and solar panels,have increased,leading to significant loss of human life and property.Addressing ...In recent decades,annual urban fire incidents,including those involving ancient wooden buildings burned,transportation,and solar panels,have increased,leading to significant loss of human life and property.Addressing this issue without altering the surface morphology or interfering with optical behavior of flammable materials poses a substantial challenge.Herein,we present a transparent,low thickness,ceramifiable nanosystem coating composed of a highly adhesive base(poly(SSS1-co-HEMA1)),nanoscale layered double hydroxide sheets as ceramic precursors,and supramolecular melamine di-borate as an accelerator.We demonstrate that this hybrid coating can transform into a porous,fire-resistant protective layer with a highly thermostable vitreous phase upon exposure to flame/heat source.A nanosystem coating of just~100μm thickness can significantly increase the limiting oxygen index of wood(Pine)to 37.3%,dramatically reduce total heat release by 78.6%,and maintain low smoke toxicity(CIT_G=0.016).Detailed molecular force analysis,combined with a comprehensive examination of the underlying flame-retardant mechanisms,underscores the effectiveness of this coating.This work offers a strategy for creating efficient,environmentally friendly coatings with fire safety applications across various industries.展开更多
In this study,the catalysis function of Na_(2)CO_(3) to the structural properties of xylan char was well investigated with Na_(2)CO_(3) on,and the electrochemical performance of xylan char as an anode material for sod...In this study,the catalysis function of Na_(2)CO_(3) to the structural properties of xylan char was well investigated with Na_(2)CO_(3) on,and the electrochemical performance of xylan char as an anode material for sodium-ion batteries was tested.The characterization of X-ray microscopy and scanning electron microscopy demonstrated that the morphological structure of xylan char was altered due to the addition of Na_(2)CO_(3) catalyst.The increasement of the Na_(2)CO_(3)/xylan ratio resulted in a slenderization of the triangular prism shape of the char skeleton and a reduction in porosity.X-ray diffraction analysis revealed that Na_(2)CO_(3) promoted the growth of the(004)crystal plane of graphite during xylan pyrolysis,while inhibiting the formation of the(100/101)crystal planes.Raman spectroscopy analysis indicated that the presence of Na_(2)CO_(3)had changed the graphitization degree of xylan char.Electrochemical tests further showed that char prepared with a Na_(2)CO_(3)/xylan mass ratio of 1∶1 exhibited the highest sodium storage capacity.This study provides a pathway for the rational design carbon materials derived from xylan for future applications in energy storage devices.展开更多
Catalytic oxidation of NO at room temperature was carried out over nitrogen(N)-doped sludge char(SC)prepared from pyrolysis ofmunicipal sewage sludge,and urea was adopted as nitrogen source.The effects of different N-...Catalytic oxidation of NO at room temperature was carried out over nitrogen(N)-doped sludge char(SC)prepared from pyrolysis ofmunicipal sewage sludge,and urea was adopted as nitrogen source.The effects of different N-doping methods(one-step and two-step method),dried sludge(DS)/urea mass ratios(5:1,4:1,3:1,2:1,and 1:1),SC preparation procedures(pyrolysis only,pyrolysis with acid washing,and pyrolysis with KOH activation and acid washing),and different pyrolysis temperatures(500,600,700,and 800°C)on the catalytic oxidation of NO were compared to optimize the procedure for SC preparation.The results indicated that N-doping could obviously promote the catalytic performance of SC.The one-step method with simultaneous sludge pyrolysis(at 700°C),KOH activation,and N-doping(DS/urea of 3:1)was the optimal procedure for preparing the N-doped SC with the NO conversion rate of 54.7%,whereas the optimal NO conversion rate of SC without N-doping was only 47.3%.Urea worked both as carbon and nitrogen source,which could increase about 2.9%-16.5%of carbon and 24.8%-42.7%of nitrogen content in SC pyrolyzed at 700°C.N-doping significantly promoted microporosity of SC.The optimal N-doped SC showed specific surface areas of 571.38 m^(2)/g,much higher than 374.34 m^(2)/g of the optimal SC without N-doping.In addition,N-doping also increased amorphousness and surface basicity of SC through the formation of N-containing groups.Finally,three reaction paths,i.e.microporous reactor,active sites,and basic site control path,were proposed to explain the mechanism of N-doping on promoting the catalytic performance of NO.展开更多
