Pretreatment of poplar with eco-friendly levulinic acid to achieve efficient utilization of biomass

Efficient Separation of Poplar Lignin Using a New Carboxylic Acid-Based Deep Eutectic Solvents - Choline Chloride/Malonic Acid

Separation of lignin by pretreatment is an important step in biomass refining. This study investigated how a novel dicarboxylic acid-based deep eutectic solvent (DES) - choline chloride (ChCl)/malonic acid (MA) - affected the process of separating lignin from poplar. At 140 °C for 3.0 h, with a ChCl: MA molar ratio of 1: 3.5, the ideal pretreatment conditions were met, and 91.8 % lignin was obtained. Even after five DES reuses, the consistent and effective separation efficiency of 77.9 % remains unchanged. The hydrolysate contained 92.4 % of the recovered lignin, with a purity of 94.6 %. Moreover, the regenerated lignin obtained through the new DES pretreatment exhibited a high phenolic hydroxyl content of 1.9 mmol g-1 and a low polydispersity index of 1.4. The results showed efficient and selective separation of lignin using the new binary carboxylic acid-based DES pretreatment was achieved. This research offers a novel approach to effectively separate wood fiber biomass and extract valuable lignin.

Research progress on organic acid pretreatment of lignocellulose

Lignocellulosic biomass is a naturally occurring, renewable resource that is utilized to produce a variety of high-value-added products, such as fuels, acids, and building block chemicals. The pretreatment of lignocellulosic biomass is a crucial step in the deconstruction and fractionation of its components. Organic acids, such as formic, acetic, lactic, and maleic acids, have been widely studied for their effectiveness in lignocellulose pretreatment. Organic acid-based pretreatment techniques are gaining increased attention due to their ability to selectively separate hemicellulose and cellulose, promote oligomer formation, and minimize byproducts. This paper presents a comprehensive review of the various advancements in the science and application of organic acids for the pretreatment of lignocellulose. Furthermore, the significant challenges of organic acid recovery after pretreatment are highlighted, and different recovery methods are discussed. The future challenges related to utilizing organic acids for lignocellulose pretreatment are summarized, with a strong emphasis on adopting a sustainable approach to converting valuable bioresources into renewable products.

Selective separation of poplar hemicellulose and simultaneous enrichment of soluble xylose in the hydrolysate by itaconic acid pretreatment

Organic-acid pretreatments designed to efficiently separate hemicellulose and preserve high-value soluble monosaccharides in hydrolysates have become a significant research focus. In this study, the efficiency of the catalytic degradation of a lignocellulosic model using itaconic acid (IA) was evaluated. The exceptional selectivity of IA for xylan degradation was confirmed. The separation yield of poplar fractions was assessed after IA pretreatment. The yield of xylose was 81.91 % under the optimal conditions (IA concentration: 5.0 wt%, 160 °C, 60 min). The hydrolysate contained up to 12.10 g/L xylose, exceeding that obtained with formic acid and levulinic acid pretreatments. The simultaneous separation of hemicellulose and protection of soluble sugars was achieved. The high crystallinity index (66.69 %) of the residual solid (RS) confirmed the effective protection of cellulose by IA pretreatment. Additionally, the lignin in the RS contained 53.45 % β-O-4 and 1.21 mmol/g phenolic hydroxyl. This suggests that the IA-pretreated lignin retains more active functional groups, which are advantageous for subsequent conversion and utilization. These findings offer a novel approach for efficient hemicellulose separation and the effective protection of soluble xylose during organic-acid pretreatment.

