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At least 307 records · Page 17

Comparison of the Chemical Composition of Liquids from the Pyrolysis and Hydrothermal Liquefaction of Lignocellulosic Materials

Major differences in thermal stability and hydrotreatment behavior of HTL and pyrolysis oils have been reported in the literature. However, little is known about the variations in the chemical composition of these oils that could explain such differences. Two commercial wood pyrolysis oils (Pyrovac and BTG), and their water-soluble (WS) and water-insoluble fractions (WIS) were analyzed and compared with the aqueous (WS WD-57 ) and oily (WIS WS-57 ) fractions obtained from hydrothermal liquefaction (HTL) of Douglas-fir. The samples were characterized by GC/MS, Karl Fischer titration, carbonyl content, total acid number, elemental composition, calorific value, proximate analysis, Fourier Transform Infrared Spectroscopy (FTIR), Folin-Ciocalteu (FC), and UV fluorescence. All the fractions were also analyzed by Fourier Transform Ion Cyclotron Resonance Mass Spectroscopy (FT-ICR-MS) and by Electrospray Ionization (EI). The most prevalent class of compounds in the water insoluble phases were phenols derived from lignin. Water-soluble phases contain mostly the oxygenated compounds derived from cellulose and hemicellulose and were richer in carbonyl functional groups. The water content of the resulting aqueous phases were between: 65 (WS BTG ) and 96 (WS Pyrovac ) wt. %. The bio-oil from BTG has higher water content and lower HHV, compared to Pyrovac oil. The GC/MS results of BTG oil show the presence of a more prominent acetic acid peak and higher TAN number than the Pyrovac oil. The GC/MS of Pyrovac oil showed more obvious mono-phenol peaks. The quantification of this family by Folin-Ciocalteu method confirmed higher content of monophenolic compounds compared with the BTG oil. The lower thermal stability of pyrolysis oils compared with HTL biocrudes can be partially explained by the fact that pyrolysis oils (BTG and Pyrovac) contain carbohydrates while HTL biocrude (WIS WD-57 ) doesn’t. Thus, we decided to further investigate the chemical differences between the phenolic rich fractions insoluble in water and the holocellulose derived compounds soluble in water. Even after water extraction, the acid content of the water insoluble fraction from BTG (WISBTG) was higher than the acid content of the water insoluble fraction obtained by HTL (WISWSD-57). Likewise, the acid content of the aqueous phases derived from pyrolysis oils (WS Pyrovac , WS BTG ) was also higher than for the aqueous phase obtained by HTL (WSWSD-57). This result is in part due to the use of bases in the HTL process that neutralizes the acid formed in that process. Moreover, the starting feedstock may also influence the differences between the oils. Although, the UV-Fluorescence spectra, ICR-MS and the EI analyses showed some minor differences in the molecular weight and chemical make-up of the oligomers soluble and insoluble in water from pyrolysis and HTL; the differences observed were not large enough to justify the differences in behavior between these oils reported in the literature. Our results suggest that the differences observed between HTL biocrudes and pyrolysis oils are likely partially due to the presence of holocellulose derived products in the pyrolysis oils and higher acid contents.

09 BIOMASS FUELS↗

Feedstock/Pretreatment Screening for Bioconversion of Sugars and Lignin Residues

This project will conduct biomass deconstruction (pretreatment and enzymatic saccharification) on two representative biomass feedstocks and four different pretreatment processes, including three high temperature steam/chemical pretreatments and one low temperature chemical/mechanical pretreatment. A third biomass feedstock will undergo biomass deconstruction with three different pretreatment processes, including two high temperature chemical pretreatments and one low temperature chemical/mechanical pretreatment. Several pretreatment conditions will be performed in a screening study using NLR pilot-scale pretreatment equipment to generate a range of pretreated biomass substrates. A selected number of these substrates will be chosen for enzymatic saccharification evaluation, based on standard compositional analysis of the pretreated substrates as a primary indicator of pretreatment efficacy. Resulting enzymatic hydrolysis slurries will be analyzed to determine overall biomass sugar yields. Additional compositional analysis will be performed to determine oligomeric sugar composition and structure, to analyze structural characteristics of solids fractions on native, pretreated, and enzymatically saccharified biomass residues for one of the biomass feedstocks, corn stover. The enzymatically saccharified materials will undergo 2,3-butanediol fermentation in a shaker flask as bench scale. Using relevant process performance data collected in these various conversion steps, technoeconomic analysis activities will be performed to compare the economic potential of the various biomass feedstock and pretreatment processes and to identify key economic drivers and sustainability metrics.

