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
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
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
Hydrothermal carbonization of biomass is a promising method to prepare carbonaceous materials.Generally,post physical or chemical activation is necessary to increase surface area and porosity of the carbon.Herein,poro...Hydrothermal carbonization of biomass is a promising method to prepare carbonaceous materials.Generally,post physical or chemical activation is necessary to increase surface area and porosity of the carbon.Herein,porous carbonaceous material（FPC） with large surface area（481.7 m^2/g） and pore volume（0.73 cm^3/g） was prepared directly from hydrothermal carbonization of fructose and phloroglucinol in hydroalcoholic mixture.Structure characteristics of the FPC and its adsorption capacity for a representative antibiotic tetracycline in aqueous solution were investigated.This work provides a green and efficient method to fabricate porous carbonaceous adsorbent that has great potential applications in chemical and environmental fields.展开更多
Ni/Carbon was prepared in two steps： initially cellulose as carbon source and NiCl2·6H2O as catalyst of the carbonization process were submitted to hydrothermal treatment at 200 ℃ and further to thermal treatme...Ni/Carbon was prepared in two steps： initially cellulose as carbon source and NiCl2·6H2O as catalyst of the carbonization process were submitted to hydrothermal treatment at 200 ℃ and further to thermal treatment at 900 ℃ under argon atmosphere. The obtained material contains Ni nanoparticles with face-centered cubic （fcc） structure dispersed on amorphous carbon with graphitic domains. PtRu/C electrocatalysts （carbon- supported PtRu nanoparticles） were prepared by an alcohol-reduction process using Ni/Carbon as support. The materials were characterized by thermogravimetric analysis, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy and tested as anodes in single direct methanol fuel cell （DMFC）. The performances of PtRu/C electrocatalysts using Ni/Carbon as support were superior to those obtained for PtRu/C using commercial carbon black Vulcan XC72 as support.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
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
Hydrothermal carbonization(HTC)stands out as an eco-friendly,cost-effective method for generating renewable carbon-based materials from biomass.The HTC process yields products such as hydrochars and carbon dots(CDs),p...Hydrothermal carbonization(HTC)stands out as an eco-friendly,cost-effective method for generating renewable carbon-based materials from biomass.The HTC process yields products such as hydrochars and carbon dots(CDs),possessed of notable photocatalytic capabilities due to their unique physicochemical features.Additionally,pairing traditional photocatalysts with hydrochar derivatives elevates their performance,rendering them more effective.Recent times have witnessed a surge in interest in these hydrochar based photocatalysts(HC-photocatalysts).Their appeal stems from multiple attributes:impeccable performance,adaptability to visible light,and adjustable physicochemical properties.This review delves deep into the evolving landscape of these HC-photocatalysts,segmenting them into three distinct categories:hydrochars,hydrochar-based CDs(HC-CDs),and hydrochar-based composites(HC-composites).For each category,we dissect their synthesis routes,unravel the photocatalytic mechanisms,and explore various enhancement strategies.We further traverse their versatile applications,spanning environmental treatment,disinfection,energy conversion,and organic synthesis.In the end,we spotlight the prevailing challenges and uncharted territories in the domain of HC-photocatalysts.In essence,this review serves as a guide,furnishing a theoretical foundation and steering directions for future explorations and tangible implementations of HC-photocatalysts.展开更多
The use of beach-cast macroalgae as a fertilizer(F)or soil amendment(SA)is coming back into focus,due to its highly efficient transformation of CO_(2),nutrients,salts and minerals from its aqueous surroundings into bi...The use of beach-cast macroalgae as a fertilizer(F)or soil amendment(SA)is coming back into focus,due to its highly efficient transformation of CO_(2),nutrients,salts and minerals from its aqueous surroundings into biomass.This research studied the hydrothermal carbonization(HTC)of Fucus vesiculosus macroalgae to hydrochar and evaluated its feasibility for use in soil applications.F.vesiculosus was submitted to HTC following a full factorial design of experiments with three HTC process parameters varied to assess their impact on the hydrochars:temperature(T:160,190,220℃),solid content(%So:20,35%),and process water recirculation(PWrec:yes and no).In general,F.vesiculosus and its hydrochars were rich in nutrients,but also contained regulated heavy metals.Investigation of the partitioning behavior of inorganic elements between the hydrochars and process water showed that heavy metals like Cr,Pb,Co and Cu tended to accumulate in the hydrochar,unaffected by HTC conditions.Nutrients such as P,N,B,and Mn were primarily found in the hydrochar and could be partially influenced to transfer to process water by changing%So and T.The correlation between the mass fractions of 22 elements in the hydrochar and HTC process parameters was studied.T was the most influential parameter,showing a significant positive correlation for eleven elements.