High Carbon Content Research Articles

The Effect of Palm Char Properties on Malaysian Ilmenite Ores by Carbothermal Reduction

To identify the mineral grade ore, two distinct Malaysian ilmenite ores (FeTiO3) from different placers deposits were examined. The sources of ilmenite ore were the Kinta Valley in Perak and the Langkawi Black Sand Beach in Kedah. Both of the ores were reduced by palm char as a sustainable carbon reductant. The study examined carbon characteristics and phase transitions following carbothermal reduction at 1550°C. Prior to the studies, the reductant palm char was characterized by XRF, BET surface area measurement, SEM, and ultimate with proximate analyses. It is shown that the palm char had low moisture (4.10 wt.%) and high fixed carbon (75.40 wt.%). The high carbon content, volatile matter, and porous structure of palm char played a significant role in the gas generated during the carbothermal reduction of ilmenite ores. Carbothermal reduction of both ilmenite ores with palm char-produced rutile, iron, titanium carbide, and pseudobrookite. The XRF analysis exhibits the existence of 18.41 and 35.76 wt.% of Fe and TiO2 respectively in Perak ilmenite ore. While Langkawi ilmenite ore shows 9.28 and 22.72 wt.% of Fe and TiO2 respectively.

A Comparative Account of the Sugarcane Bagasse and Rice Husk Biochar on the Physicochemical and Biological Properties of Soils from Heterogeneous Agroecosystems

ABSTRACT Biochar optimal use reduces agricultural waste and promotes sustainability in farming systems. Its production and characterization are crucial for carbon sequestration in agroecosystems. The present study elucidated the properties of Sugarcane Bagasse Biochar (SBB) and Rice Husk Biochar (RHB), synthesized under varying experimental conditions, and revealed that a pyrolytic temperature of 400°C and a duration of 90 min was optimum for the production of both biochars in terms of pH, electrical conductivity, total dissolved solids, total organic carbon, cation exchange capacity, and water holding capacity. The effect of varying concentrations of SBB and RHB (0.5%, 1%, and 1.5%) in response to control on the physicochemical and biological properties of soils revealed that 1.5% SBB had a significant increase in the soil pH and conductivity. Application of SBB increased the soil organic carbon due to its higher carbon content (64.24%) than RHB (46.04%). Also, the water-holding capacity of heterogeneous soil samples was higher with the SBB application of 1.5%. The THB was positively and significantly correlated with pH (r = 0.50, p < .05), EC (r = 0.60, p < .01), TDS (r = 0.48, p < .05), SOM (r = 0.55, p < .01), moisture content (r = 0.63, p < .01) and WHC (r = 0.90, p < .01) but negatively correlated with THF (r = -0.84, p < .01). At the same pyrolytic temperature, SBB had the highest surface area (266.51 m2/g) and pore volume (0.195 cm3/g) than RHB (39.06 m2/g and 0.095 cm3/g respectively). It is concluded that the application of SBB at 1.5% level can successfully improve the soil properties, thereby aiding in carbon sequestration.

Life Cycle Assessment of Torrefied Residual Biomass Co-Firing in Coal-Fired Power Plants: Aspects of Carbon Dioxide Emission

This study investigates the carbon dioxide (CO2) emission characteristics of using torrefied biomass (residual wood and wood chip) as co-firing materials in coal-fired power plants, based on life cycle assessment techniques. We quantify the greenhouse gas (GHG) mitigation potential of substituting coal with biomass under different torrefaction temperatures, biomass types, and co-firing ratios. Results indicate that higher co-firing ratios significantly reduce CO2 emissions. Torrefaction at 270 °C was identified as optimal, balancing high energy yield and minimized emissions, while 310 °C torrefaction showed limited mitigation benefits due to lower mass yields and higher carbon content. Pelletization and torrefaction enhanced biomass properties, but the energy intensity of these processes affected the overall emission balance. This study underscores the potential of biomass to replace imported coal and contribute to carbon neutrality, while highlighting the importance of optimizing biomass processing conditions. Future work should focus on refining torrefaction parameters and assessing other biomass characteristics to enhance operational efficiency in coal-fired power plants.

