Alkali Can Accelerate The Cellulose Dissolution In Aqueous 1-Ethyl-3-Methylimidazole Acetate (EmimAc/10% Water)

Ionic liquids are potential and successful cellulose solvent but still suffer technical and economic issues in the cellulose commercialization. In this work, a relative low-viscosity aqueous 1-ethyl-3-methylimidazole acetate (EmimAc with 10% water) was used instead of EmimAc to dissolve cellulose; the results showed that adding NaOH to water can significantly accelerate cellulose dissolution and the cellulose solubility increased with the NaOH concentration in the EmimAc/10% water solution. NaOH can weaken the strong interaction between water and EmimAc because it can bond preferentially with water by hydrogen bonding and therefore release Ac - from Ac - -water cluster; which can enhance the reaction between Emim + and Ac - and therefore improve the cellulose dissolution. Unfortunately, the NaOH introduction inevitably cause a cellulose degradation via peeling reaction.

Applications of the Hansen solubility parameter for cellulose

Based on the solubility parameter theory, the Hansen solubility parameters of various solvents were calculated and compared to predict the solubility of cellulose in various solvents, which illustrates the feasibility of Hansen solubility parameters to predict the solubility of cellulose in solvents. This paper aims to make a more accurate prediction in advance when finding suitable cellulose solvent system, and then to reduce the burden of cellulose solvent selection.

Optimisation of AgNP Synthesis in the Production and Modification of Antibacterial Cellulose Fibres

The main aim of the presented research is to determine the optimal conditions for the production of silver nanoparticles (AgNPs) in N-methylmorpholine-N-oxide (NMMO), which will potentially allow to obtain small nanoparticles with uniform diameter distribution. In this paper, NMMO is used in the fibre production process, both as a direct cellulose solvent and as an Ag+ reducing system. From an industrial point of view, this method is very promising because it allows to reduce the amount of used chemicals. The UV/Vis, DLS and TEM analysis proved that the synthesis temperature and time could play a key role in nanoparticle growth control in NMMO. It was found that the optimal conditions for AgNPs synthesis are 100 °C and 0.33 h. The estimations of the antibacterial activity of the fibres were completed. The applied AgNPs synthesis conditions allow to obtain antibacterial fibres with a wide range of applications, mainly in medicine.

Simple and Fast One-Pot Cellulose Gel Preparation in Aqueous Pyrrolidinium Hydroxide Solution–Cellulose Solvent and Antibacterial Agent

Cellulose is the main component of biomass and is the most abundant biopolymer on earth; it is a non-toxic, low-cost material that is biocompatible and biodegradable. Cellulose gels are receiving increasing attention as medical products, e.g., as wound dressings. However, the preparation of cellulose hydrogels employing unmodified cellulose is scarcely reported because of the cumbersome dissolution of cellulose. In previous studies, we developed the new promising cellulose solvent N-butyl-N-methylpyrrolidinium hydroxide in an aqueous solution, which can dissolve up to 20 wt% cellulose within a short time at room temperature. In this study, we employed this solvent system and investigated the gelation behavior of cellulose after crosslinker addition. The swelling behavior in water (swelling ratio, water uptake), the mechanical properties under compression, and the antibacterial activity against Escherichia coli and Bacillus subtilis were investigated. We have developed a simple and fast one-pot method for the preparation of cellulose gels, in which aqueous pyrrolidinium hydroxide solution was acting as the solvent and as an antibacterial reagent. The pyrrolidinium hydroxide content of the gels was controlled by adjustment of the water volume employed for swelling. Simple recovery of the solvent system was also possible, which makes this preparation method environmentally benign.

