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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.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Life-cycle analysis of integrated biorefineries with co-production of biofuels and bio-based chemicals: co-product handling methods and implications: Co-product handling methods and implications of life-cycle analysis of biofuel and bio-chemical co-producing biorefineries

New integrated biorefinery (IBR) concepts are being investigated to co-produce hydrocarbon fuels and high-value bio-based chemicals to improve the economic viability of IBRs, to enhance biomass resource utilization efficiencies, and to maximize potential greenhouse gas (GHG) emission reductions. Unlike fuel-only biorefineries, IBRs may co-produce a significant amount of bio-based chemicals, whose emission implications for specific biorefinery products and the biorefinery as a whole need to be evaluated. We discuss this in principle and apply three sets of co-product handling methods to conduct life-cycle analysis (LCA) of modeled IBRs with co-production of two bioproduct examples - succinic acid and adipic acid - alongside a renewable diesel blendstock fuel product. The LCA results for the specific co-product handling methods that were examined shed light on potential artifacts of product-specific LCA with selected co-product methods. We discuss the advantages and limitations of each method and conclude that (i) a system-level or 'black-box' LCA allocation method is too simplistic to reflect appropriately the GHG burdens of distinctly different processing trains for fuels and chemicals in the IBR context, and (ii) the displacement method is the only co-product handling method that accounts fully for the emission effects of both the fuel product and the non-fuel bio-based co-products in the IBRs within the context of the existing fuel-focused GHG regulatory framework. Alternatively, biorefinery system-level LCA combines benefits of individual products to offer a complete picture. This system-level LCA approach offers a holistic LCA without somewhat arbitrary decisions either on an allocation basis or by the selection of an evaluation metric based on specific products.

09 BIOMASS FUELS↗
DOE OSTI2020

Gas Production from Hot Water Circulation through Hydraulic Fractures in Methane Hydrate-Bearing Sediments: THC-Coupled Simulation of Production Mechanisms

Methane hydrates, widely found in permafrost and deep marine sediments, have great potential as a future energy 6 source. Conventional production schemes perform poorly for challenging hydrate reservoirs with low permeability. We propose an 7 efficient production scheme by combining hydraulic fracturing from horizontal wells and hot water circulation through fractures. A 8 fully coupled thermo-hydro-chemical (THC) model is developed to simulate the key physical processes during gas production from 9 a hydrate reservoir representative of typical geological settings in Shenhu, South China Sea. We found that the gas production 10 process has two distinct stages divided by thermal breakthrough: a relatively short prebreakthrough stage and a postbreakthrough 11 stage yielding stable gas production. Heat advection along and near the hydraulic fracture dominates the prebreakthrough stage, 12 whereas conduction-driven thermal recovery in the volume around fractures dominates the postbreakthrough stage. We identified 13 that the steady-state injection temperature has a strong effect on the performance of the proposed scheme while the fluid mass 14 circulation rate has a moderate impact beyond a threshold. The proposed scheme proves to be efficient and robust over a range of 15 reservoir conditions with respect to initial hydrate saturation and intrinsic permeability, including their spatial heterogeneities, 16 thereby offering a promising solution for challenging reservoir conditions.

gas hydrate, fracture flow, gas production, numeri↗
DOE OSTI2018

A stochastic techno-economic analysis of shrub willow production using EcoWillow 3.0S: A Stochastic Techno-Economic Analysis of Shrub Willow Production Using EcoWillow 3.0S

