NARA Publications and Patents

Interested in learning about the research that NARA is doing? Check out NARA's list of affiliated publications and patents.

Web Location:

Related Topics:
Sustainable aviation biofuel from woody biomass
Value-added polymer and carbon products from lignin
Regional supply chain coalitions
Rural economic development
Bioenergy literacy


Comparing Life-Cycle Carbon and Energy Impacts for Biofuel, Wood Product, and Forest Management Alte
The different uses of wood result in a hierarchy of carbon and energy impacts that can be characterized by their ef?ciency in displacing carbon emissions and/or in displacing fossil energy imports. Producing multiple coproducts with different uses that result in different values complicates carbon mitigation accounting. Background information is provided on existing life-cycle data and methods to evaluate prospective new processes and wood uses. Alternative management, processing, andcollection methods are evaluated for their different ef?ciencies in contributing to national objectives.

Requirement of the Type II Secretion System for Utilization of Cellulosic Substrates by Cellvibrio j
Cellulosic biofuels represent a powerful alternative to petroleum but are currently limited by the inefficiencies of the conversion process. While Gram-positive and fungal organisms have been widely explored as sources of cellulases and hemicellulases for biomass degradation, Gram-negative organisms have received less experimental attention. This article investigated the ability of Cellvibrio japonicus, a recently sequenced Gram-negative cellulolytic bacterium, to degrade bioenergy-related feedstocks.

Advanced biofuels: Future perspectives from an expert elicitation survey
This paper illustrates the main results of an expert elicitation survey on advanced (second and third generation) biofuel technologies. The survey focuses on eliciting probabilistic information on the future costs of advanced biofuels and on the potential role of Research, Development and Demonstration (RD&D) efforts in reducing these costs and in supporting the deployment of biofuels in Organisation for Economic Co-operation and Development (OECD) and non-OECD countries.

High titer ethanol production from SPORL-pretreated lodgepole pine by simultaneous enzymatic sacchar
In this article, Lodgepole wood chips were pretreated by sulfite pretreatment to overcome recalcitrance of lignocelluloses (SPORL) at 25% solids loading and 180 °C for 20 min with sulfuric acid and sodium bisulfite charges of 2.2 and 8 wt/wt% on an oven-dry wood basis, respectively

Isolation and characterization of herbaceous lignins for applications in biomaterials
The imminent industrial production of cellulosic ethanol from annual plants will generate massive amounts of herbaceous lignins that will have to be valorized. However, the chemical and physical properties of herbaceous lignins are much less known than those of wood lignins. In the present study, organosolv lignins were extracted from wheat, triticale, corn, flax, and hemp residues using microwave irradiation under similar conditions.

Extraction of Ligning from a Coproduct of the Cellulosic Ethanol Industry and Its Thermal Characteri
In this article, lignin was extracted from the solid coproduct of a lignocellulosic ethanol production by a solid-liquid extraction method using N, N-dimethyl formamide.

Lignin as Co-product of Second Generation Bioethanol Production from Ligno-cellulosic Biomass
To improve the economic viability of the biofuel production from biomass, it is of increasing importance to add value to the lignin produced as a bio-residue. Moreover, to meet the goal to replace 30% of fossil fuel by biofuels by 2030, a huge amount of lignin will soon be produced. The first major step involved to add value to the unconverted lignin is its separation from other biomass constituents to give high purity lignin. In this current work, extraction of lignin from a bio-residue (containing ca. 40% lignin) from second generation bioethanol production is presented.

Lignin-Derived Carbon Fiber as a Co-Product of Refining Cellulosic Biomass
Lignin by-products from biorefineries has the potential to provide a low-cost alternative to petroleum-based precursors to manufacture carbon fiber, which can be combined with a binding matrix to produce a structural material with much greater specific strength and specific stiffness than conventional materials such as steel and aluminum. Compared to producing ethanol alone, the addition of lignin-derived carbon fiber could increase biorefinery gross revenue by 30% to 300%.

Policies for second generation biofuels: Current status and future challenges
First generation biofuels continue to be substantially subsidized, and this has contributed to the increasing use of such fuel. However, recent studies claim that the future of biofuels lies in second generation biofuels, in particular biochemical ethanol made from cellulose. This report reviews the current status of second generation biofuels.

