Biomass Lignin Research Articles

Synthesis and characterization of biomass lignin-based PVA super-absorbent hydrogel

The traditional polyvinyl alcohol composite hydrogel exhibited poor swelling and mechanical properties, which limited its application. To solve these issues, we use biomass lignin as raw material, PVA as matrix template and epichlorohydrin as cross-linker to prepare the Lignin-PVA super-absorbent hydrogels with the swelling ratio of up to 456 g/g under mild condition. When the lignin concentration was increased from vacancy to 5%, the swelling ratio of the Lignin-PVA hydrogels was increased from 92 g/g to 456 g/g. The lignin-based hydrogel synthesized by the higher molecular weight PVA showed better swelling performance. Softwood lignin, hardwood lignin and corncob lignin could also be used to fabricate the Lignin-PVA super-absorbent hydrogels with the swelling ratio of higher than 500 g/g. However, the optimum amount varied from different lignin types, which was related to the molecular weight and phenolic hydroxyl content of lignin. The structural mechanism of the Lignin-PVA hydrogel was proposed to clearly certify the enhancing role of lignin. The adsorption capacity of the Lignin-PVA hydrogel with respect to rhodamine 6G, crystal violet and methylene blue dyes was up to 196, 169 and 179 mg/g, respectively. The Lignin-PVA hydrogel presents great potential applications in the fields of soil water retention and seed cultivation in agriculture, and dye pollutant removal.

Facile fabrication and characterization of highly stretchable lignin-based hydroxyethyl cellulose self-healing hydrogel

In this study, hydroxyethyl cellulose (HEC) and polyvinyl alcohol (PVA) as the framework, borax as the cross-linker, and biomass lignin from pulping black liquors and biorefinery as the plasticizer were used to synthesize the lignin-based HEC-PVA (LCP) self-healing conductive hydrogel with highly stretchable and thermosensitive properties by the one-step fabrication method. Compared with the PVA hydrogel, the maximum storage modulus and the elongation rate was increased by 7 times and 20 times, respectively. Uniformly distributed lignin could increase the mobility and distance of polymer molecular chains, therefore improve the viscoelasticity and stretchability of the LCP self-healing hydrogel. The LCP hydrogel could recover to the original state in 12 s after 10000% shear strain for 4 cycles. The LCP hydrogel also presented good thermosensitivity and electrical conductivity, and were very promising for applications in the fields of 3D printing and wearable electronic devices, that broadened the efficient utilization of biorefinery lignin.

Catalytic Conversion of Lignin in Woody Biomass into Phenolic Monomers in Methanol/Water Mixtures without External Hydrogen

The valorization of lignin in renewable lignocellulosic biomass is an important target in the transition to a more sustainable production of fuels and chemicals. We present here a modification of the “lignin-first” approach that does not hinge on the use of external hydrogen. Instead, we use methanol/water mixtures as a suitable solvent that can be partly reformed into hydrogen. We propose a one-step process in which in planta lignin (wood sawdust) is converted to phenolic monomers over a Pt-based catalyst in an inert atmosphere. The role of the methanol/water mixture is not only to supply hydrogen but also to extract lignin fragments from the biomass matrix. Pt catalyzes methanol reforming to obtain hydrogen and the stabilization of reactive lignin intermediates by hydrogenation of reactive bonds. The latter aspect is crucial to avoid unfavorable condensation of fragments. Under optimized conditions, a yield of phenolic monomers of nearly 50% can be obtained from birch wood at a temperature of 230 °C in 3 h.

Preparation of Polyetheramine‐Grafted Lignin and Its Application in UV‐Resistant Polyurea Coatings

AbstractLignin‐containing polyurea coating with good ultraviolet (UV) resistance is prepared by partially substituting polyetheramine with enzymatic hydrolysis lignin. Lignin is first grafted by polyetheramine chains via Mannich reaction, which improves its interfacial compatibility with polyurea matrix. The influences of the modified lignin on the chemical and corrosion resistance, UV‐aging property, and thermal stability of the polyurea coatings are studied. It is demonstrated that lignin‐containing polyurea coatings exhibit excellent UV‐aging properties. Aminating lignin with polyetheramine improves its dispersion in the polymer matrix. This work offers a novel method for the high‐value utilization of biomass lignin in anti‐UV polyurea coatings.