A novel eco-friendly charring agent(L-OH)was successfully synthesized by combining pentaerythritol(PER)with lignin through a simple two-step reaction.The structure of L-OH was characterized using Fourier transform inf...A novel eco-friendly charring agent(L-OH)was successfully synthesized by combining pentaerythritol(PER)with lignin through a simple two-step reaction.The structure of L-OH was characterized using Fourier transform infrared(FTIR),X-ray diffraction(XRD),scanning electron microscopy(SEM)and EDS.In addition,L-OH was introduced into polypropylene(PP)together with melamine(MEL)and ammonium polyphosphate(APP)as an intumescent flame retardant(IFRR).The flame retardancy of PP/IFRR composites were investigated using limited oxygen index(LOI),UL-94,thermogravimetric analysis(TGA)and cone calorimeter(CC)test.The experimental results indicate that the PP/IFRR composites pass the V-0 grade of the UL-94 test when the addition amount of IFRR is no less than 20%,and the LOI value of the composite reaches 32.2%at 30%IFRR addition.The peak heat release rate(PHRR)and peak smoke production rate(PSPR)of the composite decrease by 72.8%and 70.4%compared with pure PP,respectively.The flame retardancy mechanism was investigated by TGA,TG-FTIR and residual carbon analysis.These analyses indicate that L-OH can form a more continuous and dense carbon layer during the combustion process,which is the main factor contributing to the improved flame retardancy of PP.展开更多
Glue-laminated timber(GLT)is an engineered wood product widely used in mass timber construction for its strong structural and fire-resistant properties.However,the fire performance of GLT varies significantly due to t...Glue-laminated timber(GLT)is an engineered wood product widely used in mass timber construction for its strong structural and fire-resistant properties.However,the fire performance of GLT varies significantly due to the natural and uncertain phenomena(moisture,exposure time,isotropic,homogenous properties,etc.)of fire and timber.This makes it difficult to predict the fire behaviour of the GLT structural elements.To ensure building safety,it is crucial to assess GLT’s fire behaviour and post-fire structural integrity during the design stages.This study conducted the experimental tests of GLT beams(280 mm×560 mm)without loading(1.4 m)and under a four-point bending load(5.4 m).Tests identified thermal behaviour and charring rates of GLT beam.Then,the residual stiffness of the GLT beam was calculated,and the charring rates of the beams were compared with Australian and European standards.Reliability analysis was conducted for beams for a fire exposure of 120 min,considering the charring rates observed through the analysis and simulating the fire insulations.Results show that the charring rate of GLT made with spruce pine timber varied between 0.43 and 0.81 mm/min,with a mean rate of 0.7 mm/min,aligning with both Australian and European standards.However,considering timber density and moisture content,the charring rates in Australian standards were conservative.The study also found that structural capacity significantly degrades under fire,with a 22%reduction in flexural stiffness after 120 min of exposure.Additionally,GLT beams can safely function for 30 min under 75%of their design moment capacity and for 60 min under 50%capacity.展开更多
The carbonization processing(Paozhi)in traditional Chinese medicine(TCM)represents a unique pharmaceutical technology where thermal modification of herbal materials enhances specific therapeutic properties,particularl...The carbonization processing(Paozhi)in traditional Chinese medicine(TCM)represents a unique pharmaceutical technology where thermal modification of herbal materials enhances specific therapeutic properties,particularly hemostatic and antioxidant effects.Despite centuries of empirical applications,the scientific basis underlying these enhanced bioactivities remains poorly characterized,particularly regarding the transformation and functionalization of active components during high-temperature carbonization.This study systematically investigates carbon dots(CDs),emerging carbon-based nanomaterials spontaneously formed during the carbonization process,as potential key bioactive constituents mediating the therapeutic actions of carbonized TCM.Through multidisciplinary analysis of pyrolysis-driven CD formation mechanisms,nanostructural evolution,and surface chemistry modulation,we demonstrate that CDs exhibit size-dependent fluorescence properties and redox-active surface functional groups that correlate with their observed biological effects.Crucially,the study establishes quantitative structure-activity relationships between CDs’quantum confinement characteristics(2–8 nm diameter),oxygencontaining surface moieties(carboxyl,hydroxyl groups),and their procoagulant/antioxidant capacities.By bridging traditional processing knowledge with nanotechnology insights,this work not only deciphers the“black box”of thermal processing in TCM but also proposes a nano-biointerface paradigm for understanding Paozhi mechanisms.The findings advance quality control strategies through CD-based spectral fingerprinting and open new avenues for developing nanoscale TCM derivatives with optimized therapeutic profiles.展开更多