09 BIOMASS FUELS↗

The Impact of Ethylenediaminetetraacetic Acid (EDTA) on the Sorption of Nd(III), Th{sup (IV)}, and U(VI) onto Dolomite in WIPP-Relevant Brines, GWB and ERDA-6 - 20356

Storage of legacy, transuranic waste at the Waste Isolation Pilot Plant (WIPP) requires accurate risk models for performance assessments. These models must predict the long-term fate and transport of contaminants in the WIPP and surrounding environment. Laboratory support is necessary for the development of an accurate model through better understanding of contaminant behavior in the WIPP. The WIPP is a deep geologic repository that is characterized by high ionic strength due to evaporite deposits in the Salado formation (porewaters up to 7.4 M). High concentrations of sodium chloride (NaCl), calcium chloride (CaCl{sub 2}), and magnesium chloride (MgCl{sub 2}) are particularly of concern due to their potential impact on solubility and ultimately transport of contaminants of concern. Additionally, ligands capable of forming strong complexes with metals are found in significant concentrations in the WIPP environment due to their disposal from waste processing and formation during degradation of repository components (e.g. cellulose degradation by calcium hydroxide in cement). Consequently, there is a need to investigate the fate and transport of contaminants in the WIPP environment with a focus on the effects of high ionic strength and strongly coordinating ligands. Contaminants of high concern include the actinides (U(VI), Pu(IV), and Am(III)). Laboratory support of the WIPP modeling efforts was provided by this research. A series of batch experiments were utilized to study the impact of ionic strength, contaminant concentration, and the presence of ethylenediaminetetraacetic acid (EDTA) on the sorption of Nd(III), Th(IV), and U(VI) onto dolomite, a carbonate mineral found within the Culebra formation. The Culebra formation is the most transmissive layer above the WIPP, making transport of contaminants the most likely route in previous risk assessments. Two brines specifically designed to imitate conditions within the WIPP environment were used in these experiments. The U.S. Energy Research and Development Administration Well 6 (ERDA-6, 95%) brine simulates a low Mg environment, while the generic weep brine (GWB, 95%) simulates the WIPP environment with a high Mg concentration. Mg is added to the repository in the form of MgO as an engineered barrier and is naturally present in some formations. It is expected to scavenge carbonate from solutions decreasing formation of the highly soluble and competitive uranium-carbonate complexes. EDTA is used during manipulations of nuclear materials due to its ability to form strong, stable complexes with the actinides and may be found in high concentrations (up to 0.08 mM) within the WIPP as waste canisters degrade. Further, it may provide additional avenues for unwanted transport of contaminants. Nd(III) and Th(IV) were used as stable analogues of Am(III) and Pu(IV), respectively, to represent the most common oxidation states of actinides in the WIPP environment in addition to U(VI). The potential for colloid formation was also investigated with low and high concentrations of contaminants (10 and 1000 μg/L) using three size-dependent particle separation steps. The results of this research provide a better understanding of potential behavior of actinides in the presence of EDTA and within WIPP-relevant brines. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Complex plant-derived organic aerosol as ice-nucleating particles – more than the sums of their parts?