Fast pyrolysis of biomass catalyzed by magnetic solid base catalyst in a hydrogen atmosphere for selective production of phenol

Phenol is an important phenolic compound widely used in chemical industry. Lignin in lignocellulosic biomass materials has been recognized as a renewable source for phenol production due to its aromatic nature. In the present study, phenol was selectively prepared from fast pyrolysis of biomass using a recyclable magnetic solid base catalyst (K3PO4/Fe3O4, MSB) in an atmosphere with low hydrogen content. The study focused on the influence of pyrolysis atmosphere, pyrolysis temperature, catalyst content, and biomass type on the product distribution, as well as the recycle performance of MSB in consecutive pyrolysis experiments. Results suggested that the synergistic effect of MSB catalyst and hydrogen atmosphere significantly improved the formation of phenol. In a hydrogen atmosphere at MSB to biomass ratio of 1, the maximal phenol yield of 4.3 wt% with the selectivity of 17.6% was obtained from poplar wood pyrolysis at 550°C. Pyrolysis experiments with different biomass materials suggested that the phenol formation was positively correlated with biomass lignin content. A three consecutive run experiment indicated that the MSB catalyst had excellent performance on recovery and recycle. In addition, possible synergistic mechanism between MSB and hydrogen atmosphere was proposed.

Dilute acid pretreatment of pine needles of Pinus roxburghii by response surface methodology for bioethanol production by separate hydrolysis and fermentation

Bioethanol from lignocellulosic biomass is environment friendly and a renewable source of energy which can serve as alternative to fossil fuels particularly in transport sector. The present study investigates the efficiency of bioethanol production from pine needles of Pinus roxburghii (PNPR) using thermochemical pretreatment method. The PNPR biomass was subjected to thermochemical pretreatment using dilute concentrations (0.5%, 1%, 1.5%, and 2%) of HCl at a biomass loading of 5%, 10%, and 15%. Maximum reducing sugar (RS) yield of 96 mg/g biomass using one variable at a time (OVAT) approach was achieved using 1% HCl and a biomass loading of 5% (w/v). Central composite design (CCD) tool of response surface methodology (RSM) enhanced the RS yield to 0.2 g/g biomass under the optimized conditions. FTIR analysis revealed reduction in the lignin, cellulose, and hemicellulose content of PNPR biomass during the pretreatment process. Enzymatic hydrolysis was attempted using combinations of cellulase, xylanase, and pectinase commercial enzymes and the highest RS yield obtained was 0.43 g/g biomass. The hydrolysate was then fermented by Saccharomyces cerevisiae (MTCC-36) as well as by a combination of Saccharomyces cerevisiae (MTCC-36) and Pichia stipitis (NCIM-3498) to produce bioethanol. With a conversion efficiency of 90%, maximum bioethanol yield of 0.144 g/g biomass after 24 h was obtained from separate hydrolysis and fermentation (SHF) using combined cultures of S. cerevisiae (MTCC-36) and P. stipitis (NCIM-3498).

Сontrolled breeding of the psychrophilic strain G-034 VIZR of Trichoderma asperellum for fast crop residues’ polymers utilization and soil enhancement

Genus Trichoderma strains as the natural plant residues’ biodestructors, highly active antagonists of soil phytopathogens and phytoregulators with the widest range of optimum conditions for their development, are widely used in biologics development. Of particular importance in Russia’s northern regions, especially in winter crop cultivation, is the ability of a microorganism’s strain used in agro-technologies to maintain viability and target biological activity at low temperatures. In this connection, this work purpose is to select a psychrotolerant strain of T. asperellum for the rapid crop residues’ polymer utilization and soil enhancement at low temperature, as well as to evaluate its activity under laboratory and field conditions. In the work process, the following tasks were addressed: selecting psychrotolerant strains of T. asperellum with high cellulolytic activity; further controlled breeding of psychrophilic strains capable of rapid growth, active colonization of plant substrates and high sporulation at 4–8 °C; evaluating the target activity of the selected psychrophilic strain as a cellulolytic as well as antagonistic activity against cereal pathogens; obtaining laboratory samples of bioformulations by deep-surface cultivation on non-sterile peat and multirecycled wastes from the edible mushrooms production and assessing their efficacy in field small-plot trials. The methods for inoculum cultivation, sporulation capacity determination, modified wet chamber, estimating antagonistic activity and biologics’ quality, field small-plot trials management, quantitative estimates of biomass losses, cellulose and lignin content were used in the work. The active psychrophilic strain for the rapid crop residues’ polymer utilization and soil enhancement controlled breeding was selected during a four-step screening of 29 T. asperellum strains from All-Russian Research Institute of Plant Protection (VIZR) State Microorganisms’ Collection with high cellulolytic and antagonistic activities. In terms of linear growth rate, antagonistic and hyperparasitic activities at 4–8 °С, a high rate of wheat and maize stubble residues’ colonization, a perspective psychrophilic strain G-034 of T. asperellum was selected for developing the laboratory samples of biologics and for running field trials. In small-plot trials, the active maize crop residues’ decomposition under the T. asperellum G-034 influence was revealed, resulting in the complete loss of plant intact state in 12 months due to more than 80 % cellulose and 20 % lignin biodestruction. The maximum loss of maize crop residues biomass for 12 months was more than 70 %. The T. asperellum strain G-034 was active after field hibernation in an amount of ×104 cfu/g, resulting in a titer increase with seasonal temperature rising and the trophic base bioavailability growth.

