Isolation Of Lignin Research Articles

Low-chromophore lignin isolation from natural biomass with polyol-based deep eutectic solvents

Lignocellulose fractionation using a polyhydric-alcohol-based deep eutectic solvent to directly obtain low-chromophore lignin for sunscreen production and digestible solid for outputting fermentable sugars.

Structural changes of poplar lignin during the ternary deep eutectic solvent (DES) treatment and synergetic alkali-DES treatment

Expenditure isolation of lignin and the understanding of its structural variations during different isolation process is essential for lignin high-value utilization. A green DES consisted with choline chloride (ChCl), ethylene glycol (EG) and 4-chlorobenzene sulfonic acid (4-Cl-BSA) was proposed for rapid lignin separation from poplar in this study. About 97.01% of lignin and 87.41% of hemicellulose were removed while the cellulose preservation achieved 95.02% under 90 °C for 30 min using this DES with the molar ratio of 1:2:0.7 (ChCl: EG: 4-Cl-BSA). The percentage of β-O-4 linkages, molecular weight and associated sugar content of DES lignin declined steadily with the enhancement of treatment severity. Additionally, the pre-extraction of hemicellulose through alkali treatment on subsequent lignin separation and lignin structural variations was also elucidated. The results suggested that alkali pretreatment opened the channels of the cell wall and increased DES permeability to the material, enhancing the DES separation of lignin. It also promoted the cleavage of the β-O-4 and PB linkages during followed DES separation lignin, and reduced the molecular weight and thermal stability of isolated DES lignin. In addition, the integrated DES lignin displayed higher purity and S/G ratio compared to lignin obtained from direct DES treatment. The Py-GC/MS results indicated the obtained DES lignin was suitable for phenolic compounds production and the total phenolic compounds yield ranged from 41.56% to 62.42%. This study provides insight into lignin structural transformation during different pretreatment and guides for dismantling cell walls.

Isolation of Lignin from Sugarcane Bagasse as an Adsorbent for Chromium Ion

Isolation of Lignin from Sugarcane Bagasse as an Adsorbent for Chromium Ion

Organosolv Pretreatment of Cocoa Pod Husks: Isolation, Analysis, and Use of Lignin from an Abundant Waste Product.

Cocoa pod husks (CPHs) represent an underutilized component of the chocolate manufacturing process. While industry's current focus is understandably on the cocoa beans, the husks make up around 75 wt % of the fruit. Previous studies have been dominated by the carbohydrate polymers present in CPHs, but this work highlights the presence of the biopolymer lignin in this biomass. An optimized organosolv lignin isolation protocol was developed, delivering significant practical improvements. This new protocol may also prove to be useful for agricultural waste-derived biomasses in general. NMR analysis of the high quality lignin led to an improved structural understanding, with evidence provided to support deacetylation of the lignin occurring during the optimized pretreatment. Chemical transformation, using a tosylation, azidation, copper-catalyzed click protocol, delivered a modified lignin oligomer with an organophosphorus motif attached. Thermogravimetric analysis was used to demonstrate the oligomer's potential as a flame-retardant. Preliminary analysis of the other product streams isolated from the CPHs was also carried out.

The effect of the lignin isolation method from oil palm empty fruit bunch black liquor for seed coating material

The effect of the lignin isolation method from oil palm empty fruit bunch black liquor for seed coating material

Extraction and Isolation of Different Lignins from Sugarcane Bagasse Biomass and Its Subsequent Thermal Degradation to Renewable Fuels

Extraction and Isolation of Different Lignins from Sugarcane Bagasse Biomass and Its Subsequent Thermal Degradation to Renewable Fuels

Functional Lignin‐based Polymers: Isolation, Synthetic Methods and High‐valued Applications

