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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 505 records · Page 28
All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

Kinetic features of xylan de-polymerization in production of xylose monomer and furfural during acid pretreatment for kenaf, forage sorghums and sunn hemp feedstocks

A kinetic study of acid pretreatment was conducted for sorghum non-brown mid rib (SNBMR) ( Sorghum bicolor L Moench ), sorghum-brown mid rib (SBMR), sunn hemp ( Crotalaria juncea L ) and kenaf ( Gossypiumhirsutum L ), focusing on rates of xylose monomer and furfural formation. The kinetics was investigated using two independent variables, reaction temperature (150 and 160°C) and acid concentration (1 and 2 wt%), with a constant dry biomass loading of 10 wt% and a treatment time up to 20 min while sampling the mixture every 2 min. The experimental data were fitted using a two-step kinetic model based on irreversible pseudo first order kinetics at each step. Varied kinetic orders on the acid concentration, ranging from 0.2 to >3, were observed for both xylose and furfural formation, the values depending on the feedstock. The crystallinity index of raw biomass was shown to be a major factor influencing the rate of both xylose and furfural formation. As a result, a positive correlation was observed between the activation energy and biomass crystallinity index for xylose formation.

09 BIOMASS FUELS↗
DOE OSTI2013

Improved Method for Isolation of Microbial RNA from Biofuel Feedstock for Metatranscriptomics

Metatranscriptomics—gene express profiling via DNA sequencing—is a powerful tool to identify genes that are ac- tively expressed and might contribute to the phenotype of individual organisms or the phenome (the sum of several phenotypes) of a microbial community. Furthermore, metatranscriptome studies can result in extensive catalogues of genes that encode for enzymes of industrial relevance. In both cases, a major challenge for generating a high quality metatranscriptome is the extreme lability of RNA and its susceptibility to ubiquitous RNAses. The microbial commu- nity (the microbiome) of the cow rumen efficiently degrades lignocelullosic biomass, generates significant amounts of methane, a greenhouse gas twenty times more potent than carbon dioxide, and is of general importance for the physio- logical wellbeing of the host animal. Metatranscriptomes of the rumen microbiome from animals kept under different conditions and from various types of rumen-incubated biomass can be expected to provide new insights into these highly interesting phenotypes and subsequently provide the framework for an enhanced understanding of this socio- economically important ecosystem. The ability to isolate large amounts of intact RNA will significantly facilitate accu- rate transcript annotation and expression profiling. Here we report a method that combines mechanical disruption with chemical homogenization of the sample material and consistently yields 1 mg of intact RNA from 1 g of rumen-in- cubated biofuel feedstock. The yield of total RNA obtained with our method exceeds the RNA yield achieved with pre- viously reported isolation techniques, which renders RNA isolated with the method presented here as an ideal starting material for metatranscriptomic analyses and other molecular biology applications that require significant amounts of starting material.

Environmental Molecular Sciences Laboratory↗
DOE OSTI2022

Feedstock to Function (F2F) v1

The Feedstock to Function (F2F) tool was designed to help scientists and companies explore viable biofuels and bioproducts early in the R&D cycle to support more productive experimentation, while reducing early-stage exploration from months/years to days/weeks (feedstock-to-function.lbl.gov). The tool focuses on using machine learning to predict biomass-derived molecule properties, while evaluating the cost, benefits, and risks of promising molecules for sustainable aviation fuels. The tool successfully predicts (within 15% of experimental values) high-throughput aviation properties for over 10,000 molecules while enabling users to explore new possibilities and opportunities rapidly and effortlessly. It also links to lightweight life-cycle analysis and techno-economic tools for cost and emissions analyses. Predicted molecule properties include melting point, boiling point, flash point, yield sooting index, and heat of combustion. To date, F2F is more expansive and outperforms several other molecule property prediction models while enabling users (scientists, companies, and policy makers) to explore new possibilities and opportunities rapidly and effortlessly. F2F provides the foundation for developing an adaptive computational tool that predicts properties, cost, benefits, and risk of promising new and uncertified alternative jet fuel pathways and their blending effects.

Rapp, Vi↗
NASA NTRS1994

Lunar mineral feedstocks from rocks and soils: X-ray digital imaging in resource evaluation

The rocks and soils of the Moon provide raw materials essential to the successful establishment of a lunar base. Efficient exploitation of these resources requires accurate characterization of mineral abundances, sizes/shapes, and association of 'ore' and 'gangue' phases, as well as the technology to generate high-yield/high-grade feedstocks. Only recently have x-ray mapping and digital imaging techniques been applied to lunar resource evaluation. The topics covered include inherent differences between lunar basalts and soils and quantitative comparison of rock-derived and soil-derived ilmenite concentrates. It is concluded that x-ray digital-imaging characterization of lunar raw materials provides a quantitative comparison that is unattainable by traditional petrographic techniques. These data are necessary for accurately determining mineral distributions of soil and crushed rock material. Application of these techniques will provide an important link to choosing the best raw material for mineral beneficiation.