Sustainable Microwave-Assisted Aerobic Oxidation of Tomato Plant Waste into Bioaromatics and Organic Acids

Lignin is the second most abundant polymer in lignocellulosic biomass. A biorefinery approach to lignin valorisation, as an alternative to the use of heating, can produce bioaromatics, and this idea is attracting ever more interest. However, the isolation of lignin for further processing is really quite challenging, making the valorisation of native lignin (i.e., lignin in raw biomass) crucially important. An analysis of vanillin yields in relation to total reaction feedstock weight shows that the economic viability of the process depends on the valorisation of all biomass components. This paper reports a microwave-assisted, catalyst-free aerobic oxidation process for biomass. The protocol yields bioaromatics (mainly vanillin and syringaldehyde, with traces of p-hydroxybenzaldehyde and acetovanillone) and organic acids (38.4 wt % maximum total yield) in only 30 min. Vanillin is the most valuable of the aromatic compounds to be produced by lignin oxidation, accounting for 8.7 wt % of the initial lignin. The use of biomass as the starting material means that no pretreatment is needed for component separation. Furthermore, the use of air as the oxidant and the catalyst-free nature of the protocol render the process environmentally sustainable and scalable, as the energy consumption is counterbalanced by the clean production of high market value products.

Studies on Synthesis, Characterization of Modified Phenol Formaldehyde Resin and Metal Adsorption of Modified Resin Derived From Lignin Biomass

This study was related to development of economically viable method of extraction of lignin from saw dust in order to produce lignin modified phenolic resin and ecofriendly adhesives (bio-based resin). This study cover to improve the mechanical properties by modification of phenol formaldehyde resole resin using some additives such as boric acid, sulfuric acid and lignin biomass. The synthesis and metal adsorption capacity of resin derived from lignin biomass were explored. Lignin sample was extracted from sawdust of Acacia sp. collected from Batticaloa region by alkali extraction method called delignification process. Qualitative tests were carried out on the extracted alkali lignin and it was used to prepare modified resin. Resin synthesized by using lignin substitution phenol and allowed to condensation reaction in the presence of sodium hydroxide. Boron-modified phenol formaldehyde resin was prepared by using boric acid with formalim method. The above reaction was performed for four hours by refluxing with toluene. Which was produced a high viscous massive resin with 90% yield. The absorbtion peak of B-O bond at 1362cm-1 was observed at IR spectra. Rise in solid mass content leads to produce smooth resin surface without causing cracks and bubbling. Phenol formaldehyde resin was modified into their sulfonated forms to increase their ion exchange capacity, since the ion exchange capacity of virgin resin was found to be zero. Conductivity property shown by sulfonated resin(121mS/cm). The synthesized Lignin based PF resin was used to study the metal adsorption capacity of Cd2+ in aqueous solution. The adsorption capacity of heavy metal Cd2+ ion shown by lignin modified resin (55%) and lignin (86%). In this study sawdust lignin could be best substitution for phenol in synthesis of Phenol-Formaldehyde resin. It’s better due to their sustainability, environmental control, low production cost and their ability to adsorb heavy metals. Phenolic resin was modified with boric acid to improve thermal resistance property and to get smooth resin surface.

Identification of key residues for activities of atypical glutathione S-transferase of Ceriporiopsis subvermispora, a selective degrader of lignin in woody biomass, by crystallography and functional mutagenesis.