Deep eutectic solvent-mediated extraction of lignin: A novel strategy for producing high-quality biopolymers in controlled-release mulching applications

Microplastic contamination of low-density polyethylene mulch and nutrient loss from fertilizers present significant challenges in the crop-growing. In this study, the focus was on creating a biodegradable film that combines the advantages of plastic film, thermal insulation and water retention, as well as the controlled release of fertilizer. A key innovation was the efficient introduction of low molecular weight and low dispersibility of poplar lignin into chitosan and polyvinyl alcohol matrices. The lignin was extracted using deep eutectic solvents of binary carboxylic acids (choline chloride and maleic acid). The refined lignin was used as a superhydrophobic additive to improve the mechanical properties, hydrophobicity, and controlled nutrient release properties of the films through cross-linking. The mulch attained a tensile strength of 37.6 MPa, an elongation of 644.1 %, and a precise release of 53.1 % urea over 30 d at the ideal lignin content ratio (10 %). Furthermore, the film proficiently regulated soil temperature and moisture content. Successful enhancement of cabbage growth was achieved by actual measurements. This discovery provides innovative ideas for the development of nutrient slow-release high-strength integrated agricultural mulching films to promote sustainable, high-quality green agriculture.

Applications of modified lignocellulose and its composites prepared by different pretreatments in biomedicine: A review

Lignocellulosic biomass represents one of the most abundant renewable biological resources on earth. Despite its current underutilization as a source of high-value chemicals, it has promising applications in biomedical and other fields. Presently, lignocellulose is predominantly transformed into high-value-added products, e.g. cellulose nanocrystals (CNCs), cellulose nanofibers (CNFs), etc., through a variety of physical, chemical and biological methods. The mechanical properties and biocompatibility of these products make them important as vital components in drug delivery agents and tissue engineering materials in the biomedical field. This review offers a comprehensive overview of the underexploited lignocellulosic biomass, the main pretreatment methods for converting it into valuable compounds, and the associated limitations. It also highlights the emerging applications of these compounds in the biomedical field, including sensors, wound dressings, excipients, and artificial skin. In addition, current commercialized products and related regulations are discussed, and future research advancements in this field are also envisaged.

Integrated approach for cellulosic ethanol and succinic acid production: Gamma valerolactone-based pretreatment and co-fermentation of peanut shells

The inability to utilize pentose poses as a significant limitation to the production of cellulosic ethanol. To attain efficient raw material conversion and mitigate carbon dioxide emissions during cellulosic ethanol synthesis, a integrated approach focused on the co-processing of ethanol and succinic acid (SA) from peanut shells was proposed. The results demonstrated that the GVL system, containing 30 % water and catalyzed by dilute sulfuric acid, exhibited remarkable efficiency in pretreatment, boosting glucose yield sixfold relative to the untreated raw material. Under optimal conditions of 82 mM sulfuric acid, 141 °C, 56 min, and a solid-to-liquid ratio of 0.07, the glucose yield of the pretreated peanut shell reached 79.0 ± 0.22 %. Through recycling the pretreatment solvent, Tween 80-assisted enzymatic catalysis, and coupling of saccharification and co-fermentation processes, the complete utilization of lignocellulosic feedstocks and sustainable production of high titers of SA (86.1 g/kg) and ethanol (66.4 g/kg) were achieved. This study developed a novel integrated procedure for the efficient co-production of SA and ethanol from peanut shells, offering a new perspective for the efficient biorefinery of lignocellulosic biomass.

Preparation of hydrophobic and lipophilic carboxymethyl cellulose composite aerogel using ferrous ion/ persulfate and its directed oxidation for oil-water emulsion separation

In particular, efficient oxidative demulsification is an effective method for oil-water separation. However, the inactivation of free radicals owing to the rapid release of transition metals is the main factor that reduces the effectiveness. In this study, a hydrophobic and lipophilic CP/SiO2@Fe2+ composite aerogel was prepared using carboxymethyl cellulose as substrate, polyvinyl alcohol as reinforcement, and SiO2 nanoparticles as hydrophobic modifier. The resulting aerogel had a water contact angle of 139°, oil absorption yield of 99.9 %, higher specific surface area 132.13 m2·g-1, low density of 0.021 g·cm-3, and high porosity of 98.60 %. Fe2+ was slowly released from the composite aerogel after efficient Fe2+ loading of 65.77 mg·g-1. The drug exhibited a low release rate of 87.72 % after 9 h, which was higher than that of the composite aerogel. This promoted the efficient presence of SO4-· activated from persulfate oxidation in the catalytic oxidative demulsification system over a long period. The green and efficient separation of oily-water was achieved by the synergistic effect of the adsorption of the hydrophobic and lipophilic composite aerogel and targeted and efficient oxidative demulsification. These results demonstrate the advantages of high separation efficiency, durability, stability of the CP/SiO2@Fe2+ composite aerogel for oil-water separation.

