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The high catalytic activity and specificity of enzymes can be used to pretreat biomass. Herein, the resourceful, reproducible, cheap, and crude protein-rich cottonseed meal (CM) is selected as a precursor and the protease in the K2CO3–KHCO3 buffer solution is used as the enzyme degradation substance to pretreat CM. The crude protein content is significantly reduced by the protease degradation, and, meanwhile, it results in a looser and porous structure of CM. What is more, it significantly reduces the amount of activator. In the subsequent carbonization process, the K2CO3–KHCO3 in the buffer solution is also used as an activating agent (the mass ratio of CM to activator is 2:1), and after carbonization, the O, S, and N doped porous carbon is obtained. The optimized PCM-800-4 exhibits high heteroatom contents and a hierarchical porous structure. The specific capacitance of the prepared porous carbon reaches up to 233 F g−1 in 6M KOH even when 10 mg of active material is loaded. In addition, a K2CO3–KHCO3/EG based gel electrolyte is prepared and the fabricated flexible capacitor exhibits an energy density of 15.6 Wh kg−1 and a wide temperature range (−25 to 100 °C). This study presents a simple enzymatic degradation and reduced activator dosage strategy to prepare a cottonseed meal derived carbon material and looks forward to preparing porous carbon using other biomass. [ABSTRACT FROM AUTHOR]

A series of sulfonated carbon acid catalysts with strong acidity was prepared by simultaneous carbonization and sulfonation of biomass sucrose in the presence of the organic sulfonating agent sulfosalicylic acid under hydrothermal conditions at temperatures ranging from 150 to 200 °C. It was found from FTIR and XPS spectra that the surface of carbon was efficiently functionalized with –SO3H groups. Research on the mechanism of the sulfonation process indicated that the intermediate 5-hydroxymethyl furfural (5-HMF), which was easily hydrolyzed from sucrose, was prone to carbonization and functionalized with –SO3H groups simultaneously. Compared with 5-HMF and fructose used as the initial carbon precursor, the slow hydrolysis of sucrose to intermediate 5-HMF to suppress its rapid carbonization is favorable for the efficient grafting of –SO3H groups when sucrose is used as the initial carbon precursor. The prepared sulfonated carbons were evaluated as acid catalysts in a typical ester hydrolysis reaction, namely, hydrolysis of ethyl acetate. The sulfonic acid groups were identified to be the active sites and quantified by a cation-exchange process. The activity of the sulfonated carbon was primarily correlated with the total number of active sites. However, when the total number of the –SO3H groups did not change, higher activities were shown on the sulfonated carbon with higher surface S content. [ABSTRACT FROM AUTHOR]

An MgH2–anthraquinone carbonization product composite (denoted as MgH2–ACP composites) was successfully prepared through a hydrogenation combustion and mechanical ball-milling method using the original Mg powder to simultaneously achieve modification via in situ-formed amorphous carbon. The amorphous carbon derived from the combustion of carbonic compounds significantly enhanced the hydrogen-absorption and -desorption performances of MgH2. Results revealed that the onset decomposition temperature of the MgH2–ACP composite decreased from 638 K to 587 K in the dehydrogenation stage. Moreover, the MgH2–ACP sample delivered dehydrogenation capacities of 3.525 wt% at 598 K, whereas the as-milled MgH2 decomposed only 0.763 wt% at the same temperature. The activation energies calculated using Kissinger analysis in the dehydrogenation process of MgH2 were lowered by about 57.5 kJ mol−1. For the absorption kinetic measurements at 473 K, the MgH2-ACP sample could uptake about 4.629 wt% of H2 in 3200 s compared to 1.804 wt% taken up by the as-milled MgH2. The in situ-formed amorphous carbon and MgO were confirmed as the active species that contributed to the enhancement of hydrogen-storage properties of the composite. [ABSTRACT FROM AUTHOR]

Renewable biomass is a potent, CO2 neutral substitute to fossil coal and coke in iron making. However, there has been relatively little work on the utilization of biomass for the production of directly reduced iron (DRI). The aim of the present work is to characterize Acacia nilotica (W1), Albizia lebbeck (W2), and Leucaena leucocephala (W3) biomass and to reduce iron ore pellets primarily with the volatile matter from the wood at high temperature, yielding charcoal simultaneously as a co-product. The chemical, physical, and mechanical properties of the three biomass species were investigated. Effect of different biomasses and reduction parameters like C/O ratio, reduction temperature, and time on %Reduction (%R) was studied. DRI was characterized using %Metallization (%M), XRD, and SEM. Up to 89% reduction was achieved in the simultaneous carbonization of biomass and the reduction of iron ore pellets at a temperature of 1000 °C. The pellets cooled in the furnace after reduction resulted in lower %R (e.g., W1:57%, W2:54%, and W3:63%) than the respective air-cooled pellets (e.g., W1:88%, W2:83%, and W3:86%). Oxidation was the cause for lower %R in furnace cooled (slow cooling) reduction experiments than in the air cooled. Co-produced wood charcoal after the reduction of iron ore contained approximately 76–81% carbon which competes well with a typical value for coal of 70%. [ABSTRACT FROM AUTHOR]

An MgH2–anthraquinone carbonization product composite (denoted as MgH2–ACP composites) was successfully prepared through a hydrogenation combustion and mechanical ball-milling method using the original Mg powder to simultaneously achieve modification via in situ-formed amorphous carbon. The amorphous carbon derived from the combustion of carbonic compounds significantly enhanced the hydrogen-absorption and -desorption performances of MgH2. Results revealed that the onset decomposition temperature of the MgH2–ACP composite decreased from 638 K to 587 K in the dehydrogenation stage. Moreover, the MgH2–ACP sample delivered dehydrogenation capacities of 3.525 wt% at 598 K, whereas the as-milled MgH2 decomposed only 0.763 wt% at the same temperature. The activation energies calculated using Kissinger analysis in the dehydrogenation process of MgH2 were lowered by about 57.5 kJ mol−1. For the absorption kinetic measurements at 473 K, the MgH2-ACP sample could uptake about 4.629 wt% of H2 in 3200 s compared to 1.804 wt% taken up by the as-milled MgH2. The in situ-formed amorphous carbon and MgO were confirmed as the active species that contributed to the enhancement of hydrogen-storage properties of the composite. [ABSTRACT FROM AUTHOR]

