Nanocrystalline Cellulose Production Research Articles

High yield production of nanocrystalline cellulose from corn cob through a chemical-mechanical treatment under mild conditions

Agricultural biomass waste such as corn cob is available in large quantities and can be used as renewable materials for various applications. Corn cob was converted into nanocrystalline cellulose by using mild sulfuric acid concentrations (30 % w/v) at low temperature (50 °C) and a relatively shorter time extraction (30 min) combined with mechanical treatment using a conventional high-speed blender. NCC from cellulose and α-cellulose from corn cobs have been successfully isolated with relatively high yields and crystallinities of 50.07–65.33 % and 65.5–69.9 %, respectively. Scanning electron microscopy (SEM) evaluated the morphological variation and dimension from corn cob fiber (CF), delignification fiber (DF), cellulose, and α-cellulose, which shows that each pretreatment stage causes a decrease in fiber diameter from 16.56 to 5.48 μm. Transmission electron microscopy (TEM) images confirmed the nano-scale dimension with fiber diameters ranging between 9.35 nm and 6.51 nm. Thermogravimetric analysis shows that NCC has relatively high thermal stability ranging from 429 to 437 °C. Thus, this characteristic of NCC has the potential to be applied as a reinforcing agent in various fields of polymer composites. Finally, this study presents a method for isolating NCC from corncob waste using a conventional high-speed blender in a mild condition process with a relatively low cost, environmentally friendly pathway, and high yield that was still preserved.

Bleaching-free, lignin-tolerant, high-yield production of nanocrystalline cellulose from lignocellulosic biomass

Nanocrystalline cellulose (NCC) preparation in an integrated fractionation manner is expected to solve the problems of low yield and environmental impact in the traditional process. An integrated fractionation strategy for NCC production from wood was developed through catalytic biomass fractionation, the partial dissolution of cellulose-rich materials (CRMs) in aqueous tetrabutylphosphonium hydroxide, and short-term ultrasonication. The presented process could tolerate a high CRM lignin content of 21.2wt% and provide a high NCC yield of 76.6wt% (34.3wt% of the original biomass). The increase in the CRM lignin content decreased the NCC yield, facilitated the crystal transition of NCC from cellulose I to cellulose II, and showed no apparent effects on the NCC morphology. A partial/selective dissolution mechanism is proposed for the presented strategy. This study provided a promising efficient fractionation-based method toward comprehensive and high-value utilization of lignocellulosic biomass through effective delignification and high-yield NCC production.

Conversion of Sugarcane Trash to Nanocrystalline Cellulose and its Life Cycle Assessment

Sugarcane trash (SCT) is a promising, underutilized raw material for producing value-added bio-based materials. Nanocrystalline cellulose (NCC) production conditions were obtained from the experiment. On the other hand, bioethanol production conditions were retrieved from the secondary data. This study compared the environmental impact of SCT in NCC production to that of bioethanol. For NCC production, SCT was subjected to organosolv pretreatment (140, 160, or 180 °C) in a mixed solvent system (methyl isobutyl ketone (MIBK), ethanol, and water), bleached, and then hydrolyzed with different concentrations of sulfuric acid (50 and 58%) for varying times. Organosolv pretreatment at 180 °C removed 98.24 and 81.15% of the hemicellulose and lignin, respectively, resulting in 73.51 and 79.72% cellulose purity and recovery. In addition, bleaching increased the cellulose purity to 95.42%. Field Emission Transmission Electron Microscopy (FE-TEM) analysis showed that NCC’s small 2:1 elliptical particles were found at the hydrolysis of 50% H2SO4 for 45 min. The X-ray diffraction (XRD) pattern revealed 70% crystalline index values for NCC obtained from 50% H2SO4 with 45 min retention times. Then, the optimum conditions of NCC production were used for LCA analysis (Sigmapro software). The analysis included global warming, marine ecotoxicity, fresh water, and human carcinogenic toxicity. NCC production’s electricity consumption (freeze-dried step) was the highest environmental impact on LCA analysis.