Chemical Pretreatment And Enzymatic Hydrolysis Of Mixed Source-Separated Organic (SSO) And Wood Waste

This paper examines the effectiveness of two pretreatments on Source-Separated Organic waste (SSO) mixed with wood wastes: long term lime for SSO mixed with forestry waste (hardwoods), and the cellulose solvent-organic lignocellulose fractionation (COSLIF) method, with SSO and demolition waste (softwoods). For long term lime treatment, the highest overall conversions from cellulose to glucose and xylose were 50.4%, and 43.5% respectively. The best temperature found for long term lime pretreatment was 65°C. The COSLIF pretreatment glucose yield was found to be 93.7%. The highest enzyme hydrolysis yield found was 93.5% for a cellulase loading of 30 FPU/g glucan at 50°C. The best hydrolysis yield found at lower loading (10 FPT/g glucan), was 83.5%. At 40 and 50°C, all peak hydrolysis yields were achieved between 12 and 24 hours. A drop in temperature below 40°C caused a slowing of the hydrolysis rate.

Chemical Pretreatment And Enzymatic Hydrolysis Of Mixed Source-Separated Organic (SSO) And Wood Waste

This paper examines the effectiveness of two pretreatments on Source-Separated Organic waste (SSO) mixed with wood wastes: long term lime for SSO mixed with forestry waste (hardwoods), and the cellulose solvent-organic lignocellulose fractionation (COSLIF) method, with SSO and demolition waste (softwoods). For long term lime treatment, the highest overall conversions from cellulose to glucose and xylose were 50.4%, and 43.5% respectively. The best temperature found for long term lime pretreatment was 65°C. The COSLIF pretreatment glucose yield was found to be 93.7%. The highest enzyme hydrolysis yield found was 93.5% for a cellulase loading of 30 FPU/g glucan at 50°C. The best hydrolysis yield found at lower loading (10 FPT/g glucan), was 83.5%. At 40 and 50°C, all peak hydrolysis yields were achieved between 12 and 24 hours. A drop in temperature below 40°C caused a slowing of the hydrolysis rate.

Acid pretreatment and fractionation of source-separated organic waste for lignocellulosic saccharification

This study compared two acidic pretreatments on Source-Separated Organic (SSO) waste preprocessed by Aufbereitungs Technology and System thermal-screw, on the basis of fermentable sugars for bioethanol production. The result showed that the SSO contained on average 27% glucan, 5.4% xylan, 1.2% arabinan, 5.7% mannan and 1.2% galactan. Dilute sulfuric acid pretreatment (at 121°C and 16.2 psi) was insufficient to solubilize cellulose and hemicellulose and did not remove much of the lignin. Cellulose-solvent and Organic Solvent-based Lignocellulose Fractionation (COSLIF) (at 50°C and atmospheric pressure) generated high glucose yield (70%). Substituting ethanol for acetone as organic solvent increased the yield to 89.5%. Fermentation using Zymomonas mobilis 8b with this hydrolysate confirmed the pretreatment is promising for the SSO conversion. Amenability of the SSO for biofuel production is validated. Enzymatic hydrolysis of both pretreatments using Accellerase 1500 is preferred over Celluclast 1.5L due to higher activity. Future work includes design of an appropriate batch and/or continuous bioreactor, and further understanding of Zymomonas mobilis 8b.

Acid pretreatment and fractionation of source-separated organic waste for lignocellulosic saccharification

This study compared two acidic pretreatments on Source-Separated Organic (SSO) waste preprocessed by Aufbereitungs Technology and System thermal-screw, on the basis of fermentable sugars for bioethanol production. The result showed that the SSO contained on average 27% glucan, 5.4% xylan, 1.2% arabinan, 5.7% mannan and 1.2% galactan. Dilute sulfuric acid pretreatment (at 121°C and 16.2 psi) was insufficient to solubilize cellulose and hemicellulose and did not remove much of the lignin. Cellulose-solvent and Organic Solvent-based Lignocellulose Fractionation (COSLIF) (at 50°C and atmospheric pressure) generated high glucose yield (70%). Substituting ethanol for acetone as organic solvent increased the yield to 89.5%. Fermentation using Zymomonas mobilis 8b with this hydrolysate confirmed the pretreatment is promising for the SSO conversion. Amenability of the SSO for biofuel production is validated. Enzymatic hydrolysis of both pretreatments using Accellerase 1500 is preferred over Celluclast 1.5L due to higher activity. Future work includes design of an appropriate batch and/or continuous bioreactor, and further understanding of Zymomonas mobilis 8b.