Porous ceramic oxides have gained significant interest as components in a wide variety of energy storage devices. Their use, however, is limited by long and high-temperature processing methods. We recently demonstrated Porogen-integrated Rapid Oxidation (PiRO) as a new method to manufacture porous aluminum oxide in significantly shorter times and with substantial manufacturing cost savings, but challenges remain with the resultant porous matrices. First, carbonaceous residue remains in the films after the combustion event, which is necessary to minimize for electronic applications. Second, the porous structure is not stable at elevated temperatures (>250 °C), which are often required for nanocomposite applications of the matrices where filling with a second phase is achieved through high-temperature annealing. Here, we address these challenges by using post-processing treatments, including UV/Ozone, high-temperature nitrogen oven anneals, and oxygen plasma. First, we characterize the treatments' efficacy in carbon removal using FTIR and measure bulk carbon removal with XPS. Second, we characterize the matrices' thickness collapse and porosity changes after treatments with ellipsometry. Finally, we use nanoindentation to understand changes in stiffness resulting from the various treatments. By understanding the treatments' roles in removing carbon from the films and stabilizing the matrix structure, we are able to select optimal post-processing treatments for designing a stable platform for further applications of the mesoporous oxide.

The growing demand for sustainable and renewable energy sources has led to extensive research into biomass as an alternative fuel. Despite the unique properties of coconut shell, palm kernel shell, and wood sawdust, there has been no comprehensive study on their combined combustion characteristics. This study, therefore, evaluates the combustion behaviour and energy potential of biomass admixtures consisting of palm kernel shell, coconut shell, and wood sawdust. Ultimate and proximate analyses were conducted following ASTM standards to determine key combustion parameters such as carbon (C), hydrogen (H), nitrogen (N), oxygen (O), and sulphur (S) content, as well as moisture content (MC), volatile matter (VM), fixed carbon (FC), and ash content (AC). The higher heating value (HHV) was also assessed to establish the energy efficiency of the samples. The results revealed that among the individual biomass samples, palm kernel exhibited a very highest carbon content 75.82% and heating value (18.03 MJ/kg), while coconut shell had the highest volatile matter (72.45%) and lowest ash content (0.95%). The admixtures (Palm kernel shell + Coconut shell + sawdust) demonstrated improved combustion properties, with PCSB recording the highest fixed carbon content (23.65%) and a moderate HHV of 18.21 MJ/kg. The oxygen content varied across samples, influencing their combustion efficiency. The analysis revealed that blending biomass materials enhances their overall energy potential by optimizing combustion characteristics

Kraft lignin (KL), a major byproduct of the pulp and paper industry, is still largely underutilized, limiting its value in advanced materials. This work investigates whether incorporating carbonized kraft lignin (CKL) into polyvinyl alcohol (PVA) films can enhance their structural and functional properties and enable their use as gas-sensor membranes. PVA films containing 0, 10, 30, and 50 weight percent (wt.%) CKL were prepared and characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), water-contact-angle (wettability) measurements, and tensile testing, followed by ammonia (NH3), ethanol (C2H5OH), and toluene (C7H8) sensing. CKL increased thermal stability (temperature at 5% mass loss, T5%, up to 135 °C vs. 80 °C for neat PVA), raised carbonaceous residue to 15%, and improved Young’s modulus while reducing elongation and water contact angle. Gas-sensing tests revealed a strong, reversible current response to NH3, with PVA/50 wt.% CKL exhibiting the highest current (ca. 23 µA), along with detectable responses to ethanol and toluene. These results demonstrate that CKL is an effective bio-derived additive that upgrades PVA films for sustainable, high-performance gas-sensing applications.