%So and PWrec showed inconsistent effects on different elements.When process water was recirculated,some elements decreased(Ca,Cd,Fe)while others increased(K,Na,B,N)in the hydrochar.Assessment against various regulations and standards for F and SA revealed that F.vesiculosus complied with Cd limit values for most rules including the EURF and B,and was regulated only in the RAL for SA,over the limit value.In contrast,the limit value of Cd for both F and SA applications was surpassed in the 13 hydrochars.The contents of N,P,K,S,and Na in the feedstock and hydrochars complied with European F and SA rules,while they were too high for German rules on SA.The other limits for F rules were achieved(under certain HTC process parameters)except for P(lower than the requirements in F for F.vesiculosus and its hydrochars).展开更多
Hydrothermal carbonization(HTC)is a thermochemical conversion technology to produce hydrochar from wet biomass without drying,but it is time-consuming and expensive to experimentally determine the optimal HTC operatio...Hydrothermal carbonization(HTC)is a thermochemical conversion technology to produce hydrochar from wet biomass without drying,but it is time-consuming and expensive to experimentally determine the optimal HTC operational conditions of specific biomass to produce desired hydrochar.Therefore,a machine learning(ML)approach was used to predict and optimize hydrochar properties.Specifically,biochemical components(proteins,lipids,and carbohydrates)of biomass were predicted and analyzed first via elementary composition.Then,accurate single-biomass(no mixture)based ML multi-target models(average R^(2)=0.93 and RMSE=2.36)were built to predict and optimize the hydrochar properties(yield,elemental composition,elemental atomic ratio,and higher heating value).Biomass composition(elemental and biochemical),proximate analyses,and HTC conditions were inputs herein.Interpretation of the model results showed that ash,temperature,and the N and C content of biomass were the most critical factors affecting the hydrochar properties,and that the relative importance of biochemical composition(25%)for the hydrochar was higher than that of operating conditions(19%).Finally,an intelligent system was constructed based on a multi-target model,verified by applying it to predict the atomic ratios(N/C,O/C,and H/C).It could also be extended to optimize hydrochar production from the HTC of single-biomass samples with experimental validation and to predict hydrochar from the co-HTC of mixed biomass samples reported in the literature.This study advances the field by integrating predictive modeling,intelligent systems,and mechanistic insights,offering a holistic approach to the precise control and optimization of hydrochar production through HTC.展开更多
To optimize the CO_(2) adsorption performance of carbon materials,this study proposed a preparation method for biomass-based porous carbon through hydrothermal carbonization coupled with nitrogen source optimization a...To optimize the CO_(2) adsorption performance of carbon materials,this study proposed a preparation method for biomass-based porous carbon through hydrothermal carbonization coupled with nitrogen source optimization and K_(2)CO_(3) activation.The effects of different nitrogen sources(urea,piperazine,melamine,and polyaniline)and activation temperatures on the physicochemical features and CO_(2) adsorption characteristics of the porous carbons were systematically investigated.The results indicated that different nitrogen sources showed varying impacts on the CO_(2) uptake of porous carbons,and not all nitrogen sources enhanced the adsorption performance.The urea and piperazine doped porous carbons exhibited relatively low nitrogen contents and specific surface areas.Whereas the melamine doped carbons showed higher nitrogen contents and specific surface areas,but lacked narrow micropores,limiting their CO_(2) adsorption performance.In contrast,PAC-700,prepared using polyaniline as nitrogen source,featured a well-developed pore structure,abundant narrow micropores and pyrrolic-N groups,endowing it with enhanced CO_(2) adsorption capability.At 0℃/1 bar and 25℃/1 bar,the CO_(2) uptake of PAC-700 reached 6.85 and 4.64 mmol/g,respectively.Additionally,PAC-700 maintained a CO_(2) uptake retention ratio of 99%after 5 adsorption-desorption cycles and exhibited good CO_(2)/N_(2) selectivity of 22.4−51.6.These findings highlighted the advantageous CO_(2) adsorption performance of PAC-700,indicating its substantial application potential in the domain of carbon capture.展开更多