Multi-product biorefinery with sugarcane bagasse: Process development for nanocellulose, lignin and biohydrogen production and lifecycle analysis

Sugarcane processing sector generates large quantities of sugarcane bagasse (SCB) as the residual lignocellulosic biomass (∼30% by weight). With its rich biochemical composition, SCB can function as potential, renewable, and alternative feedstock for high valued biobased products in the framework of circular economy. Production of nanocrystalline cellulose (NCC) from SCB, integrated with co-production of lignin and biohydrogen in a biorefinery approach was studied. Pretreatment of SCB resulted in the extraction of cellulose (0.34 ± 0.02 g/g) followed by NCC production (0.15 ± 0.02 g/g SCB) through depolymerization. In the biorefinery scenario, 0.15 L/g CODR of H2, and 0.15 ± 0.05 g/g SCB of lignin was produced in addition to NCC. The products were characterized for their respective qualitative and quantitative recoveries. Further, standalone NCC production and biorefinery processes were compared for their sustainability by employing lifecycle impact assessment (LCA) tool. The biorefinery scenario has depicted nearly 30% less environmental impacts along with 24% less CO2 emissions (GWP) than the standalone process. Sensitivity analysis validated the data precision with repeatability and reproducibility of the results. Establishment SCB based biorefinery process with zero liquid discharge (ZLD) approach provides additional benefits to the sugarcane processing industries by infusing circular chemistry in the industry 4.0 framework.

Preparation of Gentamicin Conjugated Cellulose Nanocrystals and Evaluation of Efficacy on Different Microorganisms

Large amounts of waste cotton material generated in textile production cause environmental problems and resource depletion. The production of nanocrystalline cellulose is one of the effective way to the recycling of waste cotton. Cellulose nanoparticles are of great interest in biomedical applications due to their various properties. In this study cellulose nanocrystals were produced from waste cotton through acid hydrolysis in a single step. The extraction of cellulose from waste cotton was carried out by alkalin treatment, afterthat the cellulose nanocrystals were isolated by the nitric acid (68% w/w) and hydrochloride acid (37% w/w) mixture acid hydrolysis. Cellulose nanocrystals were oxidized by sodium periodate (NaIO4) for functionalization. The prepared cellulose nanocrystals were characterized by Transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR) then gentamicin conjugation studies were carried out. Gentamicin conjugated cellulose nanoparticles were examined for antimicrobial activity against Escherichia coli (E. coli), Staphylococcus aureus (S. Aureus), Pseudomonas aeruginosa(aeruginosa), Klebsiella pneumoniae (K. pneumoniae) and antifungal activity against Candida albicans (C. Albicans). The results confirmed that the periodate oxidized cellulose nanocrystals are effective on bacterai and fungus.

The Sulphate Removal via Post Alkaline Treatment on Nanocrystalline Cellulose with Different Lignin Content Extracted from Kenaf Core

The production of nanocrystalline cellulose (NCC) usually takes place through a series of chemical processes like pulping, bleaching and acid hydrolysis process. The hydrolysis processes using strong acid like H2SO4 can help the NCC to have a high degree of crystallinity and imparts a negative surface charge to NCC. However, the application of H2SO4 leads to increment in dehydration reaction and lowered the NCC thermal properties. Post alkaline treatment is the method that is commonly used to recover the effect of H2SO4 by neutralizing the acid using a strong base like sodium hydroxide (NaOH). On the other hand, the effect of lignin in fibres was able to help in improving the thermal properties and extraction of lignin was seen involving an excessive number of chemicals. The lignin part can remain in the pulp by controlling the bleaching process. Therefore in this study, NCC with different lignin content went through post alkaline treatment to remove the remaining sulphate groups. The thermal analysis revealed that the existence of lignin and removal of sulphate groups help to increase the thermal stability of the NCC by shifting the degradation and melting temperature to the higher value.

Isolation and Production of Nanocrystalline Cellulose from Conocarpus Fiber.

Conocarpus fiber is a lignocellulosic biomass rich in cellulose potentially used for producing nanocrystalline cellulose (NCC), a biomaterial extensively employed in various application fields. In the present work, different hydrolysis times of 10, 20 and 30 min were applied to chemically pre-treated Conocarpus fiber to produce CPNC1, CPNC2, and CPNC3 particles. With acid hydrolysis treatment, the yield of NCC product was successfully retained at 17–19%. Individual, rod-like shapes of NCC particles could be clearly observed under microscopy examination. From chemical composition analysis, a relatively pure cellulose compartment was produced for all NCC samples with substantial removal of lignin and hemicellulose. The physicochemical analysis proved that each nanoparticle sample possessed strong cellulose crystalline structure. For thermal analyses, the heat resistance of NCCs was gradually enhanced with the increased hydrolysis times. Therefore, the extracted NCC product from Conocarpus fiber could be a green nano-filler for developing nanocomposite material in the future.