Cross-linked polyethylene (PEX) is very stable, both chemically and mechanically. This makes its waste difficult to process. A very promising approach is slow pyrolysis catalyzed by hematite (α-Fe2O3). Such pyrolysis was carried out on a large scale (feedstock of 38 kg, catalyst amount of 2 wt.%, heating rate of 4 K min−1, end temperature of 435 °C, delay at the end temperature several hours) and provided an oil containing both liquid (up to C17) and solid hydrocarbons (>C17). Thus, the oil obtained can be a source of valuable chemicals, solvents, and paraffin, and/or used as a clean liquid fuel and/or as a source of lubricants. Pyrolysis of PEX also yielded energy gas (12 wt.%) and solid carbonaceous residue (15 wt.%) for further use. The process mass balance and parameters (temperature, heating rate, dwell time, catalyst amount), composition, and chemical (elemental analysis, XRF, GC-MS, GC, distillation curve) and physical (viscosity, density, higher and lower heating value) properties of the oil, gas, and solid carbonaceous residue obtained are presented and discussed. The main product of the proposed technology is oil with a yield of almost 73 wt.%. The by-products are energy gas (12 wt.%) and solid carbonaceous residue (15 wt.%). The results obtained showed that the proposed technology successfully recycles difficult-to-process PEX with a process efficiency of 70%.

This study aims to analyze the quality of coal from the AR_10 borehole in Muara Enim Regency, South Sumatra, based on proximate analysis. The AR_10 borehole has three coal seams (A, B, and C) that were analyzed using the standard ASTM method to determine the coal quality characteristics. The parameters analyzed include total moisture (TM), volatile matter (VM), fixed carbon (FC), ash content (Ash), calorific value (CV), and total sulfur (TS) on an as-received (AR) basis. The analysis results show that seam A has the highest moisture content (19%), seam B exhibits the optimal calorific value (6045 kcal/kg), and seam C has the highest fixed carbon content (42.63%) with the highest sulfur content (0.83%). The correlation between parameters indicates that increases in moisture and ash content negatively affect the calorific value, while an increase in fixed carbon is positively correlated with the calorific value. All three seams fall into the category of low to medium rank coal (subbituminous to high volatile bituminous) with adequate quality for power generation and industrial purposes. This research provides an important contribution to the characterization of Muara Enim Formation coal in South Sumatra for the optimization of local coal resource utilization.

This paper focuses on carbon capture and carbon collection technology. Carbon capture is to separate and enrich carbon dioxide, while carbon collection is to concentrate, store and transport the captured carbon dioxide. Technical classification covers pre-combustion, mid-combustion, post-combustion capture and direct air capture. Carbon element is separated before combustion and before fuel combustion; Fixing carbon dioxide during combustion; Separate from waste gas after combustion; Direct air capture from the atmosphere. With the innovation of materials and processes, such as the development of new adsorption materials, integrated and low-energy processes, this technology is moving towards high efficiency, economy and low energy consumption, which provides strong support for global carbon emission reduction and carbon neutrality.

The global advancement toward sustainable energy has intensified interest in hydrogen as a clean energy carrier. In the Okada region in Nigeria, agro-waste is grossly underused, contributing to environmental degradation amid persistent energy shortages. This study models and experimentally validates the production of hydrogen-rich syngas from agro-waste, utilizing chemical looping reforming to enhance efficiency and quality. In this study, cassava peel, cocoa pod skin, and plantain peel were collected, dried, pulverized, and pelletized to create uniform biomass feedstocks. These were characterized for key fuel properties, including moisture content (MC), volatile matter (VM), ash content (AC), fixed carbon (FC), elemental composition, and lower heating value (LHV). Gasification experiments using air at equivalence ratios of 0.2, 0.35, and 0.5 were conducted, with syngas analyzed via gas chromatography. An Aspen Plus model was developed to simulate the gasification process and validated, considering air as the gasifying agent, varying at equivalence ratio (ER: 0.1 to 0.55), steam-air and steam as gasifying agents, varying steam-to-air ratio (SAR: 0.1 to 1.0) and steam-to-biomass ratio (SBR: 0.1 to 1.0) respectively. Chemical looping reforming (CLR) was modeled using Fe2O3, CuFe2O4, and CuO/CuAl2O4 as oxygen carriers, assessing their impact on syngas H2 enrichment. The characterization of the biomass feedstock showed that cassava peel had the most favorable properties for gasification, with the lowest MC (7.3%), highest FC (22.63%), and lowest AC (1.9%). Cocoa pod skin exhibited the highest VM (73.4%) and LHV (17.3 MJ/kg). These findings demonstrate the significant potential of locally available agro-waste in Okada for sustainable hydrogen production, offering a viable pathway to cleaner energy, reduced environmental impact, and enhanced energy security in Nigeria.