In this study, hydrothermal carbon nanospheres(HCNs) were prepared by hydrothermal carbonization using glucose as the precursor, and introduced to improve the properties of water-based drilling fluid for the first tim...In this study, hydrothermal carbon nanospheres(HCNs) were prepared by hydrothermal carbonization using glucose as the precursor, and introduced to improve the properties of water-based drilling fluid for the first time. The variation in rheological and filtration characteristics of water-based drilling fluid with varying concentrations of HCNs were compared between the cases before and after thermal aging. The results demonstrated that HCNs had little influence on the rheological properties of bentonite base mud,but could effectively reduce its filtration loss after thermal aging at 220℃ For polymer-based drilling fluid, HCNs also exhibited minor influence on the rheology. The H-B model was the best fitting model for the rheological curves before thermal aging. After hot rolling at 220℃,the viscosity retention rate increased from 29% to 63%-90% with addition of HCNs, and the filtration loss decreased by 78% with 1.0w/v% HCNs. Meanwhile, the polymer-based drilling fluid with 0.5 w/v% HCNs maintained relatively stable rheology and low filtration loss after statically thermal aging at 200℃ for 96 h. For a bentonitefree water-based drilling fluid prepared mainly with modified natural polymers, the viscosity retention increased from 21% to 74% after hot rolling at 150℃ with 0.5 w/v% HCNs, and was further improved when HCNs and potassium formate were used in combination. The mechanism study revealed that,HCNs could trap dissolved oxygen, scavenge the free radicals and cross link with polymers, which prevented thermal oxidative degradation of polymers and improved the thermal stability of water-based drilling fluid. Meanwhile, HCNs could inhibit clay hydration and swelling in synergy with partially hydrolyzed polyacrylamide by physically sealing the micropores, contributing to shale formation stability.Furthermore, HCNs could effectively improve the lubrication and anti-wear performance of drilling fluid.This study indicated that HCNs could act as green, sustainable, and versatile additives in water-based drilling fluid.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
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 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
Innovative measure is a urgent requirement for managing the huge volume of municipal sewage sludge. The hydrothermal carbonation （HTC） shows some potential advantages for using hydrochar as a soil conditioner. The a...Innovative measure is a urgent requirement for managing the huge volume of municipal sewage sludge. The hydrothermal carbonation （HTC） shows some potential advantages for using hydrochar as a soil conditioner. The aim of this work was to investigate the properties of hydrochars, by means of the HTC of municipal sewage sludge under different temperatures （190 and 260~C） and reaction hours （1, 6, 12, 18 and 24 h）. The HTC led to the decreases of N, O and H contents by more than 54.6, 37.9 and 10.0%, respectively, and slight changes of C content. The Py-GC-MS analysis showed that a large proportion of fatty acids, in particular hexadecanoic acid, transferred into alkenes, olefins and aromatic compounds. The 13C-NMR and fourier transform infrared spectra （FTIR） confirmed the transformation and changes in chemical structure in which hydrochar contained lower oxygen-containing organic C of O-alkyl, carboxylic and carbonyl C and aliphaticity, but higher aromatic C and aromaticity. The rich hydrophobic functions induced in high positive charges in the charred sludge. The HTC facilitated the pore structure development, proved by higher specific surface area and specific pore volume, with a maximum of 17.30 and 0.83 cm^3 g^-1, respectively. The availabilities of N, P and K markedly reduced during HTC treatment. The activities of most heavy metals were depressed though they accumulated in the hydrochar. Further work is required to investigate the values and risk of the charred sludge amended to soil.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;SO;, 6 M KOH and1 M Na;SO;, using a three-electrode cell. HM700 achieved a high specific capacitance of 323.2 F/g in 1 M H;SO;（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;SO;, E = 2 V）, making the device promising for green supercapacitor applications.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
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
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 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.
