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At least 235 records · Page 13
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Ferrous and Ferric Ion-Facilitated Dilute Acid Pretreatment of Lignocellulosic Biomass under Anaerobic or Aerobic Conditions: Observations of Fe Valence Interchange and the Role of Fenton Reaction

Ferrous ion co-catalyst enhancement of dilute-acid (DA) pretreatment of biomass is a promising technology for increasing the release of sugars from recalcitrant lignocellulosic biomass. However, due to the reductive status of ferrous ion and its susceptibility to oxidation with exposure to atmosphere, its effective application presumably requires anaerobic aqueous conditions created by nitrogen gas-purging, which adds extra costs. The objective of this study was to assess the effectiveness of oxidative iron ion, (i.e., ferric ion) as a co-catalyst in DA pretreatment of biomass, using an anaerobic chamber to strictly control exposure to oxygen during setup and post-pretreatment analyses. Remarkably, the ferric ions were found to be as efficient as ferrous ions in enhancing sugar release during DA pretreatment of biomass, which may be attributed to the observation that a major portion of the initial ferric ions were converted to ferrous during pretreatment. Furthermore, the detection of hydrogen peroxide in the liquors after DA/Fe ion pretreatment suggests that Fenton reaction chemistry was likely involved in DA/Fe ion pretreatments of biomass, contributing to the observed ferric and ferrous interchanges during pretreatment. These results help define the extent and specification requirements for applying iron ions as co-catalysts in DA pretreatments of biomass.

09 BIOMASS FUELS↗
DOE OSTI2023

Fractionation of Lignocellulosic Biomass into High-Value Products - CRADA Report

Idaho National Laboratory (INL) has developed a process for adding value in the biomass feedstock supply chain. The key aspects of this process include: (1) anaerobic and chemical treatment of biomass during storage, (2) fractionation of biomass into conversion-ready feedstock and high-value coproducts, and (3) high-moisture pelleting to increase the bulk density and stabilize the feedstock. The purpose of the chemical treatment is to overcome the recalcitrant nature of the feedstock to improve the biochemical conversion process of breaking down the biomass into sugars. To maximize the utilization of the biomass, the feedstock can be fractionated into hemicellulose and lignin rich fractions. Finally, to increase the materials overall energy density, produce a shelf-stable material, and to facilitate transport, the feedstock is densified in a pelleting process. The first two steps of the processes have been verified at bench scale showing an improvement in theoretical glucose yield from 23.1% to 44.5% and an improvement in theoretical xylose yield from 8.9% to 23.1% from ground corn stover. It is hypothesized that densification will further increase the carbohydrate yield in the sample. The goal of this project was to evaluate the technical feasibility and process economics of the above process and to provide preliminary data to Golden Leaf Energy, Inc to access its potential commercialization for converting biomass to ethanol and renewable chemicals. Corn stover (CS), the largest available agricultural residue, and Chinese tallow (CT), an invasive wood species with no current commercial value, were chosen as feedstocks for this project.

09 BIOMASS FUELS↗
DOE OSTI2020

2D HSQC Chemical Shifts of Impurities from Biomass Pretreatment

Two dimensional (2D) heteronuclear single quantum coherence (HSQC) nuclear magnetic resonance (NMR) is a powerful analytical method which can be used to elucidate the structure of biomass. During processing, biomass is typically subjected to some form of chemical treatment which can be performed with a variety of compounds. The presence of these compounds, even in trace amounts, has the potential to contaminate the sample and lead to misinterpretation of the HSQC spectra. Here we report the chemical shifts of 29 compounds commonly used in biomass processing which have the potential to contaminate the biomass samples and lead to the misinterpretation of peaks associated with biomass (Populus trichocarpa ) pretreated via autohydrolysis. The identification of these chemical shifts could serve as a valuable tool in preventing errors in characterizing biomass via HSQC.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Global meta-analyses show that conservation tillage practices promote soil fungal and bacterial biomass