Enhancing photosynthetic efficiency in Phalaenopsis amabilis through bioreactor innovations

BackgroundMicro-propagation is the primary technique for the mass propagation of greenhouse orchids. However, various factors, including culture media and cultivation systems, influence the scaling-up and efficient commercialization of in vitro techniques. The utilization of liquid cultivation systems and bioreactors are relatively cost-effective and has attracted significant attention for mass production. In this study, we evaluated the effects of eight culture media, in both semi-solid and liquid forms, on the growth of in vitro mini-plantlets of Phalaenopsis orchids. We subsequently assessed the performance of four selected media: half-strength modified Murashige and Skoog (1/2 MMS), modified FAST (MFAST), and two simplified media (SM1 and SM2), across four types of cultivation systems, including semi-solid media in glass jars, liquid media in a permanent immersion system using Erlenmeyer flasks on a shaker (PIS), and a temporary immersion system (TIS) in two forms: FA-Bio bioreactor (TIS-FA-Bio) and RITA® bioreactor (TIS-RITA®).ResultsThe results indicated that the optimal culture medium for orchid growth depends on the cultivation system used. Among the eight evaluated semi-solid and liquid media, the highest plant growth was observed in the SM2 medium, attributed to the presence of additives (banana powder and activated charcoal), two types of sugar (with high carbon content), and small amounts of nickel and ascorbic acid. The high carbon content in the SM2 liquid medium, combined with the temporary immersion explants in a large volume of medium in the TIS-RITA®, resulted in the highest total carbohydrate content and enhanced plant growth. The maximum quantum efficiency of photosystem II (Fv/Fm) and the number of plantlets per liter in SM2 semi-solid medium were higher than those in the 1/2 MMS semi-solid medium (control), leading to a 61.6% reduction in production costs. Furthermore, the number of plantlets per liter in the TIS-FA-Bio containing SM2 (10.8 USD) was higher than in TIS-RITA® with 1/2 MMS (39.3 USD), resulting in a 72.5% decrease in production costs due to a lower volume of medium and the use of inexpensive equipment.ConclusionsWe recommend the use of SM2 in TIS-FA-Bio and TIS-RITA® for economical and efficient mass propagation of Phalaenopsis orchid.

Characteristics and main controlling factors for the development of shale micro pore-fracture in Tiemulike Formation, Yining Basin

Research on the type, size, structure, and other characteristics of shale micro pore-fracture and their genesis is one of the core index for Shale gas study. Based on systematically collected shale samples from outcrop profiles and well cores, the experiments of thin-section observation, scanning electron microscopy, energy-dispersive X-ray spectroscopy, whole-rock analysis, rock–eval pyrolysis and basin simulation analysis were performed to study the micro pore-fracture characteristics and its main controlling factors for the development of shale pores in Tiemulike Formation in Yining Basin. The results show that four types of micro pore-fractures were identified: organic hydrocarbon-generating micro pores, granular dissolved micro pores, intergranular micro pores, and micro-fracture. The development of micro pores in shales is influenced by the internal material composition of the shale reservoir and external temperature conditions. The high organic carbon content with a high degree of thermal evolution led to the development of numerous micro pores, and the main micro pores were produced by shrinking the hydrocarbon generation volume due to the thermal evolution of organic matter. The development of micro-fractures was found to be favoured by the high content of brittle minerals and overpressure in the formation.

Review of &lt;i&gt;Siddha&lt;/i&gt; Marine Drug - &lt;i&gt;Muthuchippi&lt;/i&gt; (Pearl Oyster Shell) for Various Medicinal Properties

