Exploitation of lignocellulosic-based biomass biorefinery: A critical review of renewable bioresource, sustainability and economic views

Lignocellulosic biomass-derived functional nanocellulose for food-related applications: A review

In recent years, nanocellulose (NC) has gained significant attention due to its remarkable properties, such as adjustable surface chemistry, extraordinary biological properties, low toxicity and low density. This review summarizes the preparation of NC derived from lignocellulosic biomass (LCB), including cellulose nanofibrils (CNF), cellulose nanocrystals (CNC), and lignin-containing cellulose nanofibrils (LCNF). It focuses on examining the impact of non-cellulosic components such as lignin and hemicellulose on the functionality of NC. Additionally, various surface modification strategies of NC were discussed, including esterification, etherification and silylation. The review also emphasizes the progress of NC application in areas such as Pickering emulsions, food packaging materials, food additives, and hydrogels. Finally, the prospects for producing NC from LCB and its application in food-related fields are examined. This work aims to demonstrate the effective benefits of preparing NC from lignocellulosic biomass and its potential application in the food industry.

A high-performance anion-exchange chromatographic method for the fast analysis and precise determination of varied glucose-derived acids during biomass biorefinery

Glucose-derived acids for the further production of value-added medicine, food additives, and polymers, will promote lignocellulosic biomass biorefinery industry. In response to the diversity and complexity, a new method was established by employing high performance anion exchange chromatography (HPAEC) coupled with a CarboPac™ PA200 column, for the precise and fast determination of glucose, gluconic acid, glucuronic acid, 2-ketogluconic acid, 5-ketogluconic acid and glucaric acid. Based on the analysis of tiny varieties in retention behavior, a gradient elution mode was designed and optimized for the quantitative and qualitative analysis. The protocol displayed acceptable linearity (R2 ≥ 0.995), commendable average recovery rate (95.28% ∼ 99.89%), satisfactory precision (RSD% ≤ 1.5%), and sufficient resolution (R > 6). Additionally, this method was successfully applied to the high-value biorefining process, which confirmed the practicability and accuracy. The results demonstrated that HPAEC has good detection performance for glucose and its derivative acids, and provide key identification technical support for the high-value utilization of lignocellulose.

A review of valorization of agricultural waste for the synthesis of cellulose membranes: Separation of organic, inorganic, and microbial pollutants

Agricultural waste presents a significant environmental challenge due to improper disposal and management practices, contributing to soil degradation, biodiversity loss, and pollution of water and air resources. To address these issues, there is a growing emphasis on the valorization of agricultural waste. Cellulose, a major component of agricultural waste, offers promising opportunities for resource utilization due to its unique properties, including biodegradability, biocompatibility, and renewability. Thus, this review explored various types of agricultural waste, their chemical composition, and pretreatment methods for cellulose extraction. It also highlights the significance of rice straw, sugarcane bagasse, and other agricultural residues as cellulose-rich resources. Among the various membrane fabrication techniques, phase inversion is highly effective for creating porous membranes with controlled thickness and uniformity, while electrospinning produces nanofibrous membranes with high surface area and exceptional mechanical properties. The review further explores the separation of pollutants including using cellulose membranes, demonstrating their potential in environmental remediation. Hence, by valorizing agricultural residues into functional materials, this approach addresses the challenge of agricultural waste management and contributes to the development of innovative solutions for pollution control and water treatment.

Integral multi-valorization of agro-industrial wastes: A review

Agriculture and industries related to the agriculture sector generate a large amount of waste each year. These wastes are usually burned or dumped, causing damage to the environment, the economy and society. Due to their composition, they have great potential for obtaining high value-added products in biorefineries. This fact, added to the growing demand for energy and chemicals from fossil resources, is driving the interest of the scientific community in them. Biorefinery processes are hardly profitable when applied individually, so a better alternative is to develop integrated multi-feedstock and multi-product biorefinery schemes using all biomass fractions in a zero-waste approach. However, for industrial scale application, extensive research, scale-up studies, and techno-economic and environmental feasibility analyses are needed. This review compiles information on integrated multi-biorefinery processes from agro-industrial wastes to shed light on the path towards sustainable development and circular bioeconomy.

All-Cellulose Nanofiber-Based Sustainable Triboelectric Nanogenerators for Enhanced Energy Harvesting

Triboelectric nanogenerators (TENGs) show promising potential in energy harvesting and sensing for various electronic devices in multiple fields. However, the majority of materials currently utilized in TENGs are unrenewable, undegradable, and necessitate complex preparation processes, resulting in restricted performance and durability for practical applications. Here, we propose a strategy that combines straightforward chemical modification and electrospinning techniques to construct all-cellulose nanofiber-based TENGs with substantial power output. By using cellulose acetate (CA) as the raw material, the prepared cellulose membranes (CMs) and fluorinated cellulose membranes (FCMs) with different functional groups and hydrophobic properties are applied as the tribopositive and tribonegative friction layers of FCM/CM-based triboelectric nanogenerators (FC-TENGs), respectively. This approach modulates the microstructure and triboelectric polarity of the friction materials in FC-TENGs, thus enhancing their triboelectric charge densities and contact areas. As a result, the assembled FC-TENGs demonstrate enhanced output performance (94 V, 8.5 µA, and 0.15 W/m2) and exceptional durability in 15,000 cycles. The prepared FC-TENGs with efficient energy harvesting capabilities can be implemented in practical applications to power various electronic devices. Our work strengthens the viability of cellulose-based TENGs for sustainable development and provides novel perspectives on the cost-effective and valuable utilization of cellulose in the future.