Despite a large number of published studies, a consensus has not been reached on how soil fungal and bacterial biomass, the primary regulators for soil organic matter decomposition, respond to conservation tillage, i.e., no or reduced tillage with >30 % residue covers. In this study we conducted a global meta-analysis of 60 studies to investigate the effects of conservation versus conventional tillage on soil fungal and bacterial biomass, fungal-to-bacterial ratios, and their relationship to other soil properties. Our results showed that conservation tillage greatly increased overall soil microbial biomass (37 %), including both fungal (31 %) and bacterial biomass (11 %), especially in top 20-cm soils or no-till agro-ecosystems, but conservation tillage effects were non-significant in sandy soils. Regardless of soil depth and tillage intensity, fungal-to-bacterial ratios did not greatly increase in conservation tillage scenarios, but were significantly affected by soil texture. Conservation tillage was also associated with significant increases in soil total C and N, and reduced soil pH. Increases in soil total C were positively associated with both fungal and bacterial biomass increases. Years under conservation tillage, time between last convention tillage to soil sampling, may indirectly affect fungal and bacterial biomass through soil C accumulation. Finally, our meta-analysis demonstrates that soil fungi and bacteria both respond positively to conservation tillage and are significantly associated with soil C content increase.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2022

Ecosystem service benefits to water users from perennial biomass production

We report although many agree that a transition to renewable energy sources is needed to avoid the climate consequences of continued reliance on fossil sources, price is a barrier. For renewable energy sources, including bioenergy, penetrating energy markets depends on lowering prices to compete with the price of fossil sources, but the tools used in decision making, such as supply curves, exclude non-market benefits from ecosystem services. Here, we extend the economic concept of an economic supply curve to account for ecosystem services co-produced with perennial biomass. We developed three new types of supply curves to visualize the increased supply of biomass (‘sustainable supply’) with sufficient water-quality benefits to offset biomass production costs. Using these tools, we show that the value of water-quality improvements could significantly reduce the break-even price of perennial feedstocks if it were available to farmers. In the most optimistic case, nearly half of potential biomass supply in a large tributary of the Mississippi river basin carried water purification value exceeding the cost of biomass production. Furthermore, adding the value to swimmers and waders offset production cost for over 90% of potential supply. Simulated benefits were context specific. For example, total value for water drinkers peaked at an intermediate level of fertilizer application. Geographically, benefits were highest in the eastern portion of the river basin. This research shows where the sustainable supply is needed and can generate value; the next step is to match this supply with credit buyers. Efforts to internalize the values of ecosystem services into biomass prices could help to meet Biden administration targets to meet 100% of sustainable aviation fuels.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

Regionalized Life Cycle Greenhouse Gas Emissions of Forest Biomass Use for Electricity Generation in the United States

This study presents a cradle-to-grave life cycle analysis (LCA) of the greenhouse gas (GHG) emissions of the electricity generated from forest biomass in different regions of the United States (U.S.), taking into consideration regional variations in biomass availabilities and logistics. The regional biomass supply for a 20 MW bioelectricity facility is estimated using the Land Use and Resource Allocation (LURA) model. Results from LURA and data on regional forest management, harvesting, and processing are incorporated into the GHGs, Regulated Emissions, and Energy Use in Technologies (GREET) model for LCA. The results suggest that GHG emissions of mill residues-based pathways can be 15-52% lower than those of pulpwood-based pathways, with logging residues falling in between. Nonetheless, our analysis suggests that screening bioenergy projects on specific feedstock types alone is not sufficient because GHG emissions of a pulpwood-based pathway in one state can be lower than those of a mill residue-based pathway in another state. Furthermore, the available biomass supply often consists of several woody feedstocks, and its composition is region-dependent. Forest biomass-derived electricity is associated with 86-93% lower life-cycle GHG emissions than the emissions of the average grid electricity in the U.S. Key factors driving bioelectricity GHG emissions include electricity generation efficiency, transportation distance, and energy use for biomass harvesting and processing.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2021

High-Efficiency Conversion of Ionic Liquid-Pretreated Woody Biomass to Ethanol at the Pilot Scale

