Removal Of Hemicellulose Research Articles

Improving enzymatic saccharification of corn stover via thioglycolic acid-mediated Fenton pretreatment

Fenton pretreatment is known as a green and mild approach, but it is usually time-consuming and inefficient in promoting lignocellulose enzymatic hydrolysis. Here we demonstrate that thioglycolic acid (TA) significantly accelerates Fenton pretreatment (FP) of corn stover (CS) and improves enzymatic hydrolysis of cellulose and xylan. The results showed that the reducing sugar yield of CS reached 77.0% with TA-assisted FP in only 16 h, while it was only 34.1% and 38.0% with FP alone in 16 h and 72 h, respectively. Via examination of the changes of composition, physical and chemical characteristics of CS before and after pretreatment, it was found that TA-assisted FP greatly improved the removal of hemicellulose and lignin, resulting in increment of the pore volume, pore size and cellulose exposure of CS substrate, which together promoted the enzymatic saccharification of CS.

Experimental Optimization with the Emphasis on Techno-Economic Analysis of Production and Purification of High Value-Added Bioethanol from Sustainable Corn Stover

Bioethanol-derived biomass is a green sustainable source of energy that is highly recommended as an efficient alternative to the replacement of fossil fuels. However, this type of bioethanol production is always expensive with very low bioethanol concentration. Therefore, this work aims to represent a facile and green approach for bioethanol production with high concentration and purity as well as reasonable cost from corn stover (CS). The goal of this study is to characterize CS and its treated samples with maleic acid (CSM) using various characterization analyses, such as proximate and ultimate analysis, HHV, TGA, FTIR, SEM, and CHNS. The bioethanol production stages: Pretreatment, enzymatic degradation, fermentation, and finally bioethanol separation and purification via the pervaporation process, which have been investigated and optimized are associated with the economic analysis. The optimum operating condition of the pretreatment process was 2% maleic acid, 1:20 solid-to-liquid ratio at 45 psi, 120 °C, and 1 h of operation in the autoclave. This process contributes to 53 and 45% lignin and hemicellulose removal, 98% cellulose recovery, and a glucose yield of 741 mg/dL. The yeast isolate succeeded in the production of 1230 mg/dL of bioethanol. This isolated yeast strain was close to Pichia nakasei with a similarity of 98%, and its amplified 18S rRNA gene sequence was deposited in GenBank with the accession number MZ675535. Poly (MMA-co-MA) membrane was synthesized, characterized, and its efficiency for increasing the bioethanol concentration was evaluated using the integrated pervaporation technique. The techno-economic analysis is presented in detail to evaluate the process profitability, which achieves a considerable profit for the whole duration of the project without any losses as it reaches a net profit of USD 1 million in 2023, reaching USD 2.1 million in 2047 for a company with a capacity of 32 thousand tons per year. The sequential strategy offers a promising approach for efficient bioethanol production under mild and environmentally friendly conditions that enable its implication industrially.

Aqueous ethanol organosolv process for the valorization of Brewer’s spent grain (BSG)

Brewers spent grain (BSG), the main solid byproduct of brewing, is annually generated by ca 37 million tons worldwide, which due to limited application, mostly ends up in landfills. This study aims to separate BSG’s fractions (lignin, cellulose, and hemicellulose) by ethanol organosolv pretreatment. Lignin-rich fractions were recovered using a two-step separation technique. The effects of temperature, retention time, and ethanol concentration on the quantity and quality of fractions were studied. The temperature considerably impacted the quality and quantity of obtained fractions, while other parameter effects greatly depended on the temperature. Substantial hemicellulose removal (90 %) along with lignin removal (56 %) and recovery (57 %) were obtained at 180 °C. The highest lignin purity (95 %) was obtained at the pretreatment conditions of 180 °C, 120 min, and 50 % ethanol concentration. This work provides an alternative route for BSG utilization, mitigating its environmental impact while enhancing the economy of a brewery.