Pyrolysis has emerged as a commercially viable material recovery process that supports circularity in the tyre industry. Here, it is demonstrated that a high degree of control can be imparted over the UK tyre waste stream and that statistically different feedstocks can be used to produce different grades of rCB based on their ash contents. The lower ash content rCB produced from truck tyres had superior in-rubber properties, closely matching those of the N550 reference. Silica, when not paired with a coupling agent, is known to be less reinforcing than CB, lowering the reinforcing behaviour of the high ash content rCB variant produced from car tyres. This justifiably places ash content within the classification and specification development discussion. However, a proximate analysis of UK waste tyres suggests that the typical rCB ash specifications of <20 wt% are unrealistic. Such limits would force producers to consider modifying process conditions to allow the deposition of carbonaceous residues to artificially dilute the ash content. This study investigates this process philosophy but conclusively demonstrates that carbonaceous residue is more detrimental to rCB performance than ash content. As such, carbonaceous residue content demands far more attention from the industry than it is currently afforded.

The Philippines still relies heavily on oil and coal as energy fuel sources, contributing to approximately 63.21% of the energy mix. It is crucial to seek alternative feedstock that can comply with the increasing demand. This study thus investigated the energy potential of bolo ( Gigantochloa levis (Blanco) Merrill) along the bottom, middle and top culm height portions, for bioenergy applications. The top culm was consistently observed to have the lowest moisture contents and the highest relative (0.4757 g/mL) and bulk (0.2003 g/mL) densities. Proximate analysis revealed a significant increase in average fixed carbon (FC) content from top (19.18%) to bottom (20.88%), while ash content showed the opposite trend, ranging from 3.59% to 5.92%. The average volatile matter (VM) content (74.90% - 75.53%) showed no significant variation along the culm. Lignin content was also analyzed and its correlation with FC and VM reveal a parabolic relationship with R 2 values of 0.84 and 0.63, respectively. Despite the top section having the lowest higher heating value, its higher density and lower moisture content resulted in the highest calculated energy density (8.13 GJ/m³ in chipped form), suggesting that the top portion has the best potential as a biomass energy source for direct combustion.

Acrylonitrile-based polymers are widely used in industrial and consumer settings, contributing to the growing amount of plastic waste. Yet, their chemical recycling has largely been neglected, partly due to the potential release of harmful gases such as HCN and NOx. Herein, we report a catalytic process that enables valorization of the polymer’s N- and C-content, without releasing harmful nitrogen gases. Our strategy uses Pd-based shuttle catalysis to transfer HCN units from the polymer’s backbone to an olefin acceptor molecule, generating a carbonaceous polyolefin residue amenable to further upcycling, alongside a useful nitrile building block. The protocol can be optimized in two ways: to efficiently functionalize olefins and produce nitriles in up to quantitative yields as a safe, cost-effective alternative to commonly employed nitrile synthesis methods, and to fully dehydrocyanate polymers using ethylene as HCN acceptor. Furthermore, we demonstrate the applicability of our strategy for the upcycling of commercial polyacrylonitrile materials.

Indonesia possesses economically valuable coal deposits distributed across the Tertiary basins of the western Sunda Shelf, particularly on the islands of Sumatra and Kalimantan, positioning the country as one of the world’s leading coal producers. This study aims to determine the ash content of coal samples from various mining sites. Samples were analyzed using the proximate analysis method to measure parameters including total moisture (TM), inherent moisture (IM), ash content (ASG), and fixed carbon (FC). This method enables the identification of variations in coal characteristics resulting from differences in mining origins. The results indicate that TM, IM, ASG, and FC levels vary across samples, reflecting differences in geological conditions and coal quality. The total moisture and fixed carbon values obtained from crucible 1 and crucible 2 were both recorded at 6%. The study concludes that coal characteristics differ by source, and proximate analysis provides a valuable preliminary insight into quality assessment. These findings serve as a foundation for developing more accurate and efficient coal analysis methods and offer a reference for industrial applications and energy research.