The Siddha system of medicine uses an opulent source of plants, metals, minerals, and marine and animal products for the preparation of medicine. The pearl oyster shell is a bivalve mollusc that lives in fresh and saltwater and generates pearls. The three major structural components of pearls are oblong, conchiolin, and calcium carbonate (CaCO3). Recently, interest in developing medications from marine materials has surged. In the fields of cancer, pain, and inflammation, many marine natural compounds are presently undergoing clinical trials. Pearl oyster shell, also known as Muthuchippi, is a key sea-derived medicine in the Siddha system of medicine. These shells include iron oxide, alumina, silica, calcium carbonate, phosphate, and sulfate of calcium and magnesium. Since it has been specially recommended to improve the strength, nutrition, and vitality of weak patients as well as for palpitations, digestion, heart tonic, and appetizer, pearl oysters are important in Siddha medicine. Traditionally, the calcined pearl oyster shell has been used to treat musculoskeletal diseases, anorectal diseases, respiratory diseases, and gastrointestinal diseases due to their high calcium carbonate content. This study aims to review several papers on the therapeutic potential of pearl oyster shells in treating various ailments. A comprehensive search of multiple databases, including PubMed and Google Scholar, yielded several papers for evaluation. According to this study, pearl oyster shells are utilized to cure a wide range of illnesses in all traditional Indian medical systems. Yet, there is scanty scientific data to support the efficacy of numerous indications. To substantiate this significant drug in the research forum, additional in-vitro and in-vivo studies must be carried out.

Effect of C–S–H seeds on the hydration reaction of Portland cement matrices blended with a high-carbon content rice husk ash

Effect of C–S–H seeds on the hydration reaction of Portland cement matrices blended with a high-carbon content rice husk ash

Preparation of rosin epoxy soybean oil acrylate with high bio-renewable carbon content for 3D printing

A kind of rosin epoxy soybean oil acrylate (RBAESO) containing high bio-renewable carbon content was synthesized by using rosin and acrylic acid (AA) to react with epoxidized soybean oil (ESO), and the effects of rosin addition amount on the properties of RBAESO resin and its cured film were investigated. The reaction activity between carboxylic acid and the epoxy group was found improved by introducing natural rosin to replace part of AA and increasing the C=C double bond density of the molecular structure. The best prepolymer resin RBAESO-15% performance was obtained with a reaction molar ratio of ESO: AA: Rosin = 1.05:0.85: 0.15. RBAESO-15% has a viscosity of 16500 mPa·s. The cured film of RBAESO-15% displayed high pencil hardness up to H, and 2mm of flexibility. The introduction of rosin also increased the high bio-renewable carbon content of the resin from 80.3% to 89.6% compared to epoxy soybean oil acrylate (AESO). UV cured tested show the C=C double-bond conversion of RBAESO-15% is about 86.4%, which is higher than that of AESO, and the tensile strength and elongation at break increased from 3.2MPa and 7.4% to 14.4MPa and 12.1%, respectively. This indicates that RBAESO displays better coating film performance than those of AESO. In addition, RBAESO-15% with 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO) can be applied to the laser cladding deposition (LCD) 3D printers.

Waste management of straw to manufacture biochar: An alternative reinforcing filler for natural rubber biocomposites

To achieve climate neutrality, alternative processes and materials should be proposed to replace those currently in use, which excessively burden the environment. Fossil fuels are non-renewable, and their resources are slowly being depleted, leading to increased prices.The aim of this work was to determine the potential of using agro-industrial residues in the form of oat straw for the production of biochar and its utilization as a filler in natural rubber biocomposites. The process of pyrolysis of plant material was used to obtain biochar with a high carbon content and a characteristic structure, which can affect selected rubber properties. The influence of the applied temperature of the pyrolysis process on the properties of the filler was determined. In this work, analysis techniques were used to enable the evaluation of both filler activity and specific properties of the final vulcanizates. The course of straw pyrolysis process, the carbon content in the fillers, and the size distribution of the bio-additive were examined. The structural, morphological, dispersion, processing, and functional properties of the compositions were examined. The reference in assessing the impact of the produced bio-additive on the properties of the product were composites filled with a commercial carbon black.The conducted research proved that the pyrolysis of straw at a temperature of 600°C was as effective as that carried out at a higher temperature, with comparable weight loss for both samples. The increase in torque was the highest in the case of biochar samples (torque gain 4,4-6,5 dNm), indicating greater intensity of the cross-linking process after the use of this type of additive. This was also confirmed by differential scanning calorimetry. Moreover, the obtained biocomposites were characterized by much higher strength parameters (tensile strength 18,3-21,3MPa) than conventional composites. Unfortunately, vulcanizates containing biochar as a filler exhibited poor resistance to thermo-oxidative aging (aging factor 0,24-0,54).