In the current era of renewable energy prominence,the wide operational capacity of coal-fired boilers has emerged as crucial for ensuring the sustainability of power plants.However,attaining ultra-low nitrogen oxides(...In the current era of renewable energy prominence,the wide operational capacity of coal-fired boilers has emerged as crucial for ensuring the sustainability of power plants.However,attaining ultra-low nitrogen oxides(NO_x)emissions during periods of low-load operations presents a significant and persistent challenge for coal power enterprises.While techniques such as biomass re-burning and advanced re-burning have shown promise in enhancing NO reduction effciency above 800℃,their elevated levels of chlorine(Cl)and alkali metals pose potential risks to boiler equipment integrity.Therefore,this study proposes the utilization of biomass char derived from pyrolysis as a dual-purpose solution to enhance NO reduction efficiency while safeguarding boiler integrity during low-load operations.Findings indicate that pyrolysis treatment effectively reduces the Cl and alkali metal content of biomass.Specifically,it was determined that biomass char produced through deeply pyrolysis at 300℃achieves the highest NO reduction efficiency while minimizing the presence of harmful components.At a reduction temperature of 700℃,both re-burning and advanced re-burning techniques exhibit NO reduction efficiencies of 55.90%and 62.22%,which is already an ideal deficiency at low temperatures.The addition of water vapor at 700-800℃obviously avoids the oxidation of ammonia to NO in advanced reburning.Upon further analysis,denitrification efficiency in biomass char re-burning and advanced reburning is influenced not only by volatile content but also by physicochemical properties such as porosity and surface functional group distribution under certain reaction conditions.This study provides a theoretical framework for the industrial implementation of biomass char for NO control in coal-fired power plants,offering insights into optimizing NO reduction efficiency while mitigating potential risks to boiler equipment.展开更多
Improving crop productivity and soil fertility through the balanced application of inorganic and organic nutrient sources is a sustainable approach in modern agriculture.Char land soils,widely distributed in riverine ...Improving crop productivity and soil fertility through the balanced application of inorganic and organic nutrient sources is a sustainable approach in modern agriculture.Char land soils,widely distributed in riverine Bangladesh,are generally low in organic matter status and deficient in necessary nutrient elements for crop production.Addressing this challenge,the present study was conducted to investigate the effects of various organic nutrient sources with inorganic fertilizers on crop yields,nutrient uptake,and soil fertility in farm(L1)and char land(L2)of Brahmaputra River in Mymensingh,Bangladesh from 2022(Y1)to 2023(Y2).For each location,eight treatments viz.T1(Control),T2[100%recommended fertilizer dose(RFD)],T3(75%RFD),T4(75%N from RFD 25%N from cow dung),T5(75%+N from RFD 25%N from poultry manure),T6(75%N from RFD 25%N from vermicompost),T7(75%N from++RFD 25%N from household compost)and T8(75%N from RFD 25%N from rice straw compost)were arranged in++a randomized complete block design with three replications using Wheat–Mungbean–T.Aman rice cropping pattern where three way interaction was considered for results.Treatment T5 performed the best in both years in both locations as it enhanced the yield components(p 0.05)and caused yield increment over control.The yield improvement in<Char land soils was higher than that in farm soils.For all three crops,treatment T5 consistently augmented the uptake of nitrogen,phosphorus,potassium,and sulphur by different parts of the crops and improved soil fertility properties such as organic matter status,cation exchange capacity,total nitrogen,available phosphorus,and sulphur as well as exchangeable potassium in both locations in both years.Cost and return analysis of different treatments for the whole cropping system showed that the highest marginal benefit-cost ratio(16.35 and 15.07)and gross return(about Tk 768,595/ha and 728,341/ha)were obtained from the T5 treatment in farm soils and Char land soils,respectively.Followed by poultry manure,vermicompost performed well in addition to mineral fertilizers for improving crop yield and soil fertility but its economic efficiency was less due to high input cost.These findings may be useful to the smallholder farmers in char areas,who could benefit from increased productivity,reduced reliance on chemical fertilizers,and improved soil health,contributing to the long-term sustainability of char land agriculture.展开更多
We reports an efficient approach for production of hydrogen from crude bio-oil and biomass char in the dual fixed-bed system by using the electrochemical catalytic reforming method. The maximal absolute hydrogen yield...We reports an efficient approach for production of hydrogen from crude bio-oil and biomass char in the dual fixed-bed system by using the electrochemical catalytic reforming method. The maximal absolute hydrogen yield reached 110.9 g H2/kg dry biomass. The product gas was a mixed gas containing 72%H2, 26%CO2, 1.9%CO, and a trace amount of CH4. It was observed that adding biomass char （a by-product of pyrolysis of biomass） could remarkably increase the absolute H2 yield （about 20%-50%）. The higher reforming temperature could enhance the steam reforming reaction of organic compounds in crude bio-oil and the reaction of CO and H20. In addition, the CuZn-Al2O3 catalyst in the water-gas shift bed could also increase the absolute H2 yield via shifting CO to CO2.展开更多
基金supported by Foundation Project of Jihua Laboratory(X200191TL200).
