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Hemicellulose is a polymer found abundantly in lignocellulosic feedstocks, with many potential market applications. However, there has yet to be a large‐scale commercial process to isolate hemicellulose from lignocellulosic biomass. A techno‐economic assessment for hemicellulose extraction from sugarcane bagasse, switchgrass, and poplar was made. Two isolation processes after alkaline extraction were considered: (1) producing total hemicellulose and (2) producing hemicellulose A (water‐insoluble fraction) only. In a greenfield scenario, a byproduct of the process is sugar, whereas in a co‐location scenario the biomass after hemicellulose extraction is returned to the pulp mill for its fiber value. Operating costs, capital investment, minimum hemicellulose selling price (MHSP), the effect of input material and product prices along with several other process parameters on the MHSP were determined for each scenario. Co‐location scenarios had a dramatically lower capital cost and MHSP relative to greenfield scenarios. This was due to co‐location scenarios utilizing existing biomass processing and utilities equipment and not requiring a sugar‐production process. Among the three biomasses, hemicellulose extraction from sugarcane bagasse had the lowest MHSP for all scenarios, mainly due to a higher hemicellulose extraction yield. Extraction of hemicellulose A from sugarcane bagasse in a co‐location scenario had a low capital cost of 56 million USD and had a reasonable MHSP of 274 USD/t (metric ton). This research indicates that there is reasonable economic potential for hemicellulose extraction from lignocellulosic biomass for applications to replace starch or as a starting material for the production of xylo‐oligomeric prebiotics. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Cellulose transparent and flexible film was prepared by dissolving micro-crystalline cellulose powder in Dimethylacetamide/Lithium Chloride (DMAc/LiCl) followed by regeneration in acetone and subsequent washing with water. The solution was cast on a glass plate. The interactions of water molecules and the swollen cellulose in the gel were examined by differential scanning calorimetry, DSC. An increased melting point of water in the gel indicated the presence of stronger bonding between water and cellulose than in the non-modified cellulose. The prepared dried films had 63 g/m² weight and 0.06 mm thickness with 1.14 g/cm3 density. The prepared dry film exhibited high transparency, around 95% with visible light. The transparency and mechanical properties of the films were stable at high temperature (120°C) and exposure to UV irradiation. Thermal analysis of the prepared sample indicated film stability up to 275 °C. The tensile strength of the cellulose film was around 120 MPa with about 10% strain to break. The mechanical properties of the films were stable in alkali and acidic solutions. [ABSTRACT FROM AUTHOR]

A rapid and green preparation of lignin nanoparticles was demonstrated starting from bio-refinery lignin containing grafted carbohydrates. The particles were prepared by recovering a fraction of the lignin, which contained 24% carbohydrate (by weight) as the insoluble fraction in 0.5 M NaOH. The carbohydrate content of this fraction was verified with a wet chemistry analytical technique, nuclear magnetic resonance, and X-ray diffraction. This fraction was then dissolved in a NaOH/urea/water system and added dropwise to water under a high shear, which rapidly formed precipitated particles in a size range of approximately 100 nm. This carbohydrate-containing fraction of the lignin was soluble in a green solvent system that was not suited for lignin alone. The generated particles were stable in different organic solvents and water. Overall, the dissolution of the bio-refinery lignin in the NaOH/urea/water system, followed by precipitation in water can be regarded as a green and rapid method to produce stable nanoparticles. The generated nanoparticles, containing both carbohydrates and lignin, are expected to have unique applications because of their bi-component nature. Furthermore, this is the first publication to show how materials with high levels of lignin can be solubilized in solvents that are conventionally used for cellulose. [ABSTRACT FROM AUTHOR]

Hemicellulose is a highly available polysaccharide but with poor industrial applications attributed mainly to difficulties in processability, owing to extensive intermolecular hydrogen bonds. In the current study, hemicellulose was subjected to a chemical modification by ring-opening graft polymerization of ε-caprolactone (CL) to improve its processability for value-added applications. Hemicellulose- graft -poly-(ε-caprolactone) (HC g PCL) copolymers were synthesized using 1,5,7-triazabicyclodecene [4.4.0] (TBD) as an organic catalyst. The extent and length of grafted PCL sidechains in HC g PCL copolymers were controlled by adjusting the molar ratios of CL monomer to anhydroxylose residues. The various characterization analysis of the physicochemical and mechanical properties of HC g PCL materials revealed a successful grafting. The NMR analyses indicated that the degree of polymerization (DP) of the grafted PCL can range between 1.82 and 4.26 based on the changes in the molar ratio of the reactants. Furthermore, results indicated that the mechanical and the hydrophobic properties of the materials were enhanced by PCL grafting onto hemicellulose. Finally, biodegradability measurements indicated a remarkable (95.3–99.7%) materials biodegradation. We anticipate that the HC g PCL copolymers will have great potential to be an eco-friendly part of the bioplastic industry. [ABSTRACT FROM AUTHOR]

Hemicellulose is an abundant and underutilized carbohydrate polymer in plants. The objective of this study was to understand the effect of delignification on hemicellulose extraction efficiency with different types of lignocellulosic biomass. In the case of pine, with a prior sodium chlorite or peracetic acid delignification, more than 50% of the original hemicellulose in the biomass could be extracted using a 10% sodium hydroxide solution; without delignification, only 3.4% of hemicellulose could be extracted from pine. In contrast, without prior delignification, acceptable hemicellulose extraction efficiencies (55.5% and 50.7%, respectively) were achieved from switchgrass and poplar. In addition, the effect of hemicellulose extraction processes on the enzymatic convertibility of the celluloserich residues after extraction was determined. The cellulose-rich residues from switchgrass after hemicellulose alkali extraction showed high glucose recovery with enzyme hydrolysis with or without prior delignification. For pine and poplar, high glucose recovery with enzyme hydrolysis of the cellulose-rich residues only occurred if the sample had a delignification step prior to hemicellulose extraction. This information on commercially available biomass feedstocks is useful for those considering isolating hemicellulose within a biorefinery concept. [ABSTRACT FROM AUTHOR]

Hemicellulose materials are arguably the second most abundant renewable component of lignocellulosic biomass after cellulose. They are relatively under-utilized hetero-polysaccharides present in lignocellulosic biomass. In this research an alkaline treatment was optimized for extraction of polymeric hemicellulose from fully bleached hardwood pulp (B-HWP) and partially delignified switchgrass (SWG). The hemicellulose extracted from B-HWP was relatively pure with zero percent lignin and 89.5% xylose content whereas the partially delignified SWG hemicellulose contained about 6-3% lignin and 72–82% xylose, depending on the NaOH concentration during extraction (3–17% NaOH solution). A maximum molecular weight of SWG hemicellulose of 64,300 g/mol was achieved for the 10% NaOH solution extraction, whereas the MW of B-HWP hemicellulose at 10% NaOH solution extraction was lower at 49,200 g/mol. We have demonstrated that the residual lignin in SWG hemicellulose lowered the system T g and this might be utilized as a way to increase the applications of hemicellulose in high value biomaterials. Furthermore, the hemicellulose could be crosslinked with zirconium to develop a water resistant gel for coating or adhesive applications. Our results showed that the loading stress required to break an hemicellulose based adhesive connection between two paper surfaces was 0.89, 2.02, 2.75, 3.46, and 3.11 (MPa) for 2, 4, 6, 8 and 10% AZC samples, indicating that up to about 8% AZC crosslinker in the hemicellulose increases the adhesive behavior of the material. [ABSTRACT FROM AUTHOR]

