ChemBioEng Reviews最新文献

The increasing global population has led to a surge in waste production across various fields including agriculture, industry, marine, and household, posing significant waste management challenges. Concurrently, the world is facing an energy crisis, emphasizing the crucial need for sustainable and renewable energy sources. This comprehensive review examines the potential of biomethane production from diverse waste biomass. Feedstock characteristics; anaerobic digestion (AD); biochemical pathways; factors influencing AD; various pretreatment methods such as physical, chemical, biological, and combined; existing policies supporting biomethane production; and potential new policy implications are discussed in this review along with the significance of waste-to-energy integration. Our findings indicate that lignocellulosic wastes, primarily agricultural waste, stand out as the most efficient biomass source for biomethane production due to their characteristics such as high carbon/nitrogen ratio, low ash content, and their abundant availability. Among pretreatment methods, combined pretreatment emerges as the most promising option, offering flexibility and effectiveness in enhancing biomethane production. Additionally, the two-stage digester configuration proves advantageous in overcoming limitations associated with single-stage digesters such as pH inhibition. Altogether, the review highlights that biomethane production from waste biomass through AD offers a sustainable solution.

A comprehensive understanding of the inter-bubble dynamics and the cluster formations in non-Newtonian fluids is pivotal for chemical and biomedical engineering applications. In this review, we summarize current research efforts to provide a fundamental understanding and engineering principles of the interactions between bubbles and the dynamics of bubble clusters in non-Newtonian fluids. Although the majority of research is still predominantly conducted through experimentation, the significance of computational fluid dynamics in elucidating interaction mechanisms has become increasingly prominent in recent years. Moreover, the gas-liquid systems reviewed in this paper are driven by gravity, which is closer to the actual industrial processes. We indicate the effects of non-Newtonian fluid special rheological properties (especially viscoelasticity and shear-dependent viscosity) on the interaction between multiple bubbles and the formation of clusters. We summarize the main empirical correlations in related research, which are useful for the optimization of industry. Ultimately, we address the current trends, limitations, and future directions in this research field.

Exploring alternative energy sources is vital amid increasing human fuel consumption. Globally, biogas, rich in methane, hydrogen sulfide, and carbon dioxide, addresses energy demands through biomass anaerobic digestion (AD). Efficient digestate management, employing techniques like solid-liquid separation and composting, is crucial for environmental protection. The goal is to optimize nutrient-rich byproduct utilization while minimizing negative impacts. This review analyzes diverse substrates, emphasizing challenges and benefits. Key considerations include nutrient ratios, moisture content, co-digestion, organic loading rate, and retention time. The study explores temperature's impact on microbial growth, biogas impurities, and upgradation techniques, including biological methods. Fermentation, microbial electrochemical techniques, and biochar use for enhanced AD are introduced. Discussing digestate's multifaceted aspects, the review highlights its nutrient value and diverse applications in aquaculture, animal feed, fermentation, bioremediation, and fine chemical production.

Despite the increasing global need for sustainable energy, biomass gasification is becoming a highly promising method for transforming raw biomass into usable energy. The present review article analyzes the essential aspects of biomass-based energy production, starting with an assessment of existing energy needs and the crucial contribution that biomass can make in fulfilling these demands. The research investigates recent advancements in several biomass gasification methods, explaining their mechanics and discussing the related difficulties. The research conducts a thorough evaluation of the efficiency, yield, and environmental consequences of biomass gasification, aiming to determine the feasibility of the technique. In addition, the study rigorously assesses the techno-economic factors of energy generation from biomass, providing valuable information on the economic viability and scalability of various biomass gasification techniques. The present study is focused on providing a comprehensive understanding of biomass gasification by analyzing current improvements and conducting a techno-economic comparison to make well-informed decisions for a sustainable energy future.

Carbon dioxide (CO₂) is a greenhouse gas which is mainly found in natural gas (NG), biogas, and flue gas. Anthropogenic CO₂ emissions are the direct result of burning fossil fuels. Meanwhile, pre- and postcombustion CO₂ separation is a current state of CO₂ removal method in an extensive manner. From environmental, economic, and transportation perspectives, removal of CO₂ has driven the development of its separation process technology. Among the reported technologies, membrane-based gas separation technologies have grown substantially, breakthroughs and advances in past decades. This review paper aims to provide an overview on competitive gas separation processes, different types of membranes available, gas transport mechanisms, and fabrication process of hollow fiber membranes, particularly dual-layer hollow fiber membrane. The performance of the membranes in CO₂ separation and effect of spinning parameters on the formation of hollow fiber membranes are highlighted. In addition, approaches to improve the dual-layer adhesion, strategies to enhance the filler compatibility in the development of dual-layer hollow fiber mixed-matrix membranes, and effect of post-treatments on the gas separation performance of membrane are also discussed. Finally, challenges and future perspectives of dual-layer hollow fiber mixed-matrix membranes toward CO₂ capture, particularly on CO₂/CH₄ and CO₂/N₂ separation, are also included, due to its substantial and direct relevance to the gas separation industry.