Dynamic organic room‐temperature phosphorescence (RTP) materials are highly promising for various applications. However, developing photo‐responsive RTP systems with simple fabrication, high reversibility, and visible‐light responsiveness presents a significant challenge. Herein, in situ embedding of boron‐doped carbon dots (B‐CDs) in amorphous polymer (pPBA) is achieved by a two‐step polymerization and carbonization process. Impressively, the B‐CDs@pPBA composite exhibits visible‐light‐activated ultralong RTP with full reversibility and a lifetime on–off ratio exceeding 280. By correlating photophysical properties with structural characterization results, it is concluded that photoinduced intensifying of the crosslinking between B‐CDs and pPBA is responsible for the dynamic RTP. More interestingly, the B‐CDs@pPBA film is found to display bending actuation and reversible deformable behavior upon light exposure. Finally, potential applications of such photo‐responsive systems in programmable information storage and encryption are demonstrated. This research may pave a new way for the development of dynamic RTP nanomaterials and promote their use in a wide range of promising applications. [ABSTRACT FROM AUTHOR]

In this paper, we prepared a new type of iron and nitrogen co-doped porous carbon material (WSC-Fe/N) using a carbonization–activation process with wheat straw as a precursor and FeCl3 and NH4Cl as co-doping agents and analyzed the electrochemical properties of the resulting electrode material. Through precise control of the doping elements and carbonization temperature (900 °C), the resulting WSC-Fe/N-900 material exhibits abundant micropores, uniform mesopores, a significant specific surface area (2576.6 m2 g−1), an optimal level of iron doping (1.7 wt.%), and excellent graphitization. These characteristics were confirmed through X-ray diffraction and Raman spectroscopy. Additionally, the WSC-Fe/N-900 electrode demonstrated a specific capacitance of 400.5 F g−1 at a current density of 0.5 A g−1, maintaining a high capacitance of 308 F g−1 even at 10 A g−1. The solid-state symmetric supercapacitor in an aqueous electrolyte achieved an energy density of 9.2 Wh kg−1 at a power density of 250 W kg−1 and maintained an energy density of 6.5 Wh kg−1 at a power density of 5000 W kg−1, demonstrating remarkable synergistic energy–power output characteristics. In terms of structural properties, the porous characteristics of WSC-Fe/N-900 not only enhance the specific surface area of the electrode but also improve the diffusion capability of electrolyte ions within the electrode, thereby enhancing capacitance performance. The reliability of the electrode material demonstrated good performance in long-term cycling tests, maintaining a capacitance retention rate of 93% after 10,000 charge–discharge cycles, indicating excellent electrochemical stability. Furthermore, over time, the aging effect of the WSC-Fe/N-900 electrode material is minimal, maintaining high electrochemical performance even after prolonged use, suggesting that this material is suitable for long-term energy storage applications. This study introduces a novel strategy for producing porous carbon materials for supercapacitors, advancing the development of economically efficient and environmentally friendly energy storage solutions. [ABSTRACT FROM AUTHOR]

Li–S batteries are promising large-scale energy storage systems but currently suffer from performance issues; a major reason is the dissolution of polysulfides in electrolytes. To this end, we report a high-energy-density Lithium–Sulfur (Li–S) battery that combines a catholyte and a sulfur-free carbon nanofiber (CNF) cathode. The cathode was synthesized by carbonizing binder-free polyacrylonitrile (PAN) nanofibers, affording a high surface area. In the catholyte, added polysulfides acted as both conductive Li salts and active materials. Investigating the electrochemical performance of this concept in both Swagelok- and pouch-type cells afforded energy densities exceeding 3 mAh cm−2 at a discharge rate of 0.1 C. This combination could also be utilized in high-capacity pouch cells with capacities of up to 250 mAh g−1. Both cell types exhibited good cycle performance. Adding LiNO3 to the electrolyte suppressed the redox shuttle reactions. Moreover, the cathode being binder-free increased the energy density and simplified cathode fabrication. Characterizing the cathode before and after cycling revealed that deposition was reversible, and that cell reactions at least partially formed sulfur as the end product, resulting in high sulfur amounts in the cell. We expect our concept to greatly aid in the development of practically applicable Li–S cells. [ABSTRACT FROM AUTHOR]

Water has different forms of existence in wood (free water and bound water), which can generate different effects on the microstructure of wood. Compared to other methods, the freeze-thawing method is equipped with simple, environmentally friendly, and low-cost features. In this paper, the permeability of wood with different ratios of free water to bound water (water content), as well as the pore structure characteristics and electrochemical properties after carbonization, were investigated by the freeze–thaw method. The results show that dry samples of poplar chips with a moisture content of 15–17% after KMnO4 and freeze–thaw cycle treatment and carbonization (PC@15%-MnO) have a specific surface area of 936.94 m2/g. The areal specific capacitance is 4784 mF/cm2 at a current density of 12 mA/cm2, which is 3.3 and 22 times higher than those of wood-derived carbon without freeze–thaw treatment, respectively. Additionally, PC@15%-MnO maintains 80% of its specific capacitance after 2000 testing cycles, indicating that the freeze–thaw method effectively enhances the permeability, pore structure, and electrochemical properties of wood-derived carbon materials. This strategy offers new avenues for the research and application of wood in electrode materials. [ABSTRACT FROM AUTHOR]