Biohydrogen and Methane Production from Sugarcane Leaves Pretreated by Deep Eutectic Solvents and Enzymatic Hydrolysis by Cellulolytic Consortia

This study determined the optimal conditions for the deep eutectic solvent (DES) pretreatment of sugarcane leaves and the best fermentation mode for hydrogen and methane production from DES-pretreated sugarcane leaves. Choline chloride (ChCl):monoethanolamine (MEA) is the most effective solvent for removing lignin from sugarcane leaves. The optimum conditions were a ChCl: MEA molar ratio of 1:6, 120 °C, 3 h, and substrate-to-DES solution ratio of 1:12. Under these conditions, 86.37 ± 0.36% lignin removal and 73.98 ± 0.42% hemicellulose removal were achieved, whereas 84.13 ± 0.77% cellulose was recovered. At a substrate loading of 4 g volatile solids (VS), the simultaneous saccharification and fermentation (SSF) and separate hydrolysis and fermentation (SHF) processes yielded maximum hydrogen productions of 3187 ± 202 and 2135 ± 315 mL H2/L, respectively. In the second stage, methane was produced using the hydrogenic effluent. SSF produced 5923 ± 251 mL CH4/L, whereas SHF produced 3583 ± 128 mL CH4/L. In a one-stage methane production process, a maximum methane production of 4067 ± 320 mL CH4/L with a substrate loading of 4 g VS was achieved from the SSF process. SSF proved to be more efficient than SHF for producing hydrogen from DES-pretreated sugarcane leaves in a two-stage hydrogen and methane production process as well as a one-stage methane production process.

Microcrystalline Cellulose from Jute Fiber: A Bright Prospect for Pharmaceutical Industry

Synthesis of microcrystalline cellulose (MCC) from jute sticks has been studied and reported in this work. The successful removal of lignin and hemi-cellulose has been confirmed through Fourier Transform Infrared (FTIR) spectroscopic technique. X-ray Diffraction (XRD) technique has been used to measure the crystal size and crystallinity index. The FTIR analysis revealed that the acid hydrolysis had an effect on the crystalline of the fibre; however it did not influence the chemical components of the fibres. Pharmaceutical standard tests were done. Higher concentration of sodium chlorite produces minimum particle size and the effective thermal degradation occurs at 340 °C.

Deep eutectic solvent with Lewis acid for highly efficient biohydrogen production from corn straw

To boost saccharification and biohydrogen production efficiency from corn straw, Lewis acid enhanced deep eutectic solvent (DES) pretreatment using choline chloride/glycerol was developed. A notable enhancement of the enzymatic hydrolysis efficiency from 26.3 % to 87.0 % was acquired when corn straw was pretreated with aqueous DES at 100 °C for 5 h using 2.0 wt% AlCl3. A maximum biohydrogen yield of 114.8 mL/g total solids (TS) was achieved in the sequential dark fermentation stage, which was 2.1 times higher than that of the raw feedstock (37.1 mL/g TS). The enhanced efficient conversion was ascribed to the effective removal of lignin and hemicellulose, which led to the bio-accessibility of the straw. This work provides new sights for the rational design of efficient AlCl3-aided aqueous DES system toward biohydrogen production from lignocellulosic biomass.

A method for chemical and physical modification of oriented pulp fibre sheets

Wood pulp fibres are promising reinforcements for biocomposites due to their renewable resource origin and mechanical properties. An oriented and dense fibre reinforcement structure is beneficial for biocomposite properties. We present a method of modifying fibres (e.g. to increase strain to failure) in pre-formed oriented high-density paper structures intended for biocomposites or as hot-pressed fibre materials. Mildly delignified, well-preserved holocellulose fibres from softwood are used. Cold alkali treatment (hemicellulose removal) and mercerisation (conversion to cellulose II) were carried out successfully on oriented fibre sheets. Controlled anisotropy and sheet density are achieved from untreated and straight fibres in the sheet formation step. High mechanical properties and increased ductility of mercerised sheets were observed, which may be valuable for hot-pressed fibre materials (E ≈ 7.1 GPa, strength of 108 MPa and strain to failure of 5.3%) and biocomposites. In contrast, modified wood pulp fibres were difficult to orient, resulting in higher sheet porosity and weak interfibre bonding.Graphical abstract

Response surface methodology and artificial neural network modelling and optimization of Colocynthis Vulgaris shrad peel sulphuric acid hydrolysis

