The paper proposes a biomass cross-upgrading process that combines hydrothermal carbonization and pyrolysis to produce high-quality blast furnace injection fuel.The results showed that after upgrading,the volatile con...The paper proposes a biomass cross-upgrading process that combines hydrothermal carbonization and pyrolysis to produce high-quality blast furnace injection fuel.The results showed that after upgrading,the volatile content of biochar ranged from 16.19%to 45.35%,and the alkali metal content,ash content,and specific surface area were significantly reduced.The optimal route for biochar pro-duction is hydrothermal carbonization-pyrolysis(P-HC),resulting in biochar with a higher calorific value,C=C structure,and increased graphitization degree.The apparent activation energy(E)of the sample ranges from 199.1 to 324.8 kJ/mol,with P-HC having an E of 277.8 kJ/mol,lower than that of raw biomass,primary biochar,and anthracite.This makes P-HC more suitable for blast furnace injection fuel.Additionally,the paper proposes a path for P-HC injection in blast furnaces and calculates potential environmental benefits.P-HC of-fers the highest potential for carbon emission reduction,capable of reducing emissions by 96.04 kg/t when replacing 40wt%coal injec-tion.展开更多
Hydrothermal carbonization is highly applicable to high moisture biomass upgrading due to the fact that moist-ure involved can be directly used as reaction media under the subcritical-water region.With this,value-adde...Hydrothermal carbonization is highly applicable to high moisture biomass upgrading due to the fact that moist-ure involved can be directly used as reaction media under the subcritical-water region.With this,value-added utilization of hydrochar as solid fuel with high carbon and energy density is one of the important pathways for biomass conversion.In this review,the dewatering properties of hydrochar after the hydrothermal carbonization of biowaste,coalification degree with elemental composition and evolution,pelletization of hydrochar to enhance the mechanical properties and density,coupled with the combustion properties of hydrochar biofuel were discussed with various biomass and carbonization parameters.Potential applications for the co-combustion with coal,cleaner properties and energy balance for biowaste hydrothermal carbonization were presented as well as the challenges.展开更多
Carbon microspheres were prepared from waste cotton fibers by hydrothermal carbonization(HTC)with the addition of copper sulphate in this work.The important influence factors,temperature,concentration of copper sulpha...Carbon microspheres were prepared from waste cotton fibers by hydrothermal carbonization(HTC)with the addition of copper sulphate in this work.The important influence factors,temperature,concentration of copper sulphate,resident time were explored here.The smooth and regular carbon microspheres could be formed at 330°C with 0.15 wt%copper sulphate after 6 h from waste cotton fibers.The crystal structures of cotton fibers were destructed in a short resident time with 0.15 wt%copper sulphate from SEM images and XRD patterns of solid products.This strategy provides a new,mild and efficient method to prepare carbon microspheres from waste cotton fibers by HTC.FTIR spectra verified that the abundant functional groups existed on the surface of synthesized carbon microspheres.From XPS and element analysis results,the copper sulphate participated in the forming process of carbon microspheres indeed.The presence of copper sulphate in the carbon microspheres provided a possibility for the application in antibacterial field.Besides,the catalytic mechanism of copper sulphate on the hydrolysis and carbonization of waste cotton fibers were also discussed.In conclusion,the copper sulphate is an efficient agent for preparing carbon microspheres by HTC from waste cotton fibers.展开更多
Hydrothermal carbonization(HTC) is a valuable approach to convert furfural residue(FR) into carbon material. The prepared biochars are usually characterized comprehensively, while the stock process water still remains...Hydrothermal carbonization(HTC) is a valuable approach to convert furfural residue(FR) into carbon material. The prepared biochars are usually characterized comprehensively, while the stock process water still remains to be studied in detail. Herein, a NMR study of the main components in stock process water generated at different HTC reaction conditions was reported. Various qualitative and quantitative NMR techniques(~1H and ^(13)C NMR,~1H-~1H COSY and ~1H-^(13)C HSQC etc.) especially 1D selective gradient total correlation spectroscopy(TOCSY NMR) were strategically applied in the analysis of HTC stock process water. Without separation and purification, it was demonstrated that the main detectable compounds are 5-hydroxymethylfurfural, formic acid, methanol, acetic acid, levulinic acid, glycerol, hydroxyacetone and acetaldehyde in this complicate mixture. Furthermore, the relationship between the concentration of major products and the reaction conditions(180-240 ℃ at 8 h, and 1-24 h at 240 ℃) was established. Finally, reasonable reaction pathways for hydrothermal conversion of FR were proposed based on this result and our previously obtained characteristics of biochars. The routine and challenging NMR methods utilized here would be an alternative other than HPLC or GC for biomass conversion research and can be extended to more studies.展开更多
Thermal treatment of biomass has been attracting attention for a decade or so, especially torrefaction. However, for the past few years, wet pyrolysis, also known as hydrothermal carbonization (HTC), has been getting ...Thermal treatment of biomass has been attracting attention for a decade or so, especially torrefaction. However, for the past few years, wet pyrolysis, also known as hydrothermal carbonization (HTC), has been getting some attention. Hydrothermal carbonization is a thermal treatment of biomass in the presence of water in a temperature range of 180°C - 260°C. This method of treating biomass has some benefits which others do not, such as it can handle extremely wet biomass. However, treating biomass may not be enough for practical use. It may need to be transported and stored. Thus, this study explored the idea of pelletizing the HTC biomass. The mechanical strength of the HTC pellets was found to be 93%, whereas, higher heating value (HHV) (dry basis) was found to be 4% higher than the corresponding white pellets. The initial results with some limited parameters indicated that it would be possible to pelletize without binder. However, extensive research on energy balance and economic assessment would be necessary to achieve economic feasibility.展开更多