Novel Fe N C electrocatalysts derived from conjugated microporous polymers based on pre-functionalization of monomers was developed, which exhibits great potential for cathodic oxygen reduction reaction in fuel cell and provides a feasible strategy of developing multi-atoms doping catalysts for heterogeneous catalysis. [Display omitted] Porous iron–nitrogen-doped carbons (Fe N C) offer a great platform for construction of cathodic oxygen reduction reaction (ORR) catalysts in fuel cells. However, challenges still remain regarding with the collapse of carbon-skeleton during pyrolysis, uneven distribution of active sites and aggregation of metal atoms. In this work, we synthesized Fe, N co-doped conjugated microporous polymer (FeN-CMP) through a facile bottom-up strategy using 1,3,5-triethynylbenzene and iron-chelated 3,8-dibromo-1,10-phenanthroline as monomers, ensuring the uniform coordination of N with Fe element in network. Then, the resulting FeN-CMP was treated by pyrolysis without structural collapse to obtain porous Fe N C electrocatalyst for ORR. The most active catalyst was fabricated under 900 °C, which exhibits remarkable ORR activity in alkaline medium with half-wave potential of 0.796 V (18 mV and 105 mV positive deviation from the commercial Pt/C catalyst and post-doping catalyst), high selectivity with nearly 4e- transfer process and excellent methanol tolerance. Our study first developed porous Fe N C electrocatalysts derived from Fe, N -anchoring CMPs based on pre-functionalization of monomers, which exhibits great potential as an alternative to commercial Pt/C catalyst for ORR, and provides a feasible strategy of developing multi-atoms doping catalysts for energy storage and conversion as well as heterogeneous catalysis. [ABSTRACT FROM AUTHOR]

The sodium storage behavior in the plateau region is crucial for determining the capacity and rate capability of hard carbon (HC) anodes in sodium‐ion batteries (SIBs). Key structural features for achieving excellent plateau performance include extended graphite domains and increased interlayer spacing. However, synchronously optimizing these two structures is challenging due to their inherent trade‐off. Herein, a tandem catalytic carbonization strategy is developed to construct HC with long graphite domains (La = 5.31 nm) and large interlayer spacing (d002 = 0.389 nm) simultaneously. Comprehensive in situ and ex situ tests unravel the catalytic selective bond breaking and aromatization effects of ZnCl2, the catalytic graphitic layers enlargement and occupied effects of formed ZnO and Zn in different temperature stages, leading to the formation of the unique structure. The optimal HCZ‐0.1 exhibits a high reversible capacity of 346.9 mAh g−1 with a plateau capacity of 249.4 mAh g−1, and high‐rate performance (114.0 mAh g−1 at 5 A g−1). In addition, the sodium storage mechanism and origin of enhanced Na+ kinetics of HCZ‐0.1 are also revealed. This work offers a precise method to engineer the graphite microcrystal structure in HC for superior sodium storage in the plateau region. [ABSTRACT FROM AUTHOR]

Using chemical activation techniques at dissimilar carbonization temperatures, activated carbon adsorbents were produced from Palmyra palm fruit biomass in this work. X‐ray diffraction, Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, laser Raman spectroscopy, scanning electron microscopy, CHNS‐elemental analysis, and N2 adsorption studies were among the characterization techniques used to assess the characteristics of the carbon adsorbents. The carbon adsorbents from Palmyra palm fruit were used to absorb CO2 in a temperature range of 25–70°C. The findings of the characterization showed that these carbons have a large surface area and microporosity. The temperature of carbonization and the activating agent had an impact on the surface characteristics. The samples with the highest adsorption capacity, 4.70 mmol/g at 25°C, were the activated carbons made by treating them with KOH and then carbonizing them at 750°C. The physicochemical properties of the adsorbents provided an explanation for their high adsorption capacity. The adsorbents showed simple desorption and maintained constant activity during ten cycles of recycling. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs), as a kind of zero‐dimensional nanomaterials, have been widely synthesized by bottom‐up methods from various precursors. However, the formation mechanism is still unclear and controversial, which also brings difficulty to the regulation of structures and properties. Only some tentative formation processes were postulated by analyzing the products obtained at different reaction times and temperatures. Here, the effect of crosslinking on the formation of carbonized polymer dots (CPDs) is explored. Crosslinking‐induced nucleation and carbonization (CINC) is proposed as the driving force for the formation of CPDs. Under hydrothermal synthesis, the precursors are initiated to polymerize and crosslink. The crosslinking brings higher hydrophobicity to generate the hydrophilic/hydrophobic microphase separation, which promotes dehydration and carbonization resulting in the formation of CPDs. Based on the principle of CINC, the influence factors of size are also revealed. Moreover, the dissipative particle dynamics (DPD) simulation is employed to support this formation mechanism. This concept of CINC will bring light to the formation process of CPDs, as well as facilitate the regulation of CPDs' size and photoluminescence. [ABSTRACT FROM AUTHOR]

In this study, carbon nanotube (CNT)/carbon nanofiber (CNF) composite electrothermal films were prepared by electrospinning, and the effects of the CNT content and carbonization temperature on the electrothermal properties of the CNT/CNF composite films were investigated. The experimental results demonstrated that the conductivity of the CNT/CNF composite electrothermal film (0.006–6.89 S/cm) was directly affected by the CNT content and carbonization temperature. The electrothermal properties of the CNT/CNF positively correlated with the CNT content, carbonization temperature, and applied voltage. The surface temperature of CNT/CNF can be controlled within 30–260 °C, and continuously heated and cooled 100 times without any loss. The convective heat transfer with air is controllable between 0.008 and 31.75. The radiation heat transfer is controllable between 0.29 and 1.92. The prepared CNT/CNF exhibited a heat transfer efficiency of up to 94.5%, and melted a 1 cm thick ice layer within 3 min by thermal convection and radiation alone. [ABSTRACT FROM AUTHOR]