基金supported by NSFC(No.21577073)the Natural Science Foundation of Tianjin(No.16JCZDJC33700)Elite Youth program of Chinese Academy of Agricultural Sciences(to Dr.Xin-Hua Qi)
文摘Hydrothermal carbonization of biomass is a promising method to prepare carbonaceous materials.Generally,post physical or chemical activation is necessary to increase surface area and porosity of the carbon.Herein,porous carbonaceous material（FPC） with large surface area（481.7 m^2/g） and pore volume（0.73 cm^3/g） was prepared directly from hydrothermal carbonization of fructose and phloroglucinol in hydroalcoholic mixture.Structure characteristics of the FPC and its adsorption capacity for a representative antibiotic tetracycline in aqueous solution were investigated.This work provides a green and efficient method to fabricate porous carbonaceous adsorbent that has great potential applications in chemical and environmental fields.
基金CNP_q,FAPESPFINEP-MCT-ProH_2 for financial support
文摘Ni/Carbon was prepared in two steps： initially cellulose as carbon source and NiCl2·6H2O as catalyst of the carbonization process were submitted to hydrothermal treatment at 200 ℃ and further to thermal treatment at 900 ℃ under argon atmosphere. The obtained material contains Ni nanoparticles with face-centered cubic （fcc） structure dispersed on amorphous carbon with graphitic domains. PtRu/C electrocatalysts （carbon- supported PtRu nanoparticles） were prepared by an alcohol-reduction process using Ni/Carbon as support. The materials were characterized by thermogravimetric analysis, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy and tested as anodes in single direct methanol fuel cell （DMFC）. The performances of PtRu/C electrocatalysts using Ni/Carbon as support were superior to those obtained for PtRu/C using commercial carbon black Vulcan XC72 as support.
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.
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funded by Shandong Province Major Scientific and Techno-logical Innovation Project(2021CXGC010803)the National Natural Science Foundation of China(21876188).
文摘Hydrothermal carbonization(HTC)stands out as an eco-friendly,cost-effective method for generating renewable carbon-based materials from biomass.The HTC process yields products such as hydrochars and carbon dots(CDs),possessed of notable photocatalytic capabilities due to their unique physicochemical features.Additionally,pairing traditional photocatalysts with hydrochar derivatives elevates their performance,rendering them more effective.Recent times have witnessed a surge in interest in these hydrochar based photocatalysts(HC-photocatalysts).Their appeal stems from multiple attributes:impeccable performance,adaptability to visible light,and adjustable physicochemical properties.This review delves deep into the evolving landscape of these HC-photocatalysts,segmenting them into three distinct categories:hydrochars,hydrochar-based CDs(HC-CDs),and hydrochar-based composites(HC-composites).For each category,we dissect their synthesis routes,unravel the photocatalytic mechanisms,and explore various enhancement strategies.We further traverse their versatile applications,spanning environmental treatment,disinfection,energy conversion,and organic synthesis.In the end,we spotlight the prevailing challenges and uncharted territories in the domain of HC-photocatalysts.In essence,this review serves as a guide,furnishing a theoretical foundation and steering directions for future explorations and tangible implementations of HC-photocatalysts.
文摘The use of beach-cast macroalgae as a fertilizer(F)or soil amendment(SA)is coming back into focus,due to its highly efficient transformation of CO_(2),nutrients,salts and minerals from its aqueous surroundings into biomass.This research studied the hydrothermal carbonization(HTC)of Fucus vesiculosus macroalgae to hydrochar and evaluated its feasibility for use in soil applications.F.vesiculosus was submitted to HTC following a full factorial design of experiments with three HTC process parameters varied to assess their impact on the hydrochars:temperature(T:160,190,220℃),solid content(%So:20,35%),and process water recirculation(PWrec:yes and no).In general,F.vesiculosus and its hydrochars were rich in nutrients,but also contained regulated heavy metals.Investigation of the partitioning behavior of inorganic elements between the hydrochars and process water showed that heavy metals like Cr,Pb,Co and Cu tended to accumulate in the hydrochar,unaffected by HTC conditions.Nutrients such as P,N,B,and Mn were primarily found in the hydrochar and could be partially influenced to transfer to process water by changing%So and T.The correlation between the mass fractions of 22 elements in the hydrochar and HTC process parameters was studied.T was the most influential parameter,showing a significant positive correlation for eleven elements.%So and PWrec showed inconsistent effects on different elements.When process water was recirculated,some elements decreased(Ca,Cd,Fe)while others increased(K,Na,B,N)in the hydrochar.Assessment against various regulations and standards for F and SA revealed that F.vesiculosus complied with Cd limit values for most rules including the EURF and B,and was regulated only in the RAL for SA,over the limit value.In contrast,the limit value of Cd for both F and SA applications was surpassed in the 13 hydrochars.The contents of N,P,K,S,and Na in the feedstock and hydrochars complied with European F and SA rules,while they were too high for German rules on SA.The other limits for F rules were achieved(under certain HTC process parameters)except for P(lower than the requirements in F for F.vesiculosus and its hydrochars).