Waste wood tar based porous carbon electrodes for supercapacitors with excellent performances through condensation cross-linking modification

Wood tar is an unavoidable by-product during a slow-pyrolysis process of biomass, which is usually discarded as a waste and results in environment pollution. Recently, wood tar has been used as a starting material for carbon electrodes because of its thermoplasticity and high carbon content. However, wood tar is mainly composed of various light phenolic molecules, which usually leads to a low carbonization yield after carbonization and an inferior electrochemical performance after activation. In this work, in order to improve the carbonization rate and electrochemical performance of these materials, wood tar was first condensed and crosslinked with formaldehyde and urea via a condensation reaction to produce condensed macromolecular resins, which were then carbonized at 550°C and activated with KOH at 800°C to prepare high-performance nitrogen-doped carbon electrodes for supercapacitors. The samples possess high carbonization yield, large specific surface area (3515.1 m2g-1) and moderate nitrogen content (1.11%). The high-performance carbon electrodes fabricated by this method achieves a high capacitance of 437.8Fg-1 (6M KOH electrolyte) at 1A/g-1. The assembled supercapacitor has an energy density of 13.41Whkg-1 at a power density of 124.93Wkg-1. And the capacitance retention was essentially 100% after 10000 cycles at 5Ag-1. The study presents an innovative strategy for the production of porous carbon for supercapacitors using wood tar and improves carbonization yield via condensation cross-linking modification.

Production and ecological function of fucoidans from marine algae in a changing ocean.

Fucoidans have multiple biological and biomedical functions, e.g., antibacterial, antiviral, immunomodulatory, inflammatory, and growth-promoting effects. Recent studies show that they also have essential ecological functions whereas our understanding in this field is very superficial. This study first reviewed the fucoidans content in algae and the highest content of 13.3 % in Undaria pinnatifida sporophyll and the lowest content of 0.1 % in Alaria angusta were found. Field investigation demonstrates that light, temperature, salinity, and nutrient can affect fucoidan production in algae; while more laboratory experiments need to be carried out to verify these conclusions. Brown algae can excrete 8-31 % of their net carbon fixation into seawater in the form of fucoidans. Fucoidans are highly recalcitrant to bacterial degradation and thus the carbon in fucoidans can be stored for centuries. Therefore, fucoidans can play an essential role in carbon sequestration. Ocean afforestation with brown algae may be an effective approach to remove atmospheric CO2 since fucoidans have a high carbon content while seldom need any nitrogen or phosphorus. Fucoidans production in a warming and CO2 enriched ocean was also discussed. This study provides new insight into production and ecological functions of fucoidans, indicating their role in carbon sequestration and climate change alleviation.

Characterization and Sustainable Applications of Galinsoga parviflora Natural Fibers: A Pathway to Eco-Friendly Material Development

This study investigates the potential of natural fibers extracted from Galinsoga parviflora as sustainable alternatives to synthetic materials, addressing the increasing demand for eco-friendly and biodegradable options in material science. The main objectives were to evaluate the structural, mechanical, and biological properties of these fibers, focusing on their applicability in structural composites. Driven by environmental sustainability, we performed a range of analyses including X-ray Diffraction (XRD) to determine crystallinity and cellulose structure, Fourier-Transform Infrared Spectroscopy (FTIR) to identify functional groups related to biodegradability, and Scanning Electron Microscopy (SEM) to examine surface morphology and fiber dimensions. Key findings include a crystallinity index of 36.3% with cellulose I dominance, a tensile strength of 17.92 MPa, and a modulus of 11.3 GPa, indicating the fibers’ potential for structural applications. Elemental analysis using Energy-Dispersive X-ray Spectroscopy (EDX) revealed a high carbon content (53.0%) and oxygen content (41.3%), along with trace elements that may enhance interaction in polymer matrices. Antibacterial testing demonstrated effective inhibition of Staphylococcus aureus biofilms, with inhibition zones reaching up to 19 mm, comparable to streptomycin. Confocal Laser Scanning Microscopy (CLSM) further confirmed the fibers' biofilm disruption capabilities.Overall, the results highlight that G. parviflora fibers show significant promise as bio-based alternatives for sustainable material development, offering both mechanical strength and biological functionality for future eco-friendly technologies.

