SEARCH · Search NASA

Results for “Lignocellulose”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 433 records · Page 24

All sources NASA NTRS DOE OSTI

DOE OSTI2021

Synergistic Improvement of Carbohydrate and Lignin Processability by Biomimicking Biomass Processing

The sustainability and economic feasibility of modern biorefinery depend on the efficient processing of both carbohydrate and lignin fractions for value-added products. By mimicking the biomass degradation process in white-rote fungi, a tailored two-step fractionation process was developed to maximize the sugar release from switchgrass biomass and to optimize the lignin processability for bioconversion. Biomimicking biomass processing using Formic Acid: Fenton: Organosolv (F 2 O) and achieved high processability for both carbohydrate and lignin. Specifically, switchgrass pretreated by the F 2 O process had 99.6% of the theoretical yield for glucose release. The fractionated lignin was also readily processable by fermentation via Rhodococcus opacus PD630 with a lipid yield of 1.16 g/L. Scanning electron microscope analysis confirmed the fragmentation of switchgrass fiber and the cell wall deconstruction by the F 2 O process. 2D-HSQC NMR further revealed the cleavage of aryl ether linkages (β-O-4) in lignin components. These results revealed the mechanisms for efficient sugar release and lignin bioconversion. The F 2 O process demonstrated effective mimicking of natural biomass utilization system and paved a new path for improving the lignin and carbohydrate processability in next generation lignocellulosic biorefinery.

09 BIOMASS FUELS↗

DOE OSTI2024

Structural and chemical changes in hardwood cell walls during early stages of flash pyrolysis

Volatile products from thermal decomposition of lignocellulosic biomass have been well characterized, but the solid- and liquid-phase reactions during the early stages of decomposition are largely unknown. Here the initial solid-phase biomass thermal deconstruction reactions were analyzed in situ and with high particle heating rates, delineating how these processes occur. A variety of instrumentation was used to quantify the extent and relative rates of deconstruction, demonstrating that biopolymers resist the thermally energetic conditions to differing degrees, even when ensconced in biomass cell walls. Hemicellulose and the more frangible lignin components decompose and volatilize more readily than cellulose, which temporarily enriches biomass with cellulose. These chemical changes manifest in larger cell wall structural and mechanical property transformations. In all, this investigation concludes that these solid-phase reactions strongly influence the production rates of volatile species and will require additional study before these processes can be modeled precisely to improve yields of desired product.

09 BIOMASS FUELS↗

DOE OSTI2023

Comparative feedstock analysis in Setaria viridis L. as a model for C 4 bioenergy grasses and panicoid crop species

Second generation feedstocks for bioethanol will likely include a sizable proportion of perennial C4 grasses, principally in the Panicoideae clade. The Panicoideae contain agronomically important annual grasses including Zea mays L. (maize), Sorghum bicolor (L.) Moench (sorghum), and Saccharum officinarum L. (sugar cane) as well as promising second generation perennial feedstocks including Miscanthus × giganteus and Panicum virgatum L. (switchgrass). The underlying complexity of these polyploid grass genomes is a major limitation for their direct manipulation and thus driving a need for rapidly cycling comparative model. Setaria viridis (green millet) is a rapid cycling C4 panicoid grass with a relatively small and sequenced diploid genome and abundant seed production. Stable, transient, and protoplast transformation technologies have also been developed for Setaria viridis making it a potentially excellent model for other C4 bioenergy grasses. Here, the lignocellulosic feedstock composition, cellulose biosynthesis inhibitor response and saccharification dynamics of Setaria viridis are compared with the annual sorghum and maize and the perennial switchgrass bioenergy crops as a baseline study into the applicability for translational research. A genome-wide systematic investigation of the cellulose synthase-A genes was performed identifying eight candidate sequences. Two developmental stages; (a) metabolically active young tissue and (b) metabolically plateaued (mature) material are examined to compare biomass performance metrics.