Municipal solid waste management challenges in developing regions: A comprehensive review and future perspectives for Asia and Africa

The rapid urbanization witnessed in developing countries in Asia and Africa has led to a substantial increase in municipal solid waste (MSW) generation. However, the corresponding disposal strategies, along with constraints in land resources and finances, compounded by unorganized public behaviour, have resulted in ineffective policy implementation and monitoring. This lack of systematic and targeted orientation, combined with blind mapping, has led to inefficient development in many areas. This review examines the key challenges of MSW management in developing countries in Asia and Africa from 2013 to 2023, drawing insights from 170 academic papers. Rather than solely focusing on recycling, the study proposes waste sorting at the source, optimization of landfill practices, thermal treatment measures, and strategies to capitalize on the value of waste as more pertinent solutions aligned with local realities. Barriers to optimizing management systems arise from socio-economic factors, infrastructural limitations, and cultural considerations. The review emphasizes the importance of integrating the study area into the circular economy framework, with a focus on enhancing citizen participation in solid waste reduction and promoting recycling initiatives, along with seeking economic assistance from international organizations.

Screw reactor design for potato peel pretreatment using the steam explosion

In this article we can observe the scanning by the literature for the pretreatment of steam explosion applied to lignocellulose biomass. A comparison of the chemical and physical characterization of potato peel as a lignocellulose biomass. Besides, the innovative design of a continuous reactor for the potato peel steam explosion process is shown, with specific temperature and pressure conditions on a pilot scale, detailing its parts. Finally, a finite element analysis was performed where stress results were obtained from the reactor material, severity factor, structural analysis and thermal analysis, providing a panorama of the reactor's behavior with the conditions specific.

Efficient hemicellulose removal from lignocellulose by induced electric field-aided dilute acid pretreatment

This study evaluated the effectiveness of induced electric field (IEF) as a novel electrotechnology to assist dilute acid pretreatment of wheat straw (WS) at atmospheric pressure and low temperature (90 °C). The effects of acid concentration and duration on cellulose recovery, hemicellulose and lignin removal were investigated. Meanwhile, the differences between IEF pretreatment and hydrothermal pretreatment were compared by quantitative and qualitative analysis. The optimal pretreatment condition was acid concentration 1 % with the period of 5 h. Under the parameters, the hemicellulose removal of WS after IEF pretreatment was up to 73.6 %, and the enzymatic efficiency was 55.8 %. In addition, the irregular surface morphology, diminished functional groups associated with hemicellulose, increased specific surface area and pore volume, as well as improved thermal stability of the residual WS support the remarkable effect of IEF pretreatment. The feasibility of IEF pretreatment is might be due to the fact that the magneto-induced electric field promotes ionization of H+ and formation of hydrated hydrogen ions, increasing the acidity of the medium. Secondly, electroporation disrupts the anti-degradation structure of WS and increases the accessibility of cellulose to cellulases. It indicated that IEF is a green and efficient strategy for assisting the separation of hemicellulose from lignocellulose.

Characterization of a novel thermostable α-l-arabinofuranosidase for improved synergistic effect with xylanase on lignocellulosic biomass hydrolysis without prior pretreatment

Utilizing thermostable enzymes in biomass conversion processes presents a promising approach to bypass pretreatment, garnering significant attention from the biorefinery industry. A novel discovered α-l-arabinofuranosidase, Abf4980, exhibits exceptional thermostability by maintaining full activity after 24 h of incubation at 70 °C. It effectively acts on polyarabinosides, cleaving α-1,2- and α-1,3-linked arabinofuranose side chains from water-soluble wheat arabinoxylan while releasing xylose. When synergistically combined with the thermostable bifunctional xylanase/β-glucanase CbXyn10C from Caldicellulosiruptor bescii at an enzyme-activity ratio of 6:1, Abf4980 achieves the highest degradation efficiency for wheat arabinoxylan. Furthermore, Abf4980 and CbXyn10C demonstrated remarkable efficacy in hydrolyzing unmodified wheat bran and corn cob to generate arabinose and xylooligosaccharides. This discovery holds promising opportunities for improving the efficiency of lignocellulosic biomass conversion into fermentable sugars.

A review on waste biomass-to-energy: integrated thermochemical and biochemical conversion for resource recovery

Integrating thermochemical–biochemical methods overcomes the single-path limits for bioenergy production. This synergy lowers costs and enhances energy sustainability, highlighting waste-to-energy's vital role in the circular economy transition.

Enhanced production of a recombinant xylanase (XT6): optimization of production and purification, and scaled-up batch fermentation in a stirred tank bioreactor

The endoxylanase XT6 produced by Geobacillus stearothermophilus is a desirable candidate for industrial applications. In this study, the gene encoding XT6 was cloned using the pET-28a expression vector and expressed in Escherichia coli BL21 (DE3) cells. Recombinant XT6 production was improved by optimizing cell lysis (sonication, chemical, and enzymatic lysis) and expression conditions. Sonication in a 0.05 M sodium phosphate (pH 6.0) buffer resulted in the highest xylanase activity (16.48 U/ml). Screening and optimization of induction conditions using the Plackett-Burman Design and Box-Behnken Design (BBD) approaches revealed that cell density pre-induction (OD600 nm), post-induction incubation time, and IPTG concentration significantly (p < 0.05) influenced the expression levels of XT6 (16.48 U/ml to 40.06 U/ml) representing a 3.60-fold increase. BBD resulted in a further 8.74-fold increase in activity to 144.02 U/ml. Batch fermentation in a 5-l stirred tank bioreactor at 1 vvm aeration boosted recombinant xylanase production levels to 165 U/ml suggesting that heterologous expression of the XT6 enzyme is suitable for scaled-up production. The pure enzyme with a molecular weight of 43 kDa and a 15.69-fold increase in purity was obtained using affinity chromatography and a cobalt column. Future studies will include application of the purified recombinant xylanase to animal feed.