An overview of biofuels from energy crops: current state and future prospects
Energy crops constitute significant potential for meeting the future energy need worldwide. In addition, agricultural lands offer an alternative to the agriculture which is referred to as energy farming. The studies on energy crops in biofuel production show that they are quite an economical and environmentally beneficial way of sustainable energy production. This study aims to present a comprehensive review on the production of biofuels from lignocellulosic agricultural products and promising energy crops.

Liquid biofuels in China: Current status, government policies, and future opportunities and challeng
China, like many other countries, is promoting the development of liquid biofuel, including bioethanol and biodiesel. The Chinese government has set biofuel development targets for the coming decade and sanctioned a series of supportive policies. This paper provides a comprehensive overview of current liquid biofuel development in China, related government policies, and the potential opportunities and challenges for its future expansion.

Biofuel and petroleum-based fuel supply chain research: A literature review
This paper provides a literature review of research on the biofuel SC. It classifies prior research according to decision time frame (i.e., strategic, tactical, operational, and integrated) as well as level in the supply chain (i.e., upstream, midstream, and downstream). In addition, it reviews related research on agri-products, which have some commonalities relative to harvesting and perishability; petroleum-based fuels, which have some commonalities related to distribution (some biofuels can be mixed with gasoline but others cannot); and generic supply chains, which provide some applicable modeling structures.

Biomass Densification workshop summary report "Transforming biomass to feedstocks"
This workshop overview describes the possible ways to make forest biomass into usable cellulosic feedstocks.

Woody Biomass Desk Guide and Toolkit
This Woody Biomass Desk Guide and Toolkit provides an overview of woody biomass production and utilization in the U.S., tips of how to provide effective outreach for your clientele, and educational handouts to share with your audiences. The purpose of this guide is to equip natural resource professionals and outreach specialists with the information and tools needed to increase awareness of the use of woody biomass for energy in the U.S.

Woody Biomass desk guide & toolkit
This Woody Biomass Desk Guide and Toolkit provides an overview of woody biomass production and utilization in the U.S., tips of how to provide effective outreach for your clientele, and educational handouts to share with your audiences.

Use of Polycarboxylic acid derived from partially depolymerized lignin as a curing agent for epoxy a
In this study, Kraft lignin was partially depolymerized through base catalyzed depolymerization (BCD) in supercritical methanol to increase its solubility in organic solvents. The resulting partially depolymerized lignin (PDL) was then converted to lignin-based polycarboxylic acid (LPCA) by reacting with succinic anhydride.

Enzymatic Saccharification of Lignocelluloses Should be Conducted at Elevated pH 5.2–6.2
This study revealed that cellulose enzymatic saccharification response curves of lignocellulosic substrates were very different from those of pure cellulosic substrates in terms of optimal pH and pH operating window.

Fractionation of Forest Residues of Douglas-fir for Fermentable Sugar Production by SPORL Pretreatme
Douglas-fir (Pseudotsuga menziesii) forest residues were physically fractionated through sieving. The bark and wood were separated for large-sized fractions (>12.7 mm), and their contents were determined. The chemical compositions of the large fractions were calculated based on the contents and chemical compositions of the bark and wood. The chemical compositions of the fine fractions were analyzed. The bark and wood content in the fine fractions was calculated based on the measured glucan and lignin contents in each fraction. It was found that fractionation by particle/chip size can effectively fractionate bark and wood and therefore lignin from carbohydrates. The large-sized fractions (>12.7 mm) represent approximately 60 % of the collected forest residues but only contain approximately 37 % of the total bark and 35 % of the total ash, or a selectivity over bark and ash of 1.6 and 1.7, respectively. Pretreatment of forest residues by sulfite pretreatment to overcome recalcitrance of lignocelluloses and subsequent enzymatic hydrolysis revealed the presence of 14.3 % bark can reduce substrate enzymatic digestibilities (SED) 16 % compared with that from a bark-free sample. The SED of a bark is 41 % compared with 73 % for wood when pretreated under the same conditions. Separating pretreatment of bark from wood is beneficial for producing a more enzymatically digestible substrate. The results from the present study could have significant implications for harvesting forest residues.

Comparison of Dilute Acid and Sulfite Pretreatment for Enzymatic Saccharification of Earlywood and L
This study applied dilute acid (DA) and sulfite pretreatment to overcome the recalcitrance of lignocelluloses (SPORL) to deconstruct earlywood and latewood cell walls of Douglas fir for fermentable sugars production through subsequent enzymatic hydrolysis.