Currently, there is very strong interest to replace synthetic polymers with biological macromolecules of natural source for applications that interact with humans or the environment. This research describes the development of drug delivery hydrogels from natural polymers, starch, lignin and hemicelluloses by means of reactive extrusion. The hydrogels show a strong swelling ability dependent on pH which may be used to control diffusion rates of water and small molecules in and out of the gel. Also the hydrogels degradation rates were studied in a physiological solution (pH 7.4) for 15 days. The results indicated that for all three macromolecules, lower molecular weight and higher level of plasticizer both increase the rate of weight loss of the hydrogels. The degradation was extremely reduced when the polymers were extruded in the presence of a catalyst. Finally the dynamic mechanical analysis revealed that the degradation of the hydrogels induce a significant reduction in the compressive modulus. This study demonstrates the characteristics and potential of natural polymers as a drug release system. [ABSTRACT FROM AUTHOR]

Mechanical refining has potential application for overcoming lignocellulosic biomass recalcitrance to enzyme hydrolysis and improving biomass digestibility. This study highlighted the ability for a pilot scale disc refiner to improve the total carbohydrate conversion to sugars from 39% (unrefined hardwood sodium carbonate biomass) to 90% (0.13 mm gap, 20% consistency, ambient temperature) by optimizing the refining variables. The different biomass properties that changed with refining indicated the expected increase in sugar conversion. Controlling the refining parameters to narrower gaps and higher consistencies increased the resulting refined biomass hydrolysis. Positive correlations that increases in net specific energy (NSE) input and refining intensity (SEL) improved the enzymatic hydrolysis. In some severe cases, over-refining occurred when smaller gaps, higher consistencies, and more energy input reached a point of diminished return. The energy input in these scenarios, however, was much greater than realistically feasible for industrial application. Although well-established in the pulp and paper industry, gaps in understanding the fundamentals of refining remain. The observations and results herein provide the justification and opportunity for further mechanical refining optimization to maximize and adapt the mechanical refining technology for maximum efficiency within the process of biochemical conversion to sugar. [ABSTRACT FROM AUTHOR]

Life cycle assessments (LCAs) have become a common tool for measuring the environmental performance of various products and processes. This study reviewed the life cycle of lignocellulosic biomass feedstock-based (pine, eucalyptus, and switchgrass) ethanol biofuels and compared the results to gasoline. Uncertainty analysis of the cradle-to-wheel results was conducted using a pedigree matrix method to address uncertainty of life cycle inventory items. A tool called stochastic multi-attribute analysis for life cycle impact assessment (SMAA-LCIA) was used to interpret the results generated from the LCA. The normalized results showed that gasoline had high environmental impacts in categories such as carcinogenics and global warming, followed by switchgrass. But the use of a single-score metric indicated that all bio-based feedstocks had similar environmental performance, all significantly better than gasoline. The SMAA-LCIA results showed that when all impacts were weighted equally, the preference from highest to lowest was for loblolly pine, eucalyptus, gasoline, and switchgrass. This rank order switched when differing weighting schemes of Producer, User, and LCA Expert were used. Overall, this method highlights the trade-offs associated with the selection of different feedstocks and improves the comparison of overall results amongst fuel sources, which can then be more clearly presented to a decision-maker. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

A process to attach fatty acids to lignin is reported which alters its thermal behavior. By attaching saturated C 18 fatty acids to OH groups, stable lignin stearates (LS) of controllable degrees of substitution (DS) were synthesized. Interesting physical properties were observed, wherein LS was observed to melt and flow at temperatures as low as 50 °C. Melting was possible due to the crystallization of stearate chains when LS was purified by precipitation. A NMR method was established for quantification of the degree of substitution. At very high %DS values (close to 100%), the melting phenomenon was reversible, but at low %DS, melting occurred only during the 1st heating ramp during thermal cycling. The ability of LS to plasticize polystyrene (PS) is reported wherein integral blend films containing up to 25% by weight of LS were formed. The T g of the blended films could be lowered by 22 °C using LS relative to PS. Lignin stearates have the potential to serve as interesting compounds for their ability to plasticize not only PS but other thermoplastic materials as well. [ABSTRACT FROM AUTHOR]

Early-stage evaluation of biofuel and bioproduct technologies is extremely complicated and involves many disparate feasibility criteria, including technical, financial, environmental, logistic, legal, social, and other aspects. Problems can arise for decision-makers when evaluating renewable technologies at this early stage due to bias, shifting preferences or priorities, occurrence of trade-offs, and decision-making complexity. Thus, a method is needed for evaluating disparate, typically non-comparable criteria concurrently. In Part 1 of this research, cradle-tograve environmental LCA was conducted for biomass delivery to a biosugar refinery using Ecoinvent v2.2 data and the TRACI 2 impact assessment method for midpoint impacts. Biomass availability, delivered cost, sugar yield, transportation distance, harvestable months per year, and other aspects of supply chain feasibility were measured for eighteen feedstock biomass types. In Part 2, stochastic multi-attribute analysis (SMAA) was used alongside LCA to develop an environmental preference single-score probability distribution function for feedstock alternatives. Weighted single-scoring and ranking, using multi-criteria decision-making analysis (MCDA), was conducted considering five criteria of biomass supply feasibility: biomass delivered cost, biosugar yield, harvestable months, transport distance, and environmental preference single-score. Corn was shown to cost the most, followed by switchgrass and U.S. primary forest products. Transport distance was found to be highest for residues due to low yield per acre and low covered area. Results of MCDA show that Brazilian eucalyptus and Malaysian empty fruit bunch biomass types were consistently preferred relative to other biomass types. In the U.S., Genera biomass sorghum is most holistically preferred. It is shown that SMAA is helpful for translating LCA data for decision science. It was shown that MCDA can be useful for early-stage biorefinery technology commercialization decision-making, using the novel decision science tool described herein. [ABSTRACT FROM AUTHOR]

Chemical production from crude oil represents a substantial percentage of the yearly fossil fuel use worldwide, and this could be partially offset by renewable feedstocks such as woody biomass and energy crops. Past techno-economic and environmental analyses have been conducted for isolated feedstocks on a regional or national scope. This study encompasses complete supply chain logistics analysis, delivered cost financial analysis, national availability, and environmental life cycle assessment (LCA) for 18 selected cellulosic feedstocks from around the world. A biochemical conversion route to monomeric sugars is assumed for estimated sugar yields and biosugar feedstock cost analysis. US corn grain was determined to have the highest delivered cost, while rice hulls in Indonesia resulted in the lowest cost of the feedstocks studied. Monomeric sugar yields from literature ranged from 358 kg BDMT-1 for US forest residues to 700 kg BDMT-1 for corn syrup. Environmental LCA was conducted in SimaPro using ecoinvent v2.2 data and the TRACI 2 impact assessment method for mid-point impacts cradle-to-incoming biorefinery gate. Carbon absorption during biomass growth contributed most substantially to the reduction of net global warming potential. Rice hulls and switchgrass resulted in the highest global warming potential, followed closely by corn and Thai sugarcane bagasse. Contribution analysis shows that chemical inputs such as fertilizer use contribute substantially to the net environmental impacts for these feedstocks. [ABSTRACT FROM AUTHOR]