Quantifying the impact of complex organic particles on the formation of ice crystals in clouds remains challenging, mostly due to the vast number of different sources ranging from sea spray to agricultural areas. In particular, there are many open questions regarding the ice nucleation properties of organic particles released from terrestrial sources such as decaying plant material. In this work, we present results from laboratory studies investigating the immersion freezing properties of individual organic compounds commonly found in plant tissue and complex organic aerosol particles from vegetated environments, without specifically investigating the contribution from biological particles, which may contribute to the overall ice nucleation efficiency observed at high temperatures. To characterize the ice nucleation properties of plant-related aerosol samples for temperatures between 242 and 267 K, we used the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) cloud chamber and the Ice Nucleation SpEctrometer of the Karlsruhe Institute of Technology (INSEKT), which is a droplet freezing assay. Individual plant components (polysaccharides, lignin, soy and rice protein) were mostly less ice active, or similarly ice active, compared to microcrystalline cellulose, which has been suggested by recent studies to be a proxy for quantifying the primary cloud ice formation caused by particles originating from vegetation. In contrast, samples from ambient sources with a complex organic matter composition (agricultural soils and leaf litter) were either similarly ice active or up to 2 orders of magnitude more ice active than cellulose. Of all individual organic plant components, only carnauba wax (i.e., lipids) showed a similarly high ice nucleation activity as that of the samples from vegetated environments over a temperature range between 245 and 252 K. Hence, based on our experimental results, we suggest considering cellulose as being representative for the average ice nucleation activity of plant-derived particles, whereas lignin and plant proteins tend to provide a lower limit. In contrast, complex biogenic particles may exhibit ice nucleation activities which are up to 2 orders of magnitude higher than observed for cellulose, making ambient plant-derived particles a potentially important contributor to the population of ice-nucleating particles in the troposphere, even though major uncertainties regarding their transport to cloud altitude remain.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Hierarchically Structured Vitrimer Biocomposites for Sustainable Manufacturing

Polymers containing dynamic covalent bonds (DCBs) exhibit thermoplastic-like flow above their topology freezing temperature (T v ) while maintaining thermoset-like properties below it, making them promising for sustainable manufacturing. However, their large-scale adoption remains limited due to challenges in accurately determining T v and achieving efficient fiber-matrix bonding in composite applications. Here, hierarchically structured epoxy-anhydride-based polyester vitrimer composites reinforced with cellulosic filaments is demonstrated, where hydroxyl groups on fiber surfaces participate directly in transesterification with the matrix. Further, this dynamic interfacial bonding delivers exceptional mechanical properties, including ≈70 MPa shear strength and >10% strain-to-failure, while enabling thermal malleability. Using a combination of nuclear magnetic resonance and nano-infrared spectroscopies, direct evidence is provided that chemical bond exchange begins well below the conventionally measured T v , supporting the hypothesis that rheologically determined T v reflects a combination of chemical exchange and frictional dynamics rather than a discrete transition. The composites demonstrate excellent processability through vacuum-assisted resin transfer molding and maintain >90% of their mechanical properties after multiple thermal reforming cycles. These findings advance both the fundamental understanding of vitrimeric transitions and the practical development of sustainable, high-performance composite materials.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Molecular-level design of alternative media for energy-saving pilot-scale fibrillation of nanocellulose

The outstanding mechanical properties, light weight, and biodegradability of cellulose nanofibrils (CNFs) make them promising components of renewable and sustainable next-generation reinforced composite biomaterials and bioplastics. Manufacturing CNFs at a pilot scale requires disc-refining fibrillation of dilute cellulose fibers in aqueous pulp suspensions to shear the fibers apart into their nanodimensional forms, which is, however, an energy-intensive process. Here, in this study, we used atomistic molecular dynamics (MD) simulation to examine media that might facilitate the reduction of interactions between cellulose fibers, thereby reducing energy consumption in fibrillation. The most suitable medium found by the simulations was an aqueous solution with 0.007:0.012 wt.% NaOH:urea, and indeed this was found in pilot-scale experiments to reduce the fibrillation energy by ~21% on average relative to water alone. The NaOH:urea-mediated CNFs have similar crystallinity, morphology, and mechanical strength to those formed in water. The NaOH and urea act synergistically on CNFs to aid fibrillation but at different length scales. NaOH deprotonates hydroxyl groups leading to mesoscale electrostatic repulsion between fibrils, whereas urea forms hydrogen bonds with protonated hydroxyl groups thus disrupting interfibril hydrogen bonds. This suggests a general mechanism in which an aqueous medium that contains a strong base and a small organic molecule acting as a hydrogen-bond acceptor and/or donor may be effectively employed in materials processes where dispersion of deprotonable polymers is required. The study demonstrates how atomic-detail computer simulation can be integrated with pilot-scale experiments in the rational design of materials processes for the circular bioeconomy.