Substrate-Related Factors Affecting Enzymatic Saccharification of Lignocelluloses: Our Recent Unders
Enzymatic saccharification of cellulose is a key step in conversion of plant biomass to advanced biofuel and chemicals. Many substrate-related factors affect saccharification. Rather than examining the role of each individual factor on overall saccharification efficiency, this study examined how each factor affects the three basic processes of a heterogeneous biochemistry reaction: (1) substrate accessibility to cellulose -- theroles of component removal and size reduction by pretreatments, (2) substrate and cellulase reactivity limited by component inhibition, and (3) reaction conditions-substrate-specific optimization

Robust enzymatic saccharification of a Douglas-fir forest harvest residue by SPORL5
Forest harvest residues can be a cost-effective feedstock for a biore?nery, but the high lignin content of forest residues is a major barrier for enzymatic sugar production. This research article looks at how cellulose digestability and delignification are affected by pretreatment.

Alkaline hydrogen peroxide pretreatment of softwood: Hemicellulose degradation pathways
This study investigated softwood hemicelluloses degradation pathways during alkaline hydrogen peroxide (AHP) pretreatment of Douglas fir. It was found that glucomannan is much more susceptible to alkaline pretreatment than xylan.

pH-Induced Lignin Surface Modification to Reduce Nonspecific Cellulase Binding and Enhance Enzymatic
This article describes research on the mechanism of the significant enhancement in the enzymatic saccharification of lignocelluloses at an elevated pH of 5.5-6.0.

An Evaluation of Alternative Measurement Techniques for Estimating the Volume of Logging Residues
Logging residue is currently one of the largest underutilized residues potentially available for biomass energy production. The cost of collection, processing, and transporting this material is high in proportion to its value; the result is that there are potentially small profit margins. Therefore, managers must develop and execute efficient supply chains. The first step in developing an efficient supply chain requires a reliable estimate of pile volume because this will allow the manager to deploy the appropriately sized transportation and processing operations. This article compares two methods used to measure logging residue piles to terrestrial light detection and ranging (LiDAR)-generated estimates; one uses a geometric base and the other uses a laser rangefinder.

Economic Impact of Truck–Machine Interference in Forest Biomass Recovery Operations on Steep Terrain
In forest biomass recovery operations from harvest residues, processing equipment can work most productively if they can work without interference or waiting on trucks. A deterministic simulation model was developed to estimate the economic effect of truck–grinder interference in forest biomass processing and transport operations on steep terrain.

Arogenate Dehydratase Isoenzymes Profoundly and Differentially Modulate Carbon Flux into Lignins
How carbon flux differentially occurs in vascular plants following photosynthesis for protein formation, phenylpropanoid metabolism (i.e. lignins), and other metabolic processes is not well understood. Our previous discovery/deduction that a six-membered arogenate dehydratase (ADT1–6) gene family encodes the final step in Phe biosynthesis in Arabidopsis thaliana raised the fascinating question whether individual ADT isoenzymes (or combinations thereof) differentially modulated carbon flux to lignins, proteins, etc. If so, unlike all other lignin pathway manipulations that target cell wall/cytosolic processes, this would be the first example of a plastid (chloroplast)-associated metabolic process influencing cell wall formation. Homozygous T-DNA insertion lines were thus obtained for five of the six ADTs and used to generate double, triple, and quadruple knockouts (KOs) in different combinations. The various mutants so obtained gave phenotypes with profound but distinct reductions in lignin amounts, encompassing a range spanning from near wild type levels to reductions of up to 68%

Revisiting renewable portfolio standard effectiveness: policy design and outcome speci?cation matter
This study investigates patterns of renewable portfolio standards policy design and analyzes the effects on policy outcomes measured at the level of utility compliance. The quantitative analysis also takes into account the complexity of renewable portfolio standards design, by making use of a state-by-state database of RPS design characteristics developed for this study.

An Innovative Approach to Identify Regional Bioenergy Infrastructure Sites
This paper describes the development of multiple empirical quantitative measures for core dimensions of community assets. This knowledge can then be used to develop a more complete understanding of how community social capital and creative capacity might play an important role in building community support for or addressing community opposition to regional bioenergy infrastructure projects.

An Innovative Approach to Identify Regional Bioenergy Infrastructure Sites
This presentation describes how NARA identifies suitable sites and communities that would support biorefineries.