Chambers, John G.↗
NASA NTRS2017

Relationship of Powder Feedstock Variability to Microstructure and Defects in Selective Laser Melted Alloy 718

Powder-bed additive manufacturing processes use fine powders to build parts layer by layer. For selective laser melted (SLM) Alloy 718, the powders that are available off-the-shelf are in the 10-45 or 15-45 micron size range. A comprehensive investigation of sixteen powders from these typical ranges and two off-nominal-sized powders is underway to gain insight into the impact of feedstock on processing, durability and performance of 718 SLM space-flight hardware. This talk emphasizes an aspect of this work: the impact of powder variability on the microstructure and defects observed in the as-fabricated and full heated material, where lab-scale components were built using vendor recommended parameters. These typical powders exhibit variation in composition, percentage of fines, roughness, morphology and particle size distribution. How these differences relate to the melt-pool size, porosity, grain structure, precipitate distributions, and inclusion content will be presented and discussed in context of build quality and powder acceptance.

Characterization↗
NASA NTRS2021

A Study of Particle Size Metrics Using Non-Spherical Feedstock for Metal Additive Manufacturing

The goal of this work was to determine which standard particle size metric derived from optical analysis most closely approximates the sieved weight percent of irregularly shaped powder intended to be used for directed energy deposition. In this investigation, equivalent circle diameter, maximum diameter, minimum diameter, and perimeter are used as metrics to “virtually sieve” the particles in samples of irregularly shaped powder into the following particle size bins: <45 µm, 45 µm - 150 µm, and >150 µm. The percentage in the 45 µm - 150 µm bin is then compared to the weight percent of the powder mechanically sieved into this size range. The absolute difference between the virtually sieved percentage and the mechanically sieved percentage was assessed for 81 samples of mechanically-generated stainless steel 316L powder all produced under different processing conditions in an oscillation ball mill. This difference was found to be on average, the least with the minimum diameter assessed as an area percentage, followed by the equivalent diameter assessed as an area percentage, and then the maximum diameter assessed as a percentage of the total number of particles ranked third. These findings may be used by powder production process engineers and quality assurance personnel to assist in process control as more diverse additive manufacturing feedstocks become utilized.

Marcus Jackson↗
NASA NTRS2021

Systematic Review on Effects of Bioenergy From Edible Versus Inedible Feedstocks on Food Security

Achieving food security is a critical challenge of the Anthropocene that may conflict with environmental and societal goals such as increased energy access. The“fuel versus food”debate coupled with climate mitigation efforts has given rise to next-generation biofuels. Findings of this systematic review indicate just over half of the studies (56% of 224 publications) reported a negative impact of bioenergy production on food security. However, no relationship was found between bioenergy feedstocks that are edible versus inedible and food security (Pvalue=0.15). A strong relationship was found between bioenergy and type of food security parameter (Pvalue < 0.001), sociodemographic index of study location (Pvalue=0.001),spatial scale (Pvalue < 0.001), and temporal scale (Pvalue=0.017). Programs and policies focused on bioenergy and climat emitigation should monitor multiple food security parameters at various scales over the long term toward achieving diverse sustainability goals.

food security↗
DOE OSTI2012

Engineered plant biomass feedstock particles

A new class of plant biomass feedstock particles characterized by consistent piece size and shape uniformity, high skeletal surface area, and good flow properties. The particles of plant biomass material having fibers aligned in a grain are characterized by a length dimension (L) aligned substantially parallel to the grain and defining a substantially uniform distance along the grain, a width dimension (W) normal to L and aligned cross grain, and a height dimension (H) normal to W and L. In particular, the L.times.H dimensions define a pair of substantially parallel side surfaces characterized by substantially intact longitudinally arrayed fibers, the W.times.H dimensions define a pair of substantially parallel end surfaces characterized by crosscut fibers and end checking between fibers, and the L.times.W dimensions define a pair of substantially parallel top and bottom surfaces. The L.times.W surfaces of particles with L/H dimension ratios of 4:1 or less are further elaborated by surface checking between longitudinally arrayed fibers. The length dimension L is preferably aligned within 30.degree. parallel to the grain, and more preferably within 10.degree. parallel to the grain. The plant biomass material is preferably selected from among wood, agricultural crop residues, plantation grasses, hemp, bagasse, and bamboo.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2014

Application of Buckmaster Electrolyte Ion Leakage Test to Woody Biofuel Feedstocks

In an earlier ASABE paper, Buckmaster reported that ion conductivity of biomass leachate in aqueous solution was directly correlated with activity access to plant nutrients within the biomass materials for subsequent biological or chemical processing. The Buckmaster test involves placing a sample of the particles in a beaker of constant-temperature deionized water and monitoring the change in electrical conductivity over time. We adapted the Buckmaster method to a range of woody biomass and other cellulosic bioenergy feedstocks. Our experimental results suggest differences of electrolyte leakage between differently processed woody biomass particles may be an indicator of their utility for conversion in bioenergy processes. This simple assay appears to be particularly useful to compare different biomass comminution techniques and particle sizes for biochemical preprocessing.