AbstractAs a major component of lignocellulosic biomass, lignin has lots of fascinating properties, such as regeneration, biocompatibility, antioxidant, hydrophilicity, unique aromatic structure, and various functional groups, which make them become interesting natural polymer raw material, and attracted more and more attention. In particular, the rich functional groups of lignin can be easily functionalized through various synthesis methods, which can endow lignin‐based polymers with new structure and function. These functional lignin‐based polymers are widely used in environmental remediation, smart hydrogel materials, catalysis, biomedical, etc. However, its various sources and types, the complex structure, relatively weak chemical reactivity, the unstable processing property, and few high value‐added products limited their practical applications. With the development of lignin varieties, modified reagent, synthesis methods, and polymerization process, many works had been published for the synthesis and application of lignin‐based polymers. In this review, the lignin isolation, modification strategies, polymerization method and process, and the promising applications were summarized and analyzed in recent years. Specially, the recent advances in the preparation of high excellent adsorbents from deconstructed lignin products are highlighted from the synthesis methods and adsorption mechanism perspective. Finally, we discussed these challenges in the green and controllable synthesis of lignin‐based polymers, and prospected their functional applications.

Isolation and characterization of soda lignin from OPEFB and evaluation of its performance as wood adhesive

The purpose of this study was to explore the mechanical properties of plywood panels that had been bound with lignin-phenol–formaldehyde (LPF) adhesive. LPF, composed of lignin that was extracted from Oil Palm Empty Fruit Bunch (OPEFB) fiber by soda pulping method and characterized by Fourier Transform Infrared (FT-IR), Nuclear Magnetic Resonance (HNMR), and Thermal Gravimetric Analyzer (TGA) analysis. Then, various compositions of soda lignin (10–50 wt%) were used as a phenol substitute in LPF synthesis. The characteristics of the synthesizedadhesive were compared to the properties of phenol formaldehyde (PF) adhesive. Plywood was fabricated with LPF and its mechanical properties were studied and evaluated using industrial standards. The result indicates that the increase of phenol substitution with soda lignin, up to 40%, improves the mechanical properties of plywood. This research demonstrated the use of lignin as a renewable replacement of phenol in PF adhesive formulation.

Extraction and Characterization of Acidolysis Lignin from Turkey Oak (Quercus cerris L.) and Eucalypt (Eucalyptus camaldulensis Dehnh.) Wood from Population Stands in Italy.

Acidolysis lignins from the species Quercus cerris L. and Eucalyptus camaldulensis Dehnh. were isolated and characterized using high pressure size exclusion chromatography (HP-SEC), Fourier-transform (FTIR) infrared spectroscopy, analytical pyrolysis-gas chromatography-mass spectrometry (Py-GCMS), and two-dimensional heteronuclear single quantum coherence (2D HSQC) NMR spectroscopy. The acidolysis lignins from the two different species varied in chemical composition and structural characteristics, with Q. cerris L. lignin having a higher S/G ratio and higher molar mass averages with a bimodal molar mass distribution. The different analytical techniques FTIR spectroscopy, Py-GCMS, and 2D NMR spectroscopy provided consistent results regarding the S/G ratio of the lignins from the two wood species. Based on the determined high S/G ratio of both oak and eucalypt lignin, the two wood sources could be promoted as substrates for efficient lignin isolation in modern forest biorefineries in order to develop innovative lignin-based value-added biorefinery products.

A novel mineral-acid free biphasic deep eutectic solvent/γ-valerolactone system for furfural production and boosting the enzymatic hydrolysis of lignocellulosic biomass

The failure of hemicellulose valorization in a deep eutectic solvent (DES) pretreatment has become a bottleneck that challenges its further development. To address this issue, this study developed a DES/GVL (γ-valerolactone) biphasic system for effective hemicellulose-furfural conversion, enhanced cellulose saccharification and lignin isolation. The results indicated that the biphasic system could significantly improve the lignin removal (as high as 89.1%), 86.0% higher than the monophasic DES, accompanied by ∼100% hemicellulose degradation. Notably, the GVL in the biphasic solvent restricted the condensation of hemicellulose degradation products, which as a result generated large amount of furfural in the pretreatment liquid with a yield of 68.6%. With the removal of hemicellulose and lignin, cellulose enzymatic hydrolysis yield was boosted and reached near 100%. This study highlighted that the novel DES/GVL is capable of fractionating the biomass and benefiting their individual utilization, which could provide a new biorefinery configuration for a DES pretreatment.

