Relative Cellulose Content Research Articles

Response relationships between the color parameters and chemical compositions of heat-treated wood

Abstract The magnitudes of the color changes in heat-treated wood are closely related to the chemical composition of the wood, and changes in the chemical composition are the essential reasons for changes in the mechanical properties of heat-treated wood. The response relationships among the color parameters of heat-treated wood and the chemical composition were constructed to provide a scientific basis for regulating the mechanical properties with the color. The effects and linear correlations of the lightness indicators (L*) for poplar (Populus tomentosa Carr.) and spruce (Picea asperata Mast.) after heat treatment were related to the chemical compositions of the heat-treated woods by constructing relationships between the L* values. The relative content of cellulose in the heat-treated poplar downward trend and was significantly positively correlated with the L* value; however, the correlation with the L* value for the heat-treated spruce was insignificant. The L* value of the heat-treated wood was significantly positively correlated with the relative contents of hemicellulose, and was significantly negatively correlated with lignin. The L* value of the heat-treated wood had a superior response relationship with the crystallite sizes. Therefore, the constructed response relationship provides a theoretical basis for accurate and nondestructive testing of the mechanical properties of heat-treated wood by using the color parameters as rapid detection indicators.

Soil accelerates the humification involved in co-composting of wheat straw and cattle manure by promoting humus formation

In aerobic organic waste composting, lignocellulose degrades and is converted slowly, reducing composting effectiveness and humus production. Soils have a porous nature, buffering capacity and a wide range of nutrients that are beneficial for the microbial contribution to composting efficiency and humus formation. This study aimed to determine how soil affects lignocellulose decomposition, humification and microbial metabolism during composting. It was found that for the control and treatments with added fluvo aquic soil (FAS), dark loessial soil (DLS) and yellow brown soil (YBS), the relative hemicellulose content decreased by 7.4, 11.8, 13.3 and 11.8%, relative cellulose content decreased by 1.5, 7.7, 6.2 and 6.8%, and humic acid content increased by 10.1, 36.4, 35.5, and 28.2% respectively, indicating that the addition of soil elevated humus content of the compost. FAS, DLS and YBS addition enriched the specific hydrolytic bacteria Corynebacterium, and its relative abundance increased by 187, 120 and 22%, respectively, which promoted organic matter degradation. In addition, in carbohydrate metabolism, glycolysis increased by up to 11%, and starch and sucrose metabolism increased by up to 12% forming substances such as reducing sugars and polyphenols, which promoted compost humification through the polyphenol and Maillard humification pathways. This study demonstrates a novel option and mechanism for rapid degradation and humification of organic materials in composting.

A comparative study on the comprehensive properties of natural microfibers isolated from the large-clustered bamboos in the southwest of China using steam explosion

ABSTRACT To develop sustainable functional fibers and expand their novel applications, the large-clustered dendrocalamus sinicus (DS) and the dendrocalamus giganteus (DG) planted in the southwest of China were effectively isolated by steam explosion (SE). The fine and uniform bamboo microfibers of DS and DG corresponding to the smallest average widths of 18.24 μm and 17.16 μm were obtained, respectively. The relative content of cellulose in two bamboo species had a marked increase after SE but a decrease for hemicellulose and lignin without any introduction of toxic chemical reagents. The SE treatment improved the thermal stability, the crystallinity, and the surface hydrophilicity of bamboo samples with their morphologies varying from rod-shaped strips to fibrous filaments. The degrees of crystallinity for DS and DG increased from 57.63% and 57.53% to 73.67% and 74.10%, respectively. The thermal stability, mechanical properties, and hydrophobicity of bamboo microfibers derived from DS were superior to those of DG, which showed a higher maximum decomposition temperature (5.24°C), tensile strength (181 MPa), elongation at break (1.1%), and water contact angle (7.8°).

The Study on Bamboo Microfibers Isolated by Steam Explosion and Their Comprehensive Properties

To overcome the shortage of wood resources as well as to develop novel natural fibers materials, the Chimonobambusa quadrangularis (CQ) and Qiongzhuea tumidinoda (QT) planted in Southwest China were effectively isolated by the steam explosion (SE). The fine and uniform bamboo microfibers derived from CQ and QT were obtained, and their smallest average widths were 12.62 μm and 16.05 μm, respectively. The effects of steam explosion on the micro-morphology, chemical composition, thermal stability, crystallinity, surface wettability, and mechanical properties of bamboo microfibers were comprehensively investigated. The results showed that the relative content of cellulose in bamboo microfibers increased but the hemicellulose and lignin contents decreased after SE. The degrees of crystallinity for CQ and QT increased from 40.49% and 39.46% to 68.90% and 55.78%, respectively. The thermal stability and surface hydrophilicity were also improved. The CQ microfibers had a maximum decomposition temperature of 2.79°C, a tensile strength of 58.54 MPa, an elongation at break of 0.6%, and a water contact angle of 2.7° higher than those of the QT microfibers.