36 MATERIALS SCIENCE↗

Synergistic enhancement of nanocellulose foam with dual in situ mineralization and crosslinking reaction

Cellulose nanocrystals (CNCs) foams have recently gained research interests because they are renewable, abundant, biodegradable and exhibit high surface area. However, the application of CNCs-based foams is still challenging, which is attributed to its lack of effective entanglements between the CNCs particles, thus lowering foam properties. In this study, a synergistic enhancement strategy was proposed, based on the in situ mineralization with hydroxyapatite (HAP) layer onto the CNCs surface, followed by a chemical crosslinking reaction. The physical and chemical structures of the composites were analyzed with SEM, STEM, XRD, FTIR, and TGA. By controlling the amount of coated HAP and the crosslinker, it is possible to manufacture a series of CNCs-based foams that are lightweight (50–75 mg/cm 3 ), highly porous (~90%) with high water absorption (>1300%) and outstanding mechanical strength properties (as high as 1.37 MPa). Moreover, our study further indicated that these CNCs/HAP materials could increase the proliferation of rat osteoblast cells. The method developed in this study presents a novel approach to design improved networked CNCs foam, which has the potential to be used in thermal-retardant material, wastewater treatment, tissue engineering, and personal care applications.

59 BASIC BIOLOGICAL SCIENCES↗

Growing Insulation in Alaska

Buildings produce 40% of all carbon emissions in the U.S. This includes the energy needed to heat, cool, and power the nation's buildings and the energy used to manufacture, ship, and assemble the construction materials. In extreme climates and remote regions, buildings use even more energy, as building materials must be produced and shipped farther to the site, increasing the greenhouse gas emissions embodied in the buildings. The U.S. National Renewable Energy Laboratory (NREL) is developing technologies that reduce how much energy our buildings use and how much carbon goes into them in the first place. NREL researchers teamed up with the Biomaterials Laboratory at the University of Alaska, U.S. Forest Service Forest Products Lab, and the VTT Centre of Finland on a three-year project to "grow" insulation using trees in Alaska - improving the efficiency of buildings by providing envelope retrofit options using local resources.

carbon negative building↗

Revisiting “Additional Carbon”: Tracking Atmosphere–Ecosystem Carbon Exchange to Establish Mitigation and Negative Emissions From Bio-Based Systems

Climate stabilization plans rely heavily on advanced bioenergy and bioproducts for substitution of fossil-based energy sources and materials, and increasingly, for negative emissions via the direct sequestration of biogenic carbon. Yet, there remain persistent, largely unresolved critiques of bioenergy assessment methodology, particularly in the areas of land use and biogenic carbon accounting. The concept of “additional carbon” calls for evaluating the climate performance of bio-based systems by whether feedstock production creates measurable new local agro-ecosystem uptake of carbon from the atmosphere. This concept is challenging to operationalize for first-generation biofuels, and has largely been advanced as a negative critique. However, carbon additionality is more straightforward to establish—and less critical to overall system mitigation performance—in advanced bioenergy systems. In this Perspective, I review the additional carbon critique, and why it is analytically challenging to address in first-generation biofuel systems based on conventional food crops with large existing markets. Next, I make a case that carbon additionality (1) is more readily achievable with cellulosic feedstocks, (2) is more directly observable for dedicated biomass crops, and (3) is not a strict requirement for achieving net mitigation in carbon-negative bio-based systems. I end by discussing how centering atmosphere–ecosystem carbon exchanges in bio-based system assessment could create new opportunities for enterprise-scale performance monitoring and verification, augmenting and diversifying the current reliance on model-based life-cycle assessment approaches.