Estimating Tree Biomass, Carbon, and Nitrogen in Two Vegetation Control Treatments in an 11-Year-Old
This research project sampled trees grown with and without competing vegetation control in an 11-year-old Douglas-fir plantation on a highly productive site in southwestern Washington to create diameter-based allometric equations for estimating individual-tree bole, branch, foliar, and total aboveground biomass

Upload/ Download: Empowering students through technology-enabled problem-based learning
This article focuses on the usage of modern media in the classroom to teach bioenergy literacy.

Pricing Forest Biomass for Power Generation
Pricing strategies for forest biomass for power generation vary throughout North America, and are still evolving in the Pacific Northwest. The energy value of forest residues depends heavily on moisture content as does the cost of transportation. Payment for forest biomass that recognizes energy value poses challenges for buyers and suppliers. Maximizing the energy value per load increases the competitiveness of forest biomass suppliers.

Northwest Advanced Renewables Alliance (NARA): A Supply Chain to Aviation Biofuels and Environmental
This one-pager descibes NARA's aim and how NARA is working with communities for domestic fuel production

A Multi-Level Analysis Approach to Measuring Variations in Biomass Recalcitrance of Douglas Fir Tree
In this study, a method was developed to determine biomass recalcitrance at three levels: chemical composition, pretreatment yield, and sugar release from the enzymatic hydrolysis. This method is designed to investigate the biomass recalcitrance variations among different families of Douglas-fir, which is the most abundant and promising softwood species for biofuel production in the Pacific Northwest region. Wood samples from 150 plantation-grown trees were collected and analyzed to test the method and the applicability of the parameters screened.

Diffusion of Molecules and Macromolecules in Thylakoid Membranes
The survival and fitness of photosynthetic organisms is critically dependent on the flexible response of the photosynthetic machinery, harbored in thylakoid membranes, to environmental changes. A central element of this flexibility is the lateral diffusion of membrane components along the membrane plane. As demonstrated, almost all functions of photosynthetic energy conversion are dependent on lateral diffusion. The mobility of both small molecules (plastoquinone, xanthophylls) as well as large protein supercomplexes is very sensitive to changes in structural boundary conditions. Knowledge about the design principles that govern the mobility of photosynthetic membrane components is essential to understand the dynamic response of the photosynthetic machinery. This review summarizes our knowledge about the factors that control diffusion in thylakoid membranes and bridges structural membrane alterations to changes in mobility and function.

Artifact-Based Energy Literacy Assessment Utilizing Rubric Scoring
This research focuses on the development of an energy literacy rubric for scoring project-type deliverables, an approach that has not been taken with respect to energy literacy assessment. The goal is to examine if a rubric-based rating approach is applicable for judging energy literacy based on competition or course deliverables or artifacts. The rubric was developed using a methodology involving related rubric review and adaptation, and an expert review. To examine if the rubric approach may be applicable, the rubric was applied to the Imagine Tomorrow competition, a high school energy competition, and trends in the results were examined to support rubric effectiveness.

Selective Conversion of Biorefinery Lignin to Dicarboxylic Acids
The emerging biomass-to-biofuel conversion industry has created an urgent need for identifying new applications for biorefinery lignin. This paper demonstrates a new route to producing dicarboxylic acids from biorefinery lignin through chalcopyrite-catalyzed oxidation in a highly selective process. Up to 95?% selectivity towards stable dicarboxylic acids was obtained for several types of biorefinery lignin and model compounds under mild, environmentally friendly reaction conditions. The findings from this study paved a new avenue to biorefinery lignin conversions and applications.

Integrating Biogeophysical and Social Assets into Biomass-to-Biofuel Supply Chain Siting Decisions
Second-generation biorefineries that utilize lignocellulosic feedstocks for producing biofuels are emerging with the aim of contributing to society's need for a sustainable liquid fuel source. Decision tools are needed to aid in siting facilities based not only on biogeophysical (BGP) assets such as feedstock and infrastructure requirements but also on the social assets of communities supporting these facilities. The research presented here provides a framework for a quantitative approach for biorefinery siting and decision-making. A Social Asset Factor (SAF) score is created to assess a community's capacity for collective action and adaptation to change. This research validates the social asset measures used for facility siting at the county level through retrospective prediction analysis.