Hydrochar produced from dairy manure is a regulated biosolid if being promoted for agricultural applications thus must have the properties that comply with all environmental standards and government regulations,includ...Hydrochar produced from dairy manure is a regulated biosolid if being promoted for agricultural applications thus must have the properties that comply with all environmental standards and government regulations,including the levels of heavy metals(HMs).In this study,systematic research was conducted on HM levels in hydrochar from dairy manure and on the effects of processing conditions,including processing temperature(180–255℃),holding time(30–120 min)and solid content of manure slurry(2%–15%),through a central composite design and statistical analyses.It was found that HMs can be retained in hydrochar,ranging from 40%to 100%.The processing temperature and solid content in the feed were the most influential process parameters that affected HMs retention in hydrochar.Statistical analysis showed that there was no single optimal point to minimize HMs retained in hydrochar,but there were minimization points at given processing time and solid content.Most HMs concentrations were higher in hydrochar than those initially in dairy manure but were greatly below the thresholds as set by the US government regulations.Thus,hydrochar is feasible for use as a phosphorus-enriched organic fertilizer and/or soil amendment for agricultural applications without serious concerns about HMs it might contain.展开更多
Hydrothermal carbonization(HTC)of biomass is a promising method to produce carbonaceous materials.The work presented in this article addresses the application of hydrothermal carbonization(HTC)to produce a solid fuel...Hydrothermal carbonization(HTC)of biomass is a promising method to produce carbonaceous materials.The work presented in this article addresses the application of hydrothermal carbonization(HTC)to produce a solid fuel named HTC-Biochar,whose characteristics are comparable to lignite coal.Biogas sludge(SD),maize silage(MS),and barley silage(BS)as a substrates were hydrothermally carbonized in a 1.5 L batch reactor at 200C for 6 h.The effect of mixing ratios of different substrates on HTC was investigated.Chemical compositions and combustion characteristics of hydro-chars obtained from mono-and co-carbonization were evaluated.Result showed that HTC increased carbon contents and higher heating values(HHV)by 1.4–14.4%and 13–36%,respectively.The evolution of the H/C and O/C atomic ratios indicated that dehydration and decarboxylation occurred during hydrothermal carbonization for all samples.Furthermore,a significant synergistic enhancement was observed for HHV and carbon content.A mixing ratio of 1:1 for BS and SD showed the best performance for co-HTC.In summary,hydrothermal co-carbonization is a promising strategy to tailor high-performance hydro-char for energy applications.展开更多
Hydrothermal carbonization(HTC)of food waste can produce hydrochar for further utilization as high-quality fuel or carbon materials,but the by-product of liquid effluent,named HTC wastewater,has a high chemical oxygen...Hydrothermal carbonization(HTC)of food waste can produce hydrochar for further utilization as high-quality fuel or carbon materials,but the by-product of liquid effluent,named HTC wastewater,has a high chemical oxygen demand(COD)content and other organic pollutants.This study focused on the feasibility of Fenton oxidation combined with activated carbon(AC)to reduce COD in HTC wastewater.The effects of different parameters including pH,dosage of hydrogen peroxide,molar ratio of Fe^(2+)/H_(2)O_(2),and reaction time were tested and discussed.Eventually,through the optimized Fenton oxidation(pH=3,H_(2)O_(2)dosage=1.5 mol/L,Fe^(2+)/H_(2)O_(2)=1:15,reaction time=60 min)combined optimized AC adsorption process(AC dosage=30 g/L),the COD value reduced from 42,000 mg/L to 3075 mg/L,indicating a COD removal efficiency of 92.7%and a color removal ratio of 91.9%,respectively.The comparison of GC/MS(gas chromatography mass spectrometer)and FTIR(Fourier transform infrared spectrometer)of liquid residual from different treatment methods also indicated that the types of organic substances in HTC wastewater were significantly reduced through Fenton oxidation and AC adsorption.展开更多
Preparation of hierarchically porous, heteroatom-rich nanostructured carbons through green and scalable routes plays a key role for practical energy storage applications. In this work, naturally abundant lignocellulos...Preparation of hierarchically porous, heteroatom-rich nanostructured carbons through green and scalable routes plays a key role for practical energy storage applications. In this work, naturally abundant lignocellulosic agricultural waste with high initial oxygen content, hazelnut shells, were hydrothermally carbonized and converted into nanostructured ‘hydrochar'. Environmentally benign ceramic/magnesium oxide(Mg O) templating was used to introduce porosity into the hydrochar. Electrochemical performance of the resulting material(HM700) was investigated in aqueous solutions of 1 M H_2SO_4, 6 M KOH and1 M Na_2SO_4, using a three-electrode cell. HM700 achieved a high specific capacitance of 323.2 F/g in 1 M H_2SO_4(at 1 A/g,-0.3 to 0.9 V vs. Ag/Ag Cl) due to the contributions of oxygen heteroatoms(13.5 wt%)to the total capacitance by pseudo-capacitive effect. Moreover, a maximum energy density of 11.1 Wh/kg and a maximum power density of 3686.2 W/kg were attained for the symmetric supercapacitor employing HM700 as electrode material(1 M Na_2SO_4, E = 2 V), making the device promising for green supercapacitor applications.展开更多
Herein we study the economic performance of hydrochar and synthetic natural gas coproduction from olive tree pruning.The process entails a combination of hydrothermal carbonization and methanation.In a previous work,w...Herein we study the economic performance of hydrochar and synthetic natural gas coproduction from olive tree pruning.The process entails a combination of hydrothermal carbonization and methanation.In a previous work,we evidenced that standalone hydrochar production via HTC results unprofitable.Hence,we propose a step forward on the process design by implementing a methanation,adding value to the gas effluent in an attempt to boost the overall process techno-economic aspects.Three different plant capacities were analyzed(312.5,625 and 1250 kg/hr).The baseline scenarios showed that,under the current circumstances,our circular economy strategy in unprofitable.An analysis of the revenues shows that hydrochar selling price have a high impact on NPV and subsidies for renewable coal production could help to boost the profitability of the process.On the contrary,the analysis for natural gas prices reveals that prices 8 times higher than the current ones in Spain must be achieved to reach profitability.This seems unlikely even under the presence of a strong subsidy scheme.The costs analysis suggests that a remarkable electricity cost reduction or electricity consumption of the HTC stage could be a potential strategy to reach profitability scenarios.Furthermore,significant reduction of green hydrogen production costs is deemed instrumental to improve the economic performance of the process.These results show the formidable techno-economic challenge that our society faces in the path towards circular economy societies.展开更多