文摘This work investigated the effect of Na_(2)CO_(3)on the char structures of cellulose and lignin,respective-ly,and examined the electrochemi-cal performance of the char by act-ing as an active material for coin cells.The morphology of char can be significantly steered by the con-centration of Na_(2)CO_(3).Scanning electron microscopy analysis demonstrated that the intro-duction of Na_(2)CO_(3)into cellulose at an appropriate concentration led to the formation of tubular structure on its surface after pyrolysis,whereas the tubular structure was absent in the lignin char with the addition of Na_(2)CO_(3)at any concentrations.X-ray diffraction and Ra-man spectroscopy characterizations revealed that all the obtained chars from both cellulose and lignin,with or without Na_(2)CO_(3),were ascribed to non-crystalline graphite.Nevertheless,the crystal orientation of graphite from cellulose and lignin changed after the catalysis of Na_(2)CO_(3).Further electrochemical tests showed that cellulose char had a higher sodium stor-age capacity than that of lignin char.The excellent electrochemical performance of carbon materials derived from cellulose might hold a prospective application in the field of energy storage.
基金performed within the framework of the SAW project "Biochar in Agriculture:Perspectives for Germany and Malaysia" funded by the Leibniz Association,Germany,within the context of the "Joint Initiative for Research and Innovation"
文摘The biodegradability of chars derived from pyrolysis and hydrothermal carbonisation(HTC) was studied in short-term dynamic incubation experiments under controlled conditions. Carbon dioxide C(CO2) emissions from soil-char mixtures in combination with solid digestate or mineral nitrogen(N) fertiliser were measured in dynamic chambers for 10 d. Compared to the original material(maize straw), pyrolysis and HTC chars showed significantly lower CO2 emissions and slower decay dynamics; and compared to the soil control, HTC char increased soil respiration to a significant extent, while pyrolysis char did not. The addition of mineral N resulted in a delayed respiration dynamics for HTC char, while the addition of digestate resulted in an increase in the respired CO2 for pyrolysis char and a decrease for HTC char. For the first time, a peculiar two-stage decay kinetics was observed for HTC char,indicating a highly inhomogeneous substrate consisting at least of two C pools.
文摘Pyrolysis temperature and feedstock type used to produce biochar influence the physicochemical properties of the obtained product, which in turn display a range of results when used as soil amendment. From soil carbon (C) sequestration strategy to nutrient source, biochar is used to enhance soil properties and to improve agricultural production. However, contrasting effects are observed from biochar application to soil results from a wide range of biochar’s properties in combination with specific environmental conditions. Therefore, elucidation on the effect of pyrolysis conditions and feedstock type on biochar properties may provide basic information to the understanding of soil and biochar interactions. In this study, biochar was produced from four different agricultural organic residues: Poultry litter, sugarcane straw, rice hull and sawdust pyrolysed at final temperatures of 350°C, 450°C, 550°C and 650°C. The effect of temperature and feedstock type on the variability of physicochemical properties of biochars was evaluated through measurements of pH, electrical conductivity, cation exchange capacity, macronutrient content, proximate and elemental analyses, Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analyses. Additionally, an incubation trial was carried under controlled conditions to determine the effect of biochar stability on CO2-eq emissions. Results showed that increasing pyrolysis temperature supported biochar stability regardless of feedstock, however, agricultural properties varied widely both as an effect of temperature and feedstock. Animal manure biochar showed higher potential as nutrient source rather than a C sequestration strategy. Improving the knowledge on the influence of pyrolysis temperature and feedstock type on the final properties of biochar will enable the use of better tailored materials that correspond to the expected results while considering its interactions with environmental conditions.
基金This work was financially supported by the National Key Research and Development Program of China(2017YFB0602601)the Key Research and Development Program of Ningxia Hui Autonomous Region(2019BCH01001).
文摘This study examined an isothermal CO2 gasification of four chars prepared via two different methods,i.e.,conventional and microwave-assisted pyrolysis,by the approach of thermogravimetric analysis.Physical,chemical,and structural behaviours of chars were examined using ultimate analysis,X-ray diffraction,and scanning electronic microscopy.Kinetic parameters were calculated by applying the shrinking unreacted core(SCM)and random pore(RPM)models.Moreover,char-CO2 gasification was further simulated by using Aspen Plus to investigate thermodynamic performances in terms of syngas composition and cold gas efficiency(CGE).The microwave-induced char has the largest C/H mass ratio and most ordered carbon structure,but the smallest gasification reactivity.Kinetic analysis indicates that the RPM is better for describing both gasification conversion and reaction rates of the studied chars,and the activation energies and pre-exponential factors varied in the range of 78.45–194.72 kJ/mol and 3.15–102,231.99 s−1,respectively.In addition,a compensation effect was noted during gasification.Finally,the microwave-derived char exhibits better thermodynamic performances than the conventional chars,with the highest CGE and CO molar concentration of 1.30%and 86.18%,respectively.Increasing the pyrolysis temperature,gasification temperature,and CO2-to-carbon molar ratio improved the CGE.