We report that with a diverse and widely distributed global resource base, woody biomass is a compelling organic feedstock for conversion to renewable liquid fuels. In California, woody biomass comprises the largest fraction of underutilized biomass available for biofuel production, but conversion to fuels is challenged both by recalcitrance to deconstruction and by toxicity toward downstream saccharification and fermentation due to organic acids and phenolic compounds generated during pretreatment. In this study, we optimize pretreatment and scale-up of an integrated one-pot process for deconstruction of California woody biomass using the ionic liquid (IL) cholinium lysinate [Ch][Lys] as a pretreatment solvent. By evaluating the impact of solid loading, solid removal, yeast acclimatization, fermentation temperature, fermentation pH, and nutrient supplementation on final ethanol yields and titers, we achieve nearly full conversion of both glucose and xylose to ethanol with commercial C5-utilizing Saccharomyces cerevisiae. We then demonstrate process scalability in 680 L pilot-scale fermentation, achieving >80% deconstruction efficiency, >90% fermentation efficiency, 27.7 g/L ethanol titer, and >80% ethanol distillation efficiency from the IL-containing hydrolysate post fermentation. This fully integrated process requires no intermediate separations and no intermediate detoxification of the hydrolysate. Using an integrated biorefinery model, current performance results in a minimum ethanol selling price of $\$$8.8/gge. Reducing enzyme loading along with other minor process improvements can reduce the ethanol selling price to $\$$3/gge. This study is the largest scale demonstration of IL pretreatment and biofuel conversion known to date, and the overall biomass-to-ethanol efficiencies are the highest reported to date for any IL-based biomass-to-biofuel conversion.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Isotopic Studies for Tracking Biogenic Carbon during Co-processing of Biomass and Vacuum Gas Oil

Co-processing bio-oils with petroleum-derived feeds in the existing multitrillion dollar refining and distribution infrastructure is an attractive option for introducing renewable energy into the fuels marketplace. Considerable research on co-processing bio-oils and vacuum gas oil (VGO) in fluid catalytic cracking units (FCC) using equilibrium catalysts (E-Cats) demonstrated that biomass-derived molecules decreased activity of and increased carbon laydown on E-Cat. In this work, 13 C-labeled biomass was co-processed with VGO using either an E-Cat or a proprietary zeolite Johnson Matthey catalyst (CP758), which is optimzed for upgrading biomass vapors in a riser reactor, to evaluate the fate of biogenic carbon in FCC products. The results from both catalysts indicate that biogenic carbon was incorporated into alkenes and aromatic hydrocarbons. While no biogenic carbon was found in linear alkanes, it was observed in cycloalkanes during experiments with E-Cat but not with CP758. All produced CO2 was biogenic as was most of the carbon laydown on the catalysts. Several partially deoxygenated biomass compounds, such as alkylphenols and benzofurans, unexpectedly contained small amounts of carbon from VGO. Although this study was conducted with labeled biomass and not bio-oil, it provides insights to reaction mechanisms for co-processing bio-oil and VGO in an FCC, which is required to develop catalysts that efficiently convert bio-oil components during FCC co-processing. This work also demonstrates that comprehensive catalyst development utilizing both biomass- and fossil-derived feeds is required to maximize the incorporation of biogenic carbon into transportation fuels.

09 BIOMASS FUELS↗
DOE OSTI2023

Importance of incorporating spatial and temporal variability of biomass yield and quality in bioenergy supply chain

Abstract Biofuels made from biomass and waste residues will largely contribute to United States’ 2050 decarbonization goal in the aviation sector. While cellulosic biofuels have the potential fuel performance equivalent to petroleum-based jet fuel, the biofuel industry needs to overcome the supply chain barrier caused by temporal and spatial variability of biomass yield and quality. This study highlights the importance of incorporating spatial and temporal variability during biomass supply chain planning via optimization modeling that incorporates 10 years of drought index data, a primary factor contributing to yield and quality variability. The results imply that the cost of delivering biomass to biorefinery may be significantly underestimated if the multi-year temporal and spatial variation in biomass yield and quality is not captured. For long term sustainable biorefinery operations, the industry should optimize supply chain strategy by studying the variability of yield and quality of biomass in their supply sheds.