Glucose-derived carbons were prepared by hydrothermal carbonization of glucose followed by carbonization or activation to obtain carbon materials with different microporosities. These microporous carbons and carbon na...Glucose-derived carbons were prepared by hydrothermal carbonization of glucose followed by carbonization or activation to obtain carbon materials with different microporosities. These microporous carbons and carbon nanotubes(CNTs) were functionalized with melamine and/or iron(Ⅱ) phthalocyanine(FePc)following three different methodologies:(i) Functionalization with melamine via thermal treatment,(ii)incorporation of the lowest amount of FePc reported in the literature via incipient wetness impregnation followed by thermal treatment and(iii) functionalization with melamine followed by Fe Pc incorporation.The chemical and textural characterization of the prepared materials and their electrochemical assessment allowed to understand the role of microporosity in the incorporation of FePc and its effect on the oxygen reduction reaction(ORR). It was observed that FePc was preferentially incorporated inside the porous structure, especially in samples with more developed microporosity. However, functionalization with melamine modified the textural properties and the surface chemistry, favoring the incorporation of FePc on the surface. Regarding the electrochemical performance, the presence of FePc greatly enhanced the electroactivity of the microporous catalysts. An onset potential of 0.88 V and a four-electron pathway were obtained for glucose-derived carbons, whereas the limiting current densities and kinetic current densities rose by 126% and 222%, respectively, in comparison to the base sample. Notwithstanding, the highest electrochemical activity was observed for the sample prepared with CNTs, due to the synergy between the active metal centers and their highly graphitic carbon structure. The electrochemical parameters of CNTFeP csurpass the commercial Pt/C. The half-wave potential is 40 mV higher, the limiting current density increases by 17%, and a negligible production of by-products(< 1%) was observed.展开更多
Nitrogen doped carbons are an important family of materials with ideal activity for oxygen reduction reaction(ORR). It is always interesting to search functional carbons with high heteroatom contents and desirable str...Nitrogen doped carbons are an important family of materials with ideal activity for oxygen reduction reaction(ORR). It is always interesting to search functional carbons with high heteroatom contents and desirable structure for ORR. Within this study, the surface modification of carbon nanotubes(CNTs) via hydrothermal carbonization(HTC) technique in the presence of glucose and urea was reported, where the surface of CNTs is successfully coated by nitrogen containing hydrothermal carbon layers. The resulting composite combines both advantages of the outstanding electrical conductivity of CNTs and the effective ORR active sites provided by doped nitrogen in the HTC carbon layers. By controlling the ratio of glucose and urea, the nitrogen contents coated on the surface of CNTs can reach up to 1.7 wt%. The resulting materials show outstanding electrochemical activity towards ORR in alkaline electrolyte, making it one of the valuable metal-free electrode materials and a competent alternative to the state-of-the-art Pt/C catalyst.展开更多
Combustion kinetics of the hydrochar was investigated using a multi-Gaussian-distributed activation energy model(DAEM)to ex-pand the knowledge on the combustion mechanisms.The results demonstrated that the kinetic par...Combustion kinetics of the hydrochar was investigated using a multi-Gaussian-distributed activation energy model(DAEM)to ex-pand the knowledge on the combustion mechanisms.The results demonstrated that the kinetic parameters calculated by the multi-Gaussian-DAEM accurately represented the experimental conversion rate curves.Overall,the feedstock combustion could be divided into four stages:the decomposition of hemicellulose,cellulose,lignin,and char combustion.The hydrochar combustion could in turn be divided into three stages:the combustion of cellulose,lignin,and char.The mean activation energy ranges obtained for the cellulose,lignin,and char were 273.7-292.8,315.1-334.5,and 354.4-370 kJ/mol,respectively,with the standard deviations of 2.1-23.1,9.5-27.4,and 12.1-22.9 kJ/mol,re-spectively.The cellulose and lignin contents first increased and then decreased with increasing hydrothermal carbonization(HTC)temperature,while the mass fraction of char gradually increased.展开更多
In this study, hydrothermal carbonization(HTC)was applied for surface functionalization of carbon nanotubes(CNTs) in the presence of glucose and urea. The HTC process allowed the deposition of thin nitrogen-doped carb...In this study, hydrothermal carbonization(HTC)was applied for surface functionalization of carbon nanotubes(CNTs) in the presence of glucose and urea. The HTC process allowed the deposition of thin nitrogen-doped carbon layers on the surface of the CNTs. By controlling the ratio of glucose to urea, nitrogen contents of up to 1.7 wt%were achieved. The nitrogen-doped carbon nanotube-supported Pd catalysts exhibited superior electrochemical activity for ethanol oxidation relative to the pristine CNTs.Importantly, a 1.5-fold increase in the specific activity was observed for the Pd/HTC-N1.67%CNTs relative to the catalyst without nitrogen doping(Pd/HTC-CNTs). Furtherexperiments indicated that the introduction of nitrogen species on the surface of the CNTs improved the Pd(0)loading and increased the binding energy.展开更多
In this study,a novel method termed hydrothermal carbonized deposition on chips(HTCDC)is proposed to prepare aluminum alloy-amorphous carbon(Al/APC)composites.The influences of glucose concentration in hydrothermally ...In this study,a novel method termed hydrothermal carbonized deposition on chips(HTCDC)is proposed to prepare aluminum alloy-amorphous carbon(Al/APC)composites.The influences of glucose concentration in hydrothermally reaction on the microstructure and wear resistance of the Al/APC composites were thoroughly studied.Amorphous carbon was deposited by HTCDC onto Al–20Si chips as a supporter.The Al/APC composites were prepared by hot extrusion from the chips.The results indicated that a uniform carbon film was successfully synthesized on the surface of the chips,improving the wear resistance of the Al/APC composites.With increasing concentration of glucose solution,the size and the number of delamination on the wear surface and the coefficient of friction decreased,and the wear rate decreased at first and then increased.In addition,the dehydration and carbonization processes in the hydrothermal reaction of glucose were analyzed.A schematic model of the wear surface of the Al/APC composites was established and the wear mechanisms were discussed.展开更多
Most known catalytic dehydration of sugar alcohols such as D-sorbitol and D-mannitol can only produce di-dehydrated forms as major product,but monodehydrated products are also useful chemicals.Moreover,both di-and mon...Most known catalytic dehydration of sugar alcohols such as D-sorbitol and D-mannitol can only produce di-dehydrated forms as major product,but monodehydrated products are also useful chemicals.Moreover,both di-and mono-dehydration demand a high temperature(150℃ or higher),which deserves further attentions.To improve the mono-dehydration efficiency,a series of metal-containing hydrothermal carbonaceous materials(HTC)are prepared as catalyst in this work.Characterization reveals that the composition of preparative solution has a key influence on the morphology of HTC.In transformation of D-sorbitol,all HTC catalysts show low conversions in water regardless of temperature,but much better outputs are obtained in ethanol,especially at a higher temperature.When D-mannitol is selected as substrate,moderate to high conversions are obtained in both water and ethanol.On the other hand,high mono-dehydration selectivity is obtained for both sugar alcohols by using all catalysts.The origin of mono-dehydration selectivity and role of carbon component in catalysis are discussed in association with calculations.This study provides an efficient,mild,eco-friendly,and cost-effective system for mono-dehydration of sugar alcohols,which means a lot to development in new detergents or other fine chemicals.展开更多