基金The present work was supported by the National Natural Science Foundation of China(U1960205 and 51574023).
文摘The gasification reactivity and kinetic parameters of coal chars for non-isothermal steam gasification were investigated.One kind of lignite and three kinds of bituminous coals were used as the samples,and their coal ranks follow the ascending order:XB<KL<ZJ<GD.As characterized by the comprehensive gasification index,the gasification reactivity of coal chars follows the descending order:XB>KL>ZJ>GD.Through systematically analyzing factors affecting gasification reactivity,it was ascertained that the gasification reactivity is mostly determined by the carbonaceous structure.The gasification reactivity is inversely proportional to the coal rank,and the higher the coal rank,the lower the gasification reactivity.A new kinetic model was proposed to calculate the kinetic parameters,in which the reaction order was considered as an unknown kinetic parameter.The reaction order n follows the ascending order:XB<KL<ZJ<GD,which are n=1.00,n=1.34,n=1.83,and n=2.63,respectively.It is proved that the reaction order is proportional to the coal rank,and the higher the coal rank,the higher the reaction order.
基金financially supported by the National Natural Science Foundation of China(U21A2062)National innovative training program for college students of China(202410792014)。
文摘Sewage sludge(SS)and SS impregnated with activating agents(ZnCl_(2) and KOH)were pyrolyzed in a fixed-bed reactor to produce gaseous fuel and activated char.The effects of heating rate,pyrolysis temperature and activator type on gas yields,pore structure and adsorption properties of activated char were systematically studied.The results demonstrated that increasing the pyrolysis temperature from 450℃ to 850℃ propo rtionally enhanced H_(2) and CO yields from the rapid pyrolysis of SS,while CH_(4) yield showed minimal variation between 650℃ and 850℃.ZnCl_(2) notably increased the CO yield,reaching71.9 ml·g^(-1)at 850℃,but caused a marked reduction in CH_(4) yield under the tested conditions.Similarly,KOH promoted CO yield at 750℃ and 850℃,with minimal impact on CH_(4) production.Both activators facilitated higher H_(2) yields in the range of 450-550℃,while the maximum H_(2) yield(109.8 ml·g^(-1))was observed at 850℃ in the absence of activator.The activated char derived from ZnCl_(2)-assisted pyrolysis exhibited well-developed micro-and mesopore structures,with specific surface areas ranging from 188.2 to 54.1 m^(2)·g^(-1)across pyrolysis temperatures of 450-850℃.When evaluated as adsorbents for methylene blue removal,activated char with greater specific surface area and total pore volume exhibited superior adsorption capacity.The adsorption process was well-described by the pseudo-second-order kinetic model.
基金Supported by National Program on Key Basic Research Project (2010CB227005-03)National Natural Science Foundation of China (21076081, 10775150)the University of Saskatchewan for the financial support given to the CLS
文摘Ca-based additives have been widely used as a sulfur adsorbent during coal pyrolysis and gasification. The Ca speciation and evolution during the pyrolysis of coal with Ca additives have attracted great attention. In this paper, Ca species in the coal chars prepared from the pyrolysis of Ca（OH）2 or CaCO3-added coals are studied by using Ca K-edge X-ray absorption near-edge structural spectroscopy. The results demonstrate that Ca（OH）2 , CaSO4 , CaS and CaO coexist in the Ca（OH）2-added chars, while Ca（OH）2 and CaSO4 are the main species in the Ca（OH）2-added chars. Besides, a carboxyl-bound Ca is also formed during both the pyrolysis for the Ca（OH）2-added and the CaCO3-added coals. A detailed discussion about the Ca speciation is given.
文摘In the current research process of coal rank char gasification reaction in China, it is found that particle size has different influence on the gasification reactivity of coal char of different ranks. Therefore, monodisperse pulverized coal was prepared from eight kinds of coal chars of different ranks in entrained-flow gasifier. The particle size and gasification temperature of coal char were analyzed for these samples. The degree of influence of carbon dioxide gasification reaction. Through research and analysis, the performance differences of these samples under different carbon conversion rates were compared, and the sample reaction under high carbon conversion rates was discussed. The experimental results show that the orderliness of the microcrystalline structure of coal char is directly proportional to the rank of coal, while the gasification activity of coal char is inversely proportional to the rank of coal. Therefore, for different coal ranks, the influence of coal char particle size on coal char gasification reaction is different. According to the experiments, smaller coal char size and higher gasification temperature can promote the reactivity of higher-order coal gasification. In order to clarify the correlation between particle size and gasification reactivity of coal chars with different ranks, this paper discussed this issue.
