Baibhaw Kumar

Woody biomass is often promoted as a low-carbon energy source in global decarbonization efforts. However, LCA (life cycle assessment) evaluations of woody biomass-to-energy systems show very different environmental performance. Variations in technology and methodology across investigations can cause these inconsistencies. This review paper analyzes methodologies of LCAs of woody biomass conversion routes such as combustion, combined heat and power, gasification, pyrolysis, torrefaction-assisted systems, and new bioenergy with carbon capture configurations. A systematic literature review was conducted using Scopus, SpringerLink, and ScienceDirect, identifying 4272 records, of which 98 studies were retained for detailed analysis following the application of defined inclusion and exclusion criteria. Functional unit selection, from biomass mass per unit to power or heat per unit, is highly variable, affecting comparability. Forest carbon stock fluctuations, infrastructure, and end-of-life treatment are inconsistently included in cradle-to-grave system boundaries. Static GWP100 methods are often used in biogenic carbon removal without considering temporal carbon dynamics. The importance of pretreatment steps like drying, pelletizing, and torrefaction cannot be overstated, even though they have a direct impact on the quality of the fuel, the efficiency of transportation, and the effectiveness of the conversion process downstream. The large range of stated emission levels for comparable technologies is further influenced by logistics assumptions, plant scale, and allocation mechanisms in cogeneration systems. The review synthesizes these methodological differences and proposes a harmonization methodology to increase woody biomass LCA transparency and comparability. By identifying important sources of outcome variability, this study helps policymakers, project developers, and industry stakeholders evaluate biomass energy investments and bring clarity to environmental decisions.

Torrefaction off-gas is commonly routed directly to oxidation for process heat recovery, but short-term buffering and controlled handling may improve oxidizer stability and heat-integration flexibility during transient operation. This study develops a process-integration screening framework for CO/CO₂-rich torrefaction off-gas generated from woody biomass with initial moisture contents of 5–20% wet basis. The framework uses gas chromatography (GC) data in which the measured species account for 85.6–92.2 vol% of the gas mixture. The remaining 7.9–14.4 vol% closure deficit is treated not as confirmed composition, but as a conservative indicator of unquantified condensable or inert fractions, including possible water vapor, oxygenated organics and sampling dilution. The measured gases are dominated by CO₂ and CO, while CH₄ and light hydrocarbons increase with biomass moisture class. Two handling modes are proposed: Mode A maintains hot, single-phase routing by avoiding water and organic-condensable dew-point crossing upstream of oxidation, whereas Mode B uses controlled cooling with condenser, knock-out, drainage and wet-service material selection. The framework links GC closure-deficit screening to routing decisions, cold-surface control, fouling prevention, wet-CO₂ corrosion risk and minimum validation requirements.

The rapid expansion of renewable energy has increased the need for systematic tools to evaluate the sustainability performance of enterprises operating in this sector. Many existing assessments focus on individual indicators or national policy outcomes, while fewer studies provide structured decision support methods for evaluating enterprise level sustainability across economic, environmental, and social dimensions. This study develops a decision support framework for evaluating sustainability performance in renewable energy enterprises based on the Triple Bottom Line concept. The framework integrates expert informed indicator selection, Analytical Hierarchy Process weighting, and Multi-Criteria Decision Analysis ranking to provide a transparent and replicable evaluation procedure. Sustainability indicators were first identified and refined through a structured expert consultation process. A survey employing Likert scale indicators assessed stakeholder priorities about economic viability, environmental stewardship, and social impact. The Analytical Hierarchy Process was utilized in the study to determine the relative weights of the sustainability pillars, while the Weighted Sum Model was employed to calculate the overall sustainability ratings for the participating enterprises. This study contributes a methodological advancement by shifting the AHP-MCDA application from project or technology selection toward enterprise-level sustainability benchmarking. The framework converts expert-validated TBL indicators into weighted composite scores and pillar-specific diagnostic profiles, allowing decision-makers to identify not only which enterprises perform better, but also which sustainability dimensions require improvement. The results demonstrate how the proposed approach converts stakeholder perceptions into quantitative sustainability assessments. The study provides a transferable methodological framework that supports enterprise-level sustainability evaluation and strategic decision-making in the renewable energy sector.

This article investigates Hungary’s growing status as a moderate innovator in the European Union, examining why it lags behind leaders like Denmark and emerging performers like Estonia. While previous research has focused on composite scores such as the European Innovation Scoreboard (EIS), this study combines these indicators with a Data Envelopment Analysis (DEA) approach to evaluate innovation efficiency. The study covers the period from 2016 to 2023 providing a temporal analysis of Hungary’s innovation deficit relative to the EU average, as well as a comparative assessment with chosen EU equivalents. The paper identifies systemic slackness in Hungary’s innovation ecosystem, notably in terms of converting R&D inputs and human capital into concrete innovation outputs.

Steel slags are major by-products of steelmaking, and their variable composition complicates recycling and valorization strategies. This study investigates four representative slag samples obtained from different production pathways at an industrial steel plant in Uzbekistan, using a combined multi-scale characterization approach. Bulk elemental composition was determined using X-ray fluorescence (XRF), while microstructural and phase-level analysis was carried out using scanning electron microscopy with energy-dispersive spectroscopy (SEM–EDS), including both point analysis and automated phase mapping. The XRF results revealed two distinct compositional groups, with one slag dominated by Mn–Si–O chemistry and three slags characterized by high Ca content. SEM–EDS phase mapping further resolved these differences at the microscale, identifying manganese silicate and oxide phases in the Mn-rich slag, Ca–F–O dominant phases in two slags associated with fluorite flux addition, and a more heterogeneous Ca-based system with localized enrichments of Mn, Zn, and Cu in the fourth sample. The combined results demonstrate that slag composition strongly reflects steel grade and fluxing practice. The integration of XRF and SEM–EDS provides a robust framework for linking bulk chemistry with phase distribution, improving slag classification and supporting informed decisions for reuse and environmental management.

Biomass torrefaction is a thermochemical process that transforms biomass into a more energy-dense fuel, producing solid biochar, volatile organic compounds, and gases such as carbon dioxide (CO₂), carbon monoxide (CO), and nitrogen oxides (NOx). In this study, the effects of solar drying, as a sustainable preprocessing method, and subsequent torrefaction were evaluated under varying initial moisture content levels of 5%, 10%, 15%, and 20%. The drying conditions of wood chips and the torrefaction process were documented for a sustainable biomass drying system using solar energy. Comprehensive proximate and final analysis and flue gas monitoring analyzed the torrefied biomass’s emission characteristics and combustion efficiency. Results showed that higher initial moisture content increased hydrogen and volatile matter, decreased fixed carbon, and marginally raised the higher heating value. This study shows that solar drying optimizes biomass pretreatment and is a cost-effective and environmentally friendly alternative to conventional drying. This work sheds light on the relationship between initial moisture content, emission characteristics, and combustion behavior, aiding bioenergy development.