ChemBioEng Reviews最新文献

Dissolved air flotation (DAF), a primary treatment for high-strength waste (HSW) dairy wastewater, generates sludge with a high organic content, posing disposal challenges. Anaerobic digestion (AD) offers a solution to promote renewable energy use and enhance the circular economy of the dairy industry by converting this sludge into biogas. However, DAF sludge has low digestibility, potential inhibitory risks, nutritional imbalances, and other challenges. This study identified potential technological solutions to optimize DAF sludge use by enhancing AD performance, including pretreatment, anaerobic co-digestion (ACoD), additives, and process modifications, which have been successfully implemented for other organic substrates. Using modified weighted scoring analysis (WSA), microaeration pretreatment was found to be a superior method, waste-activated sludge was identified as the most suitable co-substrate, and bentonite was selected as the most promising additive. Two-stage anaerobic digestion (TSAD) emerged as the most promising comprehensive solution for process modifications, addressing predominant DAF sludge AD issues and other subsidiary challenges.

Algae for biofuels as an alternative to fossil fuels. Copyright: toa555@AdobeStock

As global paper demand surges, conventional wood pulp methods raise deforestation concerns. This study explores the potential of sugar palm (SP) (Arenga pinnata) fibers, particularly in Malaysia, as a sustainable alternative for papermaking. SP, known for its versatility in food products and biofiber production, offers an eco-friendly option. It is also used for bioethanol, providing renewable energy sources. The research highlights SP biofibers as viable raw materials for the pulp and paper industry, emphasizing their seawater resistance, durability, and natural availability in woven forms. Its fibers exhibit seawater resistance, durability, and natural woven availability, with cellulose content of 45–60%, hemicellulose of 10–17%, and lignin of 16–30%, indicating strong suitability for papermaking. Comprehensive evaluation of SP properties, treatment approaches, and pulping processes demonstrates its role as a viable non-wood source, especially for forest-deficient regions. Beyond technical aspects, the study emphasizes environmental benefits, highlighting how SP utilization could reduce reliance on wood, mitigate deforestation, and foster sustainable industrial practices. This review bridges academic research on SP biomass with industrial applications, outlining current challenges, opportunities, and future directions for integrating non-wood fibers into industrial papermaking.

Electrochemical carbon dioxide reduction offers a promising strategy to convert CO₂ into valuable chemicals and fuels, addressing critical environmental and economic challenges. Key performance parameters, factors influencing catalytic efficiency, and the diverse range of catalyst types are discussed in detail. The review highlights the intrinsic challenges associated with CO₂’s chemical stability and energy barriers, as well as the effects of catalyst structure, electronic properties, and reaction environment. In addition, the economic and practical aspects of CO₂RR are considered, including the scalability of catalyst synthesis, energy input requirements, and cost-effectiveness for industrial deployment. Finally, future perspectives emphasize the importance of integrated strategies involving catalyst innovation, electrode and reactor design, and electrolyte optimization to overcome current limitations and enable the practical, large-scale deployment of CO₂ electroreduction as a sustainable solution for carbon management and renewable energy storage.

Given the depletion of fossil resources and growing environmental concerns, the development of high-value platform chemicals from lignocellulosic biomass has emerged as a sustainable alternative. Among these, 5-hydroxymethylfurfural (5-HMF) stands out as a versatile precursor for applications spanning biofuels, polymer engineering, and pharmaceutical synthesis. Heterogeneous porous solid catalysts have shown remarkable catalytic performance in biomass conversion due to their increased surface area, enhanced stability, and higher product selectivity. This review comprehensively analyzes the recent advancements in the utilization of heterogeneous porous solid catalysts for the efficient conversion of lignocellulosic biomass into 5-HMF, mapping current strategies and technologies in the heterogeneous lignocellulose transformation. The focus is mainly on factors such as porous structure, specific surface area, support properties, active sites, and their influence on the catalyst performance with some justifications. In particular, the effects of different porous structures (microporous, mesoporous, macroporous, and hierarchical porous) on specific surface area, mass transfer efficiency, catalytic activity, and product selectivity are extensively discussed. Furthermore, this review emphasizes the reusability of heterogeneous porous solid catalysts, which contributes to the reduction of waste in industrial chemical processes, energy conservation, environmental protection, and sustainability. Advantages and limitations of porous solid catalysts with diverse porous structures in the conversion of lignocellulosic biomass to 5-HMF are also evaluated in this review. Lastly, key recommendations are provided regarding the current status, challenges, and future prospects, emphasizing the opportunities and obstacles associated with the low-cost synthesis and large-scale application of heterogeneous porous solid catalysts in industrial green production.

Algae for biofuels as an alternative to fossil fuels. Copyright: toa555@AdobeStock

Coal serves as the primary energy source in China. With mining challenges intensifying, alternative coal utilization pathways are crucial. However, high pressure, slow desorption, low permeability, and other characteristics of coal beds make it hard to ensure high and stable yield, so the coal modification is vital. Microwave technology features strong penetration, high efficiency, and pollution-free heating, which can enhance heat–mass transfer capacity and reaction efficiency in coal beds. This paper briefly introduces the response characteristics of coal in a microwave field, based on both physical experiments and simulation studies. It then articulates common microwave modification devices, arrangements, and key parameters. The application scenarios are discussed, including gas extraction, underground gasification, and in situ pyrolysis of coal in several major fields. Finally, addressing uncertainties in microwave response mechanism and the need for enhanced equipment and industrial application, this paper guides microwave coal seam modification efforts, emphasizing basic research, equipment innovation, and practical implementation for efficient coal utilization in China.

This study explores sustainable sulfonated orange peel catalysts (SOPCs) for biodiesel production. The carbonization-sulfonation process used to manufacture SOPC, which is made from leftover orange peels, produces high-density sulfonic acid groups that increase SOPC's catalytic activity. Under optimal conditions, using oleic acid as feedstock, SOPC achieved a biodiesel conversion of 96.51 %. The catalyst demonstrated excellent reusability, maintaining high conversion rates over multiple cycles with minimal efficiency loss. Compared to conventional homogeneous catalysts like sodium hydroxide and sulfuric acid, SOPC's heterogeneous nature facilitates simple separation from the reaction mixture, lowering purification expenses and environmental impact. Its ability to process feedstocks with high free fatty acid content further enhances its versatility for biodiesel production from various oil sources. This highlights SOPC's potential as a cost-effective, environmentally friendly, and sustainable catalyst for biodiesel production. Continued research and optimization could accelerate its adoption, supporting the transition to cleaner, renewable energy solutions.