Influence of heat treatment time on microstructure evolution of austempered nodular cast iron evaluated by image segmentation

This study aimed to investigate the microstructural characteristics of a pearlitic austempered nodular cast iron (ADI) prepared with different austempering times. In austempering of ductile irons, the material is austenitiezed and rapidly cooled to temperatures typically between 420 and 290°C in a salt bath to allow the formation of a microstructure composed of graphite nodules dispersed in a residual austenitic matrix, stabilized with a high carbon content, and acicular ferrite, known as “ausferrite”. Presently, microstructure characterization by optical and scanning electron microscopy were carried out after different austempering times. Neural network image segmentation using ImageJ® software was employed to perform quantitative phase analysis, and the results were compared with volume fractions obtained by XRD measurements, one of the traditional methods for determining the residual austenite content in ferrous alloys. It was found that both carbon content in austenite and austenite fraction increase with austempering time and that graphite nodule geometry becomes gradually more irregular. The proposed methodology for quantitative analysis allowed classification of microstructure constituents with high accuracy in comparison to the XRD results.

Environmental degradation and recovery after termination of whaling in sub-Antarctic fjord, South Georgia

Polar ecosystems are considered very fragile, however, due to the short observation record it is hard to assess the recovery processes of the coastal and fjord environments after a major disturbance. Here, we provide a unique case study from South Georgia (sub-Antarctic), an area seriously affected by the whaling industry. The study focuses on King Edward Cove, serving as a sheltered harbor for the former whaling station at Grytviken, as well as other parts of Cumberland Bay considered to represent generally pristine areas. We studied 210Pb dated sediment cores, which were subjected to analysis of sediment geochemical composition, concentrations of anthropogenic organic markers and biomarkers, foraminiferal assemblage changes, as well as sedimentary ancient DNA. Three distinct phases have been identified. The oldest one, predating ca. 1970, recorded the whaling period, and was characterized by anoxic conditions, high organic carbon content, contamination with heavy metals, organic markers, distinct DNA signature and lack of foraminiferal microfossils. It took only a few years to establish a new ecosystem with a fully developed foraminiferal assemblage and decreased contamination characteristic for the middle phase (ca. 1970–2000). Ancient DNA suggests macro-zoobenthic recovery being delayed by a several years in comparison to benthic foraminifera. In the youngest period, around Cumberland Bay, the increase of iceberg rafted debris from rapidly retreating tidewater glaciers was noted, while the improved oxygen availability in bottom waters in King Edward Cove can be likely ascribed to frequent water mixing due to increasing traffic of large cruise vessels. The recorded pace of ecosystem recovery from major anthropogenic disturbance appears similar to that observed in the temperate fjords from the Northern Hemisphere, however, the effects of new anthropogenic threat and the ongoing climate change are already resulting in the new ecosystem disturbance.

Supercapacitor performance evaluation with changes of microstructure in carbon electrode from perylene diimide derivative

Structural regulation of carbon electrode materials is an effective route to reinforce the performance of supercapacitors. Due to its high carbon content and easy gelation, perylene diimide derivative (PDI-d) is a good precursor for preparation of microstructure-controlled carbons. Here, PDI-d is synthesized and its gels are prepared under the action of glucono delta lactone (GDL). The PDI-d gels are subjected to freezing in liquid nitrogen or refrigerator, freeze-drying, carbonization for harvest of derived carbons with different structures and element doping. The derived carbons through liquid nitrogen freezing present fiber-woven three-dimensional connected porous structures, while those subjected to freezing in refrigerators are lamellar structures. N and Sn can be doped in the carbons using triethylamine (TEA) and K2SnO3·3H2O as solvents for PDI-d dissolution, respectively. The carbons with connected pores show higher specific surface area (454 m2 g−1), and better electrochemical performance than the carbons with lamellar structures. The optimum specific capacitance (200.1 F g−1) can be acquired in 3D porous carbons. The incorporation of N and Sn can further optimize the electrochemical performance. Specially, the Sn-doped porous structure derived carbon achieves a large energy density (27.79 Wh kg−1) and keeps good cycle stability (94.7 % after 10,000 cycles).