基金the financial support from the National Natural Science Foundation of China(524B2168,U22A20149,52173081,and 52273275)。
文摘In recent decades,annual urban fire incidents,including those involving ancient wooden buildings burned,transportation,and solar panels,have increased,leading to significant loss of human life and property.Addressing this issue without altering the surface morphology or interfering with optical behavior of flammable materials poses a substantial challenge.Herein,we present a transparent,low thickness,ceramifiable nanosystem coating composed of a highly adhesive base(poly(SSS1-co-HEMA1)),nanoscale layered double hydroxide sheets as ceramic precursors,and supramolecular melamine di-borate as an accelerator.We demonstrate that this hybrid coating can transform into a porous,fire-resistant protective layer with a highly thermostable vitreous phase upon exposure to flame/heat source.A nanosystem coating of just~100μm thickness can significantly increase the limiting oxygen index of wood(Pine)to 37.3%,dramatically reduce total heat release by 78.6%,and maintain low smoke toxicity(CIT_G=0.016).Detailed molecular force analysis,combined with a comprehensive examination of the underlying flame-retardant mechanisms,underscores the effectiveness of this coating.This work offers a strategy for creating efficient,environmentally friendly coatings with fire safety applications across various industries.
基金supported by the Foundation Project of Jihua Laboratory(X200191TL200).
文摘In this study,the catalysis function of Na_(2)CO_(3) to the structural properties of xylan char was well investigated with Na_(2)CO_(3) on,and the electrochemical performance of xylan char as an anode material for sodium-ion batteries was tested.The characterization of X-ray microscopy and scanning electron microscopy demonstrated that the morphological structure of xylan char was altered due to the addition of Na_(2)CO_(3) catalyst.The increasement of the Na_(2)CO_(3)/xylan ratio resulted in a slenderization of the triangular prism shape of the char skeleton and a reduction in porosity.X-ray diffraction analysis revealed that Na_(2)CO_(3) promoted the growth of the(004)crystal plane of graphite during xylan pyrolysis,while inhibiting the formation of the(100/101)crystal planes.Raman spectroscopy analysis indicated that the presence of Na_(2)CO_(3)had changed the graphitization degree of xylan char.Electrochemical tests further showed that char prepared with a Na_(2)CO_(3)/xylan mass ratio of 1∶1 exhibited the highest sodium storage capacity.This study provides a pathway for the rational design carbon materials derived from xylan for future applications in energy storage devices.
基金supported by Shanghai Pujiang Program(No.22PJD001)the Fundamental Research Funds for the Central Universities(No.2232021G-11).
文摘Catalytic oxidation of NO at room temperature was carried out over nitrogen(N)-doped sludge char(SC)prepared from pyrolysis ofmunicipal sewage sludge,and urea was adopted as nitrogen source.The effects of different N-doping methods(one-step and two-step method),dried sludge(DS)/urea mass ratios(5:1,4:1,3:1,2:1,and 1:1),SC preparation procedures(pyrolysis only,pyrolysis with acid washing,and pyrolysis with KOH activation and acid washing),and different pyrolysis temperatures(500,600,700,and 800°C)on the catalytic oxidation of NO were compared to optimize the procedure for SC preparation.The results indicated that N-doping could obviously promote the catalytic performance of SC.The one-step method with simultaneous sludge pyrolysis(at 700°C),KOH activation,and N-doping(DS/urea of 3:1)was the optimal procedure for preparing the N-doped SC with the NO conversion rate of 54.7%,whereas the optimal NO conversion rate of SC without N-doping was only 47.3%.Urea worked both as carbon and nitrogen source,which could increase about 2.9%-16.5%of carbon and 24.8%-42.7%of nitrogen content in SC pyrolyzed at 700°C.N-doping significantly promoted microporosity of SC.The optimal N-doped SC showed specific surface areas of 571.38 m^(2)/g,much higher than 374.34 m^(2)/g of the optimal SC without N-doping.In addition,N-doping also increased amorphousness and surface basicity of SC through the formation of N-containing groups.Finally,three reaction paths,i.e.microporous reactor,active sites,and basic site control path,were proposed to explain the mechanism of N-doping on promoting the catalytic performance of NO.
