High-purity Cellulose Research Articles

Extraction and characterization of cellulose from agricultural waste of hemp (<i>Cannabis sativa)</i> and parthenium (<i>Parthenium hysterophorus)</i>

The current study focused on the extraction of cellulose from two selected plants, hemp (Cannabis sativa) and parthenium (Parthenium hysterophorus). The research successfully isolated high-purity cellulose from both plants using a chlorination and alkaline extraction process. A higher yield (%) (38.4 ± 0.18) was obtained from hemp compared to parthenium (22 ± 0.82). Characterization techniques were used to probe the structure and properties of the extracted cellulose. Fourier transform infrared spectroscopy analysis revealed functional groups characteristic of cellulose, while X-ray diffraction confirmed its highly crystalline structure in both samples. Scanning electron microscopy provided valuable insights into the cellulose morphology, indicating a smoother surface and reduced fiber diameter after treatment due to the removal of noncellulosic components. The research paved the way for the development of eco-friendly bioproducts utilizing cellulose from hemp and parthenium, promoting a more sustainable future.

Prospects of crude enzymes in replacing pure enzymes for dissolving pulp production.

High-purity cellulose from paper pulp can be obtained after appropriate treatments involving pure xylanases and cellulases/endoglucanases. This study investigated the efficacy of using crude xylanase and cellulase instead of commercial ones to improve process economics. Kraft paper grade pulp produced from veneer waste, hardwood, and non-wood sources was utilized as a more sustainable option. Crude xylanase and cellulase from isolated soil bacteria Bacillus pumilus 3GAH and Bacillus subtilis PJK6 were used for process optimization. The correlation between Fock reactivity, chain scission, and crystallinity after crude-cellulase treatment was established through chemical, FTIR, and XRD analyses. Pentosans in kraft pulp were reduced from an initial 18.7% to 4.9% through sequential treatments with crude xylanase and alkali. Subsequent crude-cellulase treatment, even at 8U/g o.d. pulp, improved Fock reactivity from 28.2% to 61.2%, fulfilling a major criterion for viscose. Thus, crude enzymes can be effectively used for the efficient and economical upgrading of paper pulp to dissolving pulp.

Ionic liquid pretreatment of lignocellulose for complete hemicellulose removal to produce high-purity cellulose mixed esters

Strategic valorization of agricultural waste can serve as waste management and promote sustainable biorefineries. Sugarcane bagasse is a readily available lignocellulosic biomass and can be converted into valuable cellulose-based thermoplastics. However, the cellulose purity significantly influences the material properties of the resulting thermoplastics, potentially limiting their applications. Therefore, conventional production necessitates harsh pretreatment of lignocellulose to isolate high-purity cellulose, followed by chemical modification. Here, we demonstrate a facile and green pretreatment method for complete removal of hemicellulose by incubating bagasse in a mixed system of an ionic liquid, 1-ethyl-3-methylimidazolium acetate (EmimOAc), and dimethyl sulfoxide (DMSO) at 140 °C, followed by precipitation in water, achieving >99 % hemicellulose removal. The pretreated bagasse, containing 71 % cellulose and 28 % lignin, underwent homogeneous transesterification with vinyl decanoate and isopropenyl acetate, using EmimOAc as both the solvent and catalyst, assisted by a co-solvent of DMSO. The polysaccharide derivative in the resulting acylated bagasse was separated from the lignin derivative by precipitation in methanol. The obtained polysaccharide derivative with high cellulose purity displayed a high weight-average molar mass of 1.5×106 g mol−1 and a polydispersity of 4. It also exhibited superior thermal stability (thermal degradation temperature, Td−5 %: 359 °C; glass transition temperature, Tg: 144 °C) compared to pulp-derived cellulose acetate decanoate (Td−5 %: 349 °C; Tg: 129 °C).

Reactive Eutectic Media for Lignocellulosic Biomass Fractionation.

This study introduces an alternative approach towards lignocellulosic biomass fractionation. For this purpose, reactive eutectic media (REM) based on ammonium formate and different organic acids are investigated, possible products are identified, and the REM are employed for lignin extraction and terminal isolation of cellulose pulp from beech wood. The method promises a considerable process intensification by simultaneous separation of high purity cellulose pulp, lignin isolation as a cationically modified species, and production of value-added chemicals from reaction products of the REM. This study puts a further focus on the generated cellulose pulp and investigates it with respect to surface charge and fiber length.