54 ENVIRONMENTAL SCIENCES↗

Unveiling real‐time crystallization with nucleators and thickeners for zinc nitrate hexahydrate as a phase change material

Abstract The primary challenge of salt hydrates as phase change materials (PCMs) is their high degree of supercooling (∆ T Sup ). Past studies have attempted to alleviate ∆ T Sup by incorporating nucleators possessing similar lattice structure, without a thorough analysis of the nucleator/PCM interactions. This work presents a novel in‐operando study to visually observe the crystallization process of zinc nitrate hexahydrate (ZNH) in real‐time using suitable nucleators and a thickener. We have introduced a new dataset where zinc acetate dihydrate (ZnAc.2H) has been employed as an additive to ZNH for thermal energy storage (TES). According to our in‐operando study, ZnAc.2H underwent hydrolysis in molten ZNH to precipitate needle‐like ZnO particles, which acted as nucleators for the PCM. In the absence of a thickener, the crystal propagation of ZNH exhibited a preferential directional tendency, whereas incorporation of thickener made the phase change process uniform along all directions. Self‐hydrolysis of ZnAc.2H generated excess water which caused the undesirable effect of broadening the endothermic peak. The addition of carboxymethyl cellulose (CMC) thickener could restrict the activity of excess water and reduce the broadening of the endothermic peak. Differential scanning calorimetry (DSC) revealed that 5 wt% ZnAc.2H additive and 2 wt% CMC thickener added to ZNH can considerably improve the TES properties of ZNH PCM (∆ H Fusion 125.9 J·g −1 , ∆ T Sup 3.0°C, melting point [M.P.] 29.0°C). Our in‐operando studies can unveil real‐time phase change behaviors to better design PCM systems with desired characteristics.

Chakraborty, Anirban↗

Production of chitosan-based composite film reinforced with lignin-rich lignocellulose nanofibers from rice husk

Lignocellulosic nanofibers (LCNFs), implying lignin-containing cellulose fibers, maintain the properties of both lignin and cellulose, which are hydrophobic and hydrophilic, respectively. The presence of hydrophobic lignin in LCNFs is expected to be an economical and attractive option that can improve the thermal and mechanical properties of polymers. Thus, this study was conducted to produce lignin-rich LCNFs from sugar-rich waste obtained from rice husks after acidic pretreatment. The LCNFs were produced from the lignin-rich solid fractions obtained after pretreatment and enzymatic hydrolysis, which were then incorporated as an additive into a chitosan-based film. The variations in lignin content in the range of approximately 50.6%-66.8% in differently obtained LCNFs gave significantly different optical strengths and mechanical properties. These controllable processes may allow for customized film formation. Additionally, the glucose-rich liquid fractions obtained after pretreatment and enzymatic hydrolysis were used as a substrate for ethanol fermentation to achieve total utilization of rice husk biomass waste. In conclusion, the lignin-rich biomass fraction holds promise as a suitable material for chitosan-LCNF film and has the potential to increase the economic feasibility of the biomaterial industry.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Realistic application of short-lived fission product delayed neutron, gamma-ray analysis for simultaneous nondestructive trace quantification of U, Pu mixtures on cellulose swipes

Detection and characterization of fissile traces are of interest to the international nuclear nonproliferation community, including the International Atomic Energy Agency. Pre-inspection check samples are analyzed by neutron activation analysis at the High Flux Isotope Reactor operated by the Oak Ridge National Laboratory under the umbrella of the IAEA Network of Analytical Laboratories. The simultaneous quantification of U and Pu mixtures was accomplished using the combined delayed neutron (DN) delayed gamma-ray (DG) method to analyze cellulose swipes with actinide loading <1ng in a blind field trial. The total fissile quantity was measured by the DN counts and the relative proportions of U, Pu were determined by calibration of the 104 Tc / 141 Ba fission product count ratio using known mixtures. The DNDG method demonstrated high accuracy in flagging the presence of 239 Pu in uranium down to <100 pg mass loading. In conclusion, peak significance tests helped to control false positive Pu flagging and simultaneous quantification of U and Pu loading was accomplished on samples that passed the significance tests.