09 BIOMASS FUELS↗

DOE OSTI2020

Chemical Free Two-Step Hydrothermal Pretreatment to Improve Sugar Yields from Energy Cane

Energy cane is an attractive lignocellulosic feedstock for processing into biofuels and bioproducts. A low-severity two-step hydrothermal pretreatment was investigated on energy cane for the production of monomeric sugar. Pretreatment temperature and time, in addition to the effect of disk milling, were observed for the glucose and xylose yields during hydrolysis. At residence times above 5 min in case of pretreatment at 200 °C, all of the hemicellulose was observed to be solubilized. The pretreatment condition of 200 °C for 10 min with disk milling was observed to provide the highest glucose concentration of 5.4%, and 200 °C for 5 min with disk milling provided the highest xylose concentration of 2.15%. The effect of disk milling in improving the sugar concentrations during hydrolysis was significant, especially at lower pretreatment temperatures and times. Low xylose yields at higher temperatures were attributed to the formation of degradation products at increased severity.

09 BIOMASS FUELS↗

NASA NTRS2023

Modeling Global Indices for Estimating Non-Photosynthetic Vegetation Cover

Non-photosynthetic vegetation (NPV) includes plant litter, senesced leaves, and crop residues. NPV plays an essential role in terrestrial ecosystem processes, and is an important indicator of drought severity, ecosystem disturbance, agricultural resilience, and wildfire danger. Current moderate spatial resolution multispectral satellite systems (e.g., Landsat and Sentinel-2) have only a single band in the 2000–2500 nm shortwave infrared “SWIR2” range where non-pigment biochemical constituents of NPV, including cellulose and lignin, have important spectral absorption features. Thus, these current systems have suboptimal capabilities for characterizing NPV cover. This research used simulated spectral mixtures accounting for variability among NPV and soils to evaluate globally-appropriate hyperspectral and multispectral indices for estimation of fractional NPV cover. The Continuum Interpolated NPV Depth Index (CINDI), a weighted ratio index measuring lignocellulose absorption near 2100 nm, was found to produce the lowest error in estimating NPV cover. CINDI was less sensitive to variability in soil spectra and green vegetation cover than competing indices. While CINDI was sensitive to the relative water content of soil and NPV, this sensitivity allowed for correcting error in estimated NPV cover as water content increased. CINDI bands were less capable than Dual Absorption NPV Index (DANI) bands for maintaining continuity with the heritage Landsat SWIR2 band, but combining multiple CINDI bands demonstrated adequate continuity. Three SWIR2 bands with band centers at 2038, 2108, and 2211 nm can provide superior capabilities for future moderate resolution multispectral/superspectral systems targeting NPV monitoring, including the next generation Landsat mission (Landsat Next). These bands and the associated CINDI index provide potential for global NPV monitoring using a constellation of future superspectral sensors and imaging spectrometers, with applications including improving soil management, preventing land degradation, evaluating impacts of drought, mapping ecosystem disturbance, and assessing wildfire danger.

Index optimization↗

DOE OSTI2020

Conversion, Stability, and Selectivity Improvements Through Catalyst Development for the Reductive Etherification Reaction

Economical pathways from lignocellulosic non-food biomass feedstocks to biofuels with appropriate fuel properties are necessary for displacing fossil-fuel derived diesel use in medium-/heavy duty vehicles. Oxygenated compounds have recently shown promise due to low sooting tendencies and autoignition properties and molecules with sufficiently high carbon numbers can meet the requisite standards for water solubility and flash point. Coupling waste biomass derived small molecules into bioblendstock targets through the reductive etherification reaction shows potential for increasing molecular weight without losing the advantages of oxygenates. However, the transition to industrial viability for this process is limited by strong catalyst deactivation in typical flow reactor systems. Strong acid resins such as Amberlyst-15 (A-15) show excellent activity in batch reactions but are limited to low temperatures and are poisoned by the side-product, water. In this talk, I will describe our recent work in catalyst synthesis and testing to select superior options with improved aqueous and thermal stability in reductive etherification flow reactions. Water-tolerant solid acid catalysts have potential to improve the conversion and selectivity to the ether target at temperatures above the degradation point of A-15. Analysis techniques such as physisorption, chemisorption, x-ray diffraction and transmission electron microscopy are being used to characterize the active sites. These techniques are also being used to evaluate degradation of the catalyst after extensive flow reactions in addition to comparative efficiency testing with standardized cyclohexene hydrogenation reactions. Finally, I will discuss a demonstration of the full pathway from bio-derived butyric acid to the performance-advantaged ether product and the additional obstacles from side-products and purification limitations in the preliminary upgrading reactions.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