09 BIOMASS FUELS↗
DOE OSTI2021

The response of coarse root biomass to long-term CO 2 enrichment and nitrogen application in a maturing Pinus taeda stand with a large broadleaved component

Elevated atmospheric CO 2 (eCO 2 ) typically increases aboveground growth in both growth chamber and free-air carbon enrichment (FACE) studies. We report on the impacts of eCO 2 and nitrogen amendment on coarse root biomass and net primary productivity (NPP) at the Duke FACE study, where half of the eight plots in a 30-year-old loblolly pine (Pinus taeda, L.) plantation, including competing naturally regenerated broadleaved species, were subjected to eCO 2 (ambient, aCO 2 plus 200 ppm) for 15–17 years, combined with annual nitrogen amendments (11.2 g N m -2 ) for 6 years. Allometric equations were developed following harvest to estimate coarse root (>2 mm diameter) biomass. Pine root biomass under eCO 2 increased 32%, 1.80 kg m -2 above the 5.66 kg m -2 observed in aCO 2 , largely accumulating in the top 30 cm of soil. In contrast, eCO2 increased broadleaved root biomass more than twofold (aCO 2 : 0.81, eCO 2 : 2.07 kg m -2 ), primarily accumulating in the 30–60 cm soil depth. Combined, pine and broadleaved root biomass increased 3.08 kg m -2 over aCO 2 of 6.46 kg m -2 , a 48% increase. Elevated CO 2 did not increase pine root:shoot ratio (average 0.24) but increased the ratio from 0.57 to 1.12 in broadleaved species. Averaged over the study (1997–2010), eCO 2 increased pine, broadleaved and total coarse root NPP by 49%, 373% and 86% respectively. Nitrogen amendment had smaller effects on any component, singly or interacting with eCO 2 . A sustained increase in root NPP under eCO 2 over the study period indicates that soil nutrients were sufficient to maintain root growth response to eCO 2 . These responses must be considered in computing coarse root carbon sequestration of the extensive southern pine and similar forests, and in modelling the responses of coarse root biomass of pine–broadleaved forests to CO 2 concentration over a range of soil N availability.

9 allometry↗
DOE OSTI2023

Triacylglycerol, total fatty acid, and biomass accumulation of metabolically engineered energycane grown under field conditions confirms its potential as feedstock for drop‐in fuel production

Abstract Metabolic engineering for hyperaccumulation of lipids in vegetative tissues of high biomass crops promises a step change in oil yields for the production of advanced biofuels. Energycane is the ideal feedstock for this approach due to its exceptional biomass production and persistence under marginal conditions. Here, we evaluated metabolically engineered energycane with constitutive expression of the lipogenic factors WRINKLED 1 ( WRI 1), DIACYLGLYCEROL ACYLTRANSFERASE 1 ( DGAT 1), and OLEOSIN 1 ( OLE 1) for the accumulation of triacylglycerol (TAG), total fatty acid (TFA), and biomass under field conditions at the University of Florida‐IFAS experiment station near Citra, Florida. TAG and TFA accumulation were highest in leaves (up to 9.9% and 12.9% of DW, respectively), followed by juice from crushed stems, stems, and roots. TAG and TFA accumulation increased up to harvest time and correlated highest with OLE 1 and DGAT 1 expression. Biomass dry weight, TAG, and TFA content differed greatly depending on DGAT 1 and OLE 1 expression in transgenic lines with similar WRI 1 expression. Biomass did not significantly differ between WT and line L2 with DAGT 1 and OLE 1 expressed at low levels and TAG and TFA accumulating to 12‐ and 1.6‐fold that of WT leaves, respectively. In contrast, line L13, with intron‐mediated enhancement of DGAT 1 expression, displayed a 245‐ to 330‐fold increase in TAG and a 4.75‐ to 6.45‐fold increase in TFA content compared with WT leaves and a biomass reduction of 52%. These results provide the basis for developing novel feedstocks for expanding plant lipid production and point to new prospects for advanced biofuels.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2025

Distillable amine-based solvents for effective pretreatment of multiple biomass feedstocks