Volatile organic compounds have posed a serious threat to the environment and human health,which require urgent and effective removal.In recent years,the preparation of porous carbon from biomass waste for volatile or...Volatile organic compounds have posed a serious threat to the environment and human health,which require urgent and effective removal.In recent years,the preparation of porous carbon from biomass waste for volatile organic compounds adsorption has attracted increasing attention as a very cost-effective and promising technology.In this study,porous carbon was synthesized from orange peel by urea-assisted hydrothermal carbonization and KOH activation.The role of typical components(cellulose,hemicellulose,and lignin)in pore development and volatile organic compounds adsorption was investigated.Among the three components,hemicellulose was the major contributor to high porosity and abundant micropores in porous carbon.Higher hemicellulose content led to more abundant–COOR,amine-N,and pyrrolic/pyridonic-N in the derived hydrochar,which were favorable for porosity formation during activation.In this case,the toluene adsorption capacity of the porous carbon improved from 382.8 to 485.3 mg·g^(–1).Unlike hemicellulose,cellulose reduced the>C=O,amine-N,and pyrrolic/pyridonic-N content of the hydrochar,which caused porosity deterioration and worse toluene adsorption performance.Lignin bestowed the hydrochar with slightly increased–COOR,pyrrolic/pyridonic-N,and graphitic-N,and reduced>C=O,resulting in comparatively poor porosity and more abundant micropores.In general,the obtained porous carbon possessed abundant micropores and high specific surface area,with the highest up to 2882 m^(2)·g^(–1).This study can provide guidance for selecting suitable biomass waste to synthesize porous carbon with better porosity for efficient volatile organic compounds adsorption.展开更多
Hydrothermal carbonization(HTC)technologies for producing value-added carbonaceous material(hydrochar)from coal waste and sewage sludge(SS)waste might be a long-term recycling strategy for hydrogen storage application...Hydrothermal carbonization(HTC)technologies for producing value-added carbonaceous material(hydrochar)from coal waste and sewage sludge(SS)waste might be a long-term recycling strategy for hydrogen storage applications,cutting disposal costs and solving waste disposal difficulties.In this study,hydrochars(HC)with high carbon content were produced using a combination of optimal HTC(HTC and Co-HTC)and chemical activation of coal tailings(CT),coal slurry(CS),and a mixture of coal discard and sewage sludge(CB).At 850℃and 800℃,respectively,with a KOH/HC ratio of 4:1 and a residence time of 135 min,activated carbons(ACs)with the highest Brunauer–Emmett–Teller specific surface(S_(BET))of 2299.25 m^(2)g^(−1)and 2243.57 m^(2)g^(−1)were obtained.The hydrogen adsorption capability of the produced ACs was further studied using gas adsorption isotherms at 77 K.At 35 bars,the values of hydrogen adsorbed onto AC-HCT(AC obtained from HTC of CT),AC-HCS(AC obtained from HTC of CS),and AC-HCB(AC obtained from HTC of the blending of coal discard(CD)and SS)were approximately 6.12%,6.8%,and 6.57%in weight,respectively.Furthermore,the cost of producing synthetic ACs for hydrogen storage is equivalent to the cost of commercial carbons.Furthermore,the high proportion of carbon retained(>70%)in ACs synthesized by HTC from CD and SS precursors should restrict their potential carbon emissions.展开更多
In the polyoxyethylene(PEO)-based solid-state electrolytes,the low ionic conductivity of lithium ions limits its application in solid-state lithium batteries,so optimizing the conduction path of lithium ions is benefi...In the polyoxyethylene(PEO)-based solid-state electrolytes,the low ionic conductivity of lithium ions limits its application in solid-state lithium batteries,so optimizing the conduction path of lithium ions is beneficial to improve the ionic conductivity.In this work,we report the use of hydrothermal carbon nano-sphere(HCS)modified glass fibers(GF)as a functional filler(GF@HCS)to improve the ionic conductivity of PEO composite solidstate electrolytes.The oxygen atoms in the hydroxyl groups on the surface of HCS can be complexed with Li ions as its transport sites,which means that it can promote the longdistance transport of Li ions along the glass fiber surface.With addition of 2 wt%GF@HCS fillers,the degree of crystallinity of PEO composite solid-state electrolyte is the smallest,and the ionic conductivity is significantly increased from 8.9×10^(-5) to 4.4×10^(-4) S·cm^(-1) at 60℃.Moreover,the PEO composite solid-state electrolyte exhibits better lithium-metal interface stability in symmetric lithium batteries and superior rate performance in LiFePO4 solid-state batteries.展开更多
Hydrochar has potential applications in soil improvement and heavy metal remediation.Hydrochar would undergo the process of aging when introduced into the soil,altering its properties.However,recent studies have focus...Hydrochar has potential applications in soil improvement and heavy metal remediation.Hydrochar would undergo the process of aging when introduced into the soil,altering its properties.However,recent studies have focused mainly on the artificial aging of hydrochar,which could not reveal the cumulative effect of multiple environmental factors.Therefore,the periodical monitoring of the property and sorption behavior of hydrochar after amending soils is necessary to better understand the multifaceted mechanisms associated with the natural aging of hydrochar.This study selected the sludge-derived hydrochar(SLHC)as a typical hydrochar and applied a 16-month rice-wheat-rice rotation to mimic the natural aging of hydrochar,focusing on changing properties and cadmium(Cd)sorption and literature contrast between aging strategies and biochar types.The porosity,O abundance,and ash content of 16-month aged SLHC increased by 37%,47%,and 8.5%,respectively,facilitating Cd sorption due to surface complexation,pore sorption,and precipitation.The sorption percentage of Cd to SLHC was in the range of 11-14%for SLHC-A0 and increased to 17-31%for SLHC-A4 and 20-32%for SLHC-A16 after natural aging.The natural aging of SLHC induced by ash content played an essential role in Cd sorption site heterogeneity.Linear regression analysis showed that aging strategies on sorption behavior significantly differed between biochars.Thus,studies involving natural aging with multiple environmental factors are preferred over those involving chemical or biological aging.Future studies should continue to explore the mechanisms of natural aging-induced heavy metal sorption between hydrochar and pyrochar.These results improve insights to appraise the potential of SLHC as soil amendments to alleviate the adverse effects of heavy metal contamination and provide an essential basis for researchers and staff in soil management and environmental prevention.展开更多
基金the National Key R&D Program of China(No.2022YFE0208100)the National Natural Science Foundation of China(No.5274316)+1 种基金the Key Research and Development Plan of Anhui Province,China(No.202210700037)the Major Science and Technology Project of Xinjiang Uygur Autonomous Region,China(No.2022A01003).