Colocynthis Vulgaris shrad peel is a lignocellulosic biomass that has been underexploited in recent years to produce value-added fuels and chemicals, however, the introduction of artificial intelligence techniques to model and predict the complex hydrolysis process parameters at a reduced time and cost is of paramount importance. This study compared the performance of response surface methodology (RSM) and artificial neural network (ANN) in modelling Colocynthis Vulgaris shrad peel (CVSP) sulphuric acid hydrolysis for fermentable sugar yield. CVSP was processed from Colocynthis Vulgaris shrad seed, washed, dried and grounded. The characterization results from the chemical analysis, Fourier transform infrared spectroscopy (FTIR), (Scanning Electron Micrograph) SEM, EDX, X-ray fluorescence spectroscopy (XRF) and X-ray diffraction (XRD) confirmed that CVSP is a promising cellulose resource for fermentable sugar yield, also, the characterization results provided an insight into the lignin and hemicellulose removal on the fibre surface. The experiments were conducted at an acid concentration (2.5–3.5 M), time (1–3 h), and temperature (80–100 °C) with output as fermentable sugar yield. ANN was evaluated with 11 backpropagation (BP) algorithms; each algorithm was evaluated with three neurons in the input layer, a hidden layer with ten neurons and an output layer with one neuron. The Bayesian regularization algorithm gave the best prediction for fermentable sugar hydrolysis. Based on experimental/algorithm design and simulations, RSM and ANN models were generated. The performance of the models was evaluated using the coefficient of determination (R2) and mean square error (MSE). Assessment of the models through R2 and MSE indicates that ANN (R2=0.9999, MSE=8.7277E-12) has a higher predictive potential compared to the RSM model (R2=0.965264, MSE=5.39) in predicting the process. However, both models' predictions were adequate and effectively predicted CVSP hydrolysis. At a temperature (80 °C), the acid concentration of 2.5 M and time of 2 h; the experimental (76%), RSM predicted (77.92%), and ANN predicted (75.9928%) fermentable sugar yield confirmed a good agreement between the observed and predicted values. The optimal value of 77.4875% sugar yield was obtained at a temperature of 80 °C, time of 1.00001 h and acid concentration of 2.5 M.

Effects of hemicellulose removal combined with polyethylene glycol impregnation on dimensional stability of wood

ABSTRACT To investigate the combined effects of hemicellulose removal and polyethylene glycol (PEG) impregnation on the dimensional stability of wood, Cunninghamia lanceolata (Lamb.) Hook. was hydrothermally treated and vacuum-impregnated with PEG. About 19.43% hemicellulose was removed, which partially facilitated the penetration and uniform distribution of PEG in wood cells suggested by SEM and FTIR analyses. The mass and volume increase as well as cell wall bulking were positively correlated with PEG concentration. Both solely hemicellulose removal and PEG treatment enhanced wood dimensional stability. The wood after combined treatments exhibited much better dimensional stability mainly due to water path block, cell wall bulking and sorption site reduction calculated by Hailwood-Horrobin theory. Moreover, higher PEG impregnation combined with hemicellulose removal caused lower water absorption, and the corresponding ASE reached 68%. Moisture sorption of wood after combined treatment was lower below about 77.6% RH, but then increased sharply because PEG 2000 became more hygroscopic at higher RH. The results confirmed the efficiency of combined modification on improving dimensional stability of wood and also indicated the importance of appropriate use of PEG in moisture sorption. The study could potentially provide useful knowledge of developing new modification techniques to improve wood dimensional stability for better utilization.

A biomimetic Janus delignified wood membrane with asymmetric wettability prepared by thiol-ol chemistry for unidirectional water transport and selective oil/water separation

Inspired by the amazing intelligent water manipulation behavior of cactus, spiders, and desert beetles, tremendous efforts have been devoted to developing intelligent Janus membrane materials with asymmetric wettability for unidirectional water transport and selective water/oil separation. However, the remaining challenges include tedious procedures, harsh conditions, expensive devices, and scaling-up problems. Inspired by the oriented tubular porosity and hierarchical scaffold of wood, biomimetic Janus wood membranes with asymmetric wettability were prepared by direct ultraviolet-induced thiol-ol chemistry. The delignified wood membranes were first prepared by the partial removal of hemicellulose and lignin from the natural balsa wood; Subsequently, an octadecanethiol/ethanol solution was sprayed onto the one side of the delignified wood membrane surfaces. After ultraviolet irradiation under ambient conditions, Janus wood membranes with asymmetric wettability were successfully prepared. The resultant Janus wood membranes exhibited unidirectional water-transport ability and selective oil/water separation; both heavy oil/water and light oil/water mixtures could be separated by merely changing the orientation of the membrane. In addition, the Janus wood membranes showed excellent separation efficiency and recyclability. This novel, facile, scalable, and low-cost strategy for preparing Janus membranes holds great potential for applications in several fields, such as droplet manipulation, multi-liquid separation, purification of industrial wastewater, and microfluidics.