OPTIMIZATION OF PROCESS FOR PRODUCTION OF NANOCRYSTALLINE CELLULOSE AND ITS COMPOSITES

In this work, optimal and waste-free technologies were proposed for the production of nanocrystalline cellulose (NCC) and its composites with inorganic pigment, as well as semi-finished products containing aggregates of nanoparticles. The following optimal hydrolysis conditions were found: concentration of sulfuric acid 40 wt%, temperature 80°C, duration 1 h, acid/cellulose ratio 7. After hydrolysis stage, the hydrolyzed cellulose was washed, diluted with water and disintegrated to isolate individual nanoparticles. Then, the diluted NCC dispersion was evaporated to obtain a commercial product - concentrated NCC paste. In order to obtain a composite, the acid in the unwashed hydrolyzed cellulose was neutralized with calcium hydroxide to precipitate a white pigment, calcium sulfate. In addition, the spent acid and acidic washings were collected and treated with hydroxylapatite (HAP) to produce a valuable by-product, superphosphate (SUP), the sale of which significantly reduces the cost of the primary product, NCC. Contaminated water collected after washing, neutralization and evaporation was purified and returned to the technological cycle. To reduce the cost of production, such expensive process steps as disintegration and evaporation of diluted dispersion were eliminated, which made it possible to obtain cheap semi-finished products containing NCC aggregates or composite of NCC with inorganic calcium sulfate particles.

High yield production of nanocrystalline cellulose by microwave-assisted dilute-acid pretreatment combined with enzymatic hydrolysis

A dilute-acid pretreatment assisted with microwave irradiation was developed to efficiently fabricate nanocrystalline cellulose (NCC) with the single use of the cellulase from Aspergillus niger. The use of microwave heating and diluted sulfuric acid solution (1, 2, 5, and 10 wt. %) in pretreatment considerably increased the NCC yield of subsequent enzymatic hydrolysis (feedstock to enzyme ratio of 2:1) with a maximum value of 84.4 wt.% from less than 10 wt.% without the pretreatment. The severity of pretreatment conditions affected the crystal dimension of rod-like nanocrystals. The crystallinity and thermal stability of extracted NCC varied by the acid concentration used in pretreatment conditions and also by the duration of enzymatic hydrolysis. The highest peak decomposition temperature of 378.1 °C as well as the highest NCC yield were recorded in the NCC extracted in 5 wt.% sulfuric acid with microwave heating. The pretreatment effectively facilitated enzymatic hydrolysis, and the synergetic effect of microwave irradiation in the presence of sulfuric acid was associated with the improved thermal stability and crystallinity in the final products.

Waste free Technologies for Production of Nanocrystalline Cellulose and its Composites

In this paper, waste-free technologies are proposed for the production of nanocrystalline cellulose (NCC), its semi-finished products and composites. The following optimal conditions for the cellulose hydrolysis stage were found: concentration of sulfuric acid 40 wt.%, temperature 80oC, duration 1 h, acid to cellulose ratio 7. After hydrolysis stage, the depolymerized cellulose was separated from the acid, washed, diluted with water and disintegrated to release individual nanocrystalline particles. Finally, the diluted dispersion of NCC was evaporated to obtain a commercial product such as concentrated NCC paste. For the production of composites, the acid in unwashed hydrolyzed cellulose was neutralized and precipitated with calcium base (e.g. calcium hydroxide) in order to obtain a white pigment, calcium sulfate (CS). Moreover, the spent sulfuric acid and acidic wastewater were collected and treated with a special auxiliary reagent to reuse and convert the acid into a valuable by-product, selling of which significantly reduces the cost of NCC. The wastewater collected after washing, neutralization and evaporation was purified and returned back to the technological cycle. To reduce the production cost, expensive stages - disintegration and evaporation of diluted dispersion, should be eliminated; as a result, cheap semi-finished products containing aggregates of NCC or its composite with inorganic particles of CS were manufactured along with by-product.

