Evaluation of the inter-particle interference of cellulose and lignin in lignocellulosic materials

Utilization of plant-derived wastes as the potential biohydrogen source: a sustainable strategy for waste management

The sustainable economy has shown a renewed interest in acquiring access to the resources required to promote innovative practices that favor recycling and the reuse of existing, unconsidered things over newly produced ones. The production of biohydrogen through dark anaerobic fermentation of organic wastes is one of the intriguing possibilities for replacing fossil-based fuels through the circular economy. At present, plant-derived waste from the agro-based industry is the main global concern. When these wastes are improperly disposed of in landfills, they become the habitat for several pathogens. Additionally, it contaminates surface water as a result of runoff, and the leachate that is created from the waste enters groundwater and degrades its quality. However, cellulose and hemicellulose-rich plant wastes from agriculture fields and agro-based industries have been employed as the most efficient feedstock since carbohydrates are the primary substrate for the synthesis of biohydrogen. To produce biohydrogen from plant-derived wastes on a large scale, it is necessary to explore comprehensive knowledge of lab-scale parameters and pretreatment strategies. This paper summarizes the problems associated with the improper management of plant-derived wastes and discusses the recent developments in dark fermentation and substrate pretreatment techniques with the goal of gaining significant insight into the biohydrogen production process. It also highlights the utilization of anaerobic digestate, which is left over after biohydrogen gas as feedstock for the development of value-added products such as volatile fatty acids (VFA), biochar, and biofertilizer.

A review on potential of green solvents in hydrothermal liquefaction (HTL) of lignin

One of the greatest challenges in biorefinery is to reduce biomass' recalcitrance and enable valorization of lignin into higher value compounds. Likewise, green solvents and hydrothermal liquefaction (HTL) with feasible economic viability, functionality, and environmental sustainability have been widely introduced in extraction and conversion of lignin. This review starts with the underscore of disadvantages and limitations of conventional pretreatment approaches and role of green solvents in lignin extraction. Subsequently, the effect of process parameters along with the reaction mechanisms and kinetics on conversion of lignin through HTL were comprehensively reviewed. The limitations of green solvents in extraction and HTL of lignin from biomass were discussed based on the current advancements of the field and future research scopes were also proposed. More details info on HTL of biomass derived lignin which avoid the energy-intensive drying procedures are crucial for the accelerated development and deployment of the advanced lignin biorefinery.

Production and characterization of bamboo-based activated carbon through single-step H3PO4 activation for CO2 capture

Bamboo is the fastest-growing plant and is abundant in Malaysia. It is employed as a starting material for activated carbon production and evaluated for its potential in CO₂ capture. A single-stage phosphoric acid (H₃PO₄) activation is adopted by varying the concentrations of H₃PO₄ between 50 and 70 wt.% at a constant temperature and holding time of 500°C and 120 min, respectively. The bamboo-based activated carbons are characterized in terms of product yield, surface area, and porosity, as well as surface chemistry properties. Referring to the experimental findings, the prepared activated carbons have BET surface area of >1000 m² g^-1, which implies the effectiveness of the single-stage H₃PO₄ activation. Furthermore, the prepared activated carbon via 50 wt.% H₃PO₄ activation shows the highest BET surface area and carbon dioxide (CO₂) adsorption capacity of 1.45 mmol g^-1 at 25°C/1 bar and 9.0 mmol g^-1 at 25°C/30 bar. With respect to both the characterization analysis and CO₂ adsorption performance, it is concluded that bamboo waste conversion to activated carbon through H₃PO₄ activation method is indeed promising.