A novel solvothermal biorefinery for production of lignocellulosic xylooligosaccharides, fermentable sugars and lignin nano-particles in biphasic system

Biorefinery plays a pivotal role in biomass economy with environmentally benign process. Herein, we report a coupling dihydrolevoglucosenone and aqueous p-toluenesulfonic acid (Cyrene/TsOH aq.) system for efficient saccharification of moso bamboo. More than 87.3 % of cellulose recovery could be observed under mild condition of 120 °C for 60 min, accompanied by 85.5 % hemicellulose removal and 79.4 % lignin extraction, respectively. Notably, 90.6 % of saccharified yield could be obtained including 67.7 % of oligosaccharide and 22.9 % of monosaccharide. Besides, the yielded lignin exhibited high purity of 99.1 % and outstanding uniform polydispersity index of 1.49 with nanoscale particle size around 347 nm, which is of great significance for further application. Furthermore, the synergistic effect between Cyrene and TsOH on efficiency and specificity of biorefinery was proposed by control experiments and verified by molecular dynamics simulation and quantum chemical calculation, which provided a new insight for full components biorefinery of lignocellulosic biomass.

Cellulose grafted with polyaniline for simultaneous adsorption of cationic and anionic dyes in wastewater effluent

The adsorbent for both cationic and anionic dye based on cellulose and polyaniline was prepared. Cellulose was purified from sugarcane bagasse through the removal of hemicellulose and lignin. Aniline was polymerized in emulsion state in the presence of cellulose and ammonium persulfate as an initiator. The results from Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM) observation and determination of porosity confirmed that polyaniline was grafted on the surface of cellulose fiber to form cellulose-graft-polyaniline (Cel-g-PAni). Polyaniline acted as adsorption sites for both cationic dye (methylene blue) and anionic dye (methyl orange). The adsorption on the surface of Cel-g-PAni followed the Langmuir model, suggesting that the adsorption sites on its surface was uniform. The extent of adsorbing capacity of Cel-g-PAni toward methylene blue and methyl orange was 1.57 and 0.75 mmol/g, respectively. These values confirmed that Cel-g-PAni was an efficient adsorbent for both cationic and anionic dyes. The adsorption of either cationic or anionic dye in a mixture solution did not restrain each other. Cel-g-PAni was expected to have potential application in practical.

Rice straw structure changes following green pretreatment with petha wastewater for economically viable bioethanol production

Energy efficient and environment friendly pretreatment processes for the production of biofuel have remained elusive and the research is further compounded by the high cost of processing lignocellulosic biomass—an essential factor for producing sustainable biofuels. In the last few decades, a number of pretreatment methods have been proposed, specifically chemical pretreatments but are either expensive or harmful to the environment. To address this urgent need, we propose a green pretreatment method that utilises the highly alkaline by-product, petha wastewater to pretreat the lignocellulosic waste rice straw (RS). The effectiveness of the pretreatment was analysed by monitoring both enhanced cellulose content and reducing sugar yield along with removal of hemicellulose and lignin. We found that PWW pretreatment yielded five times more reducing sugar than native RS with 10.12% increment in cellulose content. SEM and EDX studies further revealed that our process enhanced surface roughness and carbon content (from 32.19% increased to 41.59% and 41.66% for A and D, respectively) along with reduction in silica content (from 8.68% in RS to 4.30% and 7.72% for A and D, respectively). XRD and FTIR analyses indicate crystallinity index (CI) and alteration in lignocellulosic structure of RS, respectively. Decrease in CI was about 43.4% in A whereas only 4.5% in D as compared to native RS (CI 54.55%). Thereby we found PWW to be better substitute of an alkali for pretreatment of RS with negligible environmental impacts.