Fractionation of lignin and fermentable sugars from wheat straw using an alkaline hydrogen peroxide/pentanol biphasic pretreatment

To breakthrough the delignification saturation point (DSP) of alkaline hydrogen peroxide (AHP) pretreatment, a biphasic AHP/pentanol (AHPP) pretreatment was proposed in this work. The temperature and H2O2 concentration were evaluated. Under the optimal conditions (110 °C, 2 h, 4 % H2O2), 70.73 % of lignin was removed, which was increased by 11.65 % than the traditional AHP pretreatment, indicating successful overcoming of the DSP by adding pentanol. 85.74 % and 88.62 % of glucan and xylan digestibility were achieved, respectively, which increased by 7.41 % and 5.87 % as compared to AHP pretreatment. Furthermore, the lignin extracted from the organic phase accounted for 38.51 % of the delignification, and it had a low molecular weight, effectively preserving the β-O-4 bonds. Finally, satisfied pentanol recovery (77.91 %) and delignification (57.19 %) along with excellent glucan (76.11 %) and xylan (77.52 %) digestibility were reached after fourth recycling of AHPP pretreatment. Therefore, AHPP pretreatment was a promising method for biomass valorization within biorefinery concept.

Optimizing lignin demethylation using a novel proton- based ionic liquid: 1, 2-propanediamine/glycolic acid catalyst

Demethylation modification of lignin is an effective strategy to overcome the barrier to its high-value conversion. The purpose of this study focuses on the new proton-based ionic liquid (PIL) 1, 2-propanediamine/glycolic acid (PD/GA) as a catalyst and solvent to achieve the targeted oxidation of lignin. The PD/GA solvents have higher selectivity and efficiency. Optimal phenolic hydroxyl (PH)-increment was achieved, demonstrating enhanced demethylating effect on lignin by modulating the acid-base molar ratio, reaction temperature, and reaction time. Compared to ethanolamine/acetic acid (CE/AC) treatment, the PD/GA treatment at molar ratio 1.25, temperature 60 °C, and 3 h increased the PH-content from 37.74 to 59.91 %. Additionally, the lignin treated with PD/GA exhibited excellent recyclability, featuring a larger Brunauer-Emmett-Teller surface area (1.45 m2.g-1), total pore volume (9.51*10-3 cm3.g-1), and mesoporous size (26.15 nm). The treated lignin yielded maximum ultraviolet resistance and antioxidant activity. These results present new avenues for the development of green and efficient lignin demethylation methods.

The outlooks and key challenges in renewable biomass feedstock utilization for value-added platform chemical via bioprocesses

The conversion of renewable biomass feedstock into value-added products via bioprocessing platforms has become attractive because of environmental and health concerns. Process performance and cost competitiveness are major factors in the bioprocess design to produce desirable products from biomass feedstock. Proper pretreatment allows delignification and hemicellulose removal from the liquid fraction, allowing cellulose to be readily hydrolyzed to monomeric sugars. Several industrial products are produced via sugar fermentation using either naturally isolated or genetically modified microbes. Microbial platforms play an important role in the synthesis of several products, including drop-in chemicals, as-in products, and novel compounds. The key elements in developing a fermentation platform are medium formulation, sterilization, and active cells for inoculation. Downstream bioproduct recovery may seem like a straightforward chemical process, but is more complex, wherein cost competitiveness versus recovery performance becomes a challenge. This review summarizes the prospects for utilizing renewable biomass for bioprocessing.