EcoWillow 3.0S is a techno-economic analysis (TEA) tool that calculates realistic willow biomass production costs using data from field trials of willow production in New York State. The model represents the input parameters for diesel fuel price, wood price, and willow yield as data-derived probability distributions rather than as single values. This study uses EcoWillow 3.0S with Oracle Crystal Ball to perform a stochastic TEA of shrub willow production in the Northeastern United States. Two outputs obtained from this model are a 24-year net present value (NPV) and minimum selling price (MSP) of shrub willow production under price and yield uncertainty. The MSP for dry willow ranges within a 95% confidence interval from $\$ 59$. -$\$ 102$/Mg. The NPV, also within a 95% confidence interval, ranges from -$\$ 153$ 819 to $\$ 207$ 129 for 40 ha of willow harvested seven times over 24 years. The relevance of this study is to utilize the TEA methodology to assess the financial feasibility of shrub willow production as a bioenergy feedstock. The results of this analysis provide the bioenergy field with NPV and MSP probability distributions on shrub willow production that have previously been absent from the refereed literature. Using data collected from field operations over a number of years, EcoWillow 3.0S captures some of the key inputs that influence the variation in the delivered cost of willow biomass crops.

09 BIOMASS FUELS↗
DOE OSTI2016

Measurement of exclusive γ γ → W + W - production and search for exclusive Higgs boson production in p p collisions at s = 8 TeV using the ATLAS detector

Searches for exclusively produced W boson pairs in the process p p ( γ γ ) → p W + W - p and an exclusively produced Higgs boson in the process p p ( g g ) → p H p have been performed using e ± μ ∓ final states. These measurements use 20.2 fb - 1 of p p collisions collected by the ATLAS experiment at a center-of-mass energy √ s = 8 TeV at the LHC. Exclusive production of W + W - consistent with the Standard Model prediction is found with 3.0 σ significance. The exclusive W + W - production cross section is determined to be σ ( γ γ → W + W - → e ± μ ∓ X ) = 6.9 ± 2.2 ( stat ) ± 1.4 ( sys ) fb , in agreement with the Standard Model prediction. Limits on anomalous quartic gauge couplings are set at 95% confidence level as - 1.7 × 10 - 6 < a W 0 / Λ 2 < 1.7 × 10 - 6 GeV - 2 and - 6.4 × 10 - 6 < a W C / Λ 2 < 6.3 × 10 - 6 GeV - 2 . A 95% confidence-level upper limit on the total production cross section for an exclusive Higgs boson is set to 1.2 pb.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2018

Modularized Production of Fuels and other Value-Added Products from Distributed, Wasted, or Stranded Feedstocks

Distributed, wasted, or stranded feedstocks, when converted and upgraded into fuels, could replace about 6% of the US demand for liquid fuels, which is about 25% of the net import of petroleum by the US. We review the current state of modular approaches for conversion of these feedstocks, including the technology and economics associated with processing carbon-containing waste and stranded, carbon-containing gas. The wide geographic distribution of the feedstocks will require technology that can be scaled down effectively and that can be manufactured, installed, operated and monitored in ways that gain economies of mass production rather than economies of throughput scaling.

Weber, Robert S.↗
DOE OSTI2014

Cobalt Complexes Containing Pendant Amines in the Second Coordination Sphere as Electrocatalysts for H2 Production

A series of heteroleptic 17e- cobalt complexes, [CpCoII(PtBu2NPh2)](BF4), [CpC6F5CoII(PtBu2NPh2)](BF4), [CpC5F4NCoII(PtBu2NPh2)](BF4), [where P2tBuN2Ph = 1,5-diphenyl-3,7-di(tert-butyl)-1,5-diaza-3,7-diphosphacyclooctane, CpC6F5 = C5H4(C6F5), and CpC5F4N = C5H4(C5F4N)] were synthesized, and structures of all three were determined by X-ray crystallography. Electrochemical studies showed that the CoIII/II couple of [CpC5F4NCoII(PtBu2NPh2)]+ appears 250 mV positive of the CoIII/II couple of [CpCoII(PtBu2NPh2)] as a result of the strongly electron-withdrawing perfluorpyridyl substituent on the Cp ring. Reduction of these paramagnetic CoII complexes by KC8 led to the diamagnetic 18e- complexes CpICo(PtBu2NPh2), CpC6F5CoI(PtBu2NPh2), CpC5F4NCoI(PtBu2NPh2), which were also characterized by crystallography. Protonation of these neutral CoI complexes led to the cobalt hydrides [CpCoIII(PtBu2NPh2)H](BF4), [CpC6F5CoIII(PtBu2NPh2)H](BF4), and [CpC5F4NCoIII(PtBu2NPh2)H](BF4). The cobalt hydride with the most electron-withdrawing Cp ligand, [CpC5F4NCoIII(PtBu2NPh2)H]+ is an electrocatalyst for production of H2 using 4-MeOC6H4NH3BF4 (pKaMeCN = 11.86) with a turnover frequency of 350 s-1 and an overpotential of 0.75 V. Experimental measurement of thermochemical data provided further insights into the thermodynamics of H2 elimination. This research was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences. Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.