Cellulose and lignin purified from Metroxylon sagu palm fronds by a new technology with 2-methylanthraquinone cooking and peroxymonosulfuric acid bleaching

The demand for high-purity cellulose, optimization of wood utilization, and environmentally friendly processes has increased in dissolving pulp (DP) production. Sago palm fronds (SPF), an abundant agricultural waste in Indonesia, hold great potential as a raw material for cellulose, hemicellulose, and lignin production. This study aimed to explore the production of from SPF by employing a combination of prehydrolysis, soda cooking with 2-methylanthraquinone (MAQ) as a green additive (PHS-MAQ), and totally chlorine-free (TCF) bleaching with peroxymonosulfuric acid (Psa). Furthermore, lignin was recovered from the black liquor of PHS-MAQ. The results showed that prehydrolysis at 150 ºC for 3 h, followed by soda-MAQ cooking at 160 ºC for 1.5 h using 0.03% of MAQ, 23% active alkali (AA), and a five-stage bleaching with oxygen (O), Psa, alkaline extraction with hydrogen peroxide (Ep), Psa, and Ep successfully produced high-purity cellulose as DP, with properties of 94.3% α-cellulose content, 89.9% ISO brightness (SNI ISO 2470–1:2016), 9.1 cP viscosity, and 0.13% ash content. Moreover, the soda-MAQ cooking method exhibited superior delignification compared to prehydrolysis kraft (PHK) and prehydrolysis soda (PHS) processes in a range of kappa numbers of 9.4–22.6 at 17–25% AA. The inclusion of MAQ increased pulp yields by 4.6–4.9% and decreased kappa number by 1.6–3.1 compared to the PHS without additives at similar AA. Lignin was separated from the PHS-MAQ, with yields of 69–77%. This work demonstrated the suitability of SPF processed by PHS-MAQ cooking and Psa bleaching for the preparation of viscose rayon and cellulose derivatives. The lignin recovery could be an attractive biorefinery process in modern pulp mills.

Process design for acidic and alcohol based deep eutectic solvent pretreatment and high pressure homogenization of palm bunches for nanocellulose production

This research aimed to study on nanocellulose production from palm bunch using process design and cost analysis. Choline chloride based deep eutectic solvent pretreatment was selected for high-purity cellulose separation at mild condition, followed by nano-fibrillation using mechanical treatment. Three types of choline chloride-based deep eutectic solvents employing different hydrogen-bond donors (HBDs) namely lactic acid, 1,3-butanediol and oxalic acid were studied. The optimal cellulose extraction condition was choline chloride/lactic acid (ChLa80C) pretreatment of palm empty bunch at 80 °C followed by bleaching yielding 94.96%w/w cellulose content in product. Size reduction using ultrasonication and high-pressure homogenization produced nanocellulose at 67.12%w/w based on cellulose in raw material. Different morphologies of nanocellulose were tunable in the forms of nanocrystals, nano-rods and nanofibers by using dissimilar deep eutectic solvents. This work offered a sustainable and environmentally friendly process as well as provided analysis of DES pretreatment and overview operating cost for nanocellulose production. Application of nanocellulose for the fabrication of highly functional and biodegradable material for nanomedicine, electronic, optical, and micromechanical devices is achievable in the near future.

Order matters: Methods for extracting cellulose from rice straw by coupling alkaline, ozone and enzymatic treatments

Rice straw is a widely produced residue that can be converted into value-added products. This work aimed at using greener processes combining mild alkali (A), ozone (O) and enzymatic (engineered xylanase) (E) treatments to extract cellulose and other value-added compounds from rice straw and to evaluate the effects of the order of the treatments. Solid (S) and liquid (L) fractions from the process were collected for physicochemical characterization. AOE treatment showed the best capacity to extract high purity cellulose and other valuable compounds. The lignin content was significantly decreased independently of the order of the treatments and, its content in the extract obtained after the AOE process was lower than the one obtained after the OAE process. Moreover, thermal stability of the samples increased after the enzymatic process, being higher in SAOE. The alkaline treatment increased the hemicellulose and polyphenol content (antioxidant activity) in the liquid fractions (LA and LOA). In contrast, the ozonized liquid fractions had lower polyphenol content. Therefore, alkali was fundamental in the process. In conclusion, the AOE strategy could be a more environmentally friendly method for extracting cellulose and other valuable compounds, which could be used to develop active materials in the future.