Cellulose is a natural fibrous carbohydrate, is the main structural element of plant cell walls, and is the most abundant natural polymer found in the biosphere. Due to its abundance and chemical stability, it has been used as a raw material in various industries for thousands of years. Due to developments in nanotechnology, materials that are used in macroscale abundantly are also utilized for nanomaterial design, and cellulose-based nanomaterials have gained more interest in recent years. The unique properties of cellulose-based nanomaterials including their chemical stability, high degree of crystallinity, biocompatibility, biodegradability, and tunability of their chemical (e.g., surface modification) and physical (e.g., shape) properties make them good candidates for functional nanomaterial design. This review brings advances in cellulose-based nanomaterials for application in two major fields, sustainability and therapeutics.

Lignocellulosic biomass, such as plant residues and agricultural waste, holds immense potential as a renewable resource for the production of biofuels, chemicals, and animal feed. However, the efficient degradation of lignocellulose into fermentable sugars remains a significant challenge. Recent research has highlighted the critical role of microbial diversity in lignocellulosic biomass degradation, offering new insights from a biotechnological perspective. The comprehension and utilization of microbial diversity are crucial for developing efficient biotechnological strategies for lignocellulosic biomass degradation. By uncovering the intricate relationships between microbial communities and their enzymatic machinery, researchers can optimize degradation processes, enhance biofuel production, and contribute to a more sustainable bio-based economy. Microorganisms, including bacteria, fungi, and archaea, possess diverse enzymatic capabilities, allowing them to secrete a plethora of lignocellulolytic enzymes. Microbial organisms inhabiting extreme environments, such as the rumen, hot and cold springs, deep sea trenches, and acidic and alkaline pH environments, exhibit significant potential in generating enzymes, including hemicellulolytic and lignocellulolytic enzymes, which possess superior biochemical properties essential for industrial bioconversion applications. This review explores the ability of lignocellulosic enzymes from microbial sources to efficiently break down the lignocellulosic biomass and their potential applications in industrial biotechnology.

Currently, nanotechnology is developing at an exponential rate because of its widespread applications in various fields of life sciences. Traditionally, nanoparticles are fabricated through a variety of physical and chemical approaches but because of their limited efficiency in biomedical applications, biogenic synthesis of nanoparticles has gained much attention. Biogenically fabricated magnesium oxide nanoparticles (MgONPs) possess unique features that enabled their use in therapeutics and environmental biotechnology. Biogenically MgONPs can be fabricated using plant extracts (Manihot esculenta, Rhizophora lamarckii, Ocimum sanctum, rosemary, Bauhinia purpurea, and others), bacteria (S. coelicolor, A. johnsonii RTN), fungi (Aspergillus flavus TFR-12, Aspergillus brasiliensis TFR 2, white-button mushroom's) and algae (S. whigti). These biogenically synthesized MgONPs are being reported as antifungal, antioxidant, antibacterial, antipyretic, anti-inflammatory, and anticancer agents. Moreover, their photocatalytic activity is far being discovered against certain organic dyes. This review focuses on the biogenic synthesis of MgONPs, their applications in therapeutics, and as antimicrobial agents as well as future prospects associated with their applications in the biomedical field.

Zinc oxide (ZnO) is a promising material with a diverse range of applications, spanning gas sensing, photonics, photovoltaics, energy conversion, water splitting, photocatalysis, and transparent trapping. However, ZnO limited responsiveness to visible light affected to low photogenerated electron-hole pairs (charge), low quantum efficiency, and high recombination of charge. In this review, we are addressing innovative strategies, including incorporation rare earth elements as a trap of electron to reduce recombination charge via ZnO doping from analysis 118 referenced sources. We found that hydrothermal shows very good methods for boosting efficiency up to 100 % within 60-min. We found that for rare-earth metals La and Ce as a doping show highest efficiency up to 100 % within 120 min irradiations, means that efficient as a trap for reducing recombination of charge. The potential of rare earth doped ZnO will enhance photogenerated electron-hole pairs, catalyzing the generation of radical atoms via oxidation and reduction reactions. This review encapsulates the most current findings, it serves as a valuable resource for scholars seeking to advance their understanding of rare earth doped ZnO photocatalysts and developing innovative photocatalytic technologies.

Novel ceramic membranes present unquestionable potential in wastewater treatment among the emerging technologies, while a few challenges such as cost, energy consumption, durability, and resistance in harsh mediums still limit their commercialization. Here, we review the capability of available industrial aluminosilicate waste materials in the fabrication of novel ceramic membranes using green and economical alkali-activation synthesis method. The different sources of alkali-activated aluminosilicate wastes including ashes, mining wastes, glass and ceramic wastes, slags, construction wastes, industrial byproducts, and agricultural wastes are introduced and the chemistry of geopolymers is reviewed. In this review, the major points are the following. 1) The alkali-activated structures present reasonable chemical, frost, carbonation, and mechanical resistance as well as the ability to immobilize the toxic materials. 2) The synthesis aspects of porous and nonporous alkali-activated ceramic membranes are explored by characterization methods. Furthermore, the durability analysis in harsh environments reveals that alkali-activated ceramic membranes possess high resistance against acidic, alkaline, and other antifouling chemical washing methods. In summary, it is demonstrated that the studied membranes have an undeniable capability in the separation of organic solvents in the pervaporation process as well as toxic material removal from water with high ion-exchange capacity.