基金supported by the National Key Research and Development Program of China(2021YFE0104900)the Open Project of Xiangjiang Laboratory(22xj03003)the Science and Technology Innovation Program of Hunan Province(2021RC4005,2021GK1210).
文摘Hydrothermal carbonization(HTC)is a thermochemical conversion technology to produce hydrochar from wet biomass without drying,but it is time-consuming and expensive to experimentally determine the optimal HTC operational conditions of specific biomass to produce desired hydrochar.Therefore,a machine learning(ML)approach was used to predict and optimize hydrochar properties.Specifically,biochemical components(proteins,lipids,and carbohydrates)of biomass were predicted and analyzed first via elementary composition.Then,accurate single-biomass(no mixture)based ML multi-target models(average R^(2)=0.93 and RMSE=2.36)were built to predict and optimize the hydrochar properties(yield,elemental composition,elemental atomic ratio,and higher heating value).Biomass composition(elemental and biochemical),proximate analyses,and HTC conditions were inputs herein.Interpretation of the model results showed that ash,temperature,and the N and C content of biomass were the most critical factors affecting the hydrochar properties,and that the relative importance of biochemical composition(25%)for the hydrochar was higher than that of operating conditions(19%).Finally,an intelligent system was constructed based on a multi-target model,verified by applying it to predict the atomic ratios(N/C,O/C,and H/C).It could also be extended to optimize hydrochar production from the HTC of single-biomass samples with experimental validation and to predict hydrochar from the co-HTC of mixed biomass samples reported in the literature.This study advances the field by integrating predictive modeling,intelligent systems,and mechanistic insights,offering a holistic approach to the precise control and optimization of hydrochar production through HTC.
基金supported by the National Key R&D Program(2022YFC3902403)Fundamental Research Funds for the Central Universities(2024JC001,2019JG002)Technology Innovation Special Fund of Jiangsu Province for Carbon Dioxide Emission Peaking and Carbon Neutrality(BE2022307)。
文摘To optimize the CO_(2) adsorption performance of carbon materials,this study proposed a preparation method for biomass-based porous carbon through hydrothermal carbonization coupled with nitrogen source optimization and K_(2)CO_(3) activation.The effects of different nitrogen sources(urea,piperazine,melamine,and polyaniline)and activation temperatures on the physicochemical features and CO_(2) adsorption characteristics of the porous carbons were systematically investigated.The results indicated that different nitrogen sources showed varying impacts on the CO_(2) uptake of porous carbons,and not all nitrogen sources enhanced the adsorption performance.The urea and piperazine doped porous carbons exhibited relatively low nitrogen contents and specific surface areas.Whereas the melamine doped carbons showed higher nitrogen contents and specific surface areas,but lacked narrow micropores,limiting their CO_(2) adsorption performance.In contrast,PAC-700,prepared using polyaniline as nitrogen source,featured a well-developed pore structure,abundant narrow micropores and pyrrolic-N groups,endowing it with enhanced CO_(2) adsorption capability.At 0℃/1 bar and 25℃/1 bar,the CO_(2) uptake of PAC-700 reached 6.85 and 4.64 mmol/g,respectively.Additionally,PAC-700 maintained a CO_(2) uptake retention ratio of 99%after 5 adsorption-desorption cycles and exhibited good CO_(2)/N_(2) selectivity of 22.4−51.6.These findings highlighted the advantageous CO_(2) adsorption performance of PAC-700,indicating its substantial application potential in the domain of carbon capture.