Valorization of straw biomass into lignin bio-ink, bacterial cellulose and activated nanocarbon through the trade-off alkali-catalyzed glycerol organosolv biorefinery

Integrated lignocellulosic biorefinery that transforms low-value lignocellulose into multiple value-added products is crucial for a low-carbon sustainable development. Herein, a one-pot alkali-catalyzed glycerol organosolv (ALGO) pretreatment-based integrated biorefinery process to directionally produce lignin bio-inks, bacterial celluloses (BCs), and activated nanocarbons (ANCs) was proposed. ALGO pretreatment could modify the structure of dissolved lignins by glycerolysis. The extracted lignin fragments with high-purity (>90 %), uniform with low molecular weight (2500–4000 of Mw), and abundant hydrophilic aliphatic –OH were promising candidates in 3D-printable inks preparation. The glycerolysis reaction during ALGO process also enabled pretreated substrates toward high hydrolyzability and protected pretreatment liquor from generating fermentable inhibitors, making the solid fractions more liable for enzymatic deconstruction and microbial fermentation. Without any detoxification treatments, hydrolysates from ALGO pretreated substrates were used directly as carbon sources for BCs production, resulting in the BC yields were 56 % higher than that of the commercial glucose. The enzymatic hydrolysis residue and BC fermentation waste liquid were synthesized into ANCs via a facile carbonization process, which could further increase the value of ALGO biorefinery. Calculations showed that this ALGO integrated strategy rendered the conversion of ∼75 % lignins in pretreatment liquor to bio-inks and nearly 100 % solid fractions to BCs and ANCs. Unlike the conventional “lignin-first” route to obtain high-purity cellulose by sacrificing the value-adding conversion ability of by-products, the designed technical route in this work achieved a good trade-off between fractionation ability and subsequent conversion potential, inspiring further exploration of the technical correlation between biomass fractionation and bioproduct processing.

Developing sustainable and energy efficient process to obtain high purity cellulose and its value-added chemicals from rice straw

This study addresses the environmental impact of traditional rice straw burning practices in agriculture and explores sustainable alternatives. Utilizing lignocellulose waste, the research developed an energy-efficient process involving Alkali Pretreatment and Acid & Bleaching Pretreatment to obtain highly purified cellulose, after that analysed by qualitative and quantitative analysis, FT-IR and the Van Soest method were used, respectively. Thermal stability and crystallinity of acid-treated rice straw and bleached-treated rice straw were evaluated via DSC. The outcomes showed that different pretreatments produced purified cellulose and removed 93 % of the lignin. By using transition metal catalysts for depolymerization, value-added chemicals were produced, as measured by HPLC, generated glucose, Sorbitol, Arabinose, Ribose, and organic acids (HMF, THF). Overall, this study provides insights into the potential use of rice straw as a substrate for extraction of high-purity cellulose and value-added chemicals production, offering a reliable and energy-efficient process.

Bacterial nanocellulose: Optimized synthesis and biomedical applications

Bacterial nanocellulose (BNC) is a highly crystalline, highly polymerized material with a high aspect ratio, excellent flexibility, high water holding capacity, tensile strength,and other unique features. High purity cellulose can be produced with a variety of physio-chemical properties based on that growth medium and kinds of fermentation processes. Generally regarded as safe and as one of the most biomaterial, BNC has been utilized in a broad variety of biomedical applications, such as wound healing, dentistry, medical implants, tissue engineering scaffolds fabrication, and biosensing. The major limitations of BNC such as scaling up, control of fermentation culture, lesser yield, and huge capital expenses are to be resolved before implementing to commercial scale. In light of ongoing evolution into valuable medical products, the possible synthetic methodologies, their challenges and potential consequences are discussed in this review.