Composition of Lignocellulose Hydrolysate in Different Biorefinery Strategies: Nutrients and Inhibitors

The hydrolysis and biotransformation of lignocellulose, i.e., biorefinery, can provide human beings with biofuels, bio-based chemicals, and materials, and is an important technology to solve the fossil energy crisis and promote global sustainable development. Biorefinery involves steps such as pretreatment, saccharification, and fermentation, and researchers have developed a variety of biorefinery strategies to optimize the process and reduce process costs in recent years. Lignocellulosic hydrolysates are platforms that connect the saccharification process and downstream fermentation. The hydrolysate composition is closely related to biomass raw materials, the pretreatment process, and the choice of biorefining strategies, and provides not only nutrients but also possible inhibitors for downstream fermentation. In this review, we summarized the effects of each stage of lignocellulosic biorefinery on nutrients and possible inhibitors, analyzed the huge differences in nutrient retention and inhibitor generation among various biorefinery strategies, and emphasized that all steps in lignocellulose biorefinery need to be considered comprehensively to achieve maximum nutrient retention and optimal control of inhibitors at low cost, to provide a reference for the development of biomass energy and chemicals.

Cellulose separation from ramie bone by one step process with green hydrogen peroxide-citric acid

Ramie bone (RB), an agricultural waste generated in the textile industry, is a vastly productive renewable natural resource with the potential to be used as a source of cellulose. In this study, ramie bone cellulose (RB-CE) was obtained in one step using a simple and ecologically friendly hydrogen peroxide-citric acid (HPCA) treatment procedure that avoided the use of halogenated reagents and strong acids while also streamlining the treatment processes. Various analytical methods were used to investigate the chemical composition and structure, crystallinity, morphology, thermal properties, surface area and hydration properties of cellulose separated at different treatment temperatures. HPCA successfully removed lignin and hemicellulose from RB, according to chemical composition analysis and FTIR. RB-CE had a type I cellulose crystal structure, and the crystallinity improved with increasing treatment temperature, reaching 72.51 % for RB-CE90. The RB-CE showed good thermal stability with degradation temperatures ranging from 294.2 °C to 319.1 °C. Furthermore, RB-CE had a high water/oil binding capacity, with RB-CE90 having WHC and OBC of 9.68 g/g and 7.24 g/g, respectively. The current work serves as a model for the environmentally friendly and convenient extraction of cellulose from biomass, and the cellulose obtained can be employed in the field of food and composite materials.

Selective Removal of Hemicellulose by Diluted Sulfuric Acid Assisted by Aluminum Sulfate

Hemicellulose can be selectively removed by acid pretreatment. In this study, selective removal of hemicellulose was achieved using dilute sulfuric acid assisted by aluminum sulfate pretreatment. The optimal pretreatment conditions were 160 °C, 1.5 wt% aluminum sulfate, 0.7 wt% dilute sulfuric acid, and 40 min. A component analysis showed that the removal rate of hemicellulose and lignin reached 98.05% and 9.01%, respectively, which indicated that hemicellulose was removed with high selectivity by dilute sulfuric acid assisted by aluminum sulfate pretreatment. Structural characterizations (SEM, FTIR, BET, TGA, and XRD) showed that pretreatment changed the roughness, crystallinity, pore size, and functional groups of corn straw, which was beneficial to improve the efficiency of enzymatic hydrolysis. This study provides a new approach for the high-selectivity separation of hemicellulose, thereby offering novel insights for its subsequent high-value utilization.

EnZolv delignification of cotton spinning mill waste and optimization of process parameters using response surface methodology (RSM)

BACKGROUND

EnZolv is a novel enzyme-based, eco-friendly biomass pretreatment process that has shown great potential in the field of textile engineering and biotechnology. It employs laccase from Hexagonia hirta MSF2 and 2% ethanol in the process of delignification. The process is designed to evaluate optimal conditions to remove lignin and other impurities from cotton spinning mill waste (CSMW), without compromising the quality and strength of the fibers. CSMW is a low-cost and readily available source of cellulose, making it an ideal candidate for delignification using EnZolv. By optimizing the pretreatment conditions and harnessing the potential of enzymatic delignification, this research aims to contribute to more sustainable and efficient ways of utilizing lignocellulosic biomass in various industries for the production of biochemical and bioproducts.