文摘The paper proposes a biomass cross-upgrading process that combines hydrothermal carbonization and pyrolysis to produce high-quality blast furnace injection fuel.The results showed that after upgrading,the volatile content of biochar ranged from 16.19%to 45.35%,and the alkali metal content,ash content,and specific surface area were significantly reduced.The optimal route for biochar pro-duction is hydrothermal carbonization-pyrolysis(P-HC),resulting in biochar with a higher calorific value,C=C structure,and increased graphitization degree.The apparent activation energy(E)of the sample ranges from 199.1 to 324.8 kJ/mol,with P-HC having an E of 277.8 kJ/mol,lower than that of raw biomass,primary biochar,and anthracite.This makes P-HC more suitable for blast furnace injection fuel.Additionally,the paper proposes a path for P-HC injection in blast furnaces and calculates potential environmental benefits.P-HC of-fers the highest potential for carbon emission reduction,capable of reducing emissions by 96.04 kg/t when replacing 40wt%coal injec-tion.
基金supported by the Fundamental Research Funds for the Central Universities of Southwest Jiaotong University,supported by Sichuan Science and Technology Program(2021YFS0284).
文摘Hydrothermal carbonization is highly applicable to high moisture biomass upgrading due to the fact that moist-ure involved can be directly used as reaction media under the subcritical-water region.With this,value-added utilization of hydrochar as solid fuel with high carbon and energy density is one of the important pathways for biomass conversion.In this review,the dewatering properties of hydrochar after the hydrothermal carbonization of biowaste,coalification degree with elemental composition and evolution,pelletization of hydrochar to enhance the mechanical properties and density,coupled with the combustion properties of hydrochar biofuel were discussed with various biomass and carbonization parameters.Potential applications for the co-combustion with coal,cleaner properties and energy balance for biowaste hydrothermal carbonization were presented as well as the challenges.
基金by the National Nature Science Foundation of the People’s Republic of China(No.51703153).
文摘Carbon microspheres were prepared from waste cotton fibers by hydrothermal carbonization(HTC)with the addition of copper sulphate in this work.The important influence factors,temperature,concentration of copper sulphate,resident time were explored here.The smooth and regular carbon microspheres could be formed at 330°C with 0.15 wt%copper sulphate after 6 h from waste cotton fibers.The crystal structures of cotton fibers were destructed in a short resident time with 0.15 wt%copper sulphate from SEM images and XRD patterns of solid products.This strategy provides a new,mild and efficient method to prepare carbon microspheres from waste cotton fibers by HTC.FTIR spectra verified that the abundant functional groups existed on the surface of synthesized carbon microspheres.From XPS and element analysis results,the copper sulphate participated in the forming process of carbon microspheres indeed.The presence of copper sulphate in the carbon microspheres provided a possibility for the application in antibacterial field.Besides,the catalytic mechanism of copper sulphate on the hydrolysis and carbonization of waste cotton fibers were also discussed.In conclusion,the copper sulphate is an efficient agent for preparing carbon microspheres by HTC from waste cotton fibers.
基金Supported by Shanxi Scholarship Council of China (2015-123)the Natural Science Foundation of China (51602322)the Key Research and Development Program of Shanxi Province (International Cooperation) (201703D421041) for financial support
文摘Hydrothermal carbonization(HTC) is a valuable approach to convert furfural residue(FR) into carbon material. The prepared biochars are usually characterized comprehensively, while the stock process water still remains to be studied in detail. Herein, a NMR study of the main components in stock process water generated at different HTC reaction conditions was reported. Various qualitative and quantitative NMR techniques(~1H and ^(13)C NMR,~1H-~1H COSY and ~1H-^(13)C HSQC etc.) especially 1D selective gradient total correlation spectroscopy(TOCSY NMR) were strategically applied in the analysis of HTC stock process water. Without separation and purification, it was demonstrated that the main detectable compounds are 5-hydroxymethylfurfural, formic acid, methanol, acetic acid, levulinic acid, glycerol, hydroxyacetone and acetaldehyde in this complicate mixture. Furthermore, the relationship between the concentration of major products and the reaction conditions(180-240 ℃ at 8 h, and 1-24 h at 240 ℃) was established. Finally, reasonable reaction pathways for hydrothermal conversion of FR were proposed based on this result and our previously obtained characteristics of biochars. The routine and challenging NMR methods utilized here would be an alternative other than HPLC or GC for biomass conversion research and can be extended to more studies.
文摘Thermal treatment of biomass has been attracting attention for a decade or so, especially torrefaction. However, for the past few years, wet pyrolysis, also known as hydrothermal carbonization (HTC), has been getting some attention. Hydrothermal carbonization is a thermal treatment of biomass in the presence of water in a temperature range of 180°C - 260°C. This method of treating biomass has some benefits which others do not, such as it can handle extremely wet biomass. However, treating biomass may not be enough for practical use. It may need to be transported and stored. Thus, this study explored the idea of pelletizing the HTC biomass. The mechanical strength of the HTC pellets was found to be 93%, whereas, higher heating value (HHV) (dry basis) was found to be 4% higher than the corresponding white pellets. The initial results with some limited parameters indicated that it would be possible to pelletize without binder. However, extensive research on energy balance and economic assessment would be necessary to achieve economic feasibility.
基金supported by the hatch projects of USDA National Institute of Food and Agriculture(1012741 and 1019082)Idaho Agricultural Experiment Station(IDA01575 and IDA01604)by a grant from the USDA AFRI Sustainable Agricultural Systems Program(2020-69012-31871).
文摘Hydrochar produced from dairy manure is a regulated biosolid if being promoted for agricultural applications thus must have the properties that comply with all environmental standards and government regulations,including the levels of heavy metals(HMs).In this study,systematic research was conducted on HM levels in hydrochar from dairy manure and on the effects of processing conditions,including processing temperature(180–255℃),holding time(30–120 min)and solid content of manure slurry(2%–15%),through a central composite design and statistical analyses.It was found that HMs can be retained in hydrochar,ranging from 40%to 100%.The processing temperature and solid content in the feed were the most influential process parameters that affected HMs retention in hydrochar.Statistical analysis showed that there was no single optimal point to minimize HMs retained in hydrochar,but there were minimization points at given processing time and solid content.Most HMs concentrations were higher in hydrochar than those initially in dairy manure but were greatly below the thresholds as set by the US government regulations.Thus,hydrochar is feasible for use as a phosphorus-enriched organic fertilizer and/or soil amendment for agricultural applications without serious concerns about HMs it might contain.