Combinations of mild chemical and bacterial pretreatment for improving enzymatic saccharification of corn stover

Biological pretreatment of lignocellulosic biomass plays an important role for the enzymatic hydrolysis. In this study, a nitrogen-fixing and lignin-degrading strain of bacteria was isolated from an abandoned termite colony. Then, it was identified and named as R. ornithinolytica RS-1. To improve the degradation and enzymatic saccharification in corn stover, we used pretreatment with strain RS-1 to deplete the lignin, combined with a 2.5% mild NaOH pretreatment to further deplete the hemicellulose. After only seven days, lignin was degraded by the bacteria RS-1 with a 19% decrease, while the relative content of cellulose increased with 21%. Furthermore, the corn stover cellulose conversion was up to 48.58% by a two-stage process with 2.5% NaOH pretreatment. Meanwhile, significant lignin and hemicellulose removal were observed. Manganese peroxidase activity was highest on Day 3 with the value 181.0256 U/L and lignin peroxidase activity was highest on Day 5 with the value 37.473 U/L, respectively. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) analyses showed significant chemical structural changes after the combined pretreatment. Therefore, strain RS-1 provided an efficient strategy to enhance the enzymatic hydrolysis efficiency by pretreatment of corn stover.

Study on wood chips modification and its application in wood-cement composites

Wood-cement composites have the advantages of high flexural strength, toughness, and impact resistance. However, the components such as hemicellulose and lignin in the wood chips can inhibit cement hydration, and thus the interface bonding between wood chips and cement matrix is poor. In order to address these issues, alkali cooking (mass concentration is 2–8%) and silane coupling agent (mass concentration is 1–5%) were used in this study to modify wood chips, and the resulting compressive and flexural strengths of wood-cement composites prepared from different kinds of modified wood chips were evaluated. Further, the XRD, SEM, and FT -IR tests were carried out to characterize the modified wood chips and explore the mechanism of modified wood chips incorporated composites. The results showed that the alkali cooking agent could effectively remove amorphous components, such as hemicellulose and lignin, from wood chips, improve crystallinity and relative cellulose content, and increase the surface roughness of wood chips. The silane coupling agent could chemically bond with wood chips to improve the interfacial properties between wood chips and cement matrix. The flexural strength of the composites prepared with wood chips treated with 3% silane coupling agent and 4% alkali cooking agent was increased, which was 11.9% higher than that of the composites prepared from wood chips treated only with 4% alkali cooking agent, while it was 27.1% and 31.6% higher than the composites prepared with untreated wood chips and mortar without wood chips, respectively. Alkali cooking modification and silane coupling agent treatment of wood chips can effectively improve the mechanical properties of composite materials.

Adsorptive removal of lead ion from water using banana stem scutcher generated in fiber extraction process

Lignocellulosic biomass-based adsorbents for removal of heavy metal ions from water have been reported. Importantly, a solid biomass waste known as Banana Stem Scutcher (BSS) is generated in banana stem fiber (BSF) extraction from lignocellulosic rich banana stem (BS). Here, for the first time, we report BSS characterization, and its ability for adsorption of lead (Pb(II)) ion from water. The maximum adsorption capacity for Pb(II) ion removal by BSS was determined to be 179.9 mg g−1. BSS was recycled five times without any significant loss in adsorption performance. Pb(II) ion adsorption onto BSS is exothermic (ΔH = −70.55 kJ mol−1), and spontaneous (ΔG = −3.52 kJ mol−1 at 303 K) with energy of activation as, 95.95 kJ mol−1. Further, interaction between Pb(II) ion and functional groups of BSS was confirmed by XPS and FTIR results. The relative cellulose content in BSS (74.25%) was higher than the BS (57.85%), as well as BSF (60.36%). The higher accessible cellulosic content in BSS was proposed for the enhanced Pb(II) ion adsorption by BSS, compared to BS and BSF. The study highlights a low cost and chemical free, mechanical based treatment of biomass useful to produce effective biomass-based adsorbents for removal of metal ions.