The influence of carbonization on emission characteristics of rice husk briquettes in a fixed-bed reactor were investigated in this study. Rice husk briquettes were combusted in a fixed bed operated under counterflow mode of flame propagation. Emissions levels for NOx, SOx, unburnt hydrocarbons (CxHy), CO and CO2 were measured under varying biochar and air-mass flow rate conditions. Biochar in the fuel samples were varied uniformly between 25 and 100% while air mass flux was varied uniformly between 0.02 and 0.6 kg/m2.s. It was established that carbonization increases emissions of NOx, SOx, CO2 and decreases emissions of CxHy. Briquettes with high amount of carbonized rice husks emitted high amount of NOx and SOx contrary to the amount of N and S present in these fuels indicating a stronger contribution from higher combustion temperatures. On the other hand, all emissions except CO were directly proportional to air mass flux up to stoichiometric condition which was approximately at 0.31 kg/m2.s. These findings underscore the potential of carbonized rice husk briquettes as a cleaner alternative for biomass combustion. [ABSTRACT FROM AUTHOR]

In this study, the fruit of Terminalia chebula, commonly known as chebulic myrobalan, is used as the precursor for carbon for its application in supercapacitors. The Terminalia chebula biomass-derived sponge-like porous carbon (TC-SPC) is synthesized using a facile and economical method of pyrolysis. TC-SPC thus obtained is subjected to XRD, FESEM, TEM, HRTEM, XPS, Raman spectroscopy, ATR-FTIR, and nitrogen adsorption–desorption analyses for their structural and chemical composition. The examination revealed that TC-SPC has a crystalline nature and a mesoporous and microporous structure accompanied by a disordered carbon framework that is doped with heteroatoms such as nitrogen and sulfur. Electrochemical studies are performed on TC-SPC using cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy. TC-SPC contributed a maximum specific capacitance of 145 F g−1 obtained at 1 A g−1. The cyclic stability of TC-SPC is significant with 10,000 cycles, maintaining the capacitance retention value of 96%. The results demonstrated that by turning the fruit of Terminalia chebula into an opulent product, a supercapacitor, TC-SPC generated from biomass has proven to be a potential candidate for energy storage application. [ABSTRACT FROM AUTHOR]

In this work development of structural and chemical properties of four nanoporous hybrid carbons has been presented. The carbons were synthesized by direct carbonization at 450, 600, 750 and 900 °C of the terpolymeric hybrid precursor composed of methacrylamide, divinylbenzene and trimethoxyvinylsilane and impregnated with sulfanilic acid (SA) as the surface modifier. The conditions of the carbonization process were set on the basis of the thermogravimetric analysis combined with FTIR analysis of the evolved gases (TGA-EGA). The use of SA contributed to the reduction of the carbonization temperature by about 100 °C and resulted in carbons with very uniform and bimodal porosity with the width range of about 1 and 14–28 nm. Spectral (ATR, Raman, XPS) and X-ray diffraction methods used to characterize the resulting carbon products allowed to define the gradual changes taking place in the morphological and chemical structure of the prepared materials. Cyclic and symmetrical structures of silicates species were gradually replaced by amorphous arrangements. At the same time, the increase in the sp2/sp3 carbon ratio from 1 to 65% proved progressive ordering and aromatization of the carbonized polymeric hybrid precursor. Some functional groups (e.g., N-containing) were built into carbon clusters forming pyridinic, pyrrolic and N-graphitic like structures, while others (e.g., carbonyls) were removed from the surface. [ABSTRACT FROM AUTHOR]

The volatile matter (VM) content and composition of birch biochars produced at 320 °C under elevated pressure (0.1–11 MPa) and constant pressure or constant volume reactor conditions were characterized by thermogravimetry/mass spectrometry (TG/MS) and pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS). Some of the thermal properties of the biochars and the composition of the VMs varied as a function of the maximal pressure applied during carbonization. The samples prepared at higher pressures released more volatiles up to 320 °C, while the maximal rate of thermal decomposition at around 440 °C showed decreasing tendency with the carbonization pressure. In terms of VM composition, the most apparent effect was the significant increase of the amounts of apoallobetulins from biochars prepared at elevated pressures, which were formed by dehydration, ring closure and rearrangement from the betulin content of birch. The change in the ratio of the evolved guaiacol and 4-methylguaiacol as well as that of syringol and 4-methylsyringol as a function of the maximal pressure of carbonization indicated a modification of the lignin decomposition mechanism. [ABSTRACT FROM AUTHOR]

We investigate the influence of phosphoric acid (H3PO4) activation on physiochemical characteristics of activated carbons (ACs) as a function of number of activation steps such as two‐step and three‐step and impregnation ratio (IR). Scanning electron microscopy observations identified that different morphologies in the forms of graphene sheet‐like, nano‐granular, and flake‐like carbon structure in the cases of ACs. FTIR spectroscopy confirmed that successful incorporation of phosphorous group in the ACs by H3PO4 activation. X‐ray diffraction (XRD) profile exposed that irrespective of the activation method and IR, all AC samples showed narrow and sharp XRD crystalline peak along with the amorphous signals. Raman scattering analysis suggested that three‐step activation create more defective structure as compared to two‐step activation route. Nitrogen adsorption–desorption isotherm measurements indicated that upon fabricating ACs via three‐step and two‐step activation approach, around 6.5 times and 3‐fold enhancement in the value of surface area of ACs as compared to that of carbon before activation. In addition, higher the IR value, lower the textural properties of ACs. This study demonstrated that three‐step activation methodology is capable of generating highly porous AC when compared to two‐step activation route. Cyclic voltammetry analysis showed that for the electrode developed from AC that fabricated via three‐step activation, capacitance retention of 50% is achieved upon tuning the scan rate by 10 times. The same electrode exhibited the capacitance retention of 45% upon increasing the current density by 10 times. We have also compared the electrochemical performance of symmetric and asymmetric supercapacitors. Electrochemical capacitance retention of symmetric and asymmetric supercapacitors is determined to be 100% and 92% respectively after 1000 cycles at the current density of 1 A g−1. Based on the Ragone plot study, it is observed that the maximum energy density of 5 W h kg−1 and the maximum power density of 943 W kg−1 are attained for the case of symmetric supercapacitors. Asymmetric supercapacitor displayed improved energy density of 7.15 W h kg−1 and modest power density of 432 W kg−1. [ABSTRACT FROM AUTHOR]