Fast Pyrolysis of Wood for Biofuels: Spatiotemporally Resolved Diffuse Reflectance In situ Spectrosc
Fast pyrolysis of woody biomass is a promising process capable of producing renewable transportation fuels to replace gasoline, diesel, and chemicals currently derived from nonrenewable sources. However, biomass pyrolysis is not yet economically viable and requires significant optimization before it can contribute to the existing oil-based transportation system. One method of optimization uses detailed kinetic models for predicting the products of biomass fast pyrolysis, which serve as the basis for the design of pyrolysis reactors capable of producing the highest value products. The goal of this work is to improve upon current pyrolysis models, usually derived from experiments with low heating rates and temperatures, by developing models that account for both transport and pyrolysis decomposition kinetics at high heating rates and high temperatures (>400?°C).

Use of Eugenol and Rosin as Feedstocks for Biobased Epoxy Resins and Study of Curing and Performance
In this study, an epoxy based on eugenol and an anhydride curing agent based on rosin were prepared. Curing of the eugenol epoxy with a commercial anhydride curing agent and with the rosin-derived anhydride curing agent was studied. For comparison, a commercial bisphenol A type epoxy, DER353, was also selected in the curing study. The syntheses of the eugenol epoxy and rosin anhydride were investigated and the chemical structures of the products and intermediates were characterized using 1H NMR and Fourier transform infrared spectroscopies. Non-isothermal curing of the eugenol epoxy with hexahydrophthalic anhydride and the rosin-derived maleopimaric acid was studied using differential scanning calorimetry. Thermomechanical properties and thermal stability of the cured epoxy resins were evaluated using dynamic mechanical analysis and thermogravimetric analysis, respectively. Addition of 2-ethyl-4-methylimidazole as catalyst greatly decreased the curing temperature and promoted the completion of cure reactions. The results suggest that the eugenol epoxy and the bisphenol A type epoxy have similar reactivity, dynamic mechanical properties and thermal stability.

The Value of a Tree: Comparing Carbon Sequestration to Forest Products
What is the value of a tree? Of a forest? How do we manage our forests to ensure that we create healthy habitats, balance our impact on the environment and create the products we need to fuel our energy rich lives? This lesson is designed to encourage a healthy debate about how to value the trees around us and introduce various aspects to determining a tree's value.

Partial Depolymerization of Enzymolysis Lignin via Mild Hydrogenolysis Over Raney Nickel
In this work, partial depolymerization of enzymolysis lignin collected from a woody biomass-to-ethanol process was studied via mild hydrogenolysis under the catalysis of Raney Ni. The depolymerized lignin products were low molecular weight oligomers with increased hydroxyl values. The solvent selected, use of base and various reaction parameters were all found to influence yield of depolymerization, the molecular weight and hydroxyl value of the hydrogenated product. The depolymerized lignins displayed greatly enhanced solubility in organic solvents, and therefore would have great potential to be used as feedstock for many valuable thermosetting polymer applications.

Ground-Based Thinning on Steep Slopes in Western Oregon: Soil Exposure and Strength Effects
Soil effects in vehicle trails were assessed on two cut-to-length thinning units that were very steep, averaging 65 and 58%, respectively. The thinnings in a young Douglas-fir forest included a harvester-cut, cable-yarded unit (harvester-cable) and a harvester-cut, forwarder-yarded (harvester-forwarder) unit. Steep vehicle trails covered 10% of the thinned area of harvester-forwarder and 15% of harvester-cable, and exposed soil occurred in 3% of the sample points in trail transects in harvester-cable and 7% of those in harvester-forwarder. After one harvester pass on harvester-cable, soil strength in vehicle tracks near the surface (25–200 mm) was 19–34% higher than that in undisturbed soil and 33–40% higher after a second vehicle (forwarder) pass on harvester-forwarder; the latter unit also showed 21% higher strength in the 225–300 mm layer after the second pass. Slash accumulations on the trails appeared to reduce vehicle effects on soil strength near the surface (25–100 mm) on one of the units (harvester-forwarder), whereas no clear relationship was seen with variations in trail slope. Dry season operations, limited passes, slash in trails, and low ground-pressure vehicles with enhanced stability and traction features helped control soil disturbance and probably kept it within agency guidelines.