Efficient preparation of high-purity cellulose from moso bamboo by p-toluenesulfonic acid pretreatment

This work proposed a promising biorefinery method for the deconstruction of moso bamboo by using p-toluenesulfonic acid (P-TsOH) pretreatment to product high-purity cellulose (dissolving pulp). The cellulose pulp with high α-cellulose content (82.36 %) was successfully prepared for 60 min at low pretreatment temperature (90 °C) and atmospheric pressure. After the simple bleaching and cold caustic extraction (CCE) processes, the properties of cellulose pulp, such as α-cellulose content, polymerization, ISO brightness, all met the standard of dissolving pulp. In general, the cooking method through P-TsOH pretreatment can shorten the preparation time, which can effectively reduce energy consumption and chemical consumption. Therefore, this work may provide a new perspective for the green preparation of dissolving pulp that can be used to produce lyocell fiber after ash and metal ion treatment.

Synthesis and Characterization of Bamboo Employed Environmentally Friendly Cellulose Nanofibrils Reinforced Natural Rubber Composites with Uncompromised Mechanical Properties

In this study, high-purity cellulose nanofibrils (CNFs) were environmentally friendly extracted from natural bamboo. Physical, chemical, and mechanical treatments were comprehensively investigated, and then ensembled to effectively and efficiently remove lignin and hemicellulose with low energy from raw bamboo fibers, which combine microwave liquefaction, hydrogen peroxide-acetic acid delignification, alkaline treatment, and along with acid hydrolysis. This was able to allow for the extraction of CNFs. Compositional analysis, Fourier-transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and thermogravimetric analysis were performed to investigate and confirm the successful removal of undesirable lignin and hemicellulose. The resultant cellulose fibers were then subjected to a mechanical treatment to obtain the cellulose nanofibrils. It was found that the obtained CNFs have an average diameter of 13 nm with a cellulose purity of 94.52%. Without any further surface modification, the incorporation of bamboo-based CNFs into natural rubber (NR) exhibits significant improvement in their mechanical properties including modulus (~66.67%), tensile strength (~120.83%), toughness (~139.34%), and elongation at break (~31.41%). Interestingly, there is no compromise between tensile strength and elongation at break for the nanocomposites. DMA results also showed that both storage and loss moduli were dramatically enhanced over those of neat NR in their glassy region, which is typically unusual. This study can show, if optimized for material extraction, the great promise to the potential use of natural materials to develop environmentally friendly composites with multi-functionality in a variety of real-world engineering structural applications.

Comparison of treatments for cellulose pulp from agro-industrial wastes from the Amazon region

Agroindustrial waste (AIW) is a potential source of cellulose, which can be obtained through different treatments. In this study, we evaluated four delignification treatments (10% sodium hydroxide, 50% ethanol, distilled water, and 25% Mohr's salt) to obtain cellulose pulp from four Amazonian AIWs (banana peel, cassava peel, sugarcane bagasse, and rice husk). Our results showed that sodium hydroxide treatment had the highest lignin removal and increased cellulose content, while Mohr's salt treatment had the lowest cellulose yield and lignin removal. Banana peel and rice husk had the highest cellulose yield, while cassava peel had the lowest. Distilled water treatment at medium temperature had similar lignin removal and cellulose yield to the sodium hydroxide and ethanol treatments. Our findings suggest that AIWs have great potential as a source of cellulose and that these economical, simple, and eco-friendly treatments can be used to obtain high-purity cellulose from AIWs.

Morphological, characterization and FTIR analysis of delignified pineapple leaves as raw material for cellulose production

Lignocellulose is an abundant natural polysaccharide component containing cellulose, hemicellulose and lignin. Pineapple leaves contain high levels of cellulose and their utilization as abundant plantation waste is still not optimal. The delignification process was carried out to isolate cellulose and remove lignin contained in pineapple leaf fibers. This study aims to obtain high purity cellulose and analyze the effect of delignification on morphology and FT-IR results. In this study, the pineapple leaf fiber used underwent a delignification process by adding a Deep Euteutic Solvent (DES) solvent consisting of a mixture of Choline chloride (ChCl): formic acid (1:2). The cellulose obtained was characterized by morphology and analyzed using FT-IR. FTIR pineapple leaf fiber with delignification treatment still contained lignin in the absorption area around 1600cm−1 with C=C aromatic group as shown from the peak on the FTIR graph, fiber and it was clarified in the morphology of pineapple leaves which showed that the fiber surface was smoother and looked less lignin. In this study it can be concluded that the delignification process that has been carried out can remove lignin from the material.