RESULTS

The present study emphasizes the EnZolv pretreatment in the delignification of cotton spinning mill wastes irrespective of the cellulose content. EnZolv process parameters such as, moisture content, enzyme load, incubation time, incubation temperature, and shaking speed were optimized. Under pre-optimized conditions, the percent lignin reduction was 61.34%, 61.64%, 41.85%, 35.34%, and 35.83% in blowroom droppings (BD), flat strips (FS), lickerin fly (LF), microdust (MD) and comber noils (CN), respectively. Using response surface methodology (RSM), the statistically optimized EnZolv pretreatment conditions showed lignin reduction of 59.16%, 62.88%, 48.26%, 34.64%, and 45.99% in BD, FS, LF, MD, and CN, respectively.

CONCLUSION

Traditional chemical-based pretreatment methods often involve harsh chemicals and high energy consumption, which can have detrimental effects on the environment. In contrast, EnZolv offers a greener approach by utilizing enzymes that are biodegradable and more environmentally friendly. The resulting fibers from EnZolv treatment exhibit improved properties that make them suitable for various applications. Some of the key properties include enhanced cellulose recovery, reduced lignin content, and improved biophysical and structural characteristics. These improvements can contribute to the fiber's performance and processability in different industries and future thrust for the production of cellulose-derived and lignin-derived bioproducts.

Extraction and characterization of nanocellulose from cattail leaves: Morphological, microstructural and thermal properties

Hydrogen peroxide combined with acid treatment demonstrates its respective characteristics for the separation of lignocellulosic biomass. Herein, holocellulose was extracted from Cattail leaves (CL) by a two-step treatment with alkali and hydrogen peroxide-acetic acid (HPAA). Then carboxylated nanocellulose was hydrolyzed with a mixed organic/inorganic acid. The chemical composition of the holocellulose and the physicochemical properties of the separated carboxylated nanocellulose were comparable. Carboxyl groups were introduced on the nanocellulose as a result of the esterification process with citric acid (CA), which endows the nanocellulose with high thermal stability (315-318 °C) and good light transmission (>80 %). Furthermore, morphological analyses revealed that nanocellulose had a spider-web-like structure with diameter between 5 and 20 nm.

Selective separation of hemicellulose from poplar by hydrothermal pretreatment with ferric chloride and pH buffer

As an environmentally friendly lignocellulosic biomass separation technology, hydrothermal pretreatment (HP) has a strong application prospect. However, the low separation efficiency is a main factor limiting its application. In this study, the poplar components were separated using HP with ferric chloride and pH buffer (HFB). The optimal conditions were ferric chloride concentration of 0.10 M, reaction temperature of 150 °C, reaction time of 15 min and pH 1.9. The separation of hemicellulose was increased 34.03 % to 77.02 %. The pH buffering resulted in the highest cellulose and lignin retention yields compared to ferric chloride pretreatment (FC). The high efficiency separation of hemicellulose via HFB pretreatment inhibited the degradation of xylose. The hydrolysate was effectively reused for five times. The fiber crystallinity index reached 60.05 %, and the highest C/O ratio was obtained. The results provide theoretical support for improving the efficiency of HP and promoting its application.

Delignification of the cotton stalk and ginning mill waste via EnZolv pretreatment and optimization of process parameters using response surface methodology (RSM)

The present study aimed to add value to cotton waste biomass using a more eco-friendly process, EnZolv which delignifies cotton stalk and cotton ginning mill waste. A maximum delignification of 68.68% and 65.51% was obtained using pre-optimized EnZolv parameters in cotton stalk (CS) and ginning mill waste (GMW), respectively. Optimized EnZolv process removed 78.68% of lignin in CS using Response Surface Methodology (RSM) in Box-Behnken design at 0% moisture content, 50 U laccase g-1 of biomass, 5 h incubation time, 50 ⁰C incubation temperature, and 150 rpm shaking speed. Similarly, RSM-based delignification of 70.53% in GMW was achieved under the optimized EnZolv conditions of 98.75 % moisture content, 41.59 U laccase g-1 of biomass, 9.3 h incubation time, 46.15 ⁰C incubation temperature, and 150 rpm shaking speed.