09 BIOMASS FUELS↗
DOE OSTI2014

Basic refractory and slag management for petcoke carbon feedstock in gasifiers

The disclosure provides methods of operating a slagging gasifier using a carbon feedstock having a relatively high V.sub.2O.sub.5 to SiO.sub.2 ratio, such as petcoke. The disclosure generates a combined chemical composition in the feed mixture having less than 25 wt. % SiO.sub.2, greater than 20 wt. % V.sub.2O.sub.5, and greater than 20 wt. % CaO. The method takes advantage of a novel recognition that increased levels of SiO.sub.2 tend to decrease dissolution of the V.sub.2O.sub.3 which forms under the reducing conditions of the gasifier, and utilizes the CaO additive to establish a chemical phase equilibria comprised of lower melting compounds. The method further provides for control based on the presence of Al.sub.2O.sub.3 and FeO, and provides for a total combined chemical composition of greater than about 5 wt. % MgO for use with refractory linings comprised of MgO based refractory brick.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2014

Field-to-Fuel Performance Testing of Various Biomass Feedstocks: Production and Catalytic Upgrading of Bio-Oil to Refinery Blendstocks (Presentation)

Large-scale, cost-competitive deployment of thermochemical technologies to replace petroleum oil with domestic biofuels will require inclusion of high volumes of low-cost, diverse biomass types into the supply chain. However, a comprehensive understanding of the impacts of feedstock thermo-physical and chemical variability, particularly inorganic matter (ash), on the yield and product distribution

09 BIOMASS FUELS↗
DOE OSTI2015

Manufacturing Process Development to Produce Depleted Uranium Wire for EBAM Feedstock

Wire produced from depleted uranium (DU) is needed as feedstock for the Electron-Beam Additive Manufacturing (EBAM) process. The goal is to produce long lengths of DU wire with round or rectangular cross section, nominally 1.5 mm (0.060 inches). It was found that rolling methods, rather than swaging or drawing, are preferable for production of intermediate quantities of DU wire. Trials with grooveless rolling have shown that it is suitable for initial reductions of large stock. Initial trials with grooved rolling have been successful, for certain materials. Modified square grooves (square round-bottom vee grooves) with 12.5 % reduction of area per pass have been selected for the reduction process.

36 MATERIALS SCIENCE↗
DOE OSTI2015

Apparatus and method for converting biomass to feedstock for biofuel and biochemical manufacturing processes

The present invention includes improved systems and methods for producing biomass-derived feedstocks for biofuel and biochemical manufacturing processes. The systems and methods use components that are capable of transferring relatively high concentrations of solid biomass utilizing pressure variations between vessels, and allows for the recovery and recycling of heterogeneous catalyst materials.

09 BIOMASS FUELS↗
DOE OSTI2016

Processes for converting biomass-derived feedstocks to chemicals and liquid fuels

The present invention provides processes, methods, and systems for converting biomass-derived feedstocks to liquid fuels and chemicals. The method generally includes the reaction of a hydrolysate from a biomass deconstruction process with hydrogen and a catalyst to produce a reaction product comprising one of more oxygenated compounds. The process also includes reacting the reaction product with a condensation catalyst to produce C.sub.4+ compounds useful as fuels and chemicals.

09 BIOMASS FUELS↗
DOE OSTI2013

Global Warming Potential and Eutrophication Potential of Biofuel Feedstock Crops Produced in Florida, Measured Under Different Scenarios

The agriculture sector is in a growing need to develop greenhouse gas (GHG) mitigation techniques to reduce the enhanced greenhouse effect. The challenge to the sector is not only to reduce net emissions but also increase production to meet growing demands for food, fiber, and biofuel. This study focuses on the changes in the GHG balance of three biofuel feedstock (biofuel sugarcane, energy-cane and sweet sorghum) considering changes caused by the adoption of conservationist practices such as reduced tillage, use of controlled-release fertilizers or when cultivation areas are converted from burned harvest to green harvest. Based on the Intergovernmental Panel on Climate Change (IPCC) (2006) balance and the Tools for the Reduction and Assessment of Chemical and Other Environmental Impacts (TRACI) characterization factors published by the EPA, the annual emission balance includes use energy (diesel and electricity), equipment, and ancillary materials, according to the mean annual consumption of supplies per hectare. The total amounts of GWP were 2740, 1791, and 1910 kg CO2e ha-1 y-1 for biofuel sugarcane, energy-cane and sweet sorghum, respectively, when produced with conventional tillage and sugarcane was burned prior to harvesting. Applying reduced tillage practices, the GHG emissions reduced to 13% for biofuel sugarcane, 23% for energy-cane and 8% for sweet sorghum. A similar decrease occurs when a controlled-release fertilizer practice is adopted, which helps reduce the total emission balance in 5%, 12% and 19% for biofuel sugarcane, energy-cane and sweet sorghum, respectively and a 31% average reduction in eutrophication potential. Moreover, the GHG emissions for biofuel sugarcane, with the adoption of green harvest, would result in a smaller GHG balance of 1924 kg CO2e ha-1 y-1, providing an effect strategy for GHG mitigation while still providing a profitable yield in Florida.

09 BIOMASS FUELS↗