Exploring high-performance carbon anodes that are low-cost and easily accessible is the key to the commercialization of sodium-ion batteries. Producing carbon materials from bio by-products is an intriguing strategy for sodium-ion battery anode manufacture and for high-value utilization of biomass. Herein, a novel hard carbon (PPHC) was prepared via a facile pyrolysis process followed by acid treatment using biowaste pomegranate peel as the precursor. The morphology and structure of the PPHC were influenced by the carbonization temperature, as evidenced by physicochemical characterization. The PPHC pyrolyzed at 1100 °C showed expanded interlayer spacing and appropriate oxygen group content. When used as a sodium ion battery anode, the PPHC-1100 demonstrated a reversible capacity of up to 330 mAh g−1, maintaining 174 mAh g−1 at an increased current rate of 1 C. After 200 cycles at 0.5 C, the capacity delivered by PPHC-1100 was 175 mAh g−1. The electrochemical behavior of PPHC electrodes was investigated, revealing that the PPHC-1100 possessed increased capacitive-controlled energy storage and improved ion transport properties, which explained its excellent electrochemical performance. This work underscores the feasibility of high-performance sodium-ion battery anodes derived from biowaste and provides insights into the sodium storage process in biomass-derived hard carbon. [ABSTRACT FROM AUTHOR]

The use of fossil fuels has been essential to the development of society, but has also contributed partly to global warming. For example, carbon dioxide emissions from fossil fuels and industries have increased by 60% since 1990, calling for the recycling of modern biomass in the context of a carbon neutral economy. Here we review the hydrothermal conversion of biomass into biofuels, chemicals and biomaterials with emphasis on subcritical water properties, hydrolysis of biomass, steam explosion, fractionation, carbonization, liquefaction, gasification, and fractionation of bio-oil. We observe that hydrothermal conversion of biomass in the presence of water at subcritical conditions produces value-added compounds with high process efficiency. Subcritical water allows rapid reaction rates, low mass transfer resistance, and gas-like diffusivity. [ABSTRACT FROM AUTHOR]

Carbon hollow microspheres (CHM) have been heralded as a seminal material, manifesting a multifaceted utility in domains such as catalysis, adsorption, energy storage, and conversion. In this study, the present investigation delves into the fabrication of lignin-formaldehyde resin (LFR) carbon hollow microspheres (LFR-CHM) via the nuanced methodologies of spray drying and subsequent carbonization. The precursor for CHM, a thermosetting LFR, was crafted via polycondensation in an alkaline milieu. Precision-tuning of the spray drying parameters enabled the realization of LFR hollow microspheres, characterized by particle diameters spanning 3.37 μm–24.4 μm, and shell thickness between 0.25 μm and 4.0 μm. Adjusting the inlet temperature from 110 to 180 °C resulted in LFR hollow microspheres with varying bulk densities from 0.31 g/cm3 to 0.49 g/cm3. The microporous structure of the LFR-CHM shell exhibited a malleable specific area and pore dimensionality, intricately tethered to the carbonization thermal gradient. Furthermore, changes in crystallinity and chemical bonds of LFR-CHM were noted during carbonization process. Significantly, the residual weight of LFR-CHM reached 52 % after carbonization at 800 °C, underscoring the benefits of using thermosetting lignin-formaldehyde resin as a CHM precursor. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Mechanics is the property of Chinese Journal of Applied Mechanics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Borassus flabellifer (Palmyra) fruit fiber (PFF) was extracted and converted into biocarbon materials at different carbonization temperatures of 400°C, 600°C, and 800°C under N2 atmosphere for 1 h. The physicochemical properties of obtained biocarbon materials were investigated via CHNS, SEM‐EDX, FTIR, RAMAN, XRD, BET‐specific surface area, and TGA techniques. The obtained results were correlated with the capacitive energy storage application of biocarbon materials. The highest specific surface area of 46.36 m2 g−1 was observed for the biocarbon materials obtained at 800°C, which also showed superior capacitive performances. The specific capacitances of PFF‐derived biocarbon materials obtained at 400°C, 600°C, and 800°C are respectively found to be 28.58, 37.07, and 45.76 F g−1 at 1 A g−1 employing 1M KOH as electrolyte. The biocarbon materials obtained at 800°C showed the highest specific energy and power of 1.99 and 261 W kg−1 at 1 A g−1. [ABSTRACT FROM AUTHOR]

The Ecca equivalent coal deposits in the Morupule, Mmamabula, and Mabesekwa coalfields exist within the Kalahari Karoo Basin of the Karoo Super Group. Only the Morupule coal has proved its potential for power generation; while, the utilization value of the Mmamabula and Mabesekwa coals is yet to be determined. The current study presents petrographical characteristics of the three seams from each coalfield. Reflected light microscopy combined with scanning electron microscopy was used in the study. The analyses revealed that the Morupule and Mabesekwa coals are rich in inertinite; while, the Mmamabula coal is rich in vitrinite. The vitrinite reflectance indicates that the coal rank stretches between high volatile bituminous B and high volatile bituminous A. The compositions of macerals and coal facies indicate variations in the depositional conditions for the three studied coalfields. The Morupule and Mabesekwa coals were accumulated in a terrestrial bedmont dry forest swamp through fluvial vegetation transportation; while, the Mmamabula coal was deposited in a limnic upper plain wet forest swamp through alluvial vegetation transportation. Hydrological conditions were rheotrophic except in the Mmamabula South, which had ombrotrophic conditions. Based on petrographic compositions, coals from the Mmamabula East, Mmamabula South, Morupule East Main, Morupule West Main and Morupule South would be suitable for carbonization, gasification and liquefaction processes. However, several challenges with coals from the Mmamabula South, Mabesekwa Seam B, Mabesekwa Seam C and Mabesekwa Seam E would be encountered during carbonization, gasification and liquefaction due to high ash content and inert semifusinite content. [ABSTRACT FROM AUTHOR]