As one of the most abundant natural materials in nature, cellulose has revealed enormous potential for the construction of functional materials thanks to its sustainability, non-toxicity, biocompatibility, and biodegradability. Among many fascinating applications, functional surfaces based on cellulose-derived materials have attracted increasing interest recently, as platforms for diagnostics, sensoring, robust catalysis, water treatment, ultrafiltration, and anti-microbial surfaces. This mini-review attempts to cover the general methodology for the fabrication of functional cellulose surface and a few popular applications including bioactive and non-adhesive (i.e., anti-fouling and anti-microbial) surfaces. [ABSTRACT FROM AUTHOR]

Mechanical refining has been shown to improve biomass enzymatic digestibility. In this study industrial high-yield sodium carbonate hardwood pulp was subjected to lab, pilot and industrial refining to determine if the mechanical refining improves the enzymatic hydrolysis sugar conversion efficiency differently at different refining scales. Lab, pilot and industrial refining increased the biomass digestibility for lignocellulosic biomass relative to the unrefined material. The sugar conversion was increased from 36% to 65% at 5 FPU/g of biomass with industrial refining at 67.0 kWh/t, which was more energy efficient than lab and pilot scale refining. There is a maximum in the sugar conversion with respect to the amount of refining energy. Water retention value is a good predictor of improvements in sugar conversion for a given fiber source and composition. Improvements in biomass digestibility with refining due to lab, pilot plant and industrial refining were similar with respect to water retention value. [ABSTRACT FROM AUTHOR]

There has been great attention focused on the effects of first and second generation biofuels on global warming. The Energy Independence and Security Act (EISA) and the Renewable Fuel Standard (RFS) have mandated production levels and performance criteria of biofuels in the United States. The thermochemical conversion of biomass to ethanol shows potential as a biofuel production pathway. The objective of this research was to examine the alcohol yields and GHG emissions from the thermochemical conversion process for six different feedstocks on a gate-to-gate basis. GHG analyses and life cycle assessments were performed for natural hardwood, loblolly pine, eucalyptus, miscanthus, corn stover, and switchgrass feedstocks using a NREL thermochemical model and SimaPro. Alcohol yield and GHG emission for the hybrid poplar baseline feedstock conversion were 105,400 L dry metric ton-1 and 2.8 kg CO2 eq. per liter, respectively. Compared with the baseline, loblolly pine produced the highest alcohol yields, an 8.5% increase, and the lowest GHG emissions per liter of ethanol, a 9.1% decrease. Corn stover, due to its high ash content, had the lowest yields and the highest GHG emissions per liter of ethanol. The results were highly sensitive to the ash and water content of the biomass, indicating that biomass properties can significantly affect the environmental impact of the thermochemical ethanol conversion process. [ABSTRACT FROM AUTHOR]

Highlights: [•] Mechanical refining improved the enzymatic hydrolysis sugar recovery. [•] The increase in sugar recovery correlated with the water retention value. [•] Mechanical refiners with different mechanisms affected the biomass digestibility differently. [•] A maximum in absolute enzymatic hydrolysis improvement due to refining was observed. [•] The maximum occurred at conditions that produced intermediate hydrolysis conversions. [Copyright &y& Elsevier]

Abstract: Hemicellulose material is an abundant and relatively under-utilized hetero-polysaccharides material present in lignocellulosic materials. In this research, an alkaline treatment was applied to switchgrass in order to extract hemicelluloses to subsequently produce an acetylated product. An extraction at 75°C recovered 27% of the biomass as a predominantly hemicellulose material with a number average degree of polymerization of ∼500 determined by gel permeation chromatography. These hemicelluloses were acetylated with acetic anhydride in 1-allyl-3-methylimidazolium chloride ([Amim]+Cl−) ionic liquid in a complete homogeneous procedure without catalyst for the first time. It was determined that the yield and degree of substitution increased with reaction temperature from 30 to 80°C and reaction time from 1 to 20h. The product was characterized by FTIR spectroscopy, NMR, gel permeation chromatography for molecular weight and water contact angle analysis. FTIR spectroscopic analysis showed that the characteristic absorption intensities of acetylated hemicellulose increased and the hydroxyl group decreased with the increase in the degree of substitution. Increased degree of substitution increased the water contact angle and thermal stability in nitrogen. It was possible to cast films of the acetylated hemicellulose although the films were brittle. The results obtained indicate a promising combination between the effective extraction of hemicellulose from grasses and an environmentally friendly process using acetic anhydride in an ionic liquid without a catalyst to generate hemicellulose acetate with high degree of polymerization for use in various industrial applications. [Copyright &y& Elsevier]

Abstract: Cellulose nanocrystals (CNCs) from ramie fibers are studied as stabilizers of oil-in-water emulsions. The phase behavior of heptane and water systems is studied, and emulsions stabilized by CNCs are analyzed by using drop sizing (light scattering) and optical, scanning, and freeze-fracture electron microscopies. Water-continuous Pickering emulsions are produced with cellulose nanocrystals (0.05–0.5wt%) grafted with thermo-responsive poly(NIPAM) brushes (poly(NIPAM)-g-CNCs). They are observed to be stable during the time of observation of 4months. In contrast, unmodified CNCs are unable to stabilize heptane-in-water emulsions. After emulsification, poly(NIPAM)-g-CNCs are observed to form aligned, layered structures at the oil–water interface. The emulsions stabilized by poly(NIPAM)-g-CNCs break after heating at a temperature above the LCST of poly(NIPAM), which is taken as indication of the temperature responsiveness of the brushes installed on the particles and thus the responsiveness of the Pickering emulsions. This phenomenon is further elucidated via rheological measurements, in which viscosities of the Pickering emulsions increase on approach of the low critical solution temperature of poly(NIPAM). The effect of temperature can be counterbalanced with the addition of salt which is explained by the reduction of electrostatic and steric interactions of poly(NIPAM)-g-CNCs at the oil–water interface. [Copyright &y& Elsevier]

Microfibrillated celluloses (MFCs) have mechanical properties sufficient for packaging applications but lack water vapor barrier properties in comparison to petroleum-based plastics. These properties can be modified by the use of mineral fillers, added within the film structure, or waxes, as surface coatings. In this investigation it was determined that addition of fillers resulted in films with lower densities but also lower water vapor transmission rates (WVTR). This was hypothesized to be due to decreased water vapor solubility in the films. Associated transport phenomena were analyzed by the Knudsen model for diffusion but due to the limited incorporation of chemical factors in the model and relatively large pore sizes, accurate prediction of pore diameters for filled films was not possible with this model. Modeling the filled-films with Fick's equation, however, takes into account chemical differences, as observed by the calculated tortuosity values. Interestingly, coating with beeswax, paraffin, and cooked starch resulted in MFC films with water vapor transmission rates lower than those for low density polyethylene. These coatings were modeled with a three-layer model which determined that coatings were more effective in reducing WVTR. [ABSTRACT FROM AUTHOR]