hydrogen, catalysis, electrocatalysis, proton rela↗
DOE OSTI2015

Simulating and evaluating best management practices for integrated landscape management scenarios in biofuel feedstock production: Evaluating Best Management Practices for Biofuel Feedstock Production

Sound crop and land management strategies can maintain land productivity and improve the environmental sustainability of agricultural crop and feedstock production. This study evaluates the improvement of water sustainability through an integrated landscaping management strategy, where landscaping design, land management operations, crop systems, and agricultural best management practices (BMPs) play equal roles. The strategy was applied to the watershed of the South Fork Iowa River in Iowa, with a focus on implementing riparian buffers and converting low productivity land to provide cellulosic biomass while benefiting soil and water quality. The Soil and Water Assessment Tool (SWAT) was employed to simulate the impact of integrated landscape design on nutrients, suspended sediments, and flow on the watershed and subbasin scales. First, the study evaluated the representation of buffer strip as a vegetative barrier and as a riparian buffer using trapping efficiency and area ratio methods in SWAT. For the riparian buffer, the area ratio method tends to be more conservative, especially in nitrate loadings, while the trapping efficiency method generates more optimistic results. The differences between the two methods increase with buffer width. The two methods may not be comparable for the field-scale vegetative barrier simulation because of limitations in model spatial resolution. Landscape scenarios were developed to quantify water quality under (1) current land use, (2) partial land conversion to switchgrass, and (3) riparian buffer implementation. Results show that when low productivity land (15.2% of total watershed land area) is converted to grow switchgrass, suspended sediment, total nitrogen, total phosphorus, and nitrate loadings are reduced by 69.3%, 55.5%, 46.1%, and 13.4%, respectively, in the watershed surface streams. The reduction was less extensive when riparian buffer strips (30 m or 50 m) were applied to the stream network at 1.4% of total land area in the watershed. At the subbasin level, the degree of nutrient and suspended sediment reduction varies extensively, ranging from a few percent up to 55%. Results indicate that effective landscape design on current agricultural land can potentially bring marked improvements in water quality and soil erosion control while producing food and fuel feedstock in the South Fork Iowa River watershed. The concept can be integrated with other watershed management programs to improve sustainability of land, water, and the ecosystem.

bioenergy production↗
DOE OSTI2013

Hydrogen Production using Nickel Electrocatalysts with Pendant Amines: Ligand Effects on Rates and Overpotentials

A Ni-based electrocatalyst for H2 production, [Ni(8PPh2NC6H4Br)2](BF4)2, featuring eight-membered cyclic diphosphine ligands incorporating a single amine base, 1-para-bromo-phenyl-3,7-triphenyl-1-aza-3,7-diphosphacycloheptane (8PPh2NC6H4Br) has been synthesized and characterized. X-ray ?diffraction studies reveal that the cation of [Ni(8PPh2NC6H4Br)2(CH3CN)](BF4)2 has a distorted trigonal bipyramidal geometry. In CH3CN [Ni(8PPh2NC6H4Br)2]2+ is an electrocatalyst for reduction of protons, and it has a maximum turnover frequency for H2 production of 800 s-1 with a 700 mV overpotential (at Ecat/2) when using [(DMF)H]OTf as the acid. Addition of H2O to acidic CH3CN solutions of [Ni(8PPh2NC6H4Br)2]2+ results in an increase of the turnover frequency for H2 production to a maximum of 3,300 s-1 with an overpotential of 760 mV at Ecat/2. Computational studies carried out on [Ni(8PPh2NC6H4Br)2]2+ indicate the observed catalytic rate is limited by formation of non-productive protonated isomers, diverting active catalyst from the catalytic cycle. The results of this research show that proton delivery from the exogenous acid to the correct position on the proton relay of the metal complex is essential for fast H2 production. This research was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences. Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.