Manufacture and characterisation of polylactic acid biocomposites with high-purity cellulose isolated from olive pruning waste

A two-step chemical process was carried out on olive pruning residues according to an optimised sequence that led to the isolation of natural fibre with a high cellulose content. Reaction time, temperature and HNO3 concentration in the acid hydrolysis stage were optimised by means of the Response Surface Methodology to achieve the highest removal of hemicellulose and lignin and the highest crystallinity index, minimising cellulose hydrolysis. Subsequent hydrolysis with NaOH allowed to obtain a pulp enriched in cellulose (83.28 wt.%). Analysis revealed that the cellulose isolated had a high crystallinity index (70.06%) and thermal stability ( T max = 357°C). The cellulose obtained was finally used for the manufacture of polymer biocomposites and to evaluate its viability as a filler for polymeric materials. The selected polymer matrix used was polylactic acid (PLA) and the amount of filler was 5 and 15% by weight, respectively. In general, the fibres did not improve the mechanical properties of PLA, and maintained unchanged its melting temperature. Microscopic analysis revealed that PLA/fibre adhesion was stronger for treated fibres. Contradictorily, the composites with untreated fibres presented slightly higher thermal stability. Water uptake increased with the concentration of fibres, being higher in those materials with untreated fibre.

Preparation of Higher Purity Cellulose from Kenaf Core by Acid Hydrolysis

For sustainable industries based renewable biomass, secure of raw material is important. Kenaf is a good candidate with fast-growing and high biomass productvity. Acid hydrolysis treatment of kenaf woody core is capable produced high purity cellulose for fine chemical production, which was hydrolyzed hemicelluloses (mainly xylan) to monosaccharides. The effects of various reaction temperatures (110-130℃), and reaction times (60-120 min) were investigated to get the optimum condition. 1H NMR spectroscopy was used to quantitative analysis of polysaccharide composition based on hydrolzed monosaccharides analysis. The results showed that optimum conditions for acid hydrolysis treatment was 1.00N sulfuric acid, 130℃, and 60 min for higher purity cellulose production with cellulose as 50.0%, hemicellulsoe as 1.2%) and lignin as 0.3% based on raw kenaf core biomass.

Efficient Fractionation and Catalytic Valorization of Raw Biomass in ϵ-Caprolactone and Water.

Efficient fractionation and utilization of the whole biomass is particularly attractive but remains a great challenge, owing to the recalcitrance of biomass. In this study, a simple and efficient approach is developed to obtain high-purity cellulose with a delignification degree of 97.5 % in ϵ-caprolactone and water. FTIR spectroscopy reveals that ϵ-caprolactone and water act in synergy to remove lignin from raw biomass and afford cellulose with clear macrofibrils. A linear positive correlation between the contents of hemicellulose and lignin is observed for the separated cellulose pulp. This mixed solvent exhibits good performance for the removal of lignin from various agricultural and forestry wastes. Moreover, nearly complete transformation of the whole biomass constituents is achieved with Ni-Al catalyst.

High-Yield Alpha-Cellulose from Oil Palm Empty Fruit Bunches by Optimizing Thermochemical Delignification Processes for Use as Microcrystalline Cellulose.