Using Low Temperature to Balance Enzymatic Saccharification and Furan Formation during SPORL Pretrea
Comparing analytical results for Sulfite Pretreatment to Overcome the Recalcitrance of Lignocelluloses (SPORL) of Douglas-fir (Pseudotsuga menziesii) at two different temperatures shows that the apparent activation energy of sugar degradation is higher than that of hemicellulose hydrolysis, approximately 161 kJ/mole versus 100 kJ/mole. Thus, one can balance the production of degradation products against hemicellulose hydrolysis and therefore the enzymatic saccharification efficiency of the resultant substrate by changing pretreatment temperature and duration. Specifically, pretreatment at 165 °C for 75 min significantly reduced furan formation compared with the pretreatment at 180 °C for 30 min while maintaining the same pretreatment severity and therefore the same substrate enzymatic digestibility (SED). Obtaining high SED with Douglas-fir is also limited by lignin content. Fortunately, the bisulfite in SPORL provides delignification activity. By combining kinetic models for hemicelluloses hydrolysis, sugar degradation, and delignification, the performance of pretreatment can be optimized with respect to temperature, duration, acid, and bisulfite loading. The kinetic approach taken in this study is effective to design viable low temperature pretreatment processes for effective bioconversion of lignocelluloses.

A Multi-Level Analysis Approach to Measuring Variations in Biomass Recalcitrance of Douglas Fir Tree
Biomass recalcitrance is a major bottleneck in the development of an economically viable process to convert woody biomass into fuels and other valuable chemicals. Selective breeding of trees with low recalcitrance toward biofuel conversion could help significantly reduce the cost of biofuel production, but such efforts would require a greater understanding of the nature of variations in the biomass recalcitrance of softwood species. The complexity of biomass recalcitrance, however, hinders research into determining the viability of breeding programs aimed to improve the recalcitrance of softwoods. In this study, a method was developed to determine biomass recalcitrance at three levels: chemical composition, pretreatment yield, and sugar release from the enzymatic hydrolysis.

Lignosulfonate to Enhance Enzymatic Saccharification of Lignocelluloses: The Role of Molecular Weigh
This study conducted an investigation of the effect of lignosulfonate (LS) on enzymatic saccharification of lignocelluloses. Two commercial LSs and one laboratory sulfonated kraft lignin were applied to Whatman paper, dilute acid and SPORL (sulfite pretreatment to overcome recalcitrance of lignocelluloses) pretreated aspen, and kraft alkaline and SPORL pretreated lodgepole pine. All three lignin samples inhibited cellulose saccharification of Whatman paper, but enhanced the saccharification of the four lignocellulosic substrates. The level of enhancement was related to the molecular weight and degree of sulfonation of the lignin as well as the substrate lignin structure. When different molecular weight (MW) fractions of one commercial LS (SXP), generated from sulfite pulping of hardwood, were applied to the Whatman paper, the large MW fraction (SXP1) with the lowest degree of sulfonation inhibited cellulose saccharification while the intermediate (SXP2) and smallest (SXP3) MW fractions enhanced saccharification. All MW fractions enhanced saccharification of the four lignocellulosic substrates with maximal enhancement by the smallest MW fraction, SXP3. The enhancement was most significant for the kraft lodgepole pine substrate and least significant for the SPORL pretreated lodgepole pine using all three LS and SXP fractions. The results suggest that LS acts as a surfactant to enhance pure cellullose saccharification. When LS is applied to lignocelluloses, it acts as a surfactant to block bound lignin from binding cellulase nonproductively leading to enhanced saccharification.

Bioconversion of Beetle-Killed Lodgepole Pine Using SPORL: Process Scale-up Design, Lignin Co-Produc
Mountain pine beetle killed Lodgepole pine (Pinus contorta Douglas ex Loudon) wood chips were pretreated using an acidic sulfite solution of approximately pH = 2.0 at a liquor to wood ratio of 3 and sodium bisulfite loading of 8 wt % on wood. The combined hydrolysis factor (CHF), formulated from reaction kinetics, was used to design a scale-up pretreatment on 2000 g wood chips at a relatively low temperature of 165 °C that reduced furan formation and facilitated high solids saccharification and fermentation. The pretreated solids and liquor were disk milled together to result in a biomass whole slurry of 25% total solids. The whole biomass slurry was directly used to conduct simultaneous enzymatic saccharification and combined fermentation (SSCombF) using a commercial cellulase and Saccharomyces cerevisiae YRH400 without detoxification. A terminal ethanol titer of 47.1 g L-1 with a yield of 306 L (tonne wood)-1, or 72.0% theoretical, was achieved when SSCombF was conducted at an unwashed solids loading of 18%. The lignosulfonate (LS) from SPORL was highly sulfonated and showed better dispersibility than a high purity commercial softwood LS, and therefore has potential as a directly marketable coproduct.