文摘Hydrothermal carbonization(HTC)of biomass is a promising method to produce carbonaceous materials.The work presented in this article addresses the application of hydrothermal carbonization(HTC)to produce a solid fuel named HTC-Biochar,whose characteristics are comparable to lignite coal.Biogas sludge(SD),maize silage(MS),and barley silage(BS)as a substrates were hydrothermally carbonized in a 1.5 L batch reactor at 200C for 6 h.The effect of mixing ratios of different substrates on HTC was investigated.Chemical compositions and combustion characteristics of hydro-chars obtained from mono-and co-carbonization were evaluated.Result showed that HTC increased carbon contents and higher heating values(HHV)by 1.4–14.4%and 13–36%,respectively.The evolution of the H/C and O/C atomic ratios indicated that dehydration and decarboxylation occurred during hydrothermal carbonization for all samples.Furthermore,a significant synergistic enhancement was observed for HHV and carbon content.A mixing ratio of 1:1 for BS and SD showed the best performance for co-HTC.In summary,hydrothermal co-carbonization is a promising strategy to tailor high-performance hydro-char for energy applications.
基金the financial support from the National Natural Science Foundation,China(No.51976196,No.52150410422).
文摘Hydrothermal carbonization(HTC)of food waste can produce hydrochar for further utilization as high-quality fuel or carbon materials,but the by-product of liquid effluent,named HTC wastewater,has a high chemical oxygen demand(COD)content and other organic pollutants.This study focused on the feasibility of Fenton oxidation combined with activated carbon(AC)to reduce COD in HTC wastewater.The effects of different parameters including pH,dosage of hydrogen peroxide,molar ratio of Fe^(2+)/H_(2)O_(2),and reaction time were tested and discussed.Eventually,through the optimized Fenton oxidation(pH=3,H_(2)O_(2)dosage=1.5 mol/L,Fe^(2+)/H_(2)O_(2)=1:15,reaction time=60 min)combined optimized AC adsorption process(AC dosage=30 g/L),the COD value reduced from 42,000 mg/L to 3075 mg/L,indicating a COD removal efficiency of 92.7%and a color removal ratio of 91.9%,respectively.The comparison of GC/MS(gas chromatography mass spectrometer)and FTIR(Fourier transform infrared spectrometer)of liquid residual from different treatment methods also indicated that the types of organic substances in HTC wastewater were significantly reduced through Fenton oxidation and AC adsorption.
基金supported by the Scientific and Technological Research Council of Turkey(TüBTAK)under Grant 112T570
文摘Preparation of hierarchically porous, heteroatom-rich nanostructured carbons through green and scalable routes plays a key role for practical energy storage applications. In this work, naturally abundant lignocellulosic agricultural waste with high initial oxygen content, hazelnut shells, were hydrothermally carbonized and converted into nanostructured ‘hydrochar'. Environmentally benign ceramic/magnesium oxide(Mg O) templating was used to introduce porosity into the hydrochar. Electrochemical performance of the resulting material(HM700) was investigated in aqueous solutions of 1 M H_2SO_4, 6 M KOH and1 M Na_2SO_4, using a three-electrode cell. HM700 achieved a high specific capacitance of 323.2 F/g in 1 M H_2SO_4(at 1 A/g,-0.3 to 0.9 V vs. Ag/Ag Cl) due to the contributions of oxygen heteroatoms(13.5 wt%)to the total capacitance by pseudo-capacitive effect. Moreover, a maximum energy density of 11.1 Wh/kg and a maximum power density of 3686.2 W/kg were attained for the symmetric supercapacitor employing HM700 as electrode material(1 M Na_2SO_4, E = 2 V), making the device promising for green supercapacitor applications.
基金supported by the grants FJC2021–047672-I and FJC2021–048089-Ico-financed by MCIN/AEI/10.13039/501100011033 and the European Union Next Generation EU/PRTR funds+1 种基金sponsored by Spanish Ministry of Science and Innovation through the project PLEC2021–008086 sponsored by MCIN/AEI/10.13039/501100011033 Next Generation Europe and Junta de Andalucía PAIDI program through the project P20_00667MZAMBRANO-2021–19889 excellence grant sponsored by the European Union Next Generation EU program。
文摘Herein we study the economic performance of hydrochar and synthetic natural gas coproduction from olive tree pruning.The process entails a combination of hydrothermal carbonization and methanation.In a previous work,we evidenced that standalone hydrochar production via HTC results unprofitable.Hence,we propose a step forward on the process design by implementing a methanation,adding value to the gas effluent in an attempt to boost the overall process techno-economic aspects.Three different plant capacities were analyzed(312.5,625 and 1250 kg/hr).The baseline scenarios showed that,under the current circumstances,our circular economy strategy in unprofitable.An analysis of the revenues shows that hydrochar selling price have a high impact on NPV and subsidies for renewable coal production could help to boost the profitability of the process.On the contrary,the analysis for natural gas prices reveals that prices 8 times higher than the current ones in Spain must be achieved to reach profitability.This seems unlikely even under the presence of a strong subsidy scheme.The costs analysis suggests that a remarkable electricity cost reduction or electricity consumption of the HTC stage could be a potential strategy to reach profitability scenarios.Furthermore,significant reduction of green hydrogen production costs is deemed instrumental to improve the economic performance of the process.These results show the formidable techno-economic challenge that our society faces in the path towards circular economy societies.