The enhancement of mechanical, physical, and thermal properties of modified asphalt mixture with lignin from mahogany sawdust in the presence of diphenylmethane 4,4′-diisocyanate

The road infrastructure condition, which can be easily damaged by the occurrence of potholes due to the weak adhesion between asphalt and aggregate, disrupts economic activity and requires high maintenance costs. This problem needs to be overcome by adding adhesive to modify the asphalt. Lignin is a sustainable biopolymer that can serve as a natural asphalt binder. Lignin isolated from mahogany sawdust combined with diphenylmethane 4,4′-diisocyanate has never been used to modify asphalt mixtures. This modification can improve the properties of the asphalt mixture, which is very important in road pavement engineering. This study aims to modify asphalt mixtures with lignin isolated from mahogany sawdust combined with diphenylmethane 4,4′-diisocyanate and investigate their physical, mechanical, and thermal characteristics. The isolated lignin was prepared for a modified asphalt mixture by reacting with diphenylmethane 4,4-diisocyanate and adding asphalt. Next, the asphalt mixture was mixed with sand aggregate in an extruder at 150 °C. The results showed an improvement in mechanical, physical, and thermal properties. The optimum composition of asphalt and lignin was 60:40 with a compressive strength value of 3.107 MPa, a water absorption value of 0.246%, and a melting point of 238 °C. The Fourier-transform infrared spectroscopy (FT-IR) spectrum showed a small band at 1715 cm−1, indicating the CO carbonyl group of the NH–CO–O urethane bond. The morphology showed that the surface structure of the modified asphalt mixture becomes more homogeneous due to the interaction between asphalt and polyurethane, which is the result of the reaction of lignin isolate with diphenylmethane 4,4′-diisocyanate.

Bioprocess development for levulinic acid production using sugarcane biomass

Developing technologies for converting lignocellulosic biomass to products such as energy, fuels, and value-added chemicals is an important step in making biorefineries a feasible alternative to the current oil-based productive system. In this study, the conversion of lignocellulosic biomass composed of a mixture of bagasse and sugarcane straw into a cellulose pulp and a sulfonated carbonaceous solid catalyst synthesized from lignin fraction were investigated, as well as the use of this solid acid catalyst to convert cellulose to levulinic acid, an important chemical platform. To overcome this challenge, firstly, the fractionation of lignocellulosic biomass was optimized. Then, tests were carried out to find the best condition for isolation of the soluble lignin from black liquor produced in the optimal condition of delignification. The lignin precipitate was subjected to carbonization tests followed by functionalization tests with concentrated sulfuric acid to synthesize the catalyst. This catalyst was then used to convert cellulose into levulinic acid (LA). The experimental design for cellulose recovery and lignin removal showed that under relatively mild reaction conditions of 110 °C, 117 min, and a solid/NaOH (4.4% w/v) ratio of 1:20, more than 91% of the lignin was dissolved into the black liquor, recovering a solid with a cellulose content higher than 78%. Lignin was fully recovered in the form of precipitate by simply reducing the pH of the black liquor to 3 (under this condition 11 g of precipitate were recovered per liter of liquor). Having the recovered lignin, it was then possible to synthesize a solid carbonaceous catalyst with a total acid site density of 1.48 mmol/g which was able to convert up to 17.11% of the cellulose and obtain yields of up to 38.55% of levulinic acid when a catalyst/cellulose ratio of only 8:10 (w/w) was used. Overall, the future of LA production using carbonaceous acid catalysts looks promising. As research in this area continues, there is the potential to further improve the production process and make it more cost-effective and sustainable. This could lead to wider adoption of this technology and increased use of levulinic acid in various industrial applications, including as a platform chemical to produce a range of chemicals and materials.