Abstract: The applications for hemicellulose are currently very narrow, because of its low molecular weight and varying chemical composition. In this research, novel applications for modified hemicellulose are developed making it a valuable biomaterial for absorbency applications in health care and medical textiles. The incorporation of carboxylic acid groups into hemicellulose via reaction with citric acid followed by cross linking with chitosan greatly improve the properties relative to hemicellulose, chitosan, a cellulose sponge product, and hemicellulose citrate alone. Optimum conditions for the cross linking of the hemicellulose citrate–chitosan include a 2.5h reaction time at 110°C with pH 3.5, a solid to liquid ratio of 1:100 and a hemicellulose citrate to chitosan ratio of 1:1 (w/w). The hemicellulose citrate–chitosan crosslinked foam is elastic, very soft, highly porous and durable. The hemicellulose citrate–chitosan can absorb up to 100g of a saline solution per gram of material and up to 80g of water per gram of material. Analysis of the hemicellulose citrate–chitosan foams with FTIR, DMA, and SEM confirms the crosslinked and hygroscopic behavior of the materials. [Copyright &y& Elsevier]

Abstract: Autohydrolysis is a simple, green method of recovering sugars from biomass, using only hot water. One potential drawback is that byproducts are formed during the autohydrolysis process that could interfere with subsequent hydrolysis and fermentation to ethanol. In the present work, autohydrolysis prehydrolyzate from mixed hardwood chips was detoxified with activated carbon and the removal efficiency of byproducts as well as the loss of sugars determined. The resulting detoxified prehydrolyzate was evaluated for the fermentation to ethanol with a thermophilic anaerobic bacterium. Activated carbon at a 2.5 wt % level on the prehydrolyzate was able to remove 42% of formic acid, 14% of acetic acid, 96% of hydroxymethylfurfural (HMF) and 93% of the furfural. However, 8.9% of sugars were also removed. The removal of HMF and furfural follow expected adsorption isotherms but formic acid, acetic acid, and sugars did not. Autohydrolysis prehydrolyzates from mixed hardwood detoxified with activated carbon can be fermented with Thermoanaerobacterium saccharolyticum strain MO1442 with an essentially 100% yield. T. saccharolyticum strain MO1442 is able to metabolize the glucose, xylose, and arabinose in the hydrolyzate. The results showed the detoxification process with activated carbon improved the ethanol yields by the removal of toxic compounds, mainly HMF and furfural, with moderate loss of fermentable sugars. [ABSTRACT FROM AUTHOR]

Abstract: Films of microfibrillated celluloses (MFCs) from pulps of different yields, containing varying amounts of extractives, lignin, and hemicelluloses, were produced by combining refining and high-pressure homogenization techniques. MFC films were produced using a casting-evaporation technique and the physical and mechanical properties (including density, roughness, fold endurance and tensile properties) were determined. Homogenization of bleached and unbleached Kraft pulps gave rise to highly individualized MFCs, but not for thermo-mechanical pulp (TMP). The resulting MFC films had a roughness equivalent to the surface upon which the films were cast. Interestingly, after homogenization, the presence of lignin significantly increased film toughness, tensile index, and elastic modulus. The hornification of fibers through a drying and rewetting cycle prior to refining and homogenization did not produce any significant effect compared to films from never-dried fibers, indicating that MFC films can potentially be made from low-cost recycled cellulosic materials. [Copyright &y& Elsevier]

Starch microcellular foams (SMCF) containing pores in the micron size range may be prepared by pore-preserving drying processes, developing highly porous, high specific surface area materials useful for applications such as opacifying pigments or as adsorbent materials. The objective of this research was to understand how the exchange of water with ethanol, used as a pore preserving step, affected the dimensional properties of the starch material during and after processing. SMCF were prepared from molded aquagels of cooked corn starch that were subjected to ethanol exchanges with different time intervals (6, 12, or 48 hrs) and number of exchanges (1, 2, or 3) and then air dried. To study the transformation of water-swollen starch into precipitated starch foam in ethanol, the volume of the starch material was measured in the wet state after each exchange and after final air drying. As water is replaced by ethanol, the starch material contracts, with the greatest contraction during the first ethanol exchange. The amount of contraction during air drying decreased with decreased starch water content just before air drying, presumably due to less pore collapse of the stiffer cell walls on drying. Interestingly, the minimum density of 0.37 g/cc SMCF was for the 12 hour exchange time, not the longest exchange time. Evidence of a skin-core morphology included SEM images as well as dimensional instability data on dried samples. The results indicate that SMCF of low density with fewer tendencies to deform during drying does not necessarily require extremely long exchange times. [ABSTRACT FROM AUTHOR]

Abstract: Lewis acids (AlCl3 or ZnCl2) were used to catalyze the transesterification of canola oil with methanol in the presence of terahydrofuran (THF) as co-solvent. The conversion of canola oil into fatty acid methyl esters was monitored by 1H NMR. NMR analysis demonstrated that AlCl3 catalyzes both the esterification of long chain fatty acid and the transesterification of vegetable oil with methanol suggesting that the catalyst is suitable for the preparation of biodiesel from vegetable oil containing high amounts of free fatty acids. Optimization by statistical analysis showed that the conversion of triglycerides into fatty acid methyl esters using AlCl3 as catalyst was affected by reaction time, methanol to oil molar ratio, temperature and the presence of THF as co-solvent. The optimum conditions with AlCl3 that achieved 98% conversion were 24:1 molar ratio at 110°C and 18h reaction time with THF as co-solvent. The presence of THF minimized the mass transfer problem normally encountered in heterogeneous systems. ZnCl2 was far less effective as a catalyst compared to AlCl3, which was attributed to its lesser acidity. Nevertheless, statistical analysis showed that the conversion with the use of ZnCl2 differs only with reaction time but not with molar ratio. [Copyright &y& Elsevier]

Abstract: The production of a hydrophobic starch microcellular foam (SMCF) through the addition of an alkyl ketene dimer (AKD) would be a bio-based material with valuable properties for many applications in which high specific surface area, low density and water resistance is important. Pigments for paper and coatings are a potential application. An emulsion of AKD and cooked corn starch was made by mixing AKD with cooked starch at 50°C under a high rate of shear. The effects of reaction temperature, starch concentration and pH on the reaction of AKD with starch and the resulting microcellular foam structure were studied. The starch/AKD foam particles were characterized by scanning electron microscope (SEM), elemental analysis to determine extent of reaction, thermogravimetric analysis (TGA), brightness, particle size and water swellability. The apparent viscosity of the starch solution was shown to have a linear relationship with the particle size and the brightness of the particles. The particles under all conditions had a very high brightness. The AKD was able to impart a significant hydrophobicity to the particles relative to starch alone but the water resistance was not great enough to preserve the porous structure when wetted. [Copyright &y& Elsevier]

Abstract: Water-in-CO2 reverse micelles stabilized by ionic perfluoroalkyl and non-ionic perfluoropolyether surfactants were used to host amino acids and polypeptides in supercritical (SC) CO2. The minimum pressure at which micellization occurs (P trans) was found to be affected by the surfactant concentration and H2O/CO2 ratio. Due to the differences in hydrophilic/CO2 balance, the two surfactants exhibited different phase behaviors at 19.3MPa and 40°C. At certain H2O/CO2/surfactant compositions, while coagulation was more evident when using perfluoroalkyl surfactant, flocculation was found to dominate the system containing perfluoropolyether surfactant. The presence of amino acid and polypeptide in reverse micelles was found to increase the P trans of the system due to enthalpic and entropic changes. In perfluoroalkyl reverse micelles, the P trans was found to increase with increasing hydrophilicity of the amino acid added. The presence of hydrophobic moieties in amino acids promotes interfacial solubilization that eventually resulted in lower P trans. On the other hand, the nature of the amino acid was not found to affect P trans in perfluoropolyether reverse micelle. Overall, this work demonstrates that polypeptides with varying molecular weight could be solubilized in water-in-CO2 reverse micelles using perfluoropolyether while perfluoroakyl surfactants were ineffective. [Copyright &y& Elsevier]