The Pyrolysis of Biosolids in a Novel Closed Coupled Pyrolysis and Gasification Technology: Pilot Plant Trials, Aspen Plus Modelling, and a Techno-Economic Analysis

Pyrolysis is gaining recognition as a sustainable solution for biosolid management, though scaling it commercially presents challenges. To address this, RMIT developed a novel integrated pyrolysis and gasification technology called PYROCO™, which was successfully tested in pilot-scale trials. This study introduces PYROCO™ and its application to produce biochar, highlighting the biochar properties of the results of the initial trials. In addition, an energy analysis using semi-empirical Aspen Plus modelling, paired with a preliminary techno-economic assessment, was carried out to evaluate the feasibility of this technology. The results show that the PYROCO™ pilot plant produced biochar with a ~30 wt% yield, featuring beneficial agronomic properties such as high organic carbon (210–220 g/kg) and nutrient contents (total P: 36–42 g/kg and total N: 16–18 g/kg). The system also effectively removed contaminants such as PFASs, PAHs, pharmaceuticals, and microplastics from the biochar and scrubber water and stack gas emissions. An energy analysis and Aspen Plus modelling showed that a commercial-scale PYROCO™ plant could operate energy self-sufficiently with biosolids containing &gt;30% solids and with a minimum calorific value of 11 MJ/kg. The process generates excess energy for drying biosolids and for electricity generation. Profitability is sensitive to biochar price; prices rise from AUD 300 to AUD 1000 per tonne, the NPV improves from AUD 0.24 million to AUD 4.31 million, and the payback period shortens from 26 to 12 years. The low NPV and high payback period reflect the use of a relatively high discount rate of 8%, chosen to be on the conservative side given the novel nature of the technology.

Neolithic formation of chernozem in south-eastern Germany?

The polygenetic development and age of black soils and Chernozems in Central Europe are widely discussed. The development and age of these soils in Germany is still not fully understood. While a significant share of Chernozems in Central Germany is assumed to have formed naturally during the early Holocene, such a natural formation can be excluded for all of southern Germany for paleoclimatic and –vegetative reasons. Therefore, soils with chernic horizons of natural origin are not to be expected south of the central German uplands. Active soil alteration by the human population in the Neolithic has also been observed to lead to Chernozem-like soils in other regions of Germany, like Lower Saxony and North Rhine-Westphalia. The unexpected black horizon investigated in this study is located close to Straubing in Bavaria, southeast Germany. The prevailing natural soil type in the area is a calcic Luvisol on loess substrate. The black horizon is located in close proximity to a neolithic settlement and its graveyard. We hypothesise that the inhabitants of the nearby neolithic settlement used the area with the black horizon as an agricultural field and were managing it actively. The core area with the most pronounced black horizon is rectangular and comprises within the excavation a surface of ca. 0.83 ha. Several decimetres of Holocene colluvium buried the black horizon in the Late Bronze Age and subsequent periods (OSL and 14C-Dating). Dating results from the black horizon prove human impact on the soil starting in the Linearbandkeramik (LBK) period (cal BC 5,209–4,911, 14C-Dating). NMR- and FTIR-DRIFT-analysis show high contents of pyrogenic carbon in the black horizon, which is responsible for its dark colour, even though the mean share of carbon is not higher than 0.50 ± 0.03 % (mean ± se). These results match those of recent literature and, therefore, indicate that neolithic farmers also applied their targeted soil amendment practices in southern Germany. This follows archaeological findings on the colonization of the area by the neolithic settlers: Primordially coming from the Fertile Crescent (northern Middle East), they followed the Danube through the Pannonian Region and brought their agronomic knowledge from the prior settlement area, where their active soil management is archaeologically proven.