Ceriporiopsis subvermispora (C. subvermispora) is a selective degrader of lignin in the woody biomass. Glutathione S-transferases (GSTs) are multifunctional enzymes that play important roles in cellular detoxification and metabolism. The crystal structures of a GST of C. subvermispora, CsGST83044, in GSH-free and -bound forms were solved at 1.95 and 2.19 Å resolution, respectively. The structure of the GSH-bound form revealed that CsGST83044 can be categorized as an atypical-type of GST. In the GSH-bound form of CsGST83044, Asn22, Asn24, and Tyr46 are located closest to the sulfur atom and form hydrogen bonds with the thiol group. The functional mutagenesis indicated that they are critical for the enzymatic activities of CsGST83044. The critical residues of an atypical-type GST belonging to the GSTFuA class were revealed for the first time. A previous study indicated that CsGST83044 and another GST, CsGST63524, differ in substrate preference; CsGST83044 prefers smaller substrates than CsGST63524 for its esterase activity. The GSH-bound pocket of CsGST83044 turns out to be small, which may explain the preference for smaller substrates. Protein engineering of GSTs of C. subvermispora in the light of the obtained insight may pave a path in the future for utilization of the woody biomass.

Influence of temperature and soda concentration in a thermo-mechano-chemical pretreatment for bioethanol production from sweet corn co-products

A continuous process combining an alkaline pretreatment, neutralization and injection of enzymes within a twin screw extruder was previously implemented and demonstrate industrial potential. The present work focuses on the investigation of the effects of alkali and temperature during the alkaline pretreatment of sweet corn co-products (SCC) for the production of fermentable sugars with a lower chemical input. Study of NaOH/SCC and internal temperature was performed in ranges of 4–8% (w/w) and 50–170 °C in a laboratory scale twin screw extruder. Analysis of carbohydrates and lignin of the pretreated biomass was performed and the filtration efficiency was also monitored through extrudate dry matter and filtrate mineral matter. The carbohydrate accessibility and process performances were studied by the enzymatic hydrolysis of the extrudate. Increasing temperature reinforces the effects of soda on solubilization of hemicelluloses, thus a hemicelluloses removal reach more than 50%. At optimal conditions, the cellulose-rich substrate after enzymatic hydrolysis achieve a glucose released of 70%, with glucose and xylose yields of 250 g per 1Kg of dry SCC.

Pretreatment of wheat straw with ligninolytic fungi for increased biogas productivity

Biogas production from the agriculture waste biomass is a sustainable approach to managing the energy demand in the future. To do so, pretreatment is needed to remove lignin from the agribiomass to make it easily digestible substrate for the fermentative organisms. The current study was carried out to screen the most effective lignin-degrading fungal culture from their natural habitat. Pretreatment with robust ligninolytic fungi could be an efficient and economical method to degrade lignin. The presence of lignin in lignocellulosic biomass is the rate-limiting factor which reduces the biogas production. So, the best fungal strains were selected based on maximal Azure B dye decolorization. The strains were actively producing lignin peroxidases and laccases and decreased 48.2% of lignin from the wheat straw (WS) within 7 days of batch incubation. The scanning electron micrograph demonstrated visible degradation only in the fungi-treated wheat straw. The ligninolytic fungal culture pretreatment of WS enhanced the biogas yield five times compared with the untreated WS sample. Notably, these fast-acting lignin-degrading fungi gave a biogas yield with a short pretreatment time and additionally reduced the lag phase during the anaerobic digestion process. These findings showed that pretreatment with natural ligninolytic fungi could be considered as a less expensive method. The treatment is also effective in increasing the digestibility of lignocellulosic biomass and suitable for biogas production.

High Performance Thermoplastic Elastomers with Biomass Lignin as Plastic Phase

For the first time, the coordination-based energy sacrificial bonds have been constructed in the interface between lignin and polyolefin elastomer for preparing a new class of high performance ther...