DOE OSTI2021

BETO 2021 Peer Review - Biological Upgrading of Sugars (BUS) 2.3.2.105

The Biological Upgrading of Sugars (BUS) project directly targets the anaerobic conversion of lignocellulosic feedstocks into intermediate molecules readily upgradeable to fuel precursors. Recent efforts on the BUS project have a particular emphasis on the biological production of butyric acid, an intermediate that can be readily upgraded to sustainable aviation fuel, diesel blend-stocks, and high value chemicals. The BUS project approaches this direction through a combination of strain engineering, fermentation process engineering, development of novel separations technologies, and the design and build of pilot scale systems. Our ultimate project goal is to develop an integrated cost-effective process at pilot scale to achieve DOE's MYPP targets of $2.50/GGE. The major thrust of the BUS project over the last project cycle was on the development of integrated processes surrounding the anaerobic production of carboxylic acids using diverse Clostridium species. We developed and expanded genetic tools for several Clostridium species and rewired microbial metabolism in an attempt to maximize substrate utilization and flux towards butyric acid. We designed and built novel bioreactors with an in situ product recovery system enabling the biological production and recovery of highly purified acids. We leveraged this system to generate 100s of grams of acid from corn stover hydrolysate. In this presentation we highlight data surrounding our proposed process and accompanying results from technoeconomic and life-cycle analyses of our integrated process. Finally, we detail plans of our pilot scale reactor system that is in process and discuss our future routes towards achieving economically viable and sustainable diesel and jet blendstocks.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

DOE OSTI2021

Computational Fluid Dynamics Simulation of Compressible Non-Newtonian Biomass in a Compression-Screw Feeder

Compression-screw feeders play a critical role in biorefineries to transport lignocellulosic biomass feedstocks from the feeding hoppers to biomass-conversion reactors in order to pretreat and convert biomass to hydrocarbon liquid biofuels and other power and energy resources. One of the main challenges in the operation of screw feeder is plugging and jamming of compressed biomass with high concentration of insoluble solids. The focus of this paper is to numerically investigate the screw feeder at these challenging operating conditions and help with the optimization of the screw feeder design to avoid operation failure. In this work a customized CFD model based on open-source OpenFOAM package [1] was developed to simulate the concentrated biomass as a highly viscous non-Newtonian fluid in the screw feeder. The biomass is modeled as a single-phase compressible Bingham fluid with a plastic viscosity as well as a density-dependent yield stress. The compressibility formulation (pressure-dependent density) and the density-dependent yield stress formulation in the governing equations follow the suggestions from a recent study by Duncan et al. [2]. A pilot-scale hopper/screw feeding system at NREL [3] is used to compare the experimental observations with our simulation results. The auger is 280 mm long and tapered with outer diameter changing from 80 mm to 35 mm. The auger rotates from 10 to 60 rpm in a conical throat which contains anti-rotational bars. The simulations predicted the required torque for the screw feeder and the pressure increase at the exit for biomass feedstocks with various fluid viscosity properties and auger rotating speeds. The analysis of the stress forces helped to identify the critical conditions were the screw feeder excessive wear or jamming could occur.

biofuels↗

DOE OSTI2022

Lignin Utilization

Valorization of lignin has massive potential economic and sustainability benefits for the lignocellulosic biorefinery. However, challenges remain to realize lignin conversion to coproducts, especially related to selective, high yield depolymerization to monomers and quantitative analytics on lignin, the latter of which is critical for accurate process modeling. Towards these goals, the Lignin Utilization project focuses on catalytic lignin deconstruction chemistries for C-O and C-C bond cleavage, development of analytical chemistry techniques to quantitatively characterize lignin, and syntheses of requisite model compounds for understanding lignin transformations. This work is done with and supports multiple BETO projects, including the Biological Lignin Valorization (BLV) project, the Separations Consortium, and others. Outcomes of Lignin Utilization for analytics and synthesis include 1) development of new mass spectrometry (MS) methods to characterize lignin dimers/oligomers in process streams, 2) deployment of a computational-experimental tool (with Biochemical Process Modeling and Simulation) to identify lignin-derived compounds with high fidelity from MS, and 3) delivery of >40 unique compounds. From a catalysis perspective, we have developed new oxidative approaches to cleave C-O and C-C bonds and produce >50% bio-available aromatic monomers for biological funneling for the BLV project and have developed recoverable bases for base-catalyzed deconstruction of lignin.