Isolation and Screening of Lignin Degrading Fungi from Wood

Abstract: Wood and lignocellulosic biomass is a low cost and abundant resource that can be used in the large scale production of fuels and chemicals. Lignocellulose can be converted into many products replacing products produced from fossil, such as bioenergy, biochemicals and biomaterial products through several treatment. In the bioethanol production, the lignin content in lignocellulose causes the conversion of cellulose to ethanol is less optimal. This research aimed to screen a number of fungal isolated from tropical forests to obtain the lignin-degrading fungi which are potentially used in lignocellulose biotreatment. The presences of covalent lignin carbohydrate linkage between sugar hydroxyl of hemicelluloses and phenylpropane subunits in lignin gives lignocellulose protection against degradation. Biofuel plays an essential role in replacing petroleum based fuels in current worldwide energy situation. The aim of the project is to identify new stain of fungi with high potential in degradation of lignin. The fungi is isolated from rotting wood piece for the study . Pereformed different methods to isolate the efficient fungi to degrade the lignin.

Effects of the incorporation of modified kraft lignin on the mechanical properties of epoxy adhesive: experimental and theoretical approaches

ABSTRACT Several lignin-based adhesives were developed during the last decades. More recently, lignin isolation methods were improved, leading to technical grade lignins with constant properties. This recent scenario created the required conditions for the industrial use of lignin in adhesive applications, at large scale, with reliable properties. In this work, technical grade kraft lignin was epoxidized and incorporated in industrial epoxy resin, resulting into a partly biobased epoxy resin. Notwithstanding, the mechanical properties of cured partly biobased epoxy were investigated using Arcan device, aiming to reproduce realistic load conditions for the adhesively bonded joints. At last, failure envelopes were obtained from Drucker–Prager and von Mises models, revealing the most reliable model to calculate the failure prediction. Results pointed out to the development of a partly biobased epoxy adhesive with slightly superior mechanical properties, in comparison with industrial epoxy adhesive. Indeed, an important contribution was provided for the lignin revalorization and the mechanical characterization and failure prediction of epoxy adhesive based on the modified lignin.

A Review on Eco-friendly Isolation of Lignin by Natural Deep Eutectic Solvents from Agricultural Wastes

A Review on Eco-friendly Isolation of Lignin by Natural Deep Eutectic Solvents from Agricultural Wastes

Bioactivity-Guided High Performance Counter-Current Chromatography and Following Semi-Preparative Liquid Chromatography Method for Rapid Isolation of Anti-Inflammatory Lignins from Dai Medicinal Plant, Zanthoxylum acanthopodium var. timbor.

The development of Dai medicine is relatively slow, and Zanthoxylum has great economic and medicinal value. It is still difficult to obtain medicinal components from the low-polarity parts of Zanthoxylum belonging to Dai medicine. In this study, we introduced one simple and quick strategy of separating target compounds from the barks of Z. acanthopodium var. timbor by high-performance countercurrent chromatography (HPCCC) with an off-line anti-inflammatory activity screening mode. The development of this strategy was based on the TLC-based generally useful estimation of solvent systems (GUESS) method and HPCCC in combination. This paper presented a rapid method for obtaining target anti-inflammatory compounds. Three lignins were enriched by HPCCC with an off-line inhibition mode of nitric oxide production in lipopolysaccharide-stimulated RAW264.7 macrophage cells, using petroleum ether-ethyl acetate-methanol-water (3:2:3:2) as the solvent system. The results showed that this method was simple and practical and could be applied to trace the anti-inflammatory components of the low-polarity part in Dai medicine.

Efficient and eco-friendly isolation and purification of lignin from black liquor with choline chloride-based deep eutectic solvents

Abstract This study developed an efficient and green method for isolating and purifying lignin from black liquor (BL) using deep eutectic solvents (DESs). After the short and mild process (700 W microwave-assisted, 100 °C, DES: BL 1:5 (v: v), 30 min) using optimized DES (lactic acid (LA): choline chloride (ChCl) 10:1, molar ratio), the yield and purity of lignin obtained from 100 mL BL was 1.58 g and 88.12%, respectively, which was more efficient than the results of 1.18 g and 78.54% of the conventional process. Furthermore, more than 95% of initial results were obtained after three cycles. The composition and structure of DESs and conventionally purified lignin were slightly different. The solvent costs for both processes were also evaluated, showing that the DES process has great potential to replace traditional bulky and environmentally unfriendly procedures for lignin isolation and purification and to help develop new strategies for the potential added value of lignin.