An Overview of Recent Developments in Hetero-Catalytic Conversion of Cellulosic Biomass


 
 
 In recent years, research activities involved in the production of nanocellulosic materials have grown substantially, rapidly stimulating the development of innovative production techniques. These materials are chemically extracted by acid-catalyzed Hydrolysis of the renewable and widely available cellulosic biomass. In this regard, sulfuric acid-catalyzed Hydrolysis of cellulosic biomass is a commonly known method for the production of nanostructured cellulose. However, this method may result in many disadvantages, including short catalyst-lifetime, corrosive to the reactor materials and managing the spent sulfuric acid resulted from the production process. This dictates the implementation of an eco-industrial alternative for the catalytic production of nanocrystalline cellulose (NCC). A viable and practical alternative is the application of heterogeneous (solid acids) catalysts, which can be more conducive in providing favorable platforms for efficient cellulose hydrolysis. This review highlights the current production methods of nanocrystalline cellulose. Further, recent literature on the heterogeneous-catalytic conversion of cellulosic biomass is briefly discussed. The limitations and disadvantages of these techniques are also described.
 
 

A Step Closer to Sustainable Industrial Production: Tailor the Properties of Nanocrystalline Cellulose from Oil Palm Empty Fruit Bunch

Abstract There is an imperative need to tackle the huge amount of solid wastes from the palm oil production. The current utilization of oil palm biomass and waste management were deemed ineffective to the economic and environmental development. We proposed a sustainable solution to the management of oil palm waste using empty fruit bunch (EFB) to obtain nanocrystalline cellulose (NCC). The diverse properties of NCC were largely attributed to the origin of biomass and the isolation method. This demonstrated the importance of investigating the process parameters in a quantitative manner to ensure the effective production and exploitation of NCC. Response surface methodology was adopted to analyze the interaction effects of size, yield and crystallinity on the NCC production. The size of the acid-hydrolyzed NCC ranging from 15–27 nm in width and 170–317 nm in length was confirmed through the scanning transmission electron microscopy. The crystallinity obtained from the experiments as developed by Box-Behnken design was in the range of 70.35–83.20%, where it exhibited an inverse relation with the hydrolysis yield of NCC in the range of 4.11–80.23%. Through investigating the correlation of responses, an optimum point was obtained at which the yield and crystallinity of NCC were the highest, while the size of NCC was the lowest. The good model reliability indicated that the tailoring of the properties of EFB-origin NCC is feasible, suggesting EFB as a highly promising alternative to alleviate the resource depletion of wood pulp in the development of bio-based material.

Impact of pretreatment methods on production of bioethanol and nanocrystalline cellulose

Cellulose, the most abundant terrestrial biopolymer, has immense potential for a range of applications, such as textiles, biomedical applications, and sustainable building components. Due to the recalcitrant nature of lignocellulosic materials, various alkaline and acid pretreatment methods have been developed to recover mono sugars for fermentation. Simultaneous production of bioethanol and nanocrystalline cellulose (NCC) from pretreated Formosan alder biomass was conducted in two stages. Formosan alder biomass was treated using unbleached kraft (UEK), acid steam explosion (SEP), and bleached acid steam explosion (BSEP) and hydrolyzed using cellulase. Filter paper (FP) and alpha-cellulose were used as positive controls. Bioethanol fermentation using E. coli Ko11 was conducted. Residual biomass was further recovered to produce NCC. After 96 h enzyme hydrolysis, the highest sugar yields were 383.4 and 329.84 mg glucose/g biomass for the FP and UEK samples. The highest bioethanol fermentation yields were 4.18 and 3.62 g bioethanol/g biomass for FP and UEK samples. During enzyme hydrolysis of the biomass, crystallinity increased. NCC yields were 613.93 nm (68%) and 1583 nm (73%) for the FP and UEK samples. The negative impact of lignin content was reflected in the particle length of the final NCC. Further lignin removal is required for optimal NCC production. This study showed that Formosan alder biomass could be used to produce both bioethanol and NCC.