Co-hydrothermal carbonization of pretreatment lignocellulose biomass and polyvinyl chloride for clean solid fuel production: Hydrochar properties and its formation mechanism

The production of coal as an alternative to solid fuel through co-hydrothermal carbonization (co-HTC) of polyvinyl chloride (PVC) and lignocellulose biomass can play a key role in improving the environment and energy supply. However, how to improve the synergistic effect of the reaction is still an urgent problem. In this study, the co-HTC method of acid-base pretreated straw and PVC was proposed to improve the synergistic effect of the reaction. Through the comparison and analysis of the products, the change of reaction mechanism and the reason for the increase of synergistic effect were speculated. The results showed that these pretreatment methods could effectively enhance the synergistic effect of the co-HTC process. Alkali pretreatment destroyed the connection between hemicellulose and lignin, increased the relative content of cellulose, accelerated the hydrothermal reaction, and increased the energy density of the product. The HHV of hydrochar increased from 26.89MJ/kg to 30.83MJ/kg and the energy recovery efficiency reached 68.85% by using base modified straw powder (BSP). Acid pretreatment destroyed the connection between cellulose and hemicellulose in straw, degraded part of lignin into phenols, which strengthened the substitution reaction of Cl in the co-HTC process and improved the dechlorination efficiency of the product. The chlorine content of hydrochar decreased from 7.84% to 6.44% and the carbon retention reached 84.49% by using acid-modified straw powder (ASP). The ICP-OES analysis showed that more insoluble metal salts in hydrochar were dissolved in solution, which reduced the risk of slagging and corrosion when hydrochar as a substitute for coal combustion.

Differential responses of roots for varying tolerance to salinity stress in wheat with special reference to elasticity

Two salt-sensitive (Yongliang-15, GS-6058) and two salt-tolerant (JS-7, Xinchun-31) wheat cultivars were used to investigate the extension, extensibility (viscoelastic parameters), and chemical composition of the cell walls in their root elongation regions (apical 10 mm-long root segments), under salinity stress. The elasticity of the root cell wall, indicated by E0, significantly decreased in the salt-sensitive cultivars, whereas the E0 in the salt-tolerant cultivars was maintained at the same level as that in the non-saline condition. Root extension and the differences among cultivars were largely dependent on elastic extension, which accounts for one-half to two-thirds of the total extension. Viscosity, indicated by η0, and the plastic extension of the root cell walls did not change across the treatments and cultivars. The significant decrease in cell wall elasticity in the root elongation region was one of the factors that depressed root growth in salt-sensitive cultivars under the saline condition. The well-maintained elasticity of salt-tolerant cultivars alleviated the depression of root growth by NaCl. Cell wall elasticity was positively correlated with the relative pectin and hemicellulose I contents and negatively correlated with the relative cellulose content. Under saline conditions, the relative hemicellulose II content did not change in the salt-sensitive cultivars; however, it decreased in the salt-tolerant ones. Thus, changes in chemical composition of the cell wall were correspond with the cell wall extensibility and root growth in wheat cultivars with different degrees of salt tolerance.

Facilely reducing recalcitrance of lignocellulosic biomass by a newly developed ethylamine-based deep eutectic solvent for biobutanol fermentation

BackgroundBiobutanol is promising and renewable alternative to traditional fossil fuels and could be produced by Clostridium species from lignocellulosic biomass. However, biomass is recalcitrant to be hydrolyzed into fermentable sugars attributed to the densely packed structure by layers of lignin. Development of pretreatment reagents and processes for increasing surface area, removing hemicellulose and lignin, and enhancing the relative content of cellulose is currently an area of great interest. Deep eutectic solvents (DESs), a new class of green solvents, are effective in the pretreatment of lignocellulosic biomass. However, it remains challenging to achieve high titers of total sugars and usually requires combinatorial pretreatment with other reagents. In this study, we aim to develop novel DESs with high application potential in biomass pretreatment and high biocompatibility for biobutanol fermentation.ResultsSeveral DESs with betaine chloride and ethylamine chloride (EaCl) as hydrogen bond acceptors were synthesized. Among them, EaCl:LAC with lactic acid as hydrogen bond donor displayed the best performance in the pretreatment of corncob. Only by single pretreatment with EaCl:LAC, total sugars as high as 53.5 g L−1 could be reached. Consecutive batches for pretreatment of corncob were performed using gradiently decreased cellulase by 5 FPU g−1. At the end of the sixth batch, the concentration and specific yield of total sugars were 58.8 g L−1 and 706 g kg−1 pretreated corncob, saving a total of 50% cellulase. Utilizing hydrolysate as carbon source, butanol titer of 10.4 g L−1 was achieved with butanol yield of 137 g kg−1 pretreated corncob by Clostridium saccharobutylicum DSM13864.ConclusionsEthylamine and lactic acid-based deep eutectic solvent is promising in pretreatment of corncob with high total sugar concentrations and compatible for biobutanol fermentation. This study provides an efficient pretreatment reagent for facilely reducing recalcitrance of lignocellulosic materials and a promising process for biobutanol fermentation from renewable biomass.