Exploring the potential of advanced distillable solvents as efficient biomass pretreatment agents is critical for biorefineries, enhancing fermentable sugar yields while enabling solvent recovery and recycling without suffering significant losses. Here, we employ distillable amine-based solvents for pretreating a wide range of lignocellulosic feedstocks, aiming to facilitate the industrial release of fermentable sugars from diverse feedstocks through enzymatic hydrolysis. Twenty-two diverse feedstocks, sourced from different geographical regions and representing various biomass categories, were surveyed for chemical (mainly carbohydrates and lignin) and lignin (S, G, and H units) profiles. Several solvents, including ethanolamine, ethanolammonium acetate, butylamine, butylammonium acetate, and triethylamine, were tested for the pretreatment of eight selected biomasses. Among these solvents, butylamine emerged as the most effective due to its favorable sugar release, excellent solvent removal rate, and low boiling point, facilitating solvent recovery and recycling. Extending butylamine pretreatment to all 22 feedstocks demonstrated desirable sugar yields and highly efficient solvent removal in the majority of the biomass sources tested. Agricultural residues and their mixtures showed particularly favorable sugar release. Despite minimal changes in cellulose crystallinity, XRD characterization of sorghum, poplar, and pine before and after butylamine pretreatment showed a decrease in intensity and a slight shift of certain peaks, indicating alterations in cellulose structure. Fourier-transform infrared spectroscopy and thermogravimetric analysis analyses suggested disruption of biomass linkages in hemicellulose and lignin, enhancing enzymatic digestibility. Scale-up experiments of the mixed agricultural feedstocks in a 1 L Parr reactor achieved over 90% glucose liberation and more than 99% butylamine removal, highlighting the scalability of the method. The resulting hydrolysates supported the growth of diverse bacterial and fungal strains, indicating downstream compatibility with commercial fermentation processes. This study presents butylamine as an effective, recoverable pretreatment solvent for a wide range of lignocellulosic feedstocks, offering a promising solution to key biorefinery challenges. The demonstrated scalability and compatibility with various biomass types and blends underscore its potential for industrial application, advancing sustainable biofuel and biochemical production.

biomass composition↗
DOE OSTI2022

Using Chemical Reactor Models to Predict Fluidized Bed Pyrolysis Yields of Biomass Feedstocks

A detailed biomass pyrolysis kinetics scheme is implemented in reduced-order reactor models to predict chemical species yields from a fluidized bed reactor. The biomass composition in terms of cellulose, hemicellulose, lignins, and extractives are determined for several biomass feedstocks. Model results are compared to yields measured from a two-inch diameter bench-scale fluidized bed reactor operating at fast pyrolysis conditions. The reduced-order chemical reactor models compare favorably with the experimental measurements and capture trends in product yields due to biomass compositional effects such as high ash content. This work offers a computationally inexpensive approach to predict the quality of biomass pyrolysis products in a timely manner. Source code for the reactor models along with a biomass composition web tool are made available online for future scientific research efforts.

09 BIOMASS FUELS↗
DOE OSTI2025

Mapping and Synthesis of International Biomass Supply Assessments

This report, Mapping and Synthesis of International Biomass Supply Assessments (or Global Biomass Resource Assessment) is the first step in a long-term process to assemble data from around the globe into a virtual repository that can be updated and provide user-friendly access to the data. The Clean Energy Ministerial (CEM) Biofuture Platform Initiative recommended that research be completed to “address the need for internationally accepted benchmarks quantifying sustainable biomass feedstock supplies.” To act upon the CEM Biofuture recommendation, in 2024, the U.S. Department of Energy (DOE) commissioned Oak Ridge National Laboratory (ORNL) to prepare this report as the primary deliverable for a one-year assignment to assemble data into a citable form that could help resolve the persistent question presented related to bioenergy policy, “Is there enough sustainable biomass?” In response to that query, this report includes information received by August 2024 from national CEM representatives, collaborators, and public sources on current and future sustainable biomass supplies in 62 nations,and subsequently documents (a) the approach used by ORNL to analyze and categorize the information received in a manner that enables aggregation and comparability; and (b) recommendations for next steps and guidelines to help others update and harmonize future assessments of global sustainable biomass supplies.