There is interest in replacing inorganic fillers in paper, coatings and plastics with renewable organic fillers to improve the economics, performance and environmental aspects of such products. Starch microcellular foam (SMCF) particles are promising materials in this regard. This research was undertaken to produce SMCF particles and characterize their morphology, optical properties and interaction with water. SMCF particles were produced using corn starch; which was solubilized in water. The foam structure was created by precipitating the starch using ethanol in a solvent exchange technique. The starch was also reacted with alkyl ketene dimer (AKD) wax at different levels in order to understand if the AKD could impart water resistance to the particles. Two methods were used to incorporate AKD: (1) the AKD was coated onto foam particles after foam formation, and (2) the AKD was blended with the starch before foam particle formation. Hexane extraction was used to purify a portion of each of the samples to determine if unreacted AKD existed with the starch matrix. Particles with porous structure and high brightness were developed for all combinations of starch and AKD. The brightness of the particles was significantly higher than that of the uncooked starch, presumably due to the development of a porous structure. For the AKD coated particles a minimum amount of AKD charged was needed to develop a high contact angle, low solubility, and low water retention value, higher levels of AKD in AKD coated particles did not further alter these properties. This indicates that the changes in properties with AKD level with coated particles is a surface phenomena. Starch AKD blends did not show any increased resistance to water relative to the particles with no AKD blended. This is due to the ethanol used in the precipitation process extracting the AKD, which was confirmed by elemental analysis. The particles, even with the 10% AKD coated or blended, lost their porous structure upon rewetting. Further work needs to be performed to more effectively hydrophobize the starch foams with AKD. [Copyright &y& Elsevier]

Abstract: Starch microcellular foam (SMCF) has been produced using a solvent exchange technique with a native corn starch crosslinked with glutaraldehyde. To produce a high specific surface area for the starch particles the cooked starch solution was reacted with glutaraldehyde and then precipitated under shear with ethanol. The relationship between the crosslinking density on the void structure of the SMCF has been studied. Characterization by NMR confirmed the crosslinking reaction. An increase in the glutaraldehyde concentration from 0 to 15g glutaraldehyde/100g starch was accompanied by a decrease in particle size and moisture content and an increase in brightness and specific surface area. Scanning electron microscope images of the SMCF particles show that the smallest average void diameter obtained was 0.182μm at a 7.5g glutaraldehyde/100g starch. Four starch materials having different viscosity were prepared by hydrolysis of the native corn starch with a 1N HCl/methanol system for different reaction durations to investigate the relationship between starch molecular weight and void structure of the SMCF. The starches were crosslinked with 15g glutaraldehyde/100g starch and precipitated with ethanol to form SMCF. Decreasing the starch viscosity decreased the brightness and specific surface area, and increased the particle size, void diameter and moisture content. Increases in stirring speed during the precipitation enhanced the properties of the SMCF particles. The effect of pressing the starch particles to form a pellet caused a collapse of the foam structure at pressures above about 6000psi. The results indicate that the structure/chemistry of the starch material and the processing conditions can be controlled in order to produce particles with morphology and properties useful for light scattering applications. In particular, higher molecular weight and intermolecular crosslinking and high shear during precipitation have been found to enhance the foam formation. [Copyright &y& Elsevier]

Abstract: Changes in pore size distribution during the drying of cellulose fibers were determined using differential scanning calorimetry (DSC) with an isothermal step melting procedure. Softwood bleached kraft pulp at various moisture ratios were generated from partial drying in a thermogravimetric analyzer and then analyzed in a DSC. The pore size distribution was calculated using the Gibbs–Thomson equation and specific melting point depression of water detected by DSC. It was observed that larger pores collapse first followed by the sequential collapse of smaller pores. It is suggested that pore wall collapse resistance is the primary factor that determines which size pores close. The average measured pore size in the fiber wall of the never dried fiber was calculated to be about 80nm and reduced with drying of the fibers. A constant pore size of about 20nm was observed at moisture ratios below 0.3g/g, which corresponds to one-to-two layers of non-freezing bound water tightly bound to the surface. [Copyright &y& Elsevier]

Abstract: Atomic force microscopy with chemically modified cantilever tips (chemical force microscopy) was used to study the pull-off forces (adhesion forces) on cellulose model surfaces and bleached softwood kraft pulp fibers in aqueous media. It was found that for the –COOH terminated tips, the adhesion forces are dependent on pH, whereas for the –CH3 and –OH terminated tips adhesion is not strongly affected by pH. Comparison between the cellulose model surfaces and cellulosic fibers under our experimental conditions reveal that surface roughness does not affect adhesion strongly. X-ray photoelectron spectroscopy (XPS) and Fourier Transformed Infrared (FTIR) spectroscopy reveal that both substrate surfaces have homogeneous chemical composition. The results show that chemical force microscopy can be used for the chemical characterization of cellulose surfaces at a nano-level. [Copyright &y& Elsevier]

The growing interest in bamboo fibers for pulp, paper, and board production in the USA necessitates a comprehensive financial viability assessment. This study conducts a detailed technoeconomic analysis (TEA) of bamboo fiber production, primarily for the consumer hygiene tissue market although it is also applicable to other industrial uses. The economic viability of two pulping methods – alkaline peroxide mechanical pulping (APMP) and ammonium bisulfite chemical pulping (ABS) – was explored within three different pulp mill settings to supply pulp to two nonintegrated tissue and towel mills in South Carolina, USA. The target was to produce wet lap bamboo bleached pulp at 50% consistency and 70% ISO brightness. Despite higher initial capital invesment and operating costs, ABS achieved a lower minimum required selling price – USD 544 to 686 per bone dry metric ton (BDt = 1000 BDkg) – in comparison with USD 766 to 899 BDt−1 for APMP. This price advantage is partly due to an additional revenue stream (lignosulfonate byproduct), which not only boosts revenue but also circumvents the need for expensive chemical recovery systems. When compared with traditional kraft pulping, both methods require significantly lower capital investments, with minimum required selling prices (estimated to achieve 16% IRR) below current market rates for extensively used bleached kraft pulps in the USA tissue industry. The economic benefits derive from several factors: the low cost of bamboo as raw material, reduced capital needs for new pulping technologies, lower transportation costs from the pulp mill to tissue and towel manufacturing facilities, and the high market price of bleached kraft pulp. [ABSTRACT FROM AUTHOR]

Bamboo, recognized for its rapid growth, high yield, and fiber performance is prominent in the fiber‐based bioproduct industry. However, the absence of US industrial bamboo plantations for fiber production necessitates reliance on imports or locally manufactured products using imported bamboo fibers, predominantly from China. This study evaluates the economic viability of cultivating bamboo in the Southern US for fiber production, with a case study on hygiene tissue products. The supply‐chain analysis was assessed to calculate bamboo chips' minimum selling price (MSP) at the farm gate for an 8% internal rate of return (IRR). The MSP, influenced primarily by land rental costs, ranges from USD 48 to 55 per bone‐dry metric ton (BDt). Despite an initial establishment cost of ~USD 2 000 ha−1 and profitability by year 5, bamboo is a viable, long‐term fiber alternative. Successful bamboo cultivation in the US could lead to a more sustainable implementation of alternative non‐wood fibers for hygiene tissue applications. [ABSTRACT FROM AUTHOR]