Mild isolation and characterization of surface lignin from hydrothermally pretreated lignocellulosic forestry and agro-industrial waste biomass

Within the biorefining concept, the lignocellulosic biomass wastes can serve as feedstock to produce value-added chemicals and fuels. The sustainable valorization of biomass is based on integrated processes that aim to the utilization of “whole biomass”. To this end, the first step of the efficient biomass pretreatment towards selective isolation of cellulose, hemicellulose and lignin, is of paramount importance. Hydrothermal pretreatment of biomass in neat water is a green and well-established process that enhances hemicellulose removal and recovery in the liquid fraction, affording a cellulose and lignin enriched solid which can be enzymatically hydrolyzed to glucose. A simple and efficient method to facilitate the hydrolysis is the prior extraction of the formed “surface” lignin which hinders the action of enzymes. Within this context, in this work, forestry (beechwood sawdust) and agro-industrial (vine prunings, apricot kernel shells) wastes were hydrothermally pretreated in neat water (at 220 °C, 15 min) and the formed surface lignin was extracted via soxhlet or reflux methods under mild conditions, with the use of green solvents (ethanol, acetone). The delignification degree of the pretreated biomass was in the range of 35–67 wt%, depending on the solvent and biomass feedstock. The recovered surface lignins were of high purity and exhibited similar physicochemical and structural characteristics with the organosolv lignin. The fast pyrolysis of surface lignins afforded bio-oils enriched in alkoxy-phenols and oxy-aromatics. The biomass solids recovered after lignin extraction are enriched in cellulose (70%) and exhibit high relative crystallinity and improved textural properties, thus increasing their potential valorization.

Analysis of Single-Step Pretreatments for Lignocellulosic Platform Isolation as the Basis of Biorefinery Design.

Biorefinery feasibility is highly influenced by the early design of the best feedstock transformation pathway to obtain value-added products. Pretreatment has been identified as the critical stage in biorefinery design since proper pretreatment influences subsequent reaction, separation, and purification processes. However, many pretreatment analyses have focused on preserving and valorizing six-carbon sugars for future use in bioconversion processes, leaving aside fractions such as hemicellulose and lignin. To date, there has been no pretreatment systematization for the removal of lignocellulosic fractions. This work defines pretreatment efficacy through operational, economic, environmental, and social indicators. Thus, using the data reported in the literature, as well as the results of the simulation schemes, a multi-criteria weighting of the best-performing schemes for the isolation or removal of cellulose, hemicellulose, and lignin was carried out. As a main result, it was concluded that dilute acid is the most effective for cellulose isolation and hemicellulose removal for producing platform products based on six- and five-carbon sugars, respectively. Additionally, the kraft process is the best methodology for lignin removal and its future use in biorefineries. The results of this work help to elucidate a methodological systematization of the pretreatment efficacy in the design of biorefineries as an early feasibility stage considering sustainability aspects.

A cascade valorization of Kenaf stalk for the preparation of lignin sunscreens and papermaking

Lignin has been regarded as a potential natural sun screening agent. However, the dark color of traditional industrial lignin hinders its application in the field of skincare. In this study, a green and facile approach was developed to extract light-colored lignin. p-Toluenesulfonic acid (p-TsOH) was used to separate lignin and fibers from Kenaf stalks. During the isolation of lignin, formaldehyde was added to preserve the β-O-4 bonds of lignins in the form of stable acetals. The obtained lignin was further employed to prepare nanoparticles (LNPs) as sunscreen additives. After adding 4 wt% LNPs, the SPF values of the cream increased from 7.05 to 27.84. The residual fibers from the Kenaf stalks can be utilized for papermaking as the raw materials. by mixing them with softwood pulp to reduce the consumption of commercial pulp. With the addition of 5 wt% residual fibers in commercial softwood pulp, the produced paper showed better mechanical properties. The ring crush strength index and tear index of the samples increased from 2.49 N·m/g and 4.63 mN·m2/g to 2.62 N·m/g and 4.75 mN·m2/g, respectively. This study paved a way for the comprehensive utilization of Kenaf stalks towards not only papermaking but also daily chemical products.