Coproduction of xylooligosaccharides, glucose, and less-condensed lignin from sugarcane bagasse using syringic acid pretreatment

Current strategies for the production of xylooligosaccharides (XOS) from biomass through non-enzymatic catalysis often led to a certain degree of lignin condensation, which severely restrains subsequent enzyme hydrolysis of cellulose. Herein, syringic acid (SA) pretreatment was investigated to coproduce XOS, glucose, and less-condensed lignin from sugarcane bagasse. SA acted as a catalyst and lignin condensation inhibitor during the pretreatment. The highest XOS yield of 58.7% (27.7% xylobiose and 24.7% xylotriose) was obtained at 180 °C - 20 min - 9% SA, and the corresponding xylose/XOS ratio was only 0.42. Compared with the pretreatment at 180 °C - 20 min - 0% SA, the addition of 9% SA increased the glucose yield from 85.7% to 92.4% and decreased the degree of lignin condensation from 0.55 to 0.42. Moreover, 26.7% of SA could be easily recovered. This work presents a pretreatment strategy in which the efficient production of XOS and the suppression of lignin condensation are achieved simultaneously.

Novel dual-action vanillic acid pretreatment for efficient hemicellulose separation with simultaneous inhibition of lignin condensation

Aromatic acids play a selective role in the separation of hemicellulose. Phenolic acids have demonstrated an inhibitory effect on lignin condensation. In the current study, vanillic acid (VA), which combines the characteristics of aromatic and phenolic acids, is used to separate eucalyptus. The efficient and selective separation of hemicellulose is achieved simultaneously at 170 °C, 8.0% VA concentration, and 80 min. The separation yield of xylose increased from 78.80% to 88.59% compared to acetic acid (AA) pretreatment. The separation yield of lignin decreased from 19.32% to 11.19%. In particular, the β-O-4 content of lignin increased by 5.78% after pretreatment. The results indicate that VA, as a "carbon positive ion scavenger", it preferentially reacts with the carbon-positive ion intermediate of lignin. Surprisingly, the inhibition of lignin condensation is achieved. This study provides a new starting point for the development of an efficient and sustainable commercial technology by organic acid pretreatment.

An optimum biomass fractionation strategy into maximum carbohydrates conversion and lignin valorization from poplar

Appropriate fractionation of lignocellulosic biomass into useable forms is a key challenge to achieving an economic bioethanol production. In the present study, four different fractionation strategies of hydrothermal-, NaOH-, ethanol-, and NaOH catalyzed ethanol pretreatment were investigated to compare their abilities of cellulose conversion. Results showed that NaOH catalyzed ethanol pretreatment showed a rather high extent of delignification of 85.92%, which also enhanced the retention of cellulose (92.56%) and hemicellulose (76.57%); while other pretreatments tended to produce cellulose fraction which was insufficient to achieve the whole component utilization. After simultaneous saccharification and fermentation at high solids loading, synergistic maximization of xylose (42.47 g/L) and ethanol (85.74 g/L) output was achieved via alkaline ethanol pretreatment. Lignin characterization information showed that alkaline ethanol pretreatment facilitates the cleavage of β-O-4 linkage and further converts into arylglycerol. Moreover, less condensed substructure units with high processing activity were also generated in S- and G- lignin.

Simultaneous achievement of efficient hemicellulose separation and inhibition of lignin repolymerization using pyruvic acid treatment

The efficiency of organic acid treatment in the conversion of lignocellulosic biomass fractions has been widely recognized. In this study, a novel green pyruvic acid (PA) treatment is proposed. The higher separation efficiency of eucalyptus hemicellulose was obtained at 4.0% PA and 150 °C. The hemicellulose separation yield was increased from 71.71 to 88.09% compared to glycolic acid (GA) treatment. In addition, the treatment time was significantly reduced from 180 to 40 min. The proportion of cellulose in the solid increased after PA treatment. However, the accompanying separation of lignin was not effectively controlled. Fortunately, a six-membered ring structure was formed on the diol structure of the lignin β-O-4 side chain. Fewer lignin-condensed structures were observed. High-value lignin rich in phenol hydroxyl groups were obtained. It provides a green path for the simultaneous achievement of efficient hemicellulose separation and inhibition of lignin repolymerization using organic acid treatment.