In recent years, magnesium slag has been used as a raw material for solid waste treatment using the carbonization method and has proven to be promising in reducing carbon emissions. In this study, the alkali activation reaction was introduced to promote the carbonization of magnesium slag. The resulting mechanical properties, microstructural attributes, and carbonization mechanism were studied by varying the sodium hydroxide content, temperature, and carbon dioxide concentration during the reaction process. The results showed that the amounts of calcium hydroxide, C-S-H, and calcium carbonate in the reaction products increased with the sodium hydroxide content, which enhanced the compressive strength of the composite. However, it does not influence the carbonization mechanism with the increasing reaction temperature, which only elevates the reaction rate. With the increase in the carbon dioxide concentration during alkali activation, the carbonization reaction is dominated by the amount of CO2 dissolved in the reaction medium, and the carbonization mechanism is changed. Thus, a significant decrease in the calcium hydroxide content and a sharp increase in the calcium carbonate content in the products occurred, which significantly improved the compressive strength of the resulting magnesium slag composite. Among them, the maximum compressive strength is 6.83 MPa. [ABSTRACT FROM AUTHOR]

This pioneering work explores the immense potential of young coconut waste, a continuously marginalized residue of the food and beverage industry, to serve as an indispensable feedstock in the production of biochar. Through an examination of the key carbonization factors that include time, temperature, and concentrations of the activating agent, KOH, the outcomes offer relevant insights that could be leveraged to maximize biochar production for tailored applications. This study stands out for its innovative use of Artificial Neural Network (ANN) approaches for predictive modeling. Fifty datasets, supplemented with secondary data obtained from the literature and experiments, were utilized for the purposes of training, testing, and validating the neural network model. Here, the datasets were processed utilizing the Deep Neural Network (DNN) framework, which was designed and implemented with the minimal loss function framework feasible. The architectural configuration comprises the following; an input layer, four hidden layers (128-neuron dense layer, batch normalization, and 64-neuron dense layer, batch normalization), a dropout layer, and an output layer. With an R2 of 0.8238 for biochar yield and 0.7324 for iodine number, the trained DNN model showed a relatively high degree of accuracy in making predictions. [ABSTRACT FROM AUTHOR]

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Because direct carbonation of asphalt usually yields ordered graphite structure with unfavorable storage of sodium. Here, the asphalt preoxidation at a specific temperature in the air introduces oxygen‐containing groups to connect the unsaturated aliphatic hydrocarbon and aromatic side chains, forming a disordered carbon skeleton to inhibit melting and rearrangement during carbonization. The abundant oxygen‐containing groups hinder the growth of the carbon layers during pyrolysis, which promotes the formation of disordered phases and abundant micropores in asphalt‐based hard carbons (HCs). The simultaneous increase in initial coulombic efficiency, capacity, and transport behavior of sodium ions in HCs is achieved by adjusting the carbon layer and micropore evolution. The optimized HCs display excellent initial coulombic efficiency of 86.14% with remarkable reversible capacity of 313.83 mAh g−1 at 0.1 C and high‐rate capability with 140 mAh g−1 at 5 C. Pairing with O3‐NaNi1/3Fe1/3Mn1/3O2 cathode, the full cell delivers a higher reversible capacity of 255.7 mAh g−1 with an initial coulombic efficiency of 83.7% and long cycle life. Based on the microstructure and electrochemical behaviors of asphalt‐based HCs, the “adsorption‐insertion‐pores‐filling” sodium storage mechanism is proposed, providing guidelines for designing high‐energy‐density sodium‐ion batteries. [ABSTRACT FROM AUTHOR]

The poor interfacial stability and undesirable cycling performance caused by their dramatic volume change hinder the large-scale commercial application of SiOx materials for high-energy-density lithium-ion batteries. Herein, a simple two-step carbonization process is employed to prepare highly pyrrolic-nitrogen-doped carbon modified SiOx anode materials (SiOx@NC). The designed SiOx@NC materials exhibit high electron conductivity and favorable electrochemical kinetics. As expected, the SiOx@NC electrode delivers a high specific capacity of 1003.46 mA h g−1 after 200 cycles at 500 mA g−1. The NCM622‖‖SiOx@NC full cell also demonstrates excellent cycling stability and rate performance. [ABSTRACT FROM AUTHOR]

Hard carbon (HC) has been widely regarded as the most promising anode material for sodium‐ion batteries (SIBs) due to its decent capacity and low cost. However, the poor initial Coulombic efficiency (ICE) of HC seriously hinders its practical application in SIBs. Herein, pyridinic N‐doped hard carbon polyhedra with easily accessible carbonyl groups and in situ coupled carbon nanotubes are rationally synthesized via a facile pretreated zeolitic imidazolate framework (ZIFs)‐carbonization strategy. The comprehensive ex/in situ techniques combined with theoretical calculations reveal that the synergy of pyridinic‐N and carbonyl groups promoted by the pretreatment and carbonization process would not only optimize the Na+ adsorption energy but also accelerate the desorption of Na+, significantly suppressing the irreversible capacity loss. As a result, the as‐synthesized hard carbon polyhedra as an anode can deliver an unprecedented high ICE of 98% with a large reversible capacity of 389.4 mAh g−1 at 0.03 A g−1. This work may provide an effective strategy for the structural design of HC with high ICE. [ABSTRACT FROM AUTHOR]

The closed pores play a critical role in improving the sodium storage capacity of hard carbon (HC) anode, however, their formation mechanism as well as the efficient modulation strategy at molecular level in the polymer‐derived HCs is still lacking. In this work, the steric hindrance effect has been proposed to create closed pores in the polymer‐derived HCs for the first time through grafting the aromatic rings within and between the main chains in the precursor. The experimental data and theoretical calculation demonstrate that steric‐hindrance effect from the aromatic ring side group can increase backbone rigidity and the internal free volumes in the polymer precursor, which can prevent the over graphitization and facilitate the formation of closed pores during the carbonization process. As a result, the as‐prepared HC anode exhibits a remarkably enhanced discharge capacity of 340.3 mAh/g at 0.1 C, improved rate performance (210.7 mAh/g at 5 C) as well as boosted cycling stability (86.4 % over 1000 cycles at 2 C). This work provides a new insight into the formation mechanisms of closed pores via steric hindrance engineering, which can shed light on the development of high‐performance polymer‐derived HC anode for sodium‐ion batteries. [ABSTRACT FROM AUTHOR]