Oil palm empty fruit bunches (OPEFB) are lignocellulosic materials that are a by-product of the palm oil industry, which have less use and utilization is still limited. OPEFB's high cellulose content could potentially develop into various bioproducts, especially biomaterials. The thermochemical delignification process can obtain high-yieldalpha-cellulose. The cellulose extraction process can be done by combining the bleaching process under acidic conditions and alkaline delignification to obtain high-purity cellulose. The bleaching conditions vary in the concentration of NaClO2, the length of bleaching, the temperature, and the number of stages. The research obtains high α-cellulose by optimizing bleaching conditions under acidic conditions in cellulose's OPEFB extraction with variability on NaClO2 concentration and bleaching time using response surface methodology (RSM). The bleaching process was implemented at an early stage with a concentration of 3% NaClO2 and a bleaching time of 2 hours as a center point with a bleaching cycle of twice at pH 4-4.5 using acetic acid. Bleached fibers were delignified using 10% NaOH for 2 hours at room temperature. The RSM analysis resulted in optimum bleaching conditions at a concentration of 3.22% NaClO2 for 1 hour, yielding OPEFB's cellulose of 82.96% ± 2.53, hemicellulose of 9.27% ± 2.28, and lignin of 1.68% ± 0.58. The validation and verification process in the bleaching conditions obtained cellulose of 84.87% and α-cellulose of 88.51%, with a crystallinity index of 70.55% and crystallite size of 2.35 nm. Scanning electron microscopy on surface cellulose morphology at optimum bleaching helped remove hemicellulose impurities, lignin, and inorganic materials and a more intensive opening of cellulose fibrils. The bleaching process optimization point was verified to improve the delignification performance and potentially produce high yield α-cellulose content for microcrystalline cellulose use.

Extraction of high-quality grade cellulose and cellulose nanocrystals from different lignocellulosic agri-food wastes

IntroductionPrompted by the increasing need for an intensified valorization of agri-food waste, in this work a three-step chemical procedure was used to extract high-purity cellulose from garlic stalk, corncob, and giant cane cut-up by a sequential removal of hemicellulose, lignin, ash, and organic compounds. Cellulose nanocrystals of potential interest for nanocomposite applications were then obtained through acid hydrolysis.MethodsThe purity of the cellulose was determined employing Nuclear Magnetic Resonance and infrared spectroscopy, whereas dynamic light scattering, optical, atomic force microscopy, and transmission electron microscopy were used for morphological characterization. The high purity and crystallinity of cellulose was confirmed by comparison with the ultra-pure bacterial cellulose originating from K. sucrofermentans, irrespective of the waste used.Results and discussionAt the end of the extraction procedure, cellulose yields of 35.73, 37.15, and 39.10%, for garlic stalk, corncob, and giant cane cut-up, respectively, were achieved. Dynamic light scattering and atomic force microscopy analyses showed that the length of the whisker-like nanocrystals depended on the raw material (from ~100 nm up to > 2μm), while the final yield was ~40–50% for all three wastes. The versatility and effectiveness of the method here proposed can be profitably used for a wide range of agro-waste feedstocks.

An ingenious cellulose membrane sensor design strategy for colorimetric detection of Ag+/Hg2+ based on redox reaction

This paper describes an ingenious cellulose membrane sensor design strategy for colorimetric detection of Ag+/Hg2+ based on redox reaction. The colorless 3,3′,5,5′-tetramethylbenzidine (TMB) can be oxidized to blue oxidized TMB (oxTMB) when exposed to Ag+/Hg2+ that with strong oxidizing properties. Based on this phenomenon, TMB can be design as a colorimetric probe for Ag+/Hg2+, and the reaction mechanism and sensing performance of TMB as Ag+/Hg2+ were explored. In addition, the TMB probe-immobilized cellulose membranes (TMB@CMs) were developed by combining TMB with high-purity cellulose membranes (CMs) carrier with porous and polyhydroxy structures. As a platform for probe immobilization, TMB@CMs can effectively improve colorimetric sensing response and stability of TMB. The colorimetric mechanism of TMB@CMs was investigated including in situ oxidation of TMB and immediate immobilization of oxTMB. The experimental results showed that the visual detection limit (VLOD) of Ag+/Hg2+ was 10 μM when TMB was used as colorimetric probe, while the VLOD of the TMB@CMs was 1 μM. In addition, TMB@CMs had good reusability and stability. Through the analysis of SEM, EDS and XPS results, the mechanism of TMB colorimetric detection of Ag+/Hg2+ was that blue oxTMB and Ag/Hg elementals were generated by redox reaction between them. This study not only verified the feasibility of TMB as an Ag+/Hg2+ colorimetric probe, but also designed a probe-immobilized cellulose membrane model with convenient operation, uniform color development and stable color, which effectively improved the colorimetric sensing response and stability.