Sewage sludge char catalyzed steam reforming of volatiles from MSW pyrolysis for H2-rich syngas production: Influence of char properties.

The development of composite materials has become a major focus of research in recent decades, especially natural fiber composites with a unique combination of physical and mechanical properties of materials. Polyester composites can be produced by utilizing synthetic and natural fibers. The natural fibers studied are the characteristics of Balinese pandan fiber and coconut fiber with NaOH solution treatment for polyester composite reinforcement. The treatment of Balinese pandan fiber and coconut fiber was carried out by soaking in a 10% NaOH solution, aiming to remove lactic acid and cellulose, in order to increase the bond between the polyester matrix and the fiber, both Balinese pandan fiber and coconut fiber. In this study, the effect of soaking time of Balinese pandan fiber and coconut fiber on the characteristics of physical properties was studied through Thermogravimetric Analysis (TGA) testing, with LECO USA machine specifications, model: 604-100-700, series: 6204 at the UNUD Mechanical Engineering Laboratory. This test was carried out by soaking Balinese pandan fiber and coconut fiber in a 10% NaOH solution at various soaking times: 1 hour, 2 hours and 3 hours. Then the Thermogravimetric Analysis (TGA) test was carried out, then the characteristics and physical properties of the Balinese pandan fiber and coconut fiber were obtained in the form of dust content, water content, volatile, fix Carbon. Based on the test results data on the 10% NaOH treatment, for coconut fiber soaked for 2 hours, the highest Fix Carbon level was obtained, namely 21.15 and the highest Balinese pandan fiber was 15.50, which can be used for bending test materials. In Balinese pandan fiber, the highest volatile level was obtained at 89.81 and coconut fiber 80.73, which can be used for sound absorption test materials.

Thermogravimetric analysis (TGA) is a key technique for evaluating the kinetics and thermodynamics of thermal degradation, providing essential data for material assessment and system design. When coupled with Fourier-transform infrared (FT-IR) spectroscopy or mass spectroscopy (MS), it enables the identification of evolved gases and correlates mass loss with specific chemical species, offering detailed insight into decomposition mechanisms. In this study, TGA was coupled with FT-IR and MS to investigate the thermal degradation behavior of Bakelite, with the aim of evaluating its kinetic and thermodynamic parameters under non-isothermal conditions, identifying evolved volatile compounds, and elucidating the degradation process. The results showed that higher heating rates led to increased decomposition temperatures and broader dTG peaks due to thermal lag effects. The degradation proceeded in multiple stages between 220 °C and 860 °C, ultimately yielding a carbonaceous residue. The activation energy increased with conversion, particularly beyond 0.5, indicating a greater energy requirement as degradation progressed. Peak values at conversion degrees of 0.8-0.9 suggested enhanced thermal stability or changes in the dominant reaction mechanism. Detailed kinetic analysis revealed complex decomposition pathways with variable activation energies and a pronounced kinetic compensation effect. Thermodynamic analysis confirmed the endothermic nature of the process, with increasing energy demand and non-spontaneous degradation of the resulting char. TGA/FT-IR and TGA/MS analyses identified the release of several compounds, including CO2, water, formaldehyde, and phenolic derivatives, at distinct stages. This comprehensive understanding of Bakelite's thermal behavior supports its optimization for high-temperature applications, enhances material reliability and safety, and contributes to sustainable processing and recycling strategies.

During thermal regeneration of styrene-saturated activated carbon (AC), styrene's C=C bonds are prone to polycondensation. It forms fixed carbon species that deposit as carbonaceous residues within AC pores, significantly decreasing the adsorption performance. To address this challenge for efficient AC regeneration and recycling, Ni and Co transition metal components were loaded onto AC and subsequently pyrolyzed to generate NiCo2O4 active species. The optimal Ni-Co loading amount was determined to be 5 wt %. Under these conditions, the adsorbent exhibited optimal cyclic adsorption performance, maintaining 75% of its initial capacity after four consecutive adsorption-regeneration cycles. Comprehensive characterization revealed that the 2.5Ni-2.5Co-AC formulation maximized AC recyclability, and this enhanced performance is attributed to the well-dispersed NiCo2O4 species and the formation of carbon defect sites within the adsorbent. This study presents a novel strategy and provides a scientific basis for solving the regeneration problem of styrene-adsorbed activated carbon.