基金supported by National Natural Science Foundation of China(No.52174013)the Fundamental Research Funds for the Central Universities(24CX02004A)+2 种基金Natural Science Foundation of Shandong Province(ZR2024ME105)The Open Fund for Sinopec's Key Laboratory of Ultra-Deep Well Drilling Engineering and Technology(36650000-23-ZC0607-0063)the Fund of State Key Laboratory of Deep Oil and Gas,China University of Petroleum(East China).
文摘In this study, hydrothermal carbon nanospheres(HCNs) were prepared by hydrothermal carbonization using glucose as the precursor, and introduced to improve the properties of water-based drilling fluid for the first time. The variation in rheological and filtration characteristics of water-based drilling fluid with varying concentrations of HCNs were compared between the cases before and after thermal aging. The results demonstrated that HCNs had little influence on the rheological properties of bentonite base mud,but could effectively reduce its filtration loss after thermal aging at 220℃ For polymer-based drilling fluid, HCNs also exhibited minor influence on the rheology. The H-B model was the best fitting model for the rheological curves before thermal aging. After hot rolling at 220℃,the viscosity retention rate increased from 29% to 63%-90% with addition of HCNs, and the filtration loss decreased by 78% with 1.0w/v% HCNs. Meanwhile, the polymer-based drilling fluid with 0.5 w/v% HCNs maintained relatively stable rheology and low filtration loss after statically thermal aging at 200℃ for 96 h. For a bentonitefree water-based drilling fluid prepared mainly with modified natural polymers, the viscosity retention increased from 21% to 74% after hot rolling at 150℃ with 0.5 w/v% HCNs, and was further improved when HCNs and potassium formate were used in combination. The mechanism study revealed that,HCNs could trap dissolved oxygen, scavenge the free radicals and cross link with polymers, which prevented thermal oxidative degradation of polymers and improved the thermal stability of water-based drilling fluid. Meanwhile, HCNs could inhibit clay hydration and swelling in synergy with partially hydrolyzed polyacrylamide by physically sealing the micropores, contributing to shale formation stability.Furthermore, HCNs could effectively improve the lubrication and anti-wear performance of drilling fluid.This study indicated that HCNs could act as green, sustainable, and versatile additives in water-based drilling fluid.
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.
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financially supported by the National Natural Science Foundation of China (41071206)
文摘Innovative measure is a urgent requirement for managing the huge volume of municipal sewage sludge. The hydrothermal carbonation （HTC） shows some potential advantages for using hydrochar as a soil conditioner. The aim of this work was to investigate the properties of hydrochars, by means of the HTC of municipal sewage sludge under different temperatures （190 and 260~C） and reaction hours （1, 6, 12, 18 and 24 h）. The HTC led to the decreases of N, O and H contents by more than 54.6, 37.9 and 10.0%, respectively, and slight changes of C content. The Py-GC-MS analysis showed that a large proportion of fatty acids, in particular hexadecanoic acid, transferred into alkenes, olefins and aromatic compounds. The 13C-NMR and fourier transform infrared spectra （FTIR） confirmed the transformation and changes in chemical structure in which hydrochar contained lower oxygen-containing organic C of O-alkyl, carboxylic and carbonyl C and aliphaticity, but higher aromatic C and aromaticity. The rich hydrophobic functions induced in high positive charges in the charred sludge. The HTC facilitated the pore structure development, proved by higher specific surface area and specific pore volume, with a maximum of 17.30 and 0.83 cm^3 g^-1, respectively. The availabilities of N, P and K markedly reduced during HTC treatment. The activities of most heavy metals were depressed though they accumulated in the hydrochar. Further work is required to investigate the values and risk of the charred sludge amended to soil.
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;SO;, 6 M KOH and1 M Na;SO;, using a three-electrode cell. HM700 achieved a high specific capacitance of 323.2 F/g in 1 M H;SO;（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;SO;, E = 2 V）, making the device promising for green supercapacitor applications.
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.