Electrochemical synthesis and carbon doping of nanostructured iron fluorides from the selection of metal current collectors in lithium-ion batteries

The use of materials that rely on conversion reactions as electrodes in lithium-ion batteries is extensively investigated due to their potential for enhanced capacity compared to traditional electrode materials. Iron fluorides, in particular, present a promising alternative in terms of specific capacity. However, these materials often face challenges related to low intrinsic conductivity. This issue is typically addressed in the literature by doping the active material with carbon particles and reducing the particle size of the active material. This study explores the feasibility of directly integrating conductive carbon from the substrate into the fluoride-based active material during the synthesis process. The synthesis employs a simple anodic method conducted directly on the chosen metallic substrate, which then functions as the current collector in the devices. This approach simplifies the synthesis process, reduces processing time, and eliminates the need for additives and binders at the conventional active material-current collector interface. Two FeF3 layers were electrochemically synthesized on steel substrates with different carbon contents. These layers were evaluated as cathode-active materials for rechargeable lithium-ion batteries. The influence of carbon on the conductivity of the conversion layer was assessed using Electrochemical Impedance Spectroscopy (EIS) with a model based on conductive porous electrodes. Morphological and thickness analyses of the layers showed a strong correlation between increased pore size and layer thickness and the carbon content in the metallic substrate. The optimal performance was observed with the layer on the substrate with higher carbon content. The electrochemical performance of the active material was further evaluated using electrochemical impedance spectroscopy and galvanostatic tests in pouch cells. The conversion layers derived from carbon steel exhibited reduced resistivity and enhanced specific capacitance and cyclability compared to layers formed on pure iron.

Co-application of glucose and phosphorus with recalcitrant high-carbon soil amendments improves N retention in a reclaimed soil: a long-term incubation study

ABSTRACT Incorporation of soil amendments with high organic carbon content (HCA) can reduce losses of mineral nitrogen (N) from agricultural soils. The magnitude of N immobilization and remobilization is strongly controlled by the availability of carbon (C) and phosphorus (P). However, the exact mechanisms and interactions between C, N, and P availability are poorly understood. An eight-month incubation experiment was conducted on recultivated mine soil with low organic C, mineral N and P background concentrations to investigate the effects of HCA in combination with 13C-labelled glucose and mineral P fertilization on greenhouse gas emissions, soil nutrient status (dissolved organic C (DOC), nitrate (NO3 –), extractable P), and microbial biomass growth. The experiment had a factorial design of one N level × two P levels × six C treatments (control, wheat straw, poplar sawdust, glucose, and combinations of wheat straw or sawdust with glucose). The HCA increased the cumulative CO2 and CH4 emissions but decreased N2O emission, except for wheat straw. Addition of 13C-labelled glucose decreased the cumulative CH4 emission by 59 and 85 % in the sawdust and sawdust + P treatment, respectively. Glucose application reduced the NO3 – content in the HCA-amended soil by 26–64 %, while P fertilizer further decreased the NO3 – content in the wheat straw and sawdust treatments by 20 and 24 %, respectively. Both HCA and glucose treatments promoted microbial biomass growth and reduced the soil mineral N content. The δ13C of microbial biomass (δ13CMB) showed an increasing trend during the whole experiment, although 13C-labelled glucose was added only once at the beginning of the experiment. Addition of HCA decreased δ13CMB, while P addition had the opposite effect. In conclusion, adding a readily available C source to HCA may increase the efficacy of retaining N in post-harvest soils, particularly of more recalcitrant types of HCA like sawdust.

Biomass valorization: Comparative analysis of tea waste pellets and wood pellets for steam generation and emission profiles

This study investigates the viability of tea waste as a biomass feedstock for pellet production and its combustion characteristics. Tea waste, an abundant agricultural byproduct, presents a promising avenue for renewable energy generation if effectively utilized. The pellets derived from tea waste were subjected to detailed analysis focusing on their calorific values and carbon composition. The calorific value of tea waste pellets was determined to be approximately 18.5 MJ/kg, comparable to conventional wood pellets. Notably, these pellets exhibit a high carbon content of 45 %, indicating a significant fixed carbon fraction that necessitates tailored combustion strategies for optimal efficiency. This research underscores the potential of tea waste pellets as a sustainable biofuel, contingent upon the development and application of precise combustion methodologies. It underscores the critical importance of understanding the chemical properties of solid biofuels in optimizing their utilization for energy production.