An integrated analytic hierarchy process and life cycle assessment model for nanocrystalline cellulose production

Nanocrystalline cellulose (NCC) is an emerging renewable bionanomaterial obtained from cellulosic materials such as agricultural waste. NCC has many promising applications in the field of pharmaceuticals, chemical, food and personal care. Research on NCC extraction from different cellulosic materials such as wood pulp, coconut fibre, carrot waste and oil palm empty fruit bunch (EFB) via different process routes has been widely reported, but few have been evaluated for environmental aspects using life cycle assessment (LCA). In particular, there has yet to be any LCA study of NCC production from EFB. Therefore, this work aims to identify the best alternative for NCC production from EFB by comparing three different process routes, namely, (i) Acid Hydrolysis I (chlorine bleaching), (ii) Acid Hydrolysis II (chlorine-free bleaching), and (iii) TEMPO-Oxidation. Since conventional LCA focuses only on environmental impact, the results might not be sufficient for the stakeholders in making important decisions. An integrated analytic hierarchy process (AHP) model incorporating LCA is thus developed to evaluate the alternatives based on environmental aspects as well as technical and economic aspects. The LCA results show that Acid Hydrolysis II has the least overall environmental impact. However, using the integrated AHP–LCA model, Acid Hydrolysis I becomes the optimal choice due to superior technical and economic characteristics.

The influence of the cation type of ionic liquid on the production of nanocrystalline cellulose and mechanical properties of chitosan-based biocomposites

In this paper three newly synthesized imidazolium ionic liquids with different structures of cations were used for hydrolysis of cellulose. It was found that type of the cation has a great influence on particle size and dispersity of produced cellulosic materials. The use of an ionic liquid with a cation with an aliphatic substituent resulted in filler characterized with wide dispersity range and some particles larger than 2 µm. Introduction of methyl group into imidazolium ring was responsible for production of particles below 350 nm. Such particles were obtained also during hydrolysis of cellulose with ionic liquid containing a benzyl substituent with that difference that in this case particles had definitely narrower dispersity range. Moreover, type of the ionic liquid used affected crystallinity degree of the produced celluloses. Produced cellulosic materials were used as fillers for chitosan matrix. A relationship between mechanical properties of polymer composites and the particle size as well as dispersity of cellulose, controlled by chemical modifications of cellulose with innovative ionic liquids was evaluated. Incorporation of filler with established dispersive properties made it possible to form composites characterized by the assumed properties, for example with high values of Young’s modulus, tensile strength or elongation at break. Understanding the dependence between the structure of ionic liquids and dispersive properties of cellulose is an important step toward the design of composite materials with optimal mechanical properties.Graphical abstract

A novel effective approach of nanocrystalline cellulose production: oxidation–hydrolysis strategy

In this work, we have applied, for the first time, solution plasma processing of cellulose-containing material to produce cellulose nanocrystals (CNC). The CNC samples produced in three different modes of solution plasma treatment were characterized using methods of dynamic light scattering, infrared spectroscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The proposed method of CNC production comprising the oxidation–hydrolysis strategy has proved to be effective and allowed us to reduce significantly the time of acid hydrolysis and to increase considerably the total CNC yield.

Extraction of Cellulose Nanocrystals with Structure I and II and Their Applications for Reduction of Graphene Oxide and Nanocomposite Elaboration

The aim of the present study is to investigate the effect of the hydrolysis process on the properties of nanocrystalline cellulose (NCC) isolated from different precursors and the subsequent use of the extracted NCC for the reduction of graphene oxide (GO). The raw materials (almond and peanut shells) chosen for the isolation of cellulose were selected on the basis of their abundance and their poorly investigation in the production of NCC. Microcrystalline cellulose (MCC) was firstly extracted by alkali and bleaching treatments, then hydrolyzed under different processes to produce NCC polymorphs with structure I (NCC-I) and NCC structure II (NCC-II). The Fourier transform infrared spectroscopy, the X-ray diffraction (XRD) and the 13C NMR studies of the alkali and bleached products confirmed the formation of cellulose type I with high purity and good crystallinity, while scanning electron microscopy (SEM) showed micrometric fibers with lengths reaching 80 µm. Sulfuric acid treatment of these microfibers results in NCC type I or II, depending on the hydrolysis process. SEM of the NCC samples exhibited nanorods with diameter and aspect ratio in the range of 20–40 and 20–25 nm, respectively. Thermogravimetric analysis (TGA) of the MCC and NCC products indicated stable materials with a degradation temperature reaching 240 and 200 °C for MCC and NCC, respectively. The other part of our work concerns the use of the obtained cellulose nanocrystals (type II) for the preparation of reduced graphene oxide composite (NCC/RGO), to demonstrate the reducing properties of the isolated NCCII.

