ABSTRACT Red mud (RM) is a kind of solid waste with high yield and strong alkalinity produced in the process of alumina extraction from bauxite. It poses significant environmental challenges due to its large‐scale accumulation and limited utilization. However, the main chemical compositions of RM are Fe 2 O 3 , Al 2 O 3 , CaO, and so forth, which make it a promising candidate for environmental applications, particularly in gas denitrification (NO x removal) and desulfurization (SO x removal). Therefore, significant efforts have been devoted to developing desulfurization and denitrification agents using RM to achieve win‐win results of gas purification and waste recycling. This review provides a comprehensive examination of the recent advancements in RM applications as a catalyst, adsorbent, and additive for gas purification. The mechanisms of NO x and SO x removal, the modification strategies to enhance RM's performance, and the economic and environmental benefits of its utilization are discussed. The review highlights the potential of RM as a sustainable and cost‐effective solution for gas purification, contributing to waste valorization and environmental protection.

ABSTRACT Electrochemical conversion of biomass and carbon dioxide (CO 2 ) to sustainable chemicals offers advantages over thermochemical methods through lower reaction temperatures, higher selectivity, and compatibility with renewable energy. Thermodynamics also offers a domain‐specific framework for assessing the viability and efficiency of these steps by evaluating the energy requirements, pathways, and restrictions imposed by catalysis. Therefore, this review aims to provide a comprehensive thermodynamic perspective on electrochemical biomass oxidation and CO 2 reduction, addressing Gibbs free energy, redox potentials, pH‐dependent Nernst relations, and free‐energy landscapes. Moreover, the relevance of multielectron and proton‐coupled reactions, overpotential demands, the stability of intermediates, and alternative pathways were discussed. Additionally, progress in electrocatalyst design, paired electrolysis configurations, and electrolyte engineering, which conceptually respond to thermodynamic limits, was highlighted. Finally, the review explores various strategies for co‐electrolyzing biomass and CO 2 , which can improve atom economy and overall process efficiency. The insights provided are intended to support further advancements toward energy‐efficient, highly selective, and sustainable chemical synthesis pathways aligned with carbon‐neutral goals.

ABSTRACT The increasing environmental impact of plastic waste from food packaging has intensified the demand for sustainable alternatives. Starch‐based films, particularly thermoplastic starch (TPS), are considered promising due to their biodegradability and renewable origin; however, their application is limited by poor mechanical strength and low water resistance. This review focuses on the use of nanocellulose as a reinforcing agent in TPS‐based bionanocomposites. It discusses the types and properties of nanocellulose and highlights its effectiveness in improving mechanical strength, barrier performance, and overall functionality of starch‐based materials. Although nanocellulose reinforcement significantly enhances packaging performance, challenges related to production cost and processing efficiency remain. Further research is, therefore, required to support large‐scale industrial application of these sustainable packaging materials.

ABSTRACT The growing interest in utilizing mixed matrix membranes (MMMs) based on polyurethane (PU) for gas separation applications has prompted extensive research efforts in both industry and academia. Although incorporating different fillers has shown promising enhancements in the efficiency and durability of PU membranes, several challenges related to optimal filler integration need to be addressed. This study aims to overcome these challenges by conducting a comprehensive investigation of the effects of incorporating commonly used fillers into PU membranes individually. Detailed outcomes for each filler are presented, highlighting their respective advantages and disadvantages. Furthermore, a comparative analysis of these fillers is performed to identify specific results efficient for industrial applications and future research. This research contributes to the advancement of MMMs by providing insights into the performance characteristics of different fillers in PU matrices. The findings serve as a valuable resource to optimize gas separation properties of PU‐based membranes and overcome challenges associated with filler integration.

ABSTRACT Carbon emissions from burning fossil fuels have intensified climate change, contributing to extreme weather, rising sea levels, and environmental degradation. In response, research has turned to algae‐integrated green building systems to support low‐carbon solutions. Microalgae biorefineries follow the principles of a circular bioeconomy by capturing carbon dioxide, converting biomass into biofuels, and aiding in wastewater treatment. Microalgae‐based biomass offers a sustainable alternative to fossil‐based products and help reduce atmospheric carbon levels. However, challenges remain in upstream and downstream processes, including the high cost of chemical culture media, energy demands for biomass harvesting, and intensive conversion techniques. Addressing these issues requires modifications in photobioreactor design and the use of affordable or recycled culture media. This review explores recent low‐carbon technologies in microalgae biotechnology, emphasizing algae‐integrated buildings. It examines various carbon capture strategies and the potential use of microalgae integrated into building systems, including energy generation, facades, and natural shading.