High-Strength, High-Water-Retention Hemicellulose-Based Hydrogel and Its Application in Urea Slow Release

The use of fertilizer is closely related to crop growth and environmental protection in agricultural production. It is of great significance to develop environmentally friendly and biodegradable bio-based slow-release fertilizers. In this work, porous hemicellulose-based hydrogels were created, which had excellent mechanical properties, water retention properties (the water retention ratio in soil was 93.8% after 5 d), antioxidant properties (76.76%), and UV resistance (92.2%). This improves the efficiency and potential of its application in soil. In addition, electrostatic interaction and coating with sodium alginate produced a stable core-shell structure. The slow release of urea was realized. The cumulative release ratio of urea after 12 h was 27.42% and 11.38%, and the release kinetic constants were 0.0973 and 0.0288, in aqueous solution and soil, respectively. The sustained release results demonstrated that urea diffusion in aqueous solution followed the Korsmeyer-Peppas model, indicating the Fick diffusion mechanism, whereas diffusion in soil adhered to the Higuchi model. The outcomes show that urea release ratio may be successfully slowed down by hemicellulose hydrogels with high water retention ability. This provides a new method for the application of lignocellulosic biomass in agricultural slow-release fertilizer.

Rational Design of Cellulosic Triboelectric Materials for Self-Powered Wearable Electronics

With the rapid development of the Internet of Things and flexible electronic technologies, there is a growing demand for wireless, sustainable, multifunctional, and independently operating self-powered wearable devices. Nevertheless, structural flexibility, long operating time, and wearing comfort have become key requirements for the widespread adoption of wearable electronics. Triboelectric nanogenerators as a distributed energy harvesting technology have great potential for application development in wearable sensing. Compared with rigid electronics, cellulosic self-powered wearable electronics have significant advantages in terms of flexibility, breathability, and functionality. In this paper, the research progress of advanced cellulosic triboelectric materials for self-powered wearable electronics is reviewed. The interfacial characteristics of cellulose are introduced from the top-down, bottom-up, and interfacial characteristics of the composite material preparation process. Meanwhile, the modulation strategies of triboelectric properties of cellulosic triboelectric materials are presented. Furthermore, the design strategies of triboelectric materials such as surface functionalization, interfacial structure design, and vacuum-assisted self-assembly are systematically discussed. In particular, cellulosic self-powered wearable electronics in the fields of human energy harvesting, tactile sensing, health monitoring, human-machine interaction, and intelligent fire warning are outlined in detail. Finally, the current challenges and future development directions of cellulosic triboelectric materials for self-powered wearable electronics are discussed.

Rapid and mild fractionation of hemicellulose through recyclable mandelic acid pretreatment

The development of organic acid pretreatments from biological sources is essential to facilitate the progress of green and sustainable chemistry. In this study, the effectiveness of mandelic acid pretreatment (MAP) was analyzed for eucalyptus hemicellulose separation. 83.66% of xylose was separated under optimal conditions (temperature: 150 °C; concentration: 6.0 wt%; time: 80 min). The hemicellulose separation selectivity is higher than acetic acid pretreatment (AAP). The stable and effective separation efficiency (56.55%) is observed even after six reuses of the hydrolysate. Higher thermal stability, larger crystallinity index and optimized surface element distribution in the samples were demonstrated by MAP. Lignin condensation is effectively inhibited through MAP, as determined from the structural of different lignin. In particular, the demethoxylation of lignin by MA was found. These results open up a new way to construct a novel organic acid pretreatment for separating hemicellulose with high efficiency.