Creep properties of compression wood fibers

To achieve efficient utilization of compression wood (CW), a deeper insight into the creep behavior of CW is necessary. In particular, the involvement of lignin for the creep behavior of CW needs to be better understood. In the present paper, wood fibers and slices from CW and normal wood were studied at both high constant humidity and cyclic 30–80% RH conditions. The micromechanical deformation explored by FTIR confirmed that in CW, lignin participated in the stress transfer during creep measurements. For all types of materials, the creep strain rate at constant and cyclic humidity conditions was linearly related to the applied load level. For single CW fibers, the creep rates were higher at a given load for native CW fibers compared to holocellulose CW fibers, due to the lower relative cellulose content. The CW fibers, with a microfibril angle of around 45°, were found to exhibit a greater creep rate during moisture cycling as compared to the higher but constant humidity level, i.e., a mechano-sorptive behavior. However, the mechano-sorptive effect, i.e., the ratio between the creep rates at constant and cyclic humidity, was only slightly higher for the CW holocellulose fibers as compared to the native CW fibers, indicating that the lignin most probably does not contribute to the mechano-sorptive effect.

Structural Features of Lignin Fractionated From Industrial Furfural Residue Using Alkaline Cooking Technology and Its Antioxidant Performance

： For furfural industry, industrial furfural residue as the solid waste was generated from the production of furfural, and is rich in cellulose and lignin with a certain degree of degradation because of strong acid (H2SO4) as catalyst. In this work, alkali cooking technology was applied to extract lignin from industrial furfural residue to explore the new route of industrial application. The effect of different alkali treatment conditions on the chemical structure of lignin was studied. And the effects of different alkali treatment conditions on the composition and chemical structure of the residue were studied by NREL, 13 C NMR and ATR. The results showed that obtained lignin contained abundant guaiacyl (G), syringyl (S) and p-hydroxyphenyl (H) structural units, among which G-type lignin structural units accounted for the main proportion. The extracted lignin samples were rich in hydroxyl, and the highest content of hydroxyl was 4.02 mM/g under the condition of alkali cooking (135 ℃-0.35 M). Oxidize resistance test showed obtained lignin samples had high inhibition effect on DPPH. Moreover, the relative content of cellulose in the solid residue decreased and the relative content of lignin increased significantly because of the lignin-like substance formation by partial degradation and carbonization of cellulose under high-severity cooking treatment. This alkali cooking technology was suitable for extracting lignin from furfural residue without significant change in lignin structure, which have the promising application as potential antioxidants in food and cosmetics.

STATISTICAL APPROACH FOR PECTINASE PRODUCTION BY Bacillus firmus SDB9 AND EVALUATION OF PECTINO-XYLANOLYTIC ENZYMES FOR PRETREATMENT OF KRAFT PULP

The present study originated with the concomitant production of 1.94 IU.mL-1 of pectinase, 0.34 IU.mL-1 xylanase and 0.086 IU.mL-1 cellulase from a newly isolated Bacillus firmus SDB9 in pectin salt media. Plackett-Burman Design (PBD) and Box-Behnken design (BBD) were used for optimization of mass production of pectinase using agro-residues. Statistical optimization of medium enhances the pectinase production to 17.55 IU.mL-1, 17.7% higher activity than that of unoptimized medium. The optimal pectinase activity was found at pH 8.5 and 45°C temperature. The enzyme was alkali-stable over a range of pH 7.0 to 10.0 for 1 h and thermostable at 35 to 70°C for 1h. Out of 12 tested metal cations at 1mM concentration, the enzyme was found to be hindered by the presence of three cations, whereas four cations were reported to augment, and the rest marginally subdued the activity. Pretreatment with 15 IU pectinase and 2.7 IU xylanase per gram of OD pulp reduce kappa number by 7.9%. After bleaching sequence D0-Ep-D1, the increment in pulp brightness was 2.7% with acceptable whiteness level. Pretreatment also led to a reduction in ClO2 consumption by 15% with superior brightness level. The 0.83% increase in pulp viscosity along with 3.2% gain in double fold number indicated the maintenance of relative cellulose content and strength of paper. Minor variations in burst index, tensile index and tear index reflected the conserved properties of the treated pulp. Synergistic application of mixed enzymes preparation produced from raw agro-residue headed by pectinase in preference to xylanase is first time set forth in the present study to help in cost economization and propel the pulp and paper industries towards environmental friendly future.