ABSTRACT Around 1.3 billion tons of food is wasted globally per year, producing 3.3 billion tons of CO 2 . Anaerobic digestion (AD) of food waste (FW) is a sustainable and economical solution to this crisis, which produces biogas and aids in environmental protection by sequestering methane, a potent greenhouse gas. The nutrient‐rich digestate slurry can be used as a bio‐fertilizer. Thus, this process enhances logistics, reduces pollution, and facilitates resource recovery by lowering waste volume and transportation cost. This review article is divided into sections on FW classification, the biochemical pathway in AD, the microflora involved, key operating parameters, limiting factors in AD, and the use of additives to enhance biogas production. It also covers the current research gaps, challenges, and future perspectives. The findings demonstrated AD as a viable technology for converting FW to biogas. It will expand the knowledge of sustainable and scalable biogas generation by combining FW heterogeneity with cutting‐edge AD methods, which can significantly improve the economic and commercial feasibility of FW valorization, pilot‐scale productivity, and energy recovery in real‐world applications.

ABSTRACT This review assesses underground hydrogen storage (UHS) with a focus on surface facilities, such as compressors, purification units, and buffer tanks. Many studies emphasize reservoir behavior, yet surface systems strongly influence injection stability, withdrawal rates, energy use, and subsurface parameters. The inherently fluctuating flow rates and variable thermodynamic conditions of renewable hydrogen affect surface operation and also propagate to the subsurface. These variations alter mixing behavior, gas composition, and well integrity. In reverse, subsurface processes—including well and cement integrity, geochemical and biochemical reactions, and compositional changes—create feedback on wellhead pressure, temperature, and flow composition that influences surface‐facility performance. A review of recent modeling frameworks highlights major gaps, especially in transient‐flow treatment, thermodynamic interactions, equipment sizing, and the absence of a complete system model that couples surface facilities with subsurface behavior. The findings underline the need for fully integrated surface–subsurface modeling to support reliable and cost‐effective UHS deployment.

ABSTRACT Cellulose‐based materials, being renewable, eco‐friendly, and abundant, have strong potential for CO 2 adsorption. Their adsorption performance depends on both the cellulose source and the preparation method. In addition, strategies for improving CO 2 capture depend on the type of cellulose used. This paper summarizes recent progress and evaluates the practical prospects of using cellulose nanomaterials for CO 2 adsorption and separation. It first introduces nanocellulose and its preparation methods. Then, it examines materials derived from cellulose, such as activated carbon and cellulose aerogels, for CO 2 capture. Also, this study compares cellulose preparation methods from different sources, analyzes their performance in CO 2 adsorption, and evaluates the impact of various modification techniques. Finally, it outlines current challenges, including scalability, cost‐effectiveness, stability under realistic conditions, and suggests directions for future research aimed at developing cellulose‐based adsorbents suitable for large‐scale and industrial use, with a particular focus on comparative analysis of processing pathways and modification strategies.

ABSTRACT Microaeration has emerged as an effective in situ approach for biogas desulfurization in anaerobic digestion (AD). This review critically assessed the effects of key microaeration parameters, including injection locations (liquid vs. gas phase), oxygen source (air vs. pure oxygen), dosage, and process control and monitoring techniques. This review identified several challenges to its large‐scale implementation, including a lack of optimal process design and limited economic analysis. Other key challenges include balancing oxygen injections to prevent methanogenic inhibition and organic co‐oxidation, managing biogas dilution by residual oxygen and nitrogen, and the operational complexities associated with elemental sulfur removal. Proportional–integral–derivative (PID)‐controlled systems that utilize oxidation‐reduction potential and H 2 S feedback have strong potential for process automation; however, real‐time monitoring tools and process control strategies are still in early stages of development. Moreover, its impact on hydrolysis, volatile solids reduction, and methane yield has been inconsistent. Addressing these gaps is crucial for the wide‐scale application in AD facilities.