Valorization of lignin biomass as a carbon feedstock in steel industry: Iron oxide reduction, steel carburizing and slag foaming

The heavy use of coal-derived coke (CDC) in steel industry makes it a major contributor to the greenhouse emissions. With the impact of global warming knocking our doors, the CDC has experienced supply shortages and increasing costs. Such scenario has raised the need to find a sustainable and renewable replacement to CDC. Hard-wood biomass has emerged as a promising alternative to the CDC. While such sources of virgin biomass remain at high cost, other types of agro-industrial residues constitute an opportunity for further sustainable utilization. In the current work, we have assessed the suitability of an abundant source of biomass waste, i.e., lignin-rich press mud (LPM), for steel industry. Hard carbons were obtained from LPM through a thermal treatment at a wide range of temperatures, and the chemical content (i.e., impurity) of all carbons was compatible with the steel making process. Before fitting the LPM-derived carbons (LPMCs) for such purpose, several carbon properties (e.g., chemical content and reactivity) and carbon-steel interactions (e.g., iron oxide/slag reduction, steel carburizing) were comprehensively studied and evaluated. The LPMC obtained at high temperature has particularly demonstrated an excellent reduction performance and desirable slag interactions compared to a typical metallurgical coke. The diffusion of S from LPMC into steel was an issue raised and discussed in this study. The reduction of S in LPMC was demonstrated and a subsequent enhanced C uptake in steel of 2.38% was achieved.

Application of Hydrodynamic Cavitation for Improving Methane Fermentation of Sida hermaphrodita Silage

Hydrodynamic cavitation was recently applied as a biomass pretreatment method. Most of the studies which used hydrodynamic cavitation were applied to pretreated sugarcane bagasse or reed. High biomass yield of Sida hermaphrodita points out the necessity of studies on its effective pretreatment before methane fermentation, especially because its “wood-like” characteristics could present different disintegration properties than other lignocellulose biomass. Thus, the aim of the study was to investigate the influence of duration of hydrodynamic cavitation on lignocellulose composition in Sida hermaphrodita silage, and the assessment of disintegrated biomass as a substrate for methane fermentation. The study showed a slight decrease in lignin, cellulose, and hemicellulose content in biomass after hydrodynamic cavitation, which resulted in a higher content of carbohydrates in the liquid fraction of disintegrated substrates. Methane production was 439.1 ± 45.0 L CH4/kg total solids (TS) from the substrate disintegrated for 20 min. However, the most effective time for methane production was hydrodynamic cavitation of the substrate for 5 min. At this pretreatment duration, the highest values for chemical oxygen demand (COD), total organic carbon (TOC), and carbohydrate reduction were also noted. The study proved that hydrodynamic cavitation applied for 5 min allowed obtaining an energy profit of 0.17 Wh/g TS. The studies on a laboratory scale indicated that the technology of hydrodynamic cavitation of Sida hermaphrodita could be economically applied for methane fermentation on a large scale.

Biomass-Derived Poly(ether-amide)s Incorporating Hydroxycinnamates.

Lignin-derived chemicals have great potential as feedstock to produce polymeric materials, due to the low cost and high abundance of lignin biomass. Lignin is one of the few nonpetroleum sources of aromatic carbon, a desirable moiety in high-performance polymers. Herein we describe the synthesis and characterization of a series of 21 poly(ether-amide)s that incorporate hydroxycinnamates derived from lignin. Three different hydroxycinnamates (coumaric acid, ferulic acid, sinapinic acid) were incorporated into dimers, and then copolymerized with a series of seven aliphatic and aromatic diamines via interfacial polymerization. The resultant polymers exhibited poor solubility in standard organic solvents (excluding DMF), but exhibited moderate glass transition temperatures and moderate thermal stabilities. Additionally, the polymers exhibit excellent resistance to hydrolysis. The modularity of this synthetic approach could be used to rapidly generate diverse polymers with a broad range of well-tuned properties.

The Effect of NaOH Concentration and microwave exposure time to the content of cellulose, hemicellulose and lignin of Corn Cob

Abstract.Currently ethanol produced from molasses, cassava and maize, thereby competing with the need for food, animals feed and other industrial raw materials, so that the supply of raw materials is not continuity. If this continues, it will certainly have an impact on food prices spike, it will create new problems on the economy of the community, and one of an alternative raw material for bioethanol production is cellulose biomass.To convert biomass into bioethanol through several stages, including pretreatment, hydrolysis and fermentation. The content of lignin in biomass will disturb the enzymatic hydrolysis process, so it is necessary to encourage the delignification in the pretreatment stage. Microwave - alkali pretreatment can reduce more lignin and hemicellulose in rice straw, so it needs to be an effort to change the composition of lignocellulose and improve the hydrolysis of corn cob is fermented to become ethanol. Pretreatment of corn cobs research was done using randomized block design arranged in factorial and repeated 2 times. The first factor is the concentration of NaOH for 0,5 N, 1 N and 1,5N. The second factor is the time of exposure to microwave heat radiation for 10, 20 and 30 minutes. The results showed that cellulose content increases with prolonged exposure concentrations of NaOH and microwave, as well as to the content of hemicellulose and lignin decreased along with the increase of exposure duration of Microwave and the increase of NaOH concentrations.