基金“UniRCell”,with the reference POCI-01-0145-FEDER-016422“AIProcMat@N2020–Advanced Industrial Processes and Materials for a Sustainable Northern Region of Portugal 2020”,with the reference NORTE-010145-FEDER-000006,supported by Norte Portugal Regional Operational Programme(NORTE 2020),under the Portugal 2020 Partnership Agreement,through the European Regional Development Fund(ERDF)+1 种基金Base Funding–UIDB/50020/2020 of the Associate Laboratory LSRE-LCM–funded by national funds through FCT/MCTES(PIDDAC)PDEQB(PD9989)。
文摘Glucose-derived carbons were prepared by hydrothermal carbonization of glucose followed by carbonization or activation to obtain carbon materials with different microporosities. These microporous carbons and carbon nanotubes(CNTs) were functionalized with melamine and/or iron(Ⅱ) phthalocyanine(FePc)following three different methodologies:(i) Functionalization with melamine via thermal treatment,(ii)incorporation of the lowest amount of FePc reported in the literature via incipient wetness impregnation followed by thermal treatment and(iii) functionalization with melamine followed by Fe Pc incorporation.The chemical and textural characterization of the prepared materials and their electrochemical assessment allowed to understand the role of microporosity in the incorporation of FePc and its effect on the oxygen reduction reaction(ORR). It was observed that FePc was preferentially incorporated inside the porous structure, especially in samples with more developed microporosity. However, functionalization with melamine modified the textural properties and the surface chemistry, favoring the incorporation of FePc on the surface. Regarding the electrochemical performance, the presence of FePc greatly enhanced the electroactivity of the microporous catalysts. An onset potential of 0.88 V and a four-electron pathway were obtained for glucose-derived carbons, whereas the limiting current densities and kinetic current densities rose by 126% and 222%, respectively, in comparison to the base sample. Notwithstanding, the highest electrochemical activity was observed for the sample prepared with CNTs, due to the synergy between the active metal centers and their highly graphitic carbon structure. The electrochemical parameters of CNTFeP csurpass the commercial Pt/C. The half-wave potential is 40 mV higher, the limiting current density increases by 17%, and a negligible production of by-products(< 1%) was observed.
基金The Award Program for Fujian Minjiang Scholar Professorship is acknowledged for financial supportfinancial support from the National Natural Science Foundation of China(NSFC Grant number 21571035)
文摘Nitrogen doped carbons are an important family of materials with ideal activity for oxygen reduction reaction(ORR). It is always interesting to search functional carbons with high heteroatom contents and desirable structure for ORR. Within this study, the surface modification of carbon nanotubes(CNTs) via hydrothermal carbonization(HTC) technique in the presence of glucose and urea was reported, where the surface of CNTs is successfully coated by nitrogen containing hydrothermal carbon layers. The resulting composite combines both advantages of the outstanding electrical conductivity of CNTs and the effective ORR active sites provided by doped nitrogen in the HTC carbon layers. By controlling the ratio of glucose and urea, the nitrogen contents coated on the surface of CNTs can reach up to 1.7 wt%. The resulting materials show outstanding electrochemical activity towards ORR in alkaline electrolyte, making it one of the valuable metal-free electrode materials and a competent alternative to the state-of-the-art Pt/C catalyst.
基金the National Nat-ural Science Foundation of China(Nos.52074029,51804026)the USTB-NTUT Joint Research Program(No.06310063)Chuan Wang would like to acknowledge the funding support from Vinnova(dnr:2017-01327).
文摘Combustion kinetics of the hydrochar was investigated using a multi-Gaussian-distributed activation energy model(DAEM)to ex-pand the knowledge on the combustion mechanisms.The results demonstrated that the kinetic parameters calculated by the multi-Gaussian-DAEM accurately represented the experimental conversion rate curves.Overall,the feedstock combustion could be divided into four stages:the decomposition of hemicellulose,cellulose,lignin,and char combustion.The hydrochar combustion could in turn be divided into three stages:the combustion of cellulose,lignin,and char.The mean activation energy ranges obtained for the cellulose,lignin,and char were 273.7-292.8,315.1-334.5,and 354.4-370 kJ/mol,respectively,with the standard deviations of 2.1-23.1,9.5-27.4,and 12.1-22.9 kJ/mol,re-spectively.The cellulose and lignin contents first increased and then decreased with increasing hydrothermal carbonization(HTC)temperature,while the mass fraction of char gradually increased.
基金financial support of the National Natural Science Foundation of China(Nos.51672045 and 11374053)Key Program of Universityindustry Collaboration from Science and Technology Department of Fujian Province(No.2015H6009)
文摘In this study, hydrothermal carbonization(HTC)was applied for surface functionalization of carbon nanotubes(CNTs) in the presence of glucose and urea. The HTC process allowed the deposition of thin nitrogen-doped carbon layers on the surface of the CNTs. By controlling the ratio of glucose to urea, nitrogen contents of up to 1.7 wt%were achieved. The nitrogen-doped carbon nanotube-supported Pd catalysts exhibited superior electrochemical activity for ethanol oxidation relative to the pristine CNTs.Importantly, a 1.5-fold increase in the specific activity was observed for the Pd/HTC-N1.67%CNTs relative to the catalyst without nitrogen doping(Pd/HTC-CNTs). Furtherexperiments indicated that the introduction of nitrogen species on the surface of the CNTs improved the Pd(0)loading and increased the binding energy.
基金financially supported by the National Natural Science Foundation of China(Nos.51704087 and 51574100)the University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province(No.UNPYSCT-2016033)。
文摘In this study,a novel method termed hydrothermal carbonized deposition on chips(HTCDC)is proposed to prepare aluminum alloy-amorphous carbon(Al/APC)composites.The influences of glucose concentration in hydrothermally reaction on the microstructure and wear resistance of the Al/APC composites were thoroughly studied.Amorphous carbon was deposited by HTCDC onto Al–20Si chips as a supporter.The Al/APC composites were prepared by hot extrusion from the chips.The results indicated that a uniform carbon film was successfully synthesized on the surface of the chips,improving the wear resistance of the Al/APC composites.With increasing concentration of glucose solution,the size and the number of delamination on the wear surface and the coefficient of friction decreased,and the wear rate decreased at first and then increased.In addition,the dehydration and carbonization processes in the hydrothermal reaction of glucose were analyzed.A schematic model of the wear surface of the Al/APC composites was established and the wear mechanisms were discussed.
基金supported by the Fundamental Research Funds for the Central Universities(No.xjj2014005).
文摘Most known catalytic dehydration of sugar alcohols such as D-sorbitol and D-mannitol can only produce di-dehydrated forms as major product,but monodehydrated products are also useful chemicals.Moreover,both di-and mono-dehydration demand a high temperature(150℃ or higher),which deserves further attentions.To improve the mono-dehydration efficiency,a series of metal-containing hydrothermal carbonaceous materials(HTC)are prepared as catalyst in this work.Characterization reveals that the composition of preparative solution has a key influence on the morphology of HTC.In transformation of D-sorbitol,all HTC catalysts show low conversions in water regardless of temperature,but much better outputs are obtained in ethanol,especially at a higher temperature.When D-mannitol is selected as substrate,moderate to high conversions are obtained in both water and ethanol.On the other hand,high mono-dehydration selectivity is obtained for both sugar alcohols by using all catalysts.The origin of mono-dehydration selectivity and role of carbon component in catalysis are discussed in association with calculations.This study provides an efficient,mild,eco-friendly,and cost-effective system for mono-dehydration of sugar alcohols,which means a lot to development in new detergents or other fine chemicals.