Static life cycle assessment (LCA) methodologies fail to consider the temporal profiles of system inputs and outputs (including emission timing), such that they underestimate the benefits of temporarily stored biogenic carbon in bioproducts, such as cotton. This research focuses on greenhouse gas emission timing and applies dynamic emission accounting to the life cycle of cotton woven pants. The significance of temporary biogenic carbon storage and emission timing is illustrated by converting the 2017 Cotton Incorporated static LCA to a dynamic model using the Dynamic Carbon Footprinter (baseline scenario). A reduction in cumulative radiative forcing for dynamic relative to static modeling of 22%, 5%, and 2% are observed at 10-years, 30-years, and 100-years, respectively. Alternative scenarios analyzed include converting cotton woven pants at end of life to bioenergy, to compost, or to building insulation, an alternative cotton production scenario using regenerative agricultural practices, and two pants extended lifetime scenarios. The regenerative agricultural practice scenario provides reductions in cumulative impacts compared to the baseline scenario of 96%, 69%, and 105% after 10, 30, and 100-years, respectively. A 3x extension in the lifetime of pants provides a benefit in reduced cumulative impacts of 31%, 40%, and 41%, after 10, 30, and 100-years, respectively. This case study with cotton demonstrates that dynamic LCA is a useful tool for assessing the benefits of biobased products, and it allows for more nuanced analysis of reductions in climate impacts in both the short- and long-term time horizons. [ABSTRACT FROM AUTHOR]

Bleaching is an important industrial operation that has significant environmental impacts. Many new bleaching technologies have been developed; nonetheless, it is challenging to quantify their potential environmental impacts due to the lack of quantitative information and robust analysis methods across different bleaching agents. This study addresses this gap by developing a general Life Cycle Assessment (LCA) framework that integrates LCA with manufacturing process simulations and lab-scale bleaching experiments. The framework was applied to a case study of Peracetic Acid (PAA), a promising bleaching agent, used in the Total Chlorine-Free (TCF) technology for wood pulp production, compared with the traditional Elemental Chlorine-Free (ECF) using chlorine dioxide. Different PAA synthetic pathways (i.e., using acetic acid or triacetin) and bleaching charges were explored using scenario analysis. Results showed that PAA-based TCF achieves a brightness similar to the conventional ECF technology with lower life-cycle impacts in categories such as global warming and eutrophication. From a process perspective, PAA-based TCF reduces the consumption of energy, water, pulping chemicals, completely avoids the use of chlorinated compounds, and provides enhanced process safety. The source of PAA significantly affects the life-cycle environmental impacts of pulp bleaching. Using PAA synthesized from triacetin rather than acetic acid leads to higher environmental impacts; however, such impacts can be mitigated by reducing excessive use of triacetin (direction for future optimization) or using bio-based glycerin in the production of the triacetin feedstock for PAA production. Although this case study focuses on PAA bleaching for wood pulp, the framework has the potential to be used for other/same bleaching agents in different industrial sectors. Image 1 • A Life Cycle Assessment framework for sustainable bleaching was developed. • The framework was applied to peracetic acid bleaching of wood pulp. • Two pulp bleaching processes using Peracetic Acid (PAA) and ClO 2 were compared. • PAA made from the traditional process was compared with a green chemistry pathway. • Bleaching with PAA eliminates chlorinated compounds and consumes fewer resources. [ABSTRACT FROM AUTHOR]

Reactive extrusion is an attractive green route for cost-effective polymer processing, which has the potential to enhance the commercial viability of biomass-derived materials. In reactive extrusion, compatibilizers can be generated in the blend preparation through polymer-polymer grafting reactions using functionalized polymers. One very interesting new green strategy for processing is the use of intense UV-irradiation to create free radicals and controllable, ultra-fast reactions. It is reasonable to expect that the use of extrusion/irradiation green technology will be an important way to improve properties and compatibility of renewable biomass-derived polymers. We believe that in the future, many more cost-effective, sustainable extrusion/irradiation reaction processes will be developed to replace inefficient conventional biomass conversion procedures and stimulate the bioproduct-based industry. [ABSTRACT FROM AUTHOR]

Optimizing drying energy in the forest products industry is critical for integrating lignocellulosic feedstocks across all manufacturing sectors. Despite substantial efforts to reduce thermal energy consumption during drying, further enhancements are possible. Cellulose, the main component of forest products, is Earth's most abundant biopolymer and a promising renewable feedstock. This study employs all-atom molecular dynamics (MD) simulations to explore the structural dynamics of a small I β -cellulose microcrystallite and surrounding water layers during drying. Molecular and atomistic profiles revealed localized water near the cellulose surface, with water structuring extending beyond 8 Å into the water bulk, influencing solvent-accessible surface area and solvation energy. With increasing temperature, there was a ∼20 % reduction in the cellulose surface available for interaction with water molecules, and a ∼22 % reduction in solvation energy. The number of hydrogen bonds increased with thicker water layers, facilitated by a "bridging" effect. Electrostatic interactions dominated the intermolecular interactions at all temperatures, creating an energetic barrier that hinders water removal, slowing the drying processes. Understanding temperature-dependent cellulose-water interactions at the molecular level will help in designing novel strategies to address drying energy consumption, advancing the adoption of lignocellulosics as viable manufacturing feedstocks. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study PLA and PHB were melt-blended with/without maleic anhydride (MA) as a compatibilizer and melt-spun into a monofilament. The aquatic biodegradation of PLA/PHB fibers was tracked regarding the PLA and PHB components and the total carbon in the blend. Pure PLA fiber was recalcitrant to aquatic biodegradation in the present conditions, whereas PHB was readily degradable, as expected. The 75/25% and 50/50% PLA/PHB fibers showed zero biodegradation. The 25/75% PLA/PHB blend showed only an 11% final biodegradation extent and a 13% PHB biodegradation extent. It is shown that an unintended consequence of blending PLA with PHB is that after biodegradation, micro/nano plastic pollution is evolved. MA increased the miscibility, which further decreased the PHB biodegradation. The lower biodegradation extent with MA indicates that increased miscibility and more intimate coverage of the biodegradable polymer with the unbiodegradable polymer may have a negative effect on the biodegradation of biodegradable polymers. [ABSTRACT FROM AUTHOR]

Arsenic and other heavy metal contaminants in water are a significant global health threat. In this study, low-cost, sulfur-free, sustainable, water-insoluble materials with heavy metal remediation properties were produced from renewable resources such as starch, xylan, citric acid, and chitosan. Synthesized starch citrate-chitosan (SCC) foam and xylan citrate-chitosan (XCC) foam were flexible, porous, and elastic. The foams' arsenic uptake in water was significantly greater than five different commercial metal remediating agents. The mercury and lead uptakes with the synthesized foams were similar to the performance of a commercial sulfur-based product, SorbaTech 450 (ST450). However, the cadmium and selenium uptakes were comparatively lower. The complexation of arsenic with oxygen and nitrogen of the SCC foam was shown with time-of-flight secondary ion mass spectrometry (TOF-SIMS). The XCC foam was also shown to adsorb potassium iodide (KI) at a similar rate to sodium chloride. This may be used to remediate water contaminated with radioactive materials, such as iodine 131. [ABSTRACT FROM AUTHOR]