Characterization of Nanocrystalline Cellulose Isolated from Empty Fruit Bunch Using Acid Hydrolysis

In recent years, there has been a great interest in the production of nanocrystalline cellulose (NCC) due to its excellent properties. In this study, empty fruit bunch (EFB) was used as the material for the production of NCC due to its high cellulose content, inexpensive and readily-available source. NCC was prepared using acid hydrolysis at 62% for 1 hours. The morphology of NCC was determined by Field Emission Scanning Electron Microscopy (FESEM). The size of NCC was less than 50 nm in width. The obtained NCC was also characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). FTIR spectra analysis showed that hemicellulose and lignin were mostly removed from the EFB after bleaching and alkaline pre-treatment. XRD diffractograms revealed that EFB nanocellulose showed a crystallinity improvement of 24.3% compared to raw EFB cellulose.

Effect of low pressure alkaline delignification process on the production of nanocrystalline cellulose from rice husk

Abstract Large scale production of nanocrystalline cellulose (NCC) remains a challenging task despite significant progress being made in the understanding of the production chemistry at a bench-scale. In this paper an attempt is made in looking into the scale-up option of a well-established chemistry to identify the bottlenecks involved in the scale-up process. For the production of NCC at a moderate volume of 2.5 L using chemical modification steps (delignification, bleaching and hydrolysis), the estimated yield of 95%) of the NCC without compromising the quality of the end products. Analyses by FT-IR, XRD, EDX, DLS, SEM, AFM, and TEM reveal that the product quality falls in the range of physical dimension as reported previously. The study suggests that a critical analysis of the reaction pathways from an engineering stand-point is essential for scaling-up of NCC production processes. The LPAD of RH using jacketed reactor enables the production of high quality pulp which might be a good approach for industrial production of NCC.

Potential aspect of rice husk biomass in Australia for nanocrystalline cellulose production

Abstract Nanocrystalline cellulose (NCC) was produced from rice husk biomass (Oryza sativa) by a chemical extraction process to explore the potential aspect of agro-waste biomass in Australia. In this work, the delignified rice husk pulp (D-RHP) was produced by alkaline delignification of raw rice husk biomass (R-RHB) using 4 mol·L− 1 alkali solutions (NaOH) in a jacketed glass reactor under specific experimental conditions. D-RHP was bleached using 15% sodium hypochlorite, and the bleached rice husk pulp was coded as B-RHP. Finally, raw suspension of NCC was produced by the acid hydrolysis of B-RHP using 4 mol·L− 1 sulphuric acid. The raw suspension of NCC was neutralized by a buffer solution and analyzed by TAPPI, FT-IR, XRD, SEM, AFM, and TEM. FT-IR spectra of NCC are different to R-RHB but similar with B-RHP and D-RHP. From XRD results, the crystallinity of NCC was found to be approximately 65%. In AFM analysis particle thicknesses have been confirmed to be in the range of (25 ± 15.14) nm or (27 ± 15.14) nm which is almost the same. From TEM analysis particle dimensions have been confirmed to be in the range of (50 ± 29.38) nm width and (550 ± 302.75) nm length with the aspect ratio ~ 11:1 (length/diameter) at a 500 nm scale bar. On the other hand, at a 200 nm scale bar the particle dimensions have been confirmed to be in the range of (35 ± 17) nm width and (275 ± 151.38) nm length with the aspect ratio ~ 8:1. The aspect ratio of individual crystalline domain was determined in TEM analysis which is 10:1 (100/10). Therefore the aspect ratios and dimensions of nanoparticles in NCC suspension are almost the same and in nano-meter scale, as confirmed from both AFM and TEM results. The yield of NCC from B-RHP was found to be approximately 95%, and the recovery of cellulose from R-RHB is about 90%.