基金This work was supported by the Shenzhen Science and Technology Program(Grant No.JSGG20210802154804013).
文摘Volatile organic compounds have posed a serious threat to the environment and human health,which require urgent and effective removal.In recent years,the preparation of porous carbon from biomass waste for volatile organic compounds adsorption has attracted increasing attention as a very cost-effective and promising technology.In this study,porous carbon was synthesized from orange peel by urea-assisted hydrothermal carbonization and KOH activation.The role of typical components(cellulose,hemicellulose,and lignin)in pore development and volatile organic compounds adsorption was investigated.Among the three components,hemicellulose was the major contributor to high porosity and abundant micropores in porous carbon.Higher hemicellulose content led to more abundant–COOR,amine-N,and pyrrolic/pyridonic-N in the derived hydrochar,which were favorable for porosity formation during activation.In this case,the toluene adsorption capacity of the porous carbon improved from 382.8 to 485.3 mg·g^(–1).Unlike hemicellulose,cellulose reduced the>C=O,amine-N,and pyrrolic/pyridonic-N content of the hydrochar,which caused porosity deterioration and worse toluene adsorption performance.Lignin bestowed the hydrochar with slightly increased–COOR,pyrrolic/pyridonic-N,and graphitic-N,and reduced>C=O,resulting in comparatively poor porosity and more abundant micropores.In general,the obtained porous carbon possessed abundant micropores and high specific surface area,with the highest up to 2882 m^(2)·g^(–1).This study can provide guidance for selecting suitable biomass waste to synthesize porous carbon with better porosity for efficient volatile organic compounds adsorption.
文摘Hydrothermal carbonization(HTC)technologies for producing value-added carbonaceous material(hydrochar)from coal waste and sewage sludge(SS)waste might be a long-term recycling strategy for hydrogen storage applications,cutting disposal costs and solving waste disposal difficulties.In this study,hydrochars(HC)with high carbon content were produced using a combination of optimal HTC(HTC and Co-HTC)and chemical activation of coal tailings(CT),coal slurry(CS),and a mixture of coal discard and sewage sludge(CB).At 850℃and 800℃,respectively,with a KOH/HC ratio of 4:1 and a residence time of 135 min,activated carbons(ACs)with the highest Brunauer–Emmett–Teller specific surface(S_(BET))of 2299.25 m^(2)g^(−1)and 2243.57 m^(2)g^(−1)were obtained.The hydrogen adsorption capability of the produced ACs was further studied using gas adsorption isotherms at 77 K.At 35 bars,the values of hydrogen adsorbed onto AC-HCT(AC obtained from HTC of CT),AC-HCS(AC obtained from HTC of CS),and AC-HCB(AC obtained from HTC of the blending of coal discard(CD)and SS)were approximately 6.12%,6.8%,and 6.57%in weight,respectively.Furthermore,the cost of producing synthetic ACs for hydrogen storage is equivalent to the cost of commercial carbons.Furthermore,the high proportion of carbon retained(>70%)in ACs synthesized by HTC from CD and SS precursors should restrict their potential carbon emissions.
基金financially supported by the National Natural Science Foundation of China(Nos.21875195,22021001 and 52172184)。
文摘In the polyoxyethylene(PEO)-based solid-state electrolytes,the low ionic conductivity of lithium ions limits its application in solid-state lithium batteries,so optimizing the conduction path of lithium ions is beneficial to improve the ionic conductivity.In this work,we report the use of hydrothermal carbon nano-sphere(HCS)modified glass fibers(GF)as a functional filler(GF@HCS)to improve the ionic conductivity of PEO composite solidstate electrolytes.The oxygen atoms in the hydroxyl groups on the surface of HCS can be complexed with Li ions as its transport sites,which means that it can promote the longdistance transport of Li ions along the glass fiber surface.With addition of 2 wt%GF@HCS fillers,the degree of crystallinity of PEO composite solid-state electrolyte is the smallest,and the ionic conductivity is significantly increased from 8.9×10^(-5) to 4.4×10^(-4) S·cm^(-1) at 60℃.Moreover,the PEO composite solid-state electrolyte exhibits better lithium-metal interface stability in symmetric lithium batteries and superior rate performance in LiFePO4 solid-state batteries.
基金the National Natural Science Foundation of China(Nos.41877090 and 42107398)Natural Science Foundation of Jiangsu Province(BK20181165 and BK20210358)+1 种基金China Postdoctoral Science Foundation(2020M68618)Yunnan Branch of China National Tobacco Corporation(2022530000241022).
文摘Hydrochar has potential applications in soil improvement and heavy metal remediation.Hydrochar would undergo the process of aging when introduced into the soil,altering its properties.However,recent studies have focused mainly on the artificial aging of hydrochar,which could not reveal the cumulative effect of multiple environmental factors.Therefore,the periodical monitoring of the property and sorption behavior of hydrochar after amending soils is necessary to better understand the multifaceted mechanisms associated with the natural aging of hydrochar.This study selected the sludge-derived hydrochar(SLHC)as a typical hydrochar and applied a 16-month rice-wheat-rice rotation to mimic the natural aging of hydrochar,focusing on changing properties and cadmium(Cd)sorption and literature contrast between aging strategies and biochar types.The porosity,O abundance,and ash content of 16-month aged SLHC increased by 37%,47%,and 8.5%,respectively,facilitating Cd sorption due to surface complexation,pore sorption,and precipitation.The sorption percentage of Cd to SLHC was in the range of 11-14%for SLHC-A0 and increased to 17-31%for SLHC-A4 and 20-32%for SLHC-A16 after natural aging.The natural aging of SLHC induced by ash content played an essential role in Cd sorption site heterogeneity.Linear regression analysis showed that aging strategies on sorption behavior significantly differed between biochars.Thus,studies involving natural aging with multiple environmental factors are preferred over those involving chemical or biological aging.Future studies should continue to explore the mechanisms of natural aging-induced heavy metal sorption between hydrochar and pyrochar.These results improve insights to appraise the potential of SLHC as soil amendments to alleviate the adverse effects of heavy metal contamination and provide an essential basis for researchers and staff in soil management and environmental prevention.