BIOMASS FUELS↗

DOE OSTI2023

BioHydrogen (BioH2) Consortium to Advance Fermentative H2 Production

The overall objective of this project is to develop a carbon-neutral, microbial dark fermentation technology to convert waste lignocellulosic biomass into H2 with a production cost less than $2/kg-H2 via strain engineering, bioprocess design for scale-up, and integrating fermentation with microbial electrolysis cell (MEC).

bioH2↗

DOE OSTI2024

BioHydrogen (BioH2) Consortium to Advance Fermentative H2 Production

bioH2↗

DOE OSTI2025

A Data-Driven Framework for Predicting the Sorting and Screening Performance of an Integrated Biomass Feedstock Preprocessing System

The characteristics of mechanically sorted and screened lignocellulosic biomass, such as the mass contents of corn stover anatomical fractions (leaves, husks, stalks, cobs, etc.), can be used to calculate the intermediate feedstock quality attributes “yield” and “purity” that indicate the conversion efficiency of biocrude. No prior study has investigated the correlations from the characteristics of raw biomass and preprocessing unit operation parameters to those intermediate feedstock quality attributes. This work presents a data-driven framework for assessing and predicting the intermediate feedstock quality attributes in an integrated biomass feedstock preprocessing system. Our study used corn stover as a typical type of herbaceous biomass because of its abundance in the U.S. It began with data acquisition of moisture content, particle size distribution, and anatomical fractions of the materials after each unit operation in the system. The objective of this preprocessing system is to minimize husks and leaves and maximizing cobs and stalks by mechanically separating the materials into three streams via disc screen and air separator. Prototype neural network models were then developed to evaluate the feasibility of predicting process outcomes based on measurable parameters. It is found that incorporating physical constraints into these prediction models significantly enhances the accuracy of the predicted yield and purity against the ground truth data. The experimental data and model predictions indicate that decreasing throughput increases purity, while higher throughput results in lower purity. Finally, an optimization problem was introduced to search optimal combinations of feed material properties and preprocessing unit operation parameters, as the intermediate feedstock quality attributes – yield and purity, appeared to be competing factors. The study also suggests the continual need to improve the data-driven framework’s predictability by incorporating more accurate physical models to describe the dynamics in the preprocessing units such as the air separator.

09 - BIOMASS FUELS↗

DOE OSTI2020

Predicted annual biomass input to maintain soil organic carbon under contrasting management

Corn (Zea mays L.) residue is an important source of lignocellulosic feedstocks for meeting the US renewable energy goals. However, there is uncertainty in how much biomass can be sustainably harvested. The objectives of this study were to (i) simulate soil organic carbon (SOC) dynamics in the 0–20, 20–30, and 0–30 cm soil depths for the 2005–2015 study period using CQESTR, a process-based C model; (ii) establish trends in SOC with residue removal and tillage management over the predictive period of 2016–2035; and (iii) recommend practices to maintain SOC stocks in a corn–soybean (Glycine max L. [Merr.]) rotation with corn residue removal in western Minnesota. The residue removal treatments in the conventional tillage since 1995 (CT 95 ) and no tillage since 1995 (NT 95 ) were initiated in 2005, and in 2006 for the no tillage since 2005 (NT 05 ). Corn residue removal treatments were none, cob removal, ~50% removal, and ~75% removal (R0, RCob, R50, and R75, respectively). Only R0 in NT 05 increased SOC (0.32 Mg C ha –1 yr –1 ) stocks in the top 30 cm soil depth by 2035 with annual aboveground biomass input of 6.30 Mg ha –1 yr –1 . It was concluded that only the NT 05 field has the potential to maintain SOC at the current rate of biomass addition, and a minimal annual aboveground C (MSC) input of 3.75 Mg C ha –1 yr –1 is required to maintain SOC until 2035. These simulation results indicate that caution should be used in removing residue especially under conventional tillage.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2023

Comparative productivity of six bioenergy cropping systems on marginal lands in the Great Lakes Region, United States