基金the equipment support of Sharing Platform of Scientific Equipments,Ministry of Education's Research Center for Comprehensive Utilization and Clean Process Engineering of Phosphrous Resources,Sichuan University。
文摘A novel eco-friendly charring agent(L-OH)was successfully synthesized by combining pentaerythritol(PER)with lignin through a simple two-step reaction.The structure of L-OH was characterized using Fourier transform infrared(FTIR),X-ray diffraction(XRD),scanning electron microscopy(SEM)and EDS.In addition,L-OH was introduced into polypropylene(PP)together with melamine(MEL)and ammonium polyphosphate(APP)as an intumescent flame retardant(IFRR).The flame retardancy of PP/IFRR composites were investigated using limited oxygen index(LOI),UL-94,thermogravimetric analysis(TGA)and cone calorimeter(CC)test.The experimental results indicate that the PP/IFRR composites pass the V-0 grade of the UL-94 test when the addition amount of IFRR is no less than 20%,and the LOI value of the composite reaches 32.2%at 30%IFRR addition.The peak heat release rate(PHRR)and peak smoke production rate(PSPR)of the composite decrease by 72.8%and 70.4%compared with pure PP,respectively.The flame retardancy mechanism was investigated by TGA,TG-FTIR and residual carbon analysis.These analyses indicate that L-OH can form a more continuous and dense carbon layer during the combustion process,which is the main factor contributing to the improved flame retardancy of PP.
文摘Glue-laminated timber(GLT)is an engineered wood product widely used in mass timber construction for its strong structural and fire-resistant properties.However,the fire performance of GLT varies significantly due to the natural and uncertain phenomena(moisture,exposure time,isotropic,homogenous properties,etc.)of fire and timber.This makes it difficult to predict the fire behaviour of the GLT structural elements.To ensure building safety,it is crucial to assess GLT’s fire behaviour and post-fire structural integrity during the design stages.This study conducted the experimental tests of GLT beams(280 mm×560 mm)without loading(1.4 m)and under a four-point bending load(5.4 m).Tests identified thermal behaviour and charring rates of GLT beam.Then,the residual stiffness of the GLT beam was calculated,and the charring rates of the beams were compared with Australian and European standards.Reliability analysis was conducted for beams for a fire exposure of 120 min,considering the charring rates observed through the analysis and simulating the fire insulations.Results show that the charring rate of GLT made with spruce pine timber varied between 0.43 and 0.81 mm/min,with a mean rate of 0.7 mm/min,aligning with both Australian and European standards.However,considering timber density and moisture content,the charring rates in Australian standards were conservative.The study also found that structural capacity significantly degrades under fire,with a 22%reduction in flexural stiffness after 120 min of exposure.Additionally,GLT beams can safely function for 30 min under 75%of their design moment capacity and for 60 min under 50%capacity.
基金supported by the Natural Science Foundation of Shandong Province(No.ZR2023ZD25)the Shandong Province Chinese Medicine Science and Technology Development Project(No.Q-2023107)the Taishan Scholars Project in Shandong Province(Nos.tstp202306 and tsqn202408246).
文摘The carbonization processing(Paozhi)in traditional Chinese medicine(TCM)represents a unique pharmaceutical technology where thermal modification of herbal materials enhances specific therapeutic properties,particularly hemostatic and antioxidant effects.Despite centuries of empirical applications,the scientific basis underlying these enhanced bioactivities remains poorly characterized,particularly regarding the transformation and functionalization of active components during high-temperature carbonization.This study systematically investigates carbon dots(CDs),emerging carbon-based nanomaterials spontaneously formed during the carbonization process,as potential key bioactive constituents mediating the therapeutic actions of carbonized TCM.Through multidisciplinary analysis of pyrolysis-driven CD formation mechanisms,nanostructural evolution,and surface chemistry modulation,we demonstrate that CDs exhibit size-dependent fluorescence properties and redox-active surface functional groups that correlate with their observed biological effects.Crucially,the study establishes quantitative structure-activity relationships between CDs’quantum confinement characteristics(2–8 nm diameter),oxygencontaining surface moieties(carboxyl,hydroxyl groups),and their procoagulant/antioxidant capacities.By bridging traditional processing knowledge with nanotechnology insights,this work not only deciphers the“black box”of thermal processing in TCM but also proposes a nano-biointerface paradigm for understanding Paozhi mechanisms.The findings advance quality control strategies through CD-based spectral fingerprinting and open new avenues for developing nanoscale TCM derivatives with optimized therapeutic profiles.