Nitrogen Leaching Following Whole-Tree and Bole-Only Harvests on Two Contrasting Pacific Northwest S
Short-term pulses of increased N leaching typically follow the harvest of forest stands, but the magnitude of these pulses after conventional bole-only (BO) and whole-tree (WT) harvests often is difficult to predict. In this study, we measured N leaching until 6 and 8 years post-harvest on two western Washington Douglas-fir (Pseudotsuga menziesii var. menziesii) sites: a relatively low-productivity site with a gravelly loamy sand soil formed in glacial outwash and a high-productivity site with a silt loam soil derived primarily from basalt. We tested BO and WT harvest treatments and presence/absence of 5 years of competing vegetation control (VC). Trends in the magnitude and duration of post-harvest N-leaching pulses differed between sites. At the higher-productivity site, estimated N leaching between years 3 and 8 following harvest totaled 250 and 94 kg N ha-1 in BO and WT harvest treatments with VC, respectively. At the lower-productivity site, estimated N leaching totaled 32 and 17 kg N ha-1 between years 3 and 6 following harvest in BO and WT harvest treatments with VC, respectively. In both BO and WT treatments, annual N leaching did not fall below 2 kg N ha-1 (the rate measured in mature forest stands at both sites) until year 8 at the higher-productivity site and until year 6 at the lower-productivity site. Cumulative amounts of N leached among site/treatment combinations were small compared to the soil total-N pool and ranged from 0.5% to 2.5%. The N leaching patterns among treatments at these two sites suggest that differences in soil N content and C:N ratio, post-harvest vegetation regrowth, and harvest residues influenced the amount of N leached. The major source of leached N was most likely the soil (including forest floor) rather than harvest debris, based on site and treatment comparisons. Although the maximum post-harvest pulse of 250 kg N ha-1 was much higher than values reported in most comparable studies, this level of N leaching is unlikely to be reached under operational conditions, where VC is less intensive than in this study.

AL@: Combining the Strengths of Adventure Learning and Place Based Education
In the 21st century, students need to be able to communicate through a variety of mediums, be cretical consumers of vast amounts of written and visual data, and possess skills and dispositions for addressing complex global issues with local implications, such as climate change. As practitioners of residential place-based environmental education that seeks to foster scientific literacy and connect studentsn to place, we have traveled cautiously into the cyber-enabled landscape because of a deeply rooted feeling that technology can be a distration to students' deep observation in the field. That said we are exploring the idea that technology may also provide tools that can transform our ability to connect students to place. Imagine this scenario: a field teacher uses a picture to show students a concept diagram of the water cycle; the students' attention is on the image rather than on the place. Instead, what if cameras were used to observe water in the immediate environment, thus, cataloging water in as many phases as the students can find? Digital voice recorders could be employed to capture the hauting, ancient whale-like sounds of liquid water beneath the frozen lake; In addition, students collect and upload data about the quality or quantity of the water. This data could then be visualized within an observational database used by scientists to better understand water resources at a hyper-local scale, thereby contributing to better predictive models that inform watershed and fisheries management. In the first scenario, an age-old technology distracts from deep observation, but in the re-imagined scenario observation is enhanced and transformed.

Characteristics of Forest-Derived Woody Biomass Collected and Processed in Oregon
The purpose of this research is to illustrate the wide diversity of field-processed grindings and chips that are currently being produced to inform managers of the potential variability in existing biomass sources. The samples vary widely with respect to moisture content, particle size distribution, species mix, and ash content. The Researchers discuss the value of residue classification for downstream processing. The primary use of forest residues is currently for combustion, but stratification of forest residues provides opportunities to create value-added products, provide rural employment, and increase transportation efficiency.