Water removal during paper manufacturing is of primary importance to production rate and cost efficiency for the pulp and paper industry. It is crucial to develop methods to reduce energy consumption by increasing the percent solids in the paper web entering the dryers from the presses. This research aimed to develop a fundamental understanding of the effect of bio-chemo-mechanical pretreatments on a bleached softwood fiber matrix and evaluate the impact on the percent solids of the paper web after pressing. Experiments included enzymatic, refining, and cationic polymer pretreatments on the bleached softwood pulps, followed by laboratory papermaking and determining the equilibrium moisture content (EMC) after pressing and the pulp and paper properties. The combined effect of mild refining, controlled enzymatic pretreatments, and cationic strength aids proved to enhance the water removal during wet pressing (up to 35 % reduction) and increase paper strength (up to 60 % increase). The results of increased solids after pressing were used to calculate the potential reduction in drying energy during paper manufacturing. Energy savings of around 10 % for paper drying could be achieved through fiber matrix modification by bio-chemo-mechanical pretreatment. Enzymatic pretreatments have previously been conventionally applied before refining as an energy-saving method. However, this research shows that synergistic actions of enzymes added after refining modify the fibers and create the optimal conditions for enhancement in drainage, press dewatering, and paper properties. [Display omitted] • Enzyme-assisted fiber modifications improve press dewatering and paper strength. • Enzyme blends can enhance fiber cell wall flexibility and fibrillation. • Synergistically, enzymes increased ∼35% press dewatering and ∼60% tensile strength. • Enzymes, mild refining, and cationic biopolymers enhance paper process efficiency. • This research introduces alternative methods for decarbonizing the paper industry. [ABSTRACT FROM AUTHOR]

Producing environmentally benign and economically viable nanomaterials is critical for large-scale applications in energy and other industries. This study presents a modeling framework to identify environmentally greener and lower-cost pathways of large-scale nanomaterial production, which encompasses life cycle assessment, Green Chemistry principles, techno-economic analysis, and eco-efficiency analysis. The framework is demonstrated by case studies of cellulose nanomaterials produced in the U.S. For cellulose nanocrystals, the framework identifies pathways that simultaneously reduce the life-cycle global warming potential (GWP) from 17.7 to 2.6 kgCO2e per dry kg cellulose nanocrystals and the minimum selling price (MSP) from US$7540 to US$4587 per dry t cellulose nanocrystals. For cellulose nanofibrils, the strategies present trade-offs of reducing GWP from 7.8 to 0.1 kgCO2e per dry kg cellulose nanofibrils but increasing MSP slightly from US$2873 to US$2985 per dry t cellulose nanofibrils. Eco-efficiency analysis quantifies the magnitudes of co-benefits and trade-offs between the environmental and economic performance of different production strategies and supports decision making for sustainability-informed process optimization. [ABSTRACT FROM AUTHOR]

Microfibers and microplastics originating from wastewater treatment plant (WWTP) effluents are significant pollutants in freshwater sources and marine environments. This research investigated the biodegradation of cotton microfibers generated from bleached cotton jersey knit fabric and commercially available flushable wipes, polypropylene-based (PP) nonwoven wipes containing a cellulose component, and tissue paper. Biodegradation was tested in wastewater treatment plants (WWTP) solids, seawater, and lakewater according to the ISO 14852 and ASTM D6691 standard methods in an ECHO respirometer. Degradation experiments continued until a plateau in CO2 emissions was reached, and the final biodegradation extent was calculated relative to the theoretical CO2 produced based on elemental analysis. The results showed that the cotton and other cellulosic materials/components biodegrade to a great extent, as expected for all conditions, whereas the PP did not degrade. In general, for the cellulose polypropylene composite wipes, the cellulose biodegraded readily; the presence of the PP did not hinder the cellulose biodegradation. [ABSTRACT FROM AUTHOR]

The relationship between the types of pulp, the tissue making technologies, and shelf price of bath tissue was evaluated for the North American market. Twenty-four market tissue samples (representing approximately 80% of the current market offering) were sourced and analyzed along with their nationwide price information. Pulp composition, drying technologies, market share, sustainability advertising, and tissue properties were evaluated. Tissue properties, including softness, ball burst strength, water absorbency, density, tensile strength, and tensile modulus were measured. Among all the drying technologies, creped through-air dry (CTAD) and creped through-air dry belt (CTADB) seemed to improve tissue softness most. The UCTAD maximized tissue bulk by drying the tissue web solely using a through-air (TAD) cylinder. Tissue samples with freeness between 575 to 650 mL seemed to have their properties improved more significantly through advanced drying technologies. It was found that the retail prices of these bath tissues were directly related to softness, bulkiness, water absorbency, and basis weight. A mathematical model was conducted to predict the retail price of bath tissue (based on product performance and attributes). This paper also identified the effect of “sustainability” on the retail price. [ABSTRACT FROM AUTHOR]

With the increasing concern about plastic waste, numerous efforts have been made to find substitutes for existing non-biodegradable synthetic polymers. Bio-based and/or purported petroleum-based biodegradable polymers are considered probable plastic replacement candidates. However, the durability of non-biodegradable plastic is a key feature of plastics. Thus, a balance must be achieved between biodegradation and environmental material stability. The objective of this study is to determine the impact of crystallinity, molecular chemistry, and hydrophilicity on the rate of aquatic biodegradation of biobased plastic materials. In the present study, twelve bio-based/purported biodegradable materials were investigated under aerobic aquatic biodegradation conditions for 56 days by tracking oxygen consumption. Crystallinity, hydrophobicity, chemistry, and chemical structure were varied to understand potential means for controlling the rate of biodegradation. The biodegradation kinetics were analyzed and discussed, relating to the characteristics of polymers. Polyvinyl alcohol (PVA), Chitosan, Rayon, Polyhydroxy-butyrate-co-valerate (PHBV), PHBH, and Polybutylene succinate (PBS) showed the biodegradation extents over 70% at 56 days. Cellulose acetates (CAs) and Polylactic acid (PLA) showed biodegradation extent lower than 20%. The chemistry of the polymer backbone chain, substituent structure, and degree of substitution were the dominant factors affecting biodegradation. The crystallinity of the polyesters had a negative correlation with the initial biodegradation rate and the ultimate biodegradation of polyesters, and the hydrophobicity of the polymers delayed the initiation of biodegradation. The aerobic aquatic biodegradation results related to the polymer characteristics are useful for product designers and environmental scientists to understand the fate of these polymeric materials in the environment. • Aquatic aerobic biodegradation of twelve bio-based/biodegradable polymers performed. • Ultimate biodegradation, rate, and lag phase determined by kinetic modeling. • Chemistry of polymer backbone and substituent was a dominant factor. • Negative correlations between crystallinity and biodegradation rate. • Effects of hydrophilicity on biodegradation kinetics. [ABSTRACT FROM AUTHOR]