This study investigates the pyrolysis of construction, renovation, and demolition (CRD) wood waste to produce biochar, with a focus on its robustness, scalability, and characterization for energy and environmental applications. Pyrolysis conditions, including the temperature, biomass residence time (BRT), and feedstock mass, were varied to evaluate their effects on biochar properties. High-temperature biochars (B800) showed the highest fixed carbon (FC) (87%) and thermostable fraction (TSF) (96%) and the lowest volatile carbon (VC) (9%), with a high carbon content (92%), a large BET surface area (300 m2/g), and a high micropore volume (0.146 cm3/g). However, the hydrogen (0.9%) and oxygen (2.2%) content, Van-Krevelen parameters (H/C: 0.1; O/C: 0.02), and biochar yield (21%) decreased with increasing temperature. Moderate-temperature biochars (B600) have balanced physicochemical properties and yields, making them suitable for adsorption applications. Methyl orange dye removal exceeded 90% under the optimal conditions, with B600 fitting well with the Freundlich isotherm model (R2 = 0.97; 1/n = 0.5) and pseudo-second-order kinetic model (R2 = 1). The study highlights biochar’s suitability for varied applications, emphasizing the need for scalability in CRD wood pyrolysis.

Introduction. According to the Russian Ministry of Natural Resources, the country currently generates 22-25 million tons of fly ash and slag waste per year, and up to 10% is disposed. By the Government Order of the Russian Federation No. 1557-p dated June 15, 2022, the “Comprehensive Plan for increasing the volume of ash and slag waste disposal of hazard class V” was approved. Ekibastuz coals are the highest ash fuel coals used at thermal power plants in the Russian Federation. The properties of fly ash and ash slags depend on the type of fuel being burned - its mineral part (overburden), as well as other technological features of the processes of preparation, combustion, capture and disposal of materials. That is why the properties of these materials should be considered in relation to a specific fuel.Methods and materials. The object of the study was fly ash and ash slag obtained by the combustion of Ekibastuz coals at Russian thermal power plants. With the use of physical and chemical analysis methods, the chemical and mineralogical composition was studied, the physical properties and environmental parameters of these materials were determined.Results. As a result of the conducted research, the chemical, mineralogical and phase composition of fly ash and ash slag of Ekibastuz coals have been established. The specific features of physical properties have been identified and the causes of their formation have been identified. Specified data on the environmental characteristics of fly ash and ash slag have been obtained.Conclusion. Ekibastuz coals are characterized by the highest ash content among all fuel coals, reaching 45%, which necessitates the active involvement of ash and slag wastes in the country’s construction industry. A number of specific properties must be taken into account for the effective use of fly ash and ash slag formed during the combustion of these coals. The fly ash of Ekibastuz coals, characterized by a superacid chemical composition, does not demostrate the properties inherent in mineral binders. However, the fly ash obtained by dry capture has the ability to interact with hydrolysis products of mineral binders and be involved in hydration processes, which indicates its potential activity in building composites. Kaolinite, which dominates the mineralogical composition of the Ekibastuz coal rock with a limited presence of fluxes, necessitates high temperatures for modification and thermal activation of the mineral component. This feature has a direct effect on the phase composition of the formed fly ash and ash slag, determining their characteristics and properties. The dissociation of minerals in finely ground coal stimulates the formation of both closed and open microporosity in ash particles. This process leads to a significant increase in their specific surface area and chemical activity, determining the physical properties of fly ash and ash slag. The slag component from the burning of Ekibastuz coals is heated only to the sintering stage, but not melting. This determines the reduced density and mechanical properties of the ash slag. Ekibastuz coals are characterized by a high content of fusain in the organic part. The petrographic characteristics of this organic mass determine the increased resistance of carbonaceous residues to aggressive influences. The radioactivity of the Ekibustuz fly ash and ash slag does not exceed the permissible limit for classifying them to the 1-st hazard class according to the specific effective activity of the latter. Ekibastuz ash and slag wastes have been assigned the V-th hazard class for the environment, defining it as practically non-hazardous waste.