H2 Production, Ni - electrocatalysis, pendant amin↗
DOE OSTI2016

Experimental and Computational Mechanistic Studies Guiding the Rational Design of Molecular Electrocatalysts for Production and Oxidation of Hydrogen

Understanding how to control the movement of protons and electrons is crucial to the design of fast, efficient electrocatalysts for hydrogen production and oxidation based on earth-abundant metals. Our work seeks to elucidate fundamental questions about proton movement. We have demonstrated that incorporating a pendant amine functioning as a proton relay in the second coordination sphere of a metal complex helps proton mobility, resulting in faster and more energy efficient catalysts. Proton transfer reactions are often rate limiting, and are influenced by several factors, such as pKa values, steric effects, hydrogen bonding, and solvation/desolvation of the exogenous base and acid employed. The presence of multiple protonation sites introduces branching points along the catalytic cycle, making less productive pathways accessible, or leading to the formation of stable off-cycle species. Using ligands with only one pendant amine mitigates this problem and results in catalysts with high rates for production of H2. For H2 oxidation catalysts, iron complexes with a high H2 binding affinity were developed. However, the improvement of H2 binding enthalpy resulted in a pKa mismatch between the protonated metal center and the protonated pendant amine, and consequently to rate-limiting intramolecular proton movement. Taken altogether, our results demonstrate the necessity of optimizing the entire catalytic cycle, as the optimization of a specific catalytic step can negatively influence another step, and not necessarily lead to better catalytic performance. We discuss a general procedure, based on thermodynamic arguments, which allows the simultaneous minimization of the free energy change of each catalytic step, yielding a nearly flat free energy surface, with no large barriers due to energy mismatches from either high- or low-energy intermediates. This research was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences. Pacific Northwest National Laboratory is operated by Battelle for DOE.

hydrogen, catalysis, quantum chemistry, proton tra↗
DOE OSTI2014

Biomass Feedstocks for Renewable Fuel Production: A review of the impacts of feedstock and pretreatment on the yield and product distribution of fast pyrolysis bio-oils and vapors

Renewable transportation fuels from biomass have the potential to substantially reduce greenhouse gas emissions and diversify global fuel supplies. Thermal conversion by fast pyrolysis converts up to 75% of the starting plant material (and its energy content) to a bio-oil intermediate suitable for upgrading to motor fuel. Woody biomass, by far the most widely-used and researched material, is generally preferred in thermochemical processes due to its low ash content and high quality bio-oil produced. However, the availability and cost of biomass resources, e.g. forest residues, agricultural residues, or dedicated energy crops, vary greatly by region and will be key determinates in the overall economic feasibility of a pyrolysis-to-fuel process. Formulation or blending of various feedstocks, combined with thermal and/or chemical pretreatment, could facilitate a consistent, high-volume, lower-cost biomass supply to an emerging biofuels industry. However, the impact of biomass type and pretreatment conditions on bio-oil yield and quality, and the potential process implications, are not well understood. This literature review summarizes the current state of knowledge regarding the effect of feedstock and pretreatments on the yield, product distribution, and upgradability of bio-oil.

09 BIOMASS FUELS↗
DOE OSTI2024

Wind Turbine Design Optimization for Hydrogen Production

To help meet the need for inexpensive green fuels, we are working on wind turbine design optimization specifically for hydrogen production. We have thus far achieved a 1.53% decrease in LCOH as compared to a turbine optimized for LCOE using the same code, design variables, and models. We accomplished this by optimizing some components of the wind turbine tower, rotor, and drivetrain design with hydrogen production and costs in the design loop.

hydrogen↗