With an increased awareness of health and wellness, prebiotics have received a great amount of attention recently. In this study, autohydrolyzate from hot water treatment of Miscanthus lignocellulosic biomass was evaluated for its prebiotic effect by fermentation of Lactobacillus brevis strain. The cell growth on raw autohydrolyzate-supplemented media was comparable to the sample grown on glucose until an incubation time of 24 h then gradually declined. Autohydrolyzate contains various inhibitors (25.9% of total dissolved solids) and it was determined that dissolved lignin had a significant inhibitory effect to bacterial growth. When the autohydrolyzate was purified using a hydrophobic resin, purified autohydrolyzate exhibited high bacterial growth (cell density (OD 600) of 4.8) and high acid production (7.7 and 3.1 g/L of lactic and acetic acid, respectively), which was comparable with commercial xylooligosaccharides. In conclusion, mixed oligosaccharides in the autohydrolyzate from Miscanthus have considerable potential as a prebiotic and are comparable with commercial xylooligosaccharides derived products. • Autohydrolyzate liquid was evaluated for prebiotic potential. • Mixed oligosaccharides in autohydrolyzate exhibited prebiotic potential. • Dissolved lignin in autohydrolyzate inhibited the bacterial growth. • Purified autohydrolyzate showed a great fermentability similar to commercial XOS. [ABSTRACT FROM AUTHOR]

Highlights • Previous research has not quantified the extent of travel required for participation in organized sport. • Participants spent an average of 106 min/week in car transport accounting for 28% of the participant's average driving time per week. • The environmental impact of this youth sport program annually is about 400 tonnes of CO2eq. • Assigning children to practice at the closest facility to their homes could reduce emissions from this travel by 12% whereas upgrading vehicle gas mileage efficiency could reduce emissions by 40%. [ABSTRACT FROM AUTHOR]

The need to decarbonize and reduce the impact of human activities is opening the window for new bioproducts. The industry of bioplastics has grown exponentially in the past years, and its production is expected to triple by 2026. Different bioplastics are currently produced, but bio-polyethylene constitute an interesting opportunity since its fossil counterpart is one of the most used materials worldwide, and its precursor, ethylene, is one of the highest contributors to GHG emissions in the chemical industry. The true environmental impact of this bio-based plastic remains under controversial discussions due to a wide distribution of environmental indicators values found in the literature for this material. We aim to thoroughly evaluate the environmental impact of bio-polyethylene made from sugarcane across the different production stages through a life cycle analysis. Our goal is also to assess unintended consequences (consequential effects) of producing it. It was determined that land-use change represents the main aspect affecting the environmental sustainability of bio-polyethylene. From an attributional point of view, this bioplastic could present lower carbon footprints than fossil polyethylene if no deforestation occurs. From a consequential standpoint, indirect deforestation as a response to producing more bioplastic could negatively impact the environmental profile of this material. Policies restricting deforestation are required to ensure that bio-polyethylene can constitute an alternative to reduce the carbon footprint of products in both scenarios. We expect this work to provide a robust evaluation to understand the environmental impact of bio-polyethylene, which will help the industry understand the place of this bio-based plastic and increase the offering of more sustainable products. • This study reports environmental impacts related to sugarcane-based polyethylene. • Land-use change highly influences the global warming potential of bio-polyethylene. • Bio-polyethylene can help fight climate change if no deforestation occurs. • Policies protecting forests are required to ensure benefits of bio-polyethylene. [ABSTRACT FROM AUTHOR]

Interdisciplinary collaborations between different academic disciplines can create knowledge and solutions to challenges that are beyond the scope of what a single discipline can achieve. However, little is known about how interdisciplinary teams of faculty and graduate students function as a whole and the processes that guide them as they work on collaborative tasks. Using Activity Theory, this qualitative study analyzed team meeting transcripts to examine interdisciplinary team interactions involving Science/Engineering and Science Education graduate students and faculty members as they co-developed laboratory activities for a grant-funded project. Several factors contributed to the team's success: shared goals (Object), environment (Community), and clear Division of Labor. Differences (contradictions) were found in the Tools, Rules, and Division of Labor; the PI and Science/Engineering graduate students tended to focus on the needed lab materials, and the Science Education members focused more on educational standards and teachers' ideas in the lab development (Tools). The PI and Science Education members set and enforced the team meeting agendas and deadlines (Rules). The Science/Engineering grad students focused on practical considerations to ensure the labs could successfully be implemented in a class setting (Rules) and were assigned the most tasks to complete (Division of Labor). The findings provide insight into the nature of interdisciplinary team dynamics between a Science/Engineering and Education grant team. The findings also suggest the importance of shared goals (Object), community development (Rules: Team Building), and the potential of capitalizing on different strengths and knowledge (contradictions) in an interdisciplinary team. [ABSTRACT FROM AUTHOR]

Under the controversial concern of using virgin fibers in hygiene tissue products, mostly Bleached Eucalyptus Kraft (BEK) and Northern Bleached Softwood Kraft (NBSK), consumers are responding by purchasing selflabeled sustainable products. As of today, there are no established sustainability reported results to inform consumers about the carbon footprint of hygiene tissue. To fill this gap, this study used Life Cycle Assessment to evaluate the environmental impacts across the supply chain (cradle to gate) to produce Premium and Ultra grades of bath tissue, including the production of feedstock, pulp production, and tissue production stages, with focus on Global Warming Potential (GWP). The results showed that one air-dried metric ton (ADmt) of BEK pulp had an associated GWP of 388 kgCO2eq, whereas one ADmt of NBSK pulp presented values ranging between 448 and 596 kgCO2eq, depending on the emissions allocation methodology used. It was estimated that the GWP of one finished metric ton of tissue weighted average could range from 1,392 to 3,075 kgCO2eq depending on mill location, electricity source, and machine technology. These results provide an understanding of the factors affecting the environmental impact of hygiene tissue products, which could guide manufacturers and consumers on decisions that impact their carbon footprint. [ABSTRACT FROM AUTHOR]

This article describes a laboratory exercise for the flotation de-inking of wastepaper. The exercise consists of disintegrating printed wastepaper in a blender and then removing the ink or toner contaminants by pumping air bubbles through the suspension using an aquarium pump or other source of air bubbles. Foam is taken off the top of the container that is rich in ink while the cleaned fiber remains in the container. After the experiment the accept and reject samples are analyzed for ink concentration and for fiber content.

Until recently, food packaging has been used as a barrier to unfavorable environmental and microbial conditions, but new technologies are arising aimed at upgrading the protective nature of these materials. Cases of bacterial and viral transmission through food and surfaces have shown the vulnerabilities of the food packaging distribution systems over the years, creating awareness about new methods to prevent the proliferation of pathogens. This has been highlighted by safety concerns due to the COVID‐19 pandemic. This work reviews the state‐of‐the‐art biobased technologies tailored for antiviral applications on surfaces, focusing on packaging materials. A survey and selection tool of essential oils (EOs) and nanoparticles that have been proven effective in reducing the proliferation or transmission of viruses through surfaces is presented. Additionally, the use of essential oil formulations or nanoparticle‐functionalized biobased materials that can be deployed to prevent virus transmission through food produce and surfaces is reviewed, including environmental and safety concerns around the use of metal nanoparticles and EOs in packaging materials. Finally, an assessment of the available technologies, challenges, opportunities and the potential role of biobased antiviral surfaces in future viral outbreaks is presented. [ABSTRACT FROM AUTHOR]