The pyrolysis of polymers is a thermal processing method largely used to convert polymeric waste into valuable products such as oils and carbonaceous residues. The NP-gram method (NP standing for normal paraffins) is useful for the global characterisation of pyrolysis oils with complex composition. Here, we present the fundamental of this method, which is based on the concept of "carbon number", in conjunction with the boiling point and the chromatographic retention time of chemical compounds. Polypropylene was selected as the model polymer due to its simple mechanism of thermal degradation. The boiling points of the main compounds in polypropylene pyrolysis oil were estimated based on the equations of Egloff and Wiener. A good correspondence was obtained for the estimated boiling points and the position of the compounds in the gas chromatogram. A distinction was made between the number of carbon atoms in the molecule and the corresponding carbon number used in characterisation of pyrolysis oils by NP-gram. Correlation with the chromatographic retention index was also discussed. The application of the NP-gram method for different polymers was also presented.

Objectives: This study aims to assess the potential of municipal solid waste (MSW)-derived solid bio-fuels as sustainable alternatives to fossil fuels. It focuses on evaluating their physical characteristics, calorific values, and flue gas emission profiles to determine their suitability for clean energy applications. Theoretical Framework: Grounded in the waste-to-energy paradigm, this review draws upon concepts of resource valorization, sustainable energy transition, and environmental management. It examines how transforming heterogeneous MSW streams into solid bio-fuels aligns with global efforts to reduce landfill burden and carbon emissions. Method: A systematic review of peer-reviewed literature was conducted using scientific databases. The analysis covered studies involving MSW briquettes, refuse-derived fuels (RDF), and biomass fractions such as food waste, paper, plastics, sawdust, and agricultural residues. Data were extracted and synthesized based on parameters like moisture content (MC), ash content (AC), volatile matter (VM), fixed carbon (FC), higher heating value (HHV), bulk density, and flue gas emissions including O₂, CO₂, CO, NOₓ, and hydrocarbons (HC). Results and Discussion: Results indicated considerable variability in feed-stock properties: MC ranged from 0.48% to 44.30%, AC from 0.4% to 42.6%, and HHV from 13.69 to 24.30 MJ/kg, with higher energy values observed in processed and plastic-rich mixtures. Bulk density spanned 170–1200 kg/m³, favoring densified forms for improved energy storage and handling. Emission data showed wide variation—O₂ (0–45.6%), CO₂ (0–23.97%), CO (0.001–2.55%), NOₓ (0.75–5000 ppm), and HC (up to 52.9 ppm)—with elevated levels often linked to plastic and organic content. Research Implications: The findings emphasize the need for standardized feed-stock preparation, blending strategies, and emission control technologies to ensure consistent fuel quality and environmental compliance. These measures are vital for integrating MSW-based solid bio-fuels into mainstream energy systems. Originality/Value: This review offers a comprehensive synthesis of existing data on MSW-derived solid bio-fuels, combining insights on fuel quality and emission behavior. It contributes to the body of knowledge by identifying practical pathways to optimize the performance and sustainability of MSW-based energy solutions.

Abstract The abundance of construction and demolition wastes, wood waste offers an initiative to compress biomass as a briquette to substitute fuel. Biomass from wood waste is a renewable energy source that is significantly more sustainable than conventional fuel however, it has low energy density due to high volatile matter (VM) and moisture content (MC), and low fixed carbon (FC) affects thermal efficiency amid combustion. This can be enhanced by the carbonization of the biomass; thermochemical method of biomass processing in minimal oxygen and gentle thermal settings to minimize MC and VM consequently increasing calorific value (CV) and FC. To guarantee high-quality biofuel briquette production, a few parameters should be considered such as carbonization temperature, carbonization time, and binder composition. The optimal binder composition range is above 5%. The produced biofuel briquettes may exhibit durability values ranging from approximately 80 to 95 %. The literature provides insights into the carbonization condition and binder composition for biofuel briquettes. However, there is a paucity of understanding of how these elements influence mechanical and the environment. This review seeks to close the comprehension void. Maximizing biochar densification improves energy efficiency, mechanical strength, and desirable briquette qualities.