Abstract Growing lignocellulosic crops on marginal lands is a promising solution for sustainable biofuel production. We evaluated the productivity of bioenergy cropping systems (switchgrass [ Panicum virgatum L., var. Cave‐In‐Rock], miscanthus [ Miscanthus × giganteus , ‘Illinois clone’], hybrid poplar [ Populus nigra × P. maximowiczii A. Henry ‘NM6’], native grasses [five species], early successional vegetation, and restored prairie vs. historical vegetation [as reference control]) with and without nitrogen fertilization on low‐fertility former cropland at five sites in the Great Lakes Region, United States. We reported biomass yields for the first 7 years after establishment. Switchgrass was most consistently productive across all sites but miscanthus was more productive at three of the five sites. When averaged across sites, years, and nitrogen (N) treatments, biomass yields followed the order miscanthus > switchgrass > hybrid poplar ≈ native grasses > restored prairie > early successional vegetation ≈ historical vegetation, but varied substantially by crop and site, with a significant crop by site interaction. Yields of miscanthus and switchgrass peaked after four–five growing seasons and declined thereafter, while yields of both native grasses and restored prairie increased throughout 6 years with no sign of follow‐on decline, suggesting that polycultures may outperform monocultures over the long term. Yields of early successional vegetation—similar in composition to historical vegetation at each site—did not improve with time. Nitrogen fertilization increased the yields of all cropping systems at all sites. Our results demonstrate the viability of low‐productivity former cropland for long‐term bioenergy production and suggest there is no single crop best suited for all low fertility soils.

Jayawardena, Dileepa M.↗

DOE OSTI2024

Simultaneous optimization of simulated moving bed adsorption and distillation for 2,3‐butanediol recovery

Abstract A combined simulated moving bed (SMB) and distillation separation scheme is developed to recover 2,3‐butanediol (BDO) from a dilute fermentation broth. The scheme was integrated into a lignocellulosic biorefinery that produces hydrocarbon fuels from corn stover with BDO as an intermediate. BDO recovery is one of the most challenging processes in this biorefinery; and given the high associated energy duties, direct distillation is considered cost‐prohibitive. An alternative separation is SMB adsorption in nanoporous materials, which can reject 90% of the water and reduce subsequent distillation costs. Rigorous models were used to optimize the SMB and distillation simultaneously. The separation can be added to the biorefinery while keeping the projected minimum fuel selling price (MFSP) below $0.66 USD (US dollars) per liter gasoline‐equivalent ($2.50/GGE, gallon gasoline equivalent). Finally, sensitivity analyses were conducted to assess the effects of cost and lifetime of the adsorbent, titer concentration, and BDO purity.

09 BIOMASS FUELS↗

DOE OSTI2025

An argument for using anaerobes as microbial cell factories to advance synthetic biology and biomanufacturing

Anaerobes thrive in the absence of oxygen and are an untapped reservoir of biotechnological potential. Therefore, bioprospecting efforts focused on anaerobic microbial diversity could rapidly uncover new enzymes, pathways, and chassis organisms to drive biotechnology innovation. Despite their potential utility, anaerobic fermenters are viewed as inefficient from a biochemical perspective because their metabolisms produce fewer ATP (~2) per molecule of glucose processed than heterotrophic respirers (~32–38 ATP). While aerobes excel at ATP generation, they are often less efficient than anaerobes at processes that compete with ATP generation for cellular resources. This perspective highlights how anaerobic adaptations are advantageous for synthetic biology and biomanufacturing applications through the engineering of microbial cell factories. We further highlight emerging applications of anaerobic bioprocessing, including the use of anaerobic metabolisms for lignocellulosic bioprocessing, human and environmental health, and value-added bioproduction.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2020

Protection Strategies Enable Selective Conversion of Biomass

Abstract Selective and economic conversion of lignocellulosic biomass components to bio‐based fuels and chemicals is the major goal of biorefineries, but low yields and selectivity for fuel precursors such as sugars, furanics, and lignin‐derived monomers pose significant disadvantages in process economics. In this Minireview we summarize the existing protection strategies used in biomass chemocatalytic conversion processes and focus the discussions on the mechanisms, challenges, and opportunities of each strategy. We introduce a concept of using analogous methods to manipulate biomass catalytic conversion pathways during the upgrading of carbohydrates to fuels and chemicals. This Minireview may provide new insights into the development of selective biorefining processes from a different perspective, expanding the options for selective conversion of biomass to fuels and chemicals.

Luo, Xiaolin↗

DOE OSTI2020

Protection Strategies Enable Selective Conversion of Biomass

Luo, Xiaolin↗