Development of anti-photo and anti-thermal high internal phase emulsions stabilized by biomass lignin as a nutraceutical delivery system.

Herein, oil-in-water high internal phase emulsions (HIPEs) were stabilized by lignin from different technical resources with the assistance of alkyl polyglycoside (APG) using an ultrasonic cavitation method. The results showed that the amphiphilicity of lignin determined the formation of HIPEs. Microscopic and rheological characterization indicated that the molecular weight and concentration of lignin, the APG dosage and the oil/water ratio had important influences on the microstructure and stability of the HIPEs. In addition, nutraceutical β-carotene could be encapsulated in the oil phase of the HIPEs, which exhibited outstanding protection against photo- and thermal-oxidative degradation of β-carotene. After storage for 30 days under room temperature/light or storage for 7 days under 55 °C/dark conditions, the retention of β-carotene in the HIPEs was 87% to 95%, which is significantly higher than that of β-carotene dispersed in bulk oil. In vitro digestion experiments indicated that the digestibility of the HIPEs also markedly improved. The largest release of free fatty acids was 80%. The bio-accessibility of β-carotene in these lignin-based HIPEs also reached 60%.

Fabrication of mesoporous SiO2@SLS composite to remove organic pollutants: hydrogen bond-induced intriguing changes of solubility

Because biomass lignin shows good adsorption activity, its derivatives such as alkali lignin and kraft lignin have been applied in water treatment; however, sodium lignosulfonate (SLS), mainly limited by its high water solubility, is not applicable in this respect. In this work, we fabricated SiO2@SLS mesoporous adsorbent using a facile solution coating method by one step. SLS coating SiO2 enables the former to be “separated” from water, accomplishing the soluble to insoluble conversion. This change makes the composite more suitable and efficient to remove organic pollutants from water than the SLS precursor. It is found that interfacial hydrogen bonds play a significant role in the conversion, which is further corroborated by density functional theory calculations. Various characterizations show that SiO2@SLS is composed of uniform particles around 80 nm in size. Abundant mesopores with diameters ranging from 2 to 3 nm are found on the surface of SiO2@SLS nanoparticles. The specific surface areas of SiO2@SLS were measured between 293.4 and 33.2 m2 g−1, depending on the SLS amount used in the preparing process. Originating from the bio-adsorbent lignin precursor, the SiO2@SLS composite shows excellent adsorption property. Representatively, SiO2@SLS-0.6 is able to efficiently remove methylene blue (MB), almost twice as much as SiO2-0 does; its adsorption capacity (Qm) reaches 206.2 mg g−1 according to the Langmuir model fitting; notably, SiO2@SLS-0.6 works very well even in a high-concentration MB solution (50 mg L−1), showing removal efficiencies at 90.0% (within 1 h) and 99.9% (720 h, i.e., 30 days). Plus having remarkable adsorption stability, our composite SiO2@SLS is anticipated to be promising in application of polluted water treatment.

Integrated Separation Process of C5 Sugars and Phenolics from Poplar Wood Using CO2-Assisted Hydrolysis Followed by Hydrogenolysis

This study presents an efficient methodology to remove hemicellulose and lignin from lignocellulosic biomass by a three-step process to obtain C5 sugars, phenolics and high purity cellulose. The first step, a CO2-assisted hydrolysis pretreatment was conducted for the selective extraction of the hemicellulose fraction. The process effectively extracted hemicellulose at 180 °C with CO2 at 20 bar initial pressure for 10 min, during which a variety of monosaccharides and other intermediates were obtained. The second step, the catalytic hydrogenolysis of the pretreated feedstock, was performed in a cosolvent isopropyl alcohol–water system with Raney Ni as the catalyst, which can catalyze the depolymerization of lignin components for phenolic products. A variety of phenolic components with lower molecular weights were detected via GC–MS and HSQC. Further treatment with alkaline hydrogen peroxide was used to extract the remaining small amount of lignin and hemicellulose fractions in biomass and to obtain high pu...