Investigation of the Structural, Thermal, and Physicochemical Properties of Nanocelluloses Extracted From Bamboo Shoot Processing Byproducts.

Nanocellulose has gained increasing interest due to its excellent properties and great potential as a functional component or carrier in food and pharmaceutical industries. This study investigated the structural, thermal, and physicochemical properties of nanofibrillated cellulose (NFC) and nanocrystalline cellulose (CNC) extracted from bamboo shoot (Leleba oldhami Nakal) processing byproducts. NFCs were prepared through low concentration acid hydrolysis combined with ultrasonic treatment. CNCs were further isolated from NFCs using sulfuric acid hydrolysis treatment. TEM images showed that NFC and CNC exhibited typical long-chain and needle-like structures, respectively. CNC suspension was stable due to its zeta potential of -34.3 ± 1.23 mV. As expected, both NFC and CNC displayed high crystallinity indexes of 68.51 and 78.87%, and FTIR analysis confirmed the successful removal of lignin and hemicellulose during the treatments. However, the thermogravimetric analysis indicated that sulfuric acid hydrolysis decreased the thermal stability of CNCs. The improved physicochemical properties of NFC and CNC suggested their potential in various applications.

Isolation and Characterization of Cellulose Nanofiber Obtained From Agriculture Waste

Background: The fibers of date palm [DPFs] were used as a raw material to isolate cellulose nanofibers [CNFs] to assess their potential as reinforcements of composite materials in producing Bioplastic. The isolation of Nano cellulose [NCs] from DPF is still lacking, and the authors are not aware of any previous publication concerning the isolation of NCs from DPF. Objective: The date palm has huge potential in the application as a reinforcement agent to manufacture bio-nano composites and can be considered a renewable source of nanofibers with an etymology to agro-waste. Method: High-purity cellulose nanofibers were isolated from DPFs through an environmentally friendly treatment process that combined chemical [alkali & bleaching] and mechanical [ball milling]. Results: A high yield of CNFs was successfully extracted, with 50% CNFs from overall DPFs. Scanning electron microscopy [SEM] results revealed the effects of isolation treatments on fiber morphology and showed long, loose nanofiber bundles with 8–100 nm in diameter. FTIR results showed that noncellulosic components were effectively removed. X-ray diffraction analysis revealed the improved crystallinity of the processed fibers with a high crystalline index of 69.78%. Conclusion: TGA results showed an enhancement in the thermal properties of the nanofibers. The removal of hemicellulose and lignin increased the crystallinity of the fibers, and the extracted CNFs were used in the synthesis of Bioplastic by using glycerol as a plasticizer and corn starch as a matrix using the casting method. The feasibility study proved that NC production is feasible in Oman and was successfully yielding cellulose nanofibers with potential in advanced applications. The availability of raw materials is sufficient to sustain the plan with a total capital investment of OMR 9,694,127, an operating cost of OMR 10,058,976, and a total annual net profit of OMR 2,235,445.926 which shows an ROI of 23%/year with a payback period of 4.34 years.

Biodiesel Production from Brassica juncea Using Oleaginous Yeast.

The present study explores the potential of Brassica juncea as a low-cost substrate for biodiesel production through the growth of oleaginous yeast. Firstly, the selected lignocellulosic biomass, i.e.,Brassica juncea, was thermochemically pretreated using dilute sodium hydroxide. Optimization of thermochemical pretreatment resulted in significant removal of lignin and hemicellulose with 8.4% increase in cellulose content. Further, the sugar hydrolysate of pretreated biomass was used as a substrate for the growth of selected oleaginous yeast (Cryptococcussp. MTCC 5455). Lipid and biomass production was optimized using central composite design (CCD) based on response surface methodology (RSM). Maximum biomass and lipid content of 32.50g/L and 11.05g/L, respectively, was obtained at 30°C temperature, pH 6.0, and after 5days of incubation. The oleaginous yeast lipid was further transesterified using immobilized lipase. The highest fatty acid methyl ester 15% FAME yield was obtained after 10h of enzymatic reaction. Next, the results of specific gravity, viscosity, flash points, and cloud point of obtained biodiesels were conformed to the ASTM D975 standard. Overall, the present study put forth the cost-effective approach for lignocellulosic biomass-based oleaginous lipid production toward the green synthesis of biodiesel.