This review analyzes in detail the topic of supercapacitors based on biochar technologies, including their advantages, disadvantages, and development potential. The main topic is the formation of precursors in the process of pyrolysis and activation, and the possibility of the application of biochar itself in various fields is brought closer. The structure, division, and principle of operation of supercondensates are discussed, where their good and bad sides are pointed out. The current state of the scientific and legal knowledge on the topic of biocarbon and its applications is verified, and the results of many authors are compared to examine the current level of the research on supercapacitors based on biochar electrodes created from lignocellulosic biomass. Current application sites for supercapacitors in transportation, electronics, and power generation (conventional and unconventional) are also examined, as is the potential for further development of the technology under discussion. [ABSTRACT FROM AUTHOR]

Carbon foams (CFs), which can be manufactured from melamine foam (MF) via direct carbonization, are promising spacecraft thermal insulation material due to their excellent performance of sound absorption, low density, high porosity and heat resistance. Carbonization temperature, heating rate and carbonization time are three key elements during the melamine carbon foam process. As an improvement, this study simultaneously researches the impacts of pre-heat treatment on the microstructure, structure parameter, mechanical properties and heat-shielding performance of the melamine-derived carbon foam (MDCF), aiming to explore the best process of MDCF production. The results showed that the cross-linking degree and defects of MF samples were directly improved by pre-heat treatment. Additionally, all MDCF samples retained the three-dimensional mesh open-cell skeleton structure. The MDCF samples obtained by carbonization at 900 °C had the smallest average pore size structure, which performed the compressive stress of 16.8 kPa at 10 % strain and lowest thermal conductivity of 0.0252 W m−1 K−1. To further study the mechanical property and thermal conductivity performance of MDCF samples, the mechanics relationships of the buckling strength and shape variables, as well as thermal conductivity and pore size structure were researched. [ABSTRACT FROM AUTHOR]

The fast developing world is in search of measures to control the accumulation of unused by‐products and waste materials generated during the production of useful commodities. Accordingly, wastes from agro‐industrial sectors can form raw materials for the production of various resources that are extensively used in many areas such as gas sorption and energy production. In the present work, cashew nut shell liquid (CNSL), the vesicant liquid present in the outer shell of cashew seed, forms the source material for the synthesis of porous organic polymers for carbon dioxide capture. Herein, novel types of hypercrosslinked polymers (HCPs) are synthesized via a simple Friedel–Crafts reaction with CNSL as the starting material. Polymerization of natural CNSL with dimethoxymethane/bis‐(chloromethyl)‐biphenyl as external crosslinker provides products in quantitative yield. One of the synthesized HCP is tuned to attain the required high porosity by carbonization at elevated temperatures using an activator. Thus, activated carbon material prepared at 700°C is found to have a high surface area of 880 m2/g with a good carbon dioxide adsorption capacity of 14.72 wt%. These porous materials had moderate isosteric heat of adsorption (23–31 kJ/mol) with excellent recycling capability. [ABSTRACT FROM AUTHOR]

This paper proposes a mechanical dispersion method of hydrated lime in a vibrating activator equipped with special blades that operate in a resonant mode. It has been found that during the vibro-activation process, hydrated lime consistently passes through proportionately increasing stages of dynamic viscosity, slowing its growth and ceasing dispersion. A new vibration method for determining the viscosity of the hydrated lime-water system has been developed. The effect of vibration treatment on changes in the dispersion of calcium hydroxide was studied. It has been found that vibration-treated lime, compared to conventional hydrated lime, has new properties: the ability to form durable coatings due to accelerated carbonization. [ABSTRACT FROM AUTHOR]

An effective oil separating technique from water-oil mixture can be used in various industrial fields such as environmental purification and resource recycling. In this study, a vitreous carbon (VC) grid structure was fabricated by carbonization of digital light processing (DLP) 3D (3-dimensional) printed parts, and its oil separation performance was evaluated. A planner DVC grid structure with pore sizes of ∼200, ∼430 and ∼520 µm was fabricated and its water-oil separation performance werewas evaluated. Despite theoretical calculations suggesting adequate water repelling pressures for pores around ∼300 and ∼360 µm, actual performance fell short due to defects from 3D printing and carbonization processes. A more robust design approach involves fabricating a cuboid shell-shaped VC grid structure with smaller pores (∼150 µm), demonstrating continuous water-oil separation capabilities. [ABSTRACT FROM AUTHOR]

The anatomical description of wood and charcoal for a wide variety of purposes is an essential tool for compiling databases to correctly identify species. This study describes and compares the anatomy of the wood and charcoal of Manilkara sp., collected in a protected area in the Pará state, Brazil. The qualitative anatomical characteristics of the wood, such as diffuse-porosity; vessels in radial multiples; alternate intervessel pits; axial parenchyma in lines or reticulate; rays uniseriate or biseriate, not storied, are corroborated in the literature. Moreover, this work reports the presence of helical thickenings in the vessel elements and possible helical thickenings in fibres in Manilkara. After the carbonization process, there were morphometric changes in the anatomical elements, as an increase in vessel frequency between 23 % and 141 %, and in ray frequency between 2.8 % and 12.9 %; while ray height decreased and ray width increased. Overall, some anatomical variations could be related to, or a result of the interaction between species plasticity, genetics, age and environmental factors. These characteristics enabled the identification of the samples at the genus level and the anatomical description of the wood and charcoal can be useful for forest inspections. [ABSTRACT FROM AUTHOR]