36 MATERIALS SCIENCE↗

Nanostructural Analysis of Enzymatic and Non-enzymatic Brown Rot Fungal Deconstruction of the Lignocellulose Cell Wall†

Brown rot (BR) decay mechanisms employ carbohydrate-active enzymes (CAZymes) as well as a unique non-enzymatic chelator-mediated Fenton (CMF) chemistry to deconstruct lignocellulosic materials. Unlike white rot fungi, BR fungi lack peroxidases for lignin deconstruction, and also lack some endoglucanase/cellobiohydrolase activities. The role that the CMF mechanism plays in “opening up” the wood cell wall structure in advance of enzymatic action, and any interaction between CMF constituents and the selective CAZyme suite that BRs possess, is still unclear. Expression patterns for CMF redox metabolites and lytic polysaccharide monooxygenase (LPMO–AA9 family) genes showed that some LPMO isozymes were upregulated with genes associated with CMF at early stages of brown rot by Gloeophyllum trabeum. In the structural studies, wood decayed by the G. trabeum was compared to CMF-treated wood, or CMF-treated wood followed by treatment with either the early-upregulated LPMO or a commercial CAZyme cocktail. Structural modification of decayed/treated wood was characterized using small angle neutron scattering. CMF treatment produced neutron scattering patterns similar to that of the BR decay indicating that both systems enlarged the nanopore structure of wood cell walls to permit enzyme access. Enzymatic deconstruction of cellulose or lignin in raw wood samples was not achieved via CAZyme cocktail or LPMO enzyme action alone. CMF treatment resulted in depolymerization of crystalline cellulose as attack progressed from the outer regions of individual crystallites. Multiple pulses of CMF treatment on raw wood showed a progressive increase in the spacing between the cellulose elementary fibrils (EFs), indicating the CMF eroded the matrix outside the EF bundles, leading to less tightly packed EFs. Peracetic acid delignification treatment enhanced subsequent CMF treatment effects, and allowed both enzyme systems to further increase spacing of the EFs. Moreover, even after a single pulse of CMF treatment, both enzymes were apparently able to penetrate the cell wall to further increase EF spacing. The data suggest the potential for the early-upregulated LPMO enzyme to work in association with CMF chemistry, suggesting that G. trabeum may have adopted mechanisms to integrate non-enzymatic and enzymatic chemistries together during early stages of brown rot decay.

59 BASIC BIOLOGICAL SCIENCES↗

Impact of Drying on Meso- and Nanoscale Structures of Citrus Fiber: A Study by SFG, ATR-IR, XRD, and DLS

Citrus fibers are a sidestream of the pectin extraction process from citrus peel. This sidestream can be converted into a functional ingredient through a shear-induced homogenization process. One technical challenge with this material is that dehydration and subsequent rehydration result in reduction of viscosity compared to the original product. In this study, various drying methods were compared with never-dried fibers to investigate the structural changes underlying the viscosity loss. Infrared and X-ray diffraction analyses confirmed no changes in chemical composition and crystalline structure of citrus fibers. Here, the dynamic light scattering and sum frequency generation analyses of citrus fiber suspension showed that the rehydration process could not fully disperse aggregated fibers, which appears to be the main cause for the viscosity loss.

09 BIOMASS FUELS↗

Ultraclean hybrid poplar lignins via liquid–liquid fractionation using ethanol–water solutions

As recovered from the byproducts stream of a cellulosic ethanol biorefinery, the renewable biopolymer lignin is too impure and polydisperse for many proposed applications. By mixing a hybrid poplar lignin with hot ethanol–water solutions, two liquid phases, one polymer-rich and one solvent-rich, are created. This liquid–liquid equilibrium phenomenon was used to generate solvated (and thus liquefied) lignin fractions of controlled molecular weight for which the impurities analyses for sugars and ash were near or below the limits of detection. Furthermore, those carbohydrates and metals impurities end up highly concentrated in a single process stream also having potential value.