09 BIOMASS FUELS↗
NASA NTRS1993

(abstract) Sensitivity to Forest Biomass Based on Analysis of Scattering Mechanism

The estimation of forest biomass on a global scale is an important input to global climate and carbon cycle models. Remote sensing using synthetic aperture radar offers a means to obtain such a data set. Although it has been clear for some time that radar signals penetrate forest canopies, only recently has it been demonstrated that these signals are indeed sensitive to biomass. Inasmuch as the majority of a forest's biomass is in the trunks, it is important that the radar is sensing the trunk biomass as opposed to the branch or leaf biomass. In this study we use polarimetric AIRSAR P- and L-band data from a variety of forests to determine if the radar penetrates to the trunk by examining the scattering mechanism as determined using van Zyl's scattering interaction model, and the levels at which saturation occurs with respect to sensitivity of radar backscatter to total biomass. In particular, the added sensitivity of P-band relative to L-band is addressed. Results using data from the Duke Forest in North Carolina, the Bonanza Creek Experimental Forest in Alaska, Shasta Forest in California, the Black Forest in Germany, the temporate/boreal transition forests in northern Michigan, and coastal forests along the Oregon Transect will be presented.

forest canopy biomass radar scattering mechanism↗
NASA NTRS2020

Widespread Biomass Burning Smoke Throughout the Remote Troposphere

Biomass burning emits ~34–41 Tg yr−1 of smoke aerosol to the atmosphere. Biomass burning aerosol directly influences the Earth’s climate by attenuation of solar and terrestrial radiation; however, its abundance and distribution on a global scale are poorly constrained, particularly after plumes dilute into the background remote troposphere and are subject to removal by clouds and precipitation. Here we report global-scale, airborne measurements of biomass burning aerosol in the remote tropo-sphere. Measurements were taken during four series of seasonal flights over the Pacific and Atlantic Ocean basins, each with near pole-to-pole latitude coverage. We find that biomass burning particles in the remote troposphere are dilute but ubiquitous, accounting for one-quarter of the accumulation-mode aerosol number and one-fifth of the aerosol mass. Comparing our obser-vations with a high-resolution global aerosol model, we find that the model overestimates biomass burning aerosol mass in the remote troposphere with a mean bias of >400%, largely due to insufficient wet removal by in-cloud precipitation. After updat-ing the model’s aerosol removal scheme we find that, on a global scale, dilute smoke contributes as much as denser plumes to biomass burning’s scattering and absorption effects on the Earth’s radiation field.

Biomass burning↗
NASA NTRS2023

Tree Growth Enhancement Drives a Persistent Biomass Gain in Unmanaged Temperate Forests

While enhanced tree growth over the last decades has been reported in forests across the globe, it remains unclear whether it drives persistent biomass increases of forest stands, particularly in mature forests. Enhanced tree growth and stand-level biomass are often linked with a simultaneous increase in density-driven mortality and a reduction in tree longevity. Identifying empirical evidence regarding the balance between these processes is challenging due to the confounding effects of stand history, management, and environmental changes. Here, we investigate the link between growth and biomass via the negative relationship between average tree size and stand density (tree number per area). We find increasing stand density for a given mean tree size in unmanaged closed-canopy forests in Switzerland over the past six decades and a positive relationship between tree growth and stand density across forest plots—qualitatively consistent with our simulations using a mechanistic, cohort-resolving ecosystem model (BiomeE). Model simulations show that, in the absence of other disturbances, enhanced tree growth persistently increases biomass stocks despite simultaneous decreases in carbon residence time and tree longevity. However, the magnitude of simulated biomass changes for a given growth enhancement critically depends on the shape of the mortality functions. Our analyses reconcile reports of growth-induced reductions of tree longevity with model predictions of persistent biomass increases, and with our finding of trends toward denser forests in response to growth—also in mature stands.

biomass stocks↗
DOE OSTI2019

Method for wet torrefaction of a biomass

A process for increasing the energy density of a biomass, which includes establishing a temperature and pressure within a reaction chamber that includes water and is at or above a desired reaction condition wherein the desired reaction condition is sufficient to increase the energy density of a reacted biomass; introducing a biomass into the reaction chamber such that the desired reaction condition is maintained or equilibrates thereto; and subjecting the biomass to the desired reaction condition for an amount of time effective to increase the energy density of the reacted biomass relative to the biomass prior to reaction.

09 BIOMASS FUELS↗