Localizing Adventure Learning: Teachers and Students as Expedition Leaders and Members
Adventure Learning (AL) is an approach to education that aims to engage learners in hybrid learning experiences that bring content alive through meaningful connections to place and personal lives. In this paper, we present and discuss five small-scale AL projects enacted at Texas and Idaho that have informed our understanding of how the AL approach can be conceptualized and used within a variety of formal and informal learning contexts. Through the diverse and varied AL projects described in this paper, we have learned invaluable lessons that will inform future work and inspire possibilities for using AL in additional venues. -

Forest Road Access Decisions for Woods Chip Trailers Using Ant Colony Optimization and Breakeven Ana
Non-coventional products provide opportunities for the forest industry to increase conomic value from forests; however, these products may require transport by specialized vehicles. The existing forest transportation network was not necessarily designed to the road standards required for these specialized vehicles. Several road modifications can be made to give specialized vehicles access to the forest transportation network including filling the ditch, removing the superelevation, reversing the superelecation, or reconstructing the roadway. For each investment, there is an associated behicle that can traverse the road segment if the investment is made. For scheduling multiple biomass operations over a road network, we use the Ant Coloney heuristic to identify the combination of optimal vehicle choices and road modifications to effectively transport non-conventional products. These combinations related to a 27% reduction in total transportation costs. For isolated biomass operations, we use breakeven analyses to make the vehicle selection and road modification option. Decisions for isolated biomass operations depend on road modification cost, transport volume, and transport costs on forest and highway roads.

Predicting Risk of Long-Term Nitrogen Depletion under Whole-Tree Harvesting in the Coastal Pacific N
In many Forest plantation ecosystems, concerns exist regarding nutrient removal rates associated with sustained whole-tree harvesting. In the coastal North American Pacific Northwest, we predicted the depletion risk of nitrogen, the region's most growth-limiting nutrient, for 68 intensively managed Douglas-fir plantations varying widely in productivity. We projected stands to rotation age using the individual-tree growth model ORGANON and then calculated a stability ratio for each stand, defined as the ratio of nitrogen removed during harvest to total site nitrogen store.

Integrating Social Capital In Biojet Feedstock Facility Siting Decisions
Development of aviation biofuels (biojet) from second-generation feedstocks is gaining significant momentum from the market, production, and overall supply chain. Nowhere is this effort more significant than in the Northwest U.S. where alliances have been formed to assess the feasibility of making this goal a reality ( To date, much effort has focused on the conversion innovations necessary for producing biojet. However, for these scientific efforts to become truly transformational for society, technologies must be compatible with regional feedstock, environmental, infrastructure, and community assets. At the local community level, siting decisions must be compatible with the existing social and cultural assets. Those assets likely include a capacity for collective action and the ability to adapt to change. Thus, siting decisions that integrate social and cultural assets into a holistic analysis of regional infrastructure and natural/ human resources may optimize site selection in multistate regional projects.

Stochastic Simulation and Optimization of Mobile Chipping Economics in Processing and Transport of F
The researchers analyzed the economics of mobile chipping and transport of biomass from forest residues for energy purposes under uncertainty. A discrete-event simulation model was developed and utilized to quantify the impacts of controllable and environmental variables on productivity in order to determine the most cost effective transportation options under steep terrain conditions. Truck-chipper interactions were analyzed to show their effect on truck and chipper standing time. A costing model was developed to account for operating and standing time cost (for the chipper and trucks). The model used information from time studies of each activity in the productive cycle and spatial-temporal information obtained from geographic information system (GIS) devices, and tracking analysis of machine and truck movements. The model was validated in field operations, and proved to be accurate in providing the expected productivity. A cost distribution was elaborated to support operational decisions of forest managers, landowners and risk-averse contractors. Different scenarios were developed to illustrate the economic effects due to changes in road characteristics such as in-highway transport distance, in-forest internal road distance and pile to trailer chipper traveling distances.

RENO: A Computerized Solution Procedure and Decision Support System for Forest Biomass Recovery Oper
A computerized decision support systems, Residue Evaluation and Network Optimization (RENO) is presented to estimate the optimal mix of methods and equipment for conducting forest biomass recovery operations given a harvest residue assortment, roading and landing access and product deliverables. The model was development using the JAVA platform and is able to read spatial data (vector) and simulate the dynamics of the productive system. The problem to be solved is classified as a special case of the multi-commodities, multi-facilities problem. The computerized model uses spatials information fo the road network and residue pile locations in order to determine travel distances and calculate costs.

Related Sub-Topics

Regional supply chain coalitions
Regional supply chain coalitions

Value-added polymer and carbon products from lignin
Value-added polymer and carbon products from lignin

Sustainable aviation biofuel from woody biomass
Sustainable aviation biofuel from woody biomass

Rural economic development
Rural economic development

Bioenergy literacy
Bioenergy literacy