基金supported by the Open Topics of State Key Laboratory of Clean and Efficient Coal-Fired Power Generation and Pollution Control(D2022FK103)National Natural Science Foundation of China(22278250)+1 种基金the Shanxi Province Science and Technology Cooperation and Exchange Special Program(202104041101014)the Shanxi Province Scholarship Council。
文摘In the current era of renewable energy prominence,the wide operational capacity of coal-fired boilers has emerged as crucial for ensuring the sustainability of power plants.However,attaining ultra-low nitrogen oxides(NO_x)emissions during periods of low-load operations presents a significant and persistent challenge for coal power enterprises.While techniques such as biomass re-burning and advanced re-burning have shown promise in enhancing NO reduction effciency above 800℃,their elevated levels of chlorine(Cl)and alkali metals pose potential risks to boiler equipment integrity.Therefore,this study proposes the utilization of biomass char derived from pyrolysis as a dual-purpose solution to enhance NO reduction efficiency while safeguarding boiler integrity during low-load operations.Findings indicate that pyrolysis treatment effectively reduces the Cl and alkali metal content of biomass.Specifically,it was determined that biomass char produced through deeply pyrolysis at 300℃achieves the highest NO reduction efficiency while minimizing the presence of harmful components.At a reduction temperature of 700℃,both re-burning and advanced re-burning techniques exhibit NO reduction efficiencies of 55.90%and 62.22%,which is already an ideal deficiency at low temperatures.The addition of water vapor at 700-800℃obviously avoids the oxidation of ammonia to NO in advanced reburning.Upon further analysis,denitrification efficiency in biomass char re-burning and advanced reburning is influenced not only by volatile content but also by physicochemical properties such as porosity and surface functional group distribution under certain reaction conditions.This study provides a theoretical framework for the industrial implementation of biomass char for NO control in coal-fired power plants,offering insights into optimizing NO reduction efficiency while mitigating potential risks to boiler equipment.
基金funded by Taif University,Saudi Arabia,Project No.(TU-DSPP-2025-30)The Science and Technology Fellowship Trust(SL No.39.00.0000.035.22.013.19.144)under the Ministry of Science and Technology of Bangladesh partially financed the current research。
文摘Improving crop productivity and soil fertility through the balanced application of inorganic and organic nutrient sources is a sustainable approach in modern agriculture.Char land soils,widely distributed in riverine Bangladesh,are generally low in organic matter status and deficient in necessary nutrient elements for crop production.Addressing this challenge,the present study was conducted to investigate the effects of various organic nutrient sources with inorganic fertilizers on crop yields,nutrient uptake,and soil fertility in farm(L1)and char land(L2)of Brahmaputra River in Mymensingh,Bangladesh from 2022(Y1)to 2023(Y2).For each location,eight treatments viz.T1(Control),T2[100%recommended fertilizer dose(RFD)],T3(75%RFD),T4(75%N from RFD 25%N from cow dung),T5(75%+N from RFD 25%N from poultry manure),T6(75%N from RFD 25%N from vermicompost),T7(75%N from++RFD 25%N from household compost)and T8(75%N from RFD 25%N from rice straw compost)were arranged in++a randomized complete block design with three replications using Wheat–Mungbean–T.Aman rice cropping pattern where three way interaction was considered for results.Treatment T5 performed the best in both years in both locations as it enhanced the yield components(p 0.05)and caused yield increment over control.The yield improvement in<Char land soils was higher than that in farm soils.For all three crops,treatment T5 consistently augmented the uptake of nitrogen,phosphorus,potassium,and sulphur by different parts of the crops and improved soil fertility properties such as organic matter status,cation exchange capacity,total nitrogen,available phosphorus,and sulphur as well as exchangeable potassium in both locations in both years.Cost and return analysis of different treatments for the whole cropping system showed that the highest marginal benefit-cost ratio(16.35 and 15.07)and gross return(about Tk 768,595/ha and 728,341/ha)were obtained from the T5 treatment in farm soils and Char land soils,respectively.Followed by poultry manure,vermicompost performed well in addition to mineral fertilizers for improving crop yield and soil fertility but its economic efficiency was less due to high input cost.These findings may be useful to the smallholder farmers in char areas,who could benefit from increased productivity,reduced reliance on chemical fertilizers,and improved soil health,contributing to the long-term sustainability of char land agriculture.
基金This work was supported by the National Basic Research Program of Ministry of Science and Technology of China （No.2007CB210206）, the National High Tech Research and Development Program （No.2009AA05Z435）, and the National Natural Science Foundation of China （No.50772107）.
文摘We reports an efficient approach for production of hydrogen from crude bio-oil and biomass char in the dual fixed-bed system by using the electrochemical catalytic reforming method. The maximal absolute hydrogen yield reached 110.9 g H2/kg dry biomass. The product gas was a mixed gas containing 72%H2, 26%CO2, 1.9%CO, and a trace amount of CH4. It was observed that adding biomass char （a by-product of pyrolysis of biomass） could remarkably increase the absolute H2 yield （about 20%-50%）. The higher reforming temperature could enhance the steam reforming reaction of organic compounds in crude bio-oil and the reaction of CO and H20. In addition, the CuZn-Al2O3 catalyst in the water-gas shift bed could also increase the absolute H2 yield via shifting CO to CO2.