Structural features and enzymatic digestibility of Napier grass fibre treated with aqueous ammonia

We characterised the structural changes of Napier grass after treatment with aqueous ammonia (27%, w/w) at a solid:liquid ratio of 1:12 for 14 days at ambient temperature and evaluated its enzymatic digestibility. This treatment protected carbohydrates in the fibre and greatly reduced lignin content (58.7% lignin removal), resulting in the deconstruction of the fibrous matrix. Although the relative cellulose content increased, the degree of crystallinity of the treated fibre increased only marginally from 42.9 to 50.0%, which can be attributed to the partial disruption of the cellulose crystal structure. Aqueous ammonia treatment markedly promoted the enzymatic cellulose digestibility, increasing from 18 to 53% with an enzyme loading of 30FPU/g biomass. Supplementation of cellulase with xylanase (30FPU cellulase+100XU xylanase/g biomass) improved the final extent of hydrolysis and greatly enhanced the final glucose yield, approaching to 80% glucan conversion.

Effect of NaOH on delignification of Saccharum spontaneum

Saccharum spontaneum abundantly available in Pakistan has great potential for production of bioethanol due to high cellulosic contents. In the present study, S. spontaneum grass was impregnated in various concentrations of NaOH (0.5%–3% wt/vol) for different soaking periods (1 h, 2 h, 4 h, 6 h, 12 h, 24 h, and 48 h). The results showed that relative cellulose contents and delignification increased with the increase in concentration of alkali and soaking time. However, maximum cellulose content and delignification (52.5% and 47.6%) was observed with 2.5% wt/vol NaOH after 24 h of soaking period. In physiochemical pretreatment, the substrate was soaked in alkaline solution for 2 h followed by steaming at 121°C for various intervals (15–60 min). Maximum relative cellulose content (81.2%) was achieved after 60 min while delignification was found 74%. These findings indicated that proper concentration of alkali as well as steaming period at specific temperature play a major role in exposure of maximum cellulosic contents of S. spontaneum to exploit it as a potential substrate for bio‐fuel production. © 2015 American Institute of Chemical Engineers Environ Prog, 35: 284–288, 2016

Inheritance and phenotype expression of functional and null alleles of aromatic alcohol dehydrogenase (CAD) in diploid wheats

Functional F and null 0 alleles of the CAD1 (Aadh1) gene, which controls the biosynthesis of aromatic alcohol dehydrogenase, were studied in hybrids of the diploid wheat T. monococcum L. and Triticum sinskajae A.Filat. et Kurk. The gene CAD1 is located in chromosome 5A and is linked with the awnless gene awnS (La) with a recombination frequency of about 32%. Plants with genotypes FF, F0, and 00 were significantly different in the height and mechanical strength of the stalk (culm). The elastic limit of the culm tissues of plants FF was considerably higher than in 00 plants. F0 heterozygotes had intermediate values. The thickness of the wall of the sclerenchyma was thinner in plants with genotype 00. The chemical structure of lignin of plants with the functional CAD allele contained units of a phloroglucinol series missing in the mutant plants. The CAD genotypes had no effect on the relative content of cellulose and lignin in stalks ofdiploid wheat and insignificantly influenced the ratio of H :G : S units in the lignin structure, as well as some components of extractives.