A Review: Research Progress in Modification of Poly (Lactic Acid) by Lignin and Cellulose

With the depletion of petroleum energy, the possibility of prices of petroleum-based materials increasing, and increased environmental awareness, biodegradable materials as a kind of green alternative have attracted more and more research attention. In this context, poly (lactic acid) has shown a unique combination of properties such as nontoxicity, biodegradability, biocompatibility, and good workability. However, examples of its known drawbacks include poor tensile strength, low elongation at break, poor thermal properties, and low crystallization rate. Lignocellulosic materials such as lignin and cellulose have excellent biodegradability and mechanical properties. Compounding such biomass components with poly (lactic acid) is expected to prepare green composite materials with improved properties of poly (lactic acid). This paper is aimed at summarizing the research progress of modification of poly (lactic acid) with lignin and cellulose made in in recent years, with emphasis on effects of lignin and cellulose on mechanical properties, thermal stability and crystallinity on poly (lactic acid) composite materials. Development of poly (lactic acid) composite materials in this respect is forecasted.

Bioethanol Production by Enzymatic Hydrolysis from Different Lignocellulosic Sources

As the need for non-renewable sources such as fossil fuels has increased during the last few decades, the search for sustainable and renewable alternative sources has gained growing interest. Enzymatic hydrolysis in bioethanol production presents an important step, where sugars that are fermented are obtained in the final fermentation process. In the process of enzymatic hydrolysis, more and more new effective enzymes are being researched to ensure a more cost-effective process. There are many different enzyme strategies implemented in hydrolysis protocols, where different lignocellulosic biomass, such as wood feedstocks, different agricultural wastes, and marine algae are being used as substrates for an efficient bioethanol production. This review investigates the very recent enzymatic hydrolysis pathways in bioethanol production from lignocellulosic biomass.

A Review of Lignocellulosic-Derived Nanoparticles for Drug Delivery Applications: Lignin Nanoparticles, Xylan Nanoparticles, and Cellulose Nanocrystals

Due to their biocompatibility, biodegradability, and non-toxicity, lignocellulosic-derived nanoparticles are very potential materials for drug carriers in drug delivery applications. There are three main lignocellulosic-derived nanoparticles discussed in this review. First, lignin nanoparticles (LNPs) are an amphiphilic nanoparticle which has versatile interactions toward hydrophilic or hydrophobic drugs. The synthesis methods of LNPs play an important role in this amphiphilic characteristic. Second, xylan nanoparticles (XNPs) are a hemicellulose-derived nanoparticle, where additional pretreatment is needed to obtain a high purity xylan before the synthesis of XNPs. This process is quite long and challenging, but XNPs have a lot of potential as a drug carrier due to their stronger interactions with various drugs. Third, cellulose nanocrystals (CNCs) are a widely exploited nanoparticle, especially in drug delivery applications. CNCs have low cytotoxicity, therefore they are suitable for use as a drug carrier. The research possibilities for these three nanoparticles are still wide and there is potential in drug delivery applications, especially for enhancing their characteristics with further surface modifications adjusted to the drugs.

Biopolymeric Delivery Systems for Cosmetic Applications Using Chlorella vulgaris Algae and Tea Tree Essential Oil

Cosmetic products in which all the skincare compounds are biomolecules, biocompatible and biodegradable constitute a request of an educated consumer corresponding to a premium cosmetic segment. For this purpose, a cellulose-based delivery system was developed to retain biomolecules for dermic applications. The 3D matrix was built with microfibrillated cellulose, nanofibrillated cellulose and carboxymethylcellulose combined with a crosslinking agent, the alginate, to obtain a 3D matrix capable of retaining and releasing bioactive components of microalgae Chlorella vulgaris and tea tree essential oil. The porosity and pore dimensions and uniformity of this support matrix were optimized using 3D computational tools. The structures of the biopolymers were characterized using SEM, EDX, FTIR-ATR and DSC techniques. The essential oil and the microalgae components were successfully incorporated in a 3D stable matrix. The results indicate that the polymeric matrix retains and releases the essential oil biomolecules in a controlled way, when compared with tea tree essential oil, which is vaporized from 25 °C to 38 °C, without this 3D polymeric matrix. The microalgae and cellulose-based delivery system proved to be an interesting option for dermic and cosmetic applications because the exposure time of the therapeutic biomolecules was improved, and this factor consists of a competitive benefit for dermic systems.