Natural bamboo coil springs with high cyclic-compression durability fabricated via a hydrothermal-molding-fixing method

Lightweight composite coil springs are still limited in their practical applications by costs of raw materials, resin impregnation and eco-environmental factors. Here, we fabricated a natural bamboo coil springs (BCS) via a facile hydrothermal-molding-fixing (HMF) treatment using moso (Phyllostachys edulis) bamboo slivers (BS). The BCS was superior to plant fiber-reinforced composite springs in terms of mechanical properties, dimensional designability and costs. The BCS basically inherited the cell structure and mechanical properties from natural BS, showing massive shrinkages of parenchymal cells and the occasional inter-fiber cells cracks, as well as the partial removal of lignin and hemicellulose after HMF treatment. Moreover, the BCS showed a stiffness retention rate of 86.3% after undergoing 8000 large-deformation compression cycles, demonstrating its high structural stability. The structure-function-compositions relationships of bamboo cells will help the design and manufacturing of curved bamboo furniture and structural bamboo coil springs for cushions application.

Green synthesis of carboxymethyl cellulose from agricultural waste its characterization

In the present study, corncob (an agricultural waste) has been explored as a source of cellulose. Cellulose was extracted from corncob through removal of hemicellulose and lignin. The carboxymethyl cellulose (CMC) was then synthesized from extracted cellulose by alkalization and etherification with 30% NaOH and 120% monochloro acetic acid (MCA) in ethanol medium respectively. Characterization of prepared CMC was carried out by various techniques like Fourier Transform Infra-Red (FTIR) spectroscopy, X-Ray Diffraction (XRD) and Scanning Electron Microscpoe (SEM). Back titration method was used to determine the Degree of Substitution (DS). The synthesized CMC obtained has a large DS value of 2.27. The purity of CMC was high at 91.65% and showed a yield of 1.20g/g, intrinsic viscosity of 1.02, water holding capacity 3.81g/g and oil holding capacity 1.66g/g. Higher degree of substitution is achieved in this work. The synthesized product is effective suitable additive for food and various pharmaceuticals industries.

Preparation and Characterization of Cellulose Nanofibers from Banana Pseudostem by Acid Hydrolysis: Physico-Chemical and Thermal Properties

Cellulose is a biopolymer that may be derived from a variety of agricultural wastes such as rice husks, wheat straw, banana, and so on. Cellulose fibril that is reduced in size, often known as nanocellulose (NC), is a bio-based polymer with nanometer-scale widths with a variety of unique properties. The use of NC as a reinforcing material for nanocomposites has become a popular research issue. This research paper focuses on the production of banana pseudostem cellulose nanofiber. Nano-sized fiber was obtained from banana pseudostem through several processes, namely, grinding, sieving, pre-treatment, bleaching, and acid hydrolysis. The product yield was found to be 40.5% and 21.8% for Musa acuminata and Musa balbisiana, respectively, by the weight of the raw fiber. The reduction in weight was due to the removal of hemicellulose and lignin during processing. Transmission electron microscopy (TEM) analysis showed that the average fiber size decreased from 180 µm to 80.3 ± 21.3 nm. Finally, FTIR analysis showed that the fibers experienced chemical changes after the treatment processes.

Physicochemical transformation and enzymatic hydrolysis promotion of reed straw after pretreatment with a new deep eutectic solvent

This work proposed a promising biorefinery method for the deconstruction of reed straw by using a novel deep eutectic solvent (DES) consisted of benzyltriethylammonium chloride/formic acid (BTEAC/FA). BTEAC/FA showed significant delignification and xylan removal while preserving most of the cellulose. Under the optimum conditions (molar ratio: 1:6), the glucose yield of cellulose-rich substrates by enzymatic hydrolysis reached 76.64%, which was about 5.24-fold higher than that of raw reed straw. The removal of lignin and hemicellulose and the changes in the cellulose crystal structure were presumed to the reason for enhancing enzymatic hydrolysis efficiency. The highest lignin yield reached 78.34%. Moreover, the lignin exhibited high purity (84.25%–91.45%), medium molecular weight (3812–9918 g/mol), and low polydispersity (1.47–2.75) because of the cleavage of β-O-4 and β-β linkages. Overall, this work provided a theoretical basis for the in-depth utilization of reed straw.