Lignin Depletion Enhances the Digestibility of Cellulose in Cultured Xylem Cells

Plant lignocellulose constitutes an abundant and sustainable source of polysaccharides that can be converted into biofuels. However, the enzymatic digestion of native plant cell walls is inefficient, presenting a considerable barrier to cost-effective biofuel production. In addition to the insolubility of cellulose and hemicellulose, the tight association of lignin with these polysaccharides intensifies the problem of cell wall recalcitrance. To determine the extent to which lignin influences the enzymatic digestion of cellulose, specifically in secondary walls that contain the majority of cellulose and lignin in plants, we used a model system consisting of cultured xylem cells from Zinnia elegans . Rather than using purified cell wall substrates or plant tissue, we have applied this system to study cell wall degradation because it predominantly consists of homogeneous populations of single cells exhibiting large deposits of lignocellulose. We depleted lignin in these cells by treating with an oxidative chemical or by inhibiting lignin biosynthesis, and then examined the resulting cellulose digestibility and accessibility using a fluorescent cellulose-binding probe. Following cellulase digestion, we measured a significant decrease in relative cellulose content in lignin-depleted cells, whereas cells with intact lignin remained essentially unaltered. We also observed a significant increase in probe binding after lignin depletion, indicating that decreased lignin levels improve cellulose accessibility. These results indicate that lignin depletion considerably enhances the digestibility of cellulose in the cell wall by increasing the susceptibility of cellulose to enzymatic attack. Although other wall components are likely to contribute, our quantitative study exploits cultured Zinnia xylem cells to demonstrate the dominant influence of lignin on the enzymatic digestion of the cell wall. This system is simple enough for quantitative image analysis, but realistic enough to capture the natural complexity of lignocellulose in the plant cell wall. Consequently, these cells represent a suitable model for analyzing native lignocellulose degradation.

Preconditioning of leaves by solar radiation and anoxia affects microbial colonisation and rate of leaf mass loss in an intermittent stream

Summary Seasonal flow intermittence in streams often coincides with early leaf abscission of riparian vegetation due to water stress. When accumulated on dry stream beds or in remaining pools, leaves are exposed to solar radiation or fermentation processes, respectively. However, very little information exists on how these preconditioning processes could affect leaf decomposition when stream flow has recovered. We simulated natural preconditioning of leaves by irradiation with UV‐VIS fluorescent lamps and incubation under anoxic conditions. Mass loss rates of preconditioned leaf litter from deciduous trees (Alnus glutinosa, Fraxinus excelsior, Populus tremula and Quercus petreae) were quantified in a temporary stream during base flow conditions. Coarse and fine mesh litter bags were used to study the effect of benthic macroinvertebrates and microorganisms on leaf mass loss. Preconditioning reduced the concentration of macronutrients such as P, K and Mg and increased the relative cellulose content of the leaves. Preconditioning changed the fungal community structure (analysed by DGGE) depending on leaf species and sampling date. Preconditioning in anoxic conditions also suppressed fungal decomposer biomass (measured as ergosterol) by 42% resulting in 33% lower mass loss rates in fine mesh bags. In contrast, mass loss rates were not affected by preconditioning when macroinvertebrate decomposers had access to the leaf litter. In streams exhibiting seasonal flow intermittence, preconditioning will influence organic carbon dynamics towards lower rates of microbially mediated turnover and towards poorer quality of downstream‐transported material.

Effect of cellobiase and surfactant supplementation on the enzymatic hydrolysis of pretreated wheat straw

Wheat straw is a suitable raw material for ethanol production since it has high cellulose content. The objective of this work was to evaluate the effect of cellobiase and surfactant on the enzymatic hydrolysis of lignocellulosic materials. For this purpose, wheat straw was first pretreated by organosolv digestion. The chemical s of raw and pretreated wheat straw were analyzed. Much of the hemicellulose and lignin were removed, and the relative cellulose content of pretreated wheat straw was 26.57% higher when compared to untreated wheat straw. Cellobiase was added into hydrolysate to improve the hydrolysis efficiency. Through experiments and analysis, the optimum cellobiase dosage was found to be 1/10 of the cellulase loading. Surfactant was also added into hydrolysate. Nonionic surfactant (Tween 80) exhibited better effect on improving enzymatic hydrolysis. When 0.06 g/g dry solids (DS) Tween 80 was also added into hydrolysate, the yield of glucose in hydrolyzate could reach 486 g/kg DS.

Investigation of liquefied wood residues based on cellulose, hemicellulose, and lignin

AbstractChinese eucalyptus was subjected to a liquefaction process using glycerol/ethylene glycol (EG) as liquefaction solvent. The effects of various liquefaction conditions, including reaction time, liquefaction temperature, acid concentration, and liquor ratio on the chemical composition of liquefied wood residues were studied. The results showed that the whole liquefaction process took place in two stages, the liquefaction yield of wood depended on the reaction temperature, acid concentration and liquor ratio. With increased acid concentration the liquefaction yield, acid‐insoluble lignin, and hemicellulose content of the residues were increased, and the relative content of cellulose was decreased. Fourier transform infrared (FT‐IR) analyses of the residues showed that hemicellulose and lignin were almost decomposed at the initial stages of reaction. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011