The study involved single-stage carbonization and physical activation of Kevlar woven fabric to convert into activated carbon fabric. The carbonization process was optimised for high carbon yield and low electrical resistivity of activated carbon fabric using Box-Behnken experimental design and response surface methodology. The three process parameters namely charcoal amount, gas flow rate, and carbonization temperature were selected. The empirical equations obtained through response surface methodology for carbon yield and electrical resistivity were found in good agreement with the experimental values. An optimum amount of charcoal, optimum nitrogen flowrate, and low carbonization temperature was found suitable for higher carbon yield. On the other hand, high charcoal amount, high carbonization temperature, and optimum nitrogen flow rate resulted in low electrical resistivity of activated carbon fabric. Later, the activated carbon fabrics were prepared under the optimum carbonization conditions to get high carbon yield and low electrical resistivity. The optimized sample for electrical resistivity showed higher electromagnetic interference (EMI) shielding properties at lower as well as higher frequencies due to its highly porous morphology and electrical conductivity. [ABSTRACT FROM AUTHOR]

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In the present study, XRD, SEM/EDS, Raman, EMR/EPR spectroscopy, and vibrating sample magnetometry (VSM) were used to analyze the reduction of hematite by the carbonization products of waste activated sludge (WAS) at 500–1000 °C. The reduction process includes the following steps: α-Fe2O3 → Fe2O3 + Fe3O4 (Ttr~500 °C) → Fe3O4 (Ttr~600–700 °C) → FeO → Feamorph. (Ttr~1000 °C). The prevalence of certain phase compositions at different hematite reduction temperatures makes it possible to predict the areas viable for the application of reduced oxides: adsorbents (after Ttr~500 °C) → soft ferromagnetic materials (after Ttr~600–700 °C) → electrically engineered amorphous iron (after Ttr~1000 °C). [ABSTRACT FROM AUTHOR]

Carbonization is a promising method of carbon fixation, but there has been little research on municipal solid waste (MSW) carbonization as a carbon capture, use, and storage technology. We focused on biomass- and fossil-derived carbon in samples produced at the Saikai City Carbonization Center and evaluated carbon fixation through the MSW carbonization process. We found that the total C content of carbonized fuels is approximately 50%, with fossil C accounting for 9.1–14.4%. Fossil carbon in MSW was considered to be derived mainly from polyethylene and polyamide (nylon 6–6). In terms of the carbon mass balance, negative emissions of 71,300–108,000 kg-CO2/month can be achieved from carbonized fuels that are not burned, such as soil amendments, compared to the case wherein all carbon in MSW is released into the atmosphere. The fossil C content of carbonized fuels is affected by the composition of the input MSW, while the influences of waste quality, desalination time, and pyrolysis temperature changes of several tens of degrees Celsius are small. Landfill disposal of carbonized fuels is limited by the capacity of the final disposal sites. The consumption of this capacity can be reduced through the use of carbonized fuels as a soil amendment. [ABSTRACT FROM AUTHOR]

The production of heterogeneous solid waste, such as municipal solid waste (MSW), construction and demolition waste (CDW), and industrial solid waste (ISW), has increased dramatically in recent decades, and its management is one of today's biggest concerns. Using waste as a resource to produce value-added materials such as char is one of the most promising strategies for successful and sustainable waste management. Virtually any type of waste, through various thermochemical technologies, including torrefaction, pyrolysis, hydrothermal carbonization, and gasification, can produce char with potential material and energy applications. Pyrolysis is the most widespread technology, and there are more studies on producing and applying waste-derived char using this technology. The properties of waste-derived char seem to be influenced by the conversion technology and conditions, as well as by the composition of the source waste. A literature search indicated that the properties of waste-derived char are highly variable with the composition of the raw material, with carbon content in the range 8–77%, a higher heating value of 2.5–28.4 MJ/kg and a specific surface area of 0.7–12 m2/g. Depending on the properties of char derived from waste, there are greater or minor difficulties in applying it, with ash content, heavy metals, and polycyclic aromatic hydrocarbon (PAH) concentrations being some of its limiting properties. Therefore, this review attempts to compile relevant knowledge on the production of waste-derived char, focusing on heterogeneous solid waste, applied technologies, and practical application routes in the real world to create a supply chain, marketing, and use of waste-derived char. Some challenges and prospects for waste-derived char are also highlighted in this study. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the potential implementation of the ISO 50001 Energy Management System (EnMS) at PT XYZ to achieve the decarbonization target. The focus is on strategic and technical planning, involving the analysis of internal and external issues to develop energy policies as well as the formation of energy teams. Technical planning includes energy performance reviews, energy consumption analysis, Significant Energy Users (SEUs), Energy Performance Indicators (EnPI), and operation control plans. The results of the 2022 review show that energy consumption is 947.8 thousand GJ with the main SEU in the Hauling and Mining systems, as well as Hauler and Excavator tools that consume more than 80% of Biosolar B30. EnPI level 1 shows an average energy intensity of 0.08 GJ per WMT, while EnPI level 2 results in a regression of Y=2.113X + 264924 with a determination of 0.892, making 2022 a baseline. The implementation of ISO 50001 has the potential to improve energy efficiency and reduce GHG emissions by up to 30% by 2030, with a target of saving 9.7 million liters of Biodiesel B30. The PDCA approach helps companies achieve targets by focusing on SEU systems and tools. [ABSTRACT FROM AUTHOR]

Copyright of Chemical Engineering (China) / Huaxue Gongcheng is the property of Hualu Engineering Science & Technology Co Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the present study, XRD, SEM/EDS, Raman, EMR/EPR spectroscopy, and vibrating sample magnetometry (VSM) were used to analyze the reduction of hematite by the carbonization products of waste activated sludge (WAS) at 500–1000 °C. The reduction process includes the following steps: α-Fe2O3 → Fe2O3 + Fe3O4 (Ttr~500 °C) → Fe3O4 (Ttr~600–700 °C) → FeO → Feamorph. (Ttr~1000 °C). The prevalence of certain phase compositions at different hematite reduction temperatures makes it possible to predict the areas viable for the application of reduced oxides: adsorbents (after Ttr~500 °C) → soft ferromagnetic materials (after Ttr~600–700 °C) → electrically engineered amorphous iron (after Ttr~1000 °C).