09 BIOMASS FUELS↗

Cellulose synthase interactive1- and microtubule-dependent cell wall architecture is required for acid growth in Arabidopsis hypocotyls

Auxin-induced cell elongation relies in part on the acidification of the cell wall, a process known as acid growth that presumably triggers expansin-mediated wall loosening via altered interactions between cellulose microfibrils. Cellulose microfibrils are a major determinant for anisotropic growth and they provide the scaffold for cell wall assembly. Little is known about how acid growth depends on cell wall architecture. To explore the relationship between acid growth-mediated cell elongation and plant cell wall architecture, two mutants (jia1-1 and csi1-3) that are defective in cellulose biosynthesis and cellulose microfibril organization were analyzed. The study revealed that cell elongation is dependent on CSI1-mediated cell wall architecture but not on the overall crystalline cellulose content. We observed a correlation between loss of crossed-polylamellate walls and loss of auxin- and fusicoccin-induced cell growth in csi1-3. Furthermore, induced loss of crossed-polylamellate walls via disruption of cortical microtubules mimics the effect of csi1 in acid growth. We hypothesize that CSI1- and microtubule-dependent crossed-polylamellate walls are required for acid growth in Arabidopsis hypocotyls.

59 BASIC BIOLOGICAL SCIENCES↗

Herbaceous Feedstock 2020 (State of Technology Report)

The Energy Independence and Security Act (EISA) of 2007 required a minimum supply of 36 million gallons of renewable fuels per year by 2022. In order to achieve these goals, the Bioenergy Technologies Office (BETO) has set cost and technology targets for producing advanced and cellulosic biofuels. One of the targets is to validate feedstock supply infrastructures and systems with 90% overall operating effectiveness and field-to-reactor throat delivered cost less than $85.51/dry ton (2016). As stated by the 2017 Multi-Year Program Plan (DOE 2017), the research and development focus of the Feedstock Technologies (FT) platform is reducing the cost, improving the supply chain logistic efficiency, improving biomass quality, and increasing the supply volume. In addition, BETO oversees annual State of Technology (SOT) report that assesses current technologies that are relevant to BETO’s targets based on actual data and experimental results. Feedstocks are essential to achieving BETO goals because the cost, quality, and quantity of feedstock available and accessible at any given time limit the maximum volume of biofuels that can be produced. In accordance with the 2016 Multi-Year Program Plan (DOE 2016a), FT focuses on (1) reducing the delivered cost of sustainably produced biomass, (2) preserving and improving the physical and chemical quality parameters of harvested biomass to meet the individual needs of biorefineries and other biomass users, and (3) expanding the quantity of feedstock materials accessible to the bioenergy industry. This is done by identifying, developing, demonstrating, and validating efficient and economical integrated systems for harvest and collection, storage, handling, transport, and preprocessing raw biomass from a variety of crops to reliably deliver the required supplies of high-quality, affordable feedstocks to biorefineries as the industry expands. The elements of cost, quality, and quantity are key considerations when developing advanced feedstock supply concepts and systems (DOE 2016a).

09 BIOMASS FUELS↗

Tuning Fabrication Factors for Reduced Graphene Oxide Forward Osmosis Membranes

Forward osmosis (FO) may serve as a near-zero energy approach for wastewater management and selective chemical enrichment with an appropriate FO membrane. There is a need for novel FO membranes with better physical stability, chemical compatibility, and enhanced reverse flux selectivity. In this work, we have systematically studied a variety of factors for fabricating thermally reduced graphene oxide (RGO) FO filtration membranes and have demonstrated that with a comparable water flux, the RGO membranes have an exceptionally large reverse flux selectivity with 1.5 M sodium sulfate draw solution, about 7 times larger than that of cellulose triacetate membranes under the same testing condition. The interlayer spacing of the membranes can be fine-tuned by varying temperatures, so that the free interlayer spacing is less than 0.7 nm after exposure to water. The RGO-based membranes offer a few advantages with high reverse flux selectivity, mechanical robustness with strong adhesion to nylong support membranes without damage after FO tests and tape peel tests, and enhanced chromate and chlorine resistance. Finally, we have further demonstrated that in the FO processes, one can concentrate waste brine while simultaneously harvesting the osmotic energy as electricity, offering potential applications of forward osmosis-based osmotic batteries for powering electronic devices.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