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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 631 records · Page 35

Optimizing tradeoffs implicit during bioenergy crop improvement: Understanding the effect of altered cell wall and sugar content on sorghum-associated pathogenic bacteria

Plant-derived production of renewable fuels and chemicals has the potential to reduce fossil fuel dependency, increase domestic energy security, enhance US farming and agricultural economic opportunities, and reduce greenhouse gas emissions. Realizing the potential of these alternate energy sources necessitates the development of high biomass-yielding crops. To limit competition with the production of food and feed, these specialized crop varieties, many of which will harbor modifications to cell wall structures and display altered carbon partitioning, will be cultivated on marginal land that does not provide ideal growing conditions. Consequently, the plants are anticipated to be more vulnerable to diseases.

09 BIOMASS FUELS↗

BIOMASS TO BIO-OIL BY LIQUEFACTION

Significant efforts have been devoted to develop processes for the conversion of biomass, an abundant and sustainable source of energy, to liquid fuels and chemicals, in order to replace diminishing fossil fuels and mitigate global warming. Thermochemical and biochemical methods have attracted the most attention. Among the thermochemical processes, pyrolysis and liquefaction are the two major technologies for the direct conversion of biomass to produce a liquid product, often called bio-oil. This chapter focuses on the liquefaction, a medium-temperature and high-pressure thermochemical process for the conversion of biomass to bio-oil. Water has been most commonly used as a solvent and the process is known as hydrothermal liquefaction (HTL). Fundamentals of HTL process, key factors determining HTL behavior, role of catalyst in HTL, properties of produced bio-oil, and the current status of the technology are summarized. The liquefaction of biomass by using organic solvents, a process called solvolysis, is also discussed. A wide range of biomass feedstocks have been tested for liquefaction including wood, crop residues, algae, food processing waste, and animal manure.

bio-oil↗

Optimization and purification of magnesium borides fabricated by combustion synthesis and by high-temperature sintering

Hydrogen as a fuel provides several benefits over the use of fossil fuels; however, one challenge in utilizing hydrogen as an energy carrier revolves around its storage. Achieving sufficient volumetric hydrogen density in a storage solution will facilitate hydrogen’s adoption for use in both stationary and mobile applications. Solid-state hydrogen storage provides a promising pathway to solving this problem. However, the hydrogenation of these materials is characterized by slow kinetics and extreme thermodynamic conditions. Magnesium borohydride (Mg(BH4)2) is a promising material in hydrogen storage due to its reversible properties and a theoretical hydrogen capacity of 14.9 wt.%. To synthesize this material, combustion synthesis of magnesium borides (MgBx) has been implemented with the aim to further lower thermodynamic requirements for direct hydrogenation. A drawback of this process is the potential formation of oxide contaminants, which decrease hydrogenation/dehydrogenation and recyclability performance. The present work focuses on identifying parameters useful for reducing contamination and evaluating potential pathways to the purification of magnesium borides with the goal of improving their quality.

Camarena, Miguel Joaquin↗

Design and modeling for hydrogen fuel cell conversion of parcel delivery trucks

With an emphasis on reducing fossil fuel consumption and emissions, major delivery service corporations have begun deploying and operating Class 6 zero emissions delivery vans. Battery electric delivery vans are currently available, but their range is a limitation and doesn’t offer flexibility in assigning vehicles to delivery routes. Fuel cell hybrid delivery vans offer a zero emissions solution with extended range and route planning flexibility. In a competitive market, a delivery van design that trades the fuel cell and battery size, performance, and cost is critical to the success and adoption of these zero emissions trucks. This paper outlines a systematic approach using real world operational data and duty cycles to properly size the fuel cell and battery for a zero emissions hybrid delivery van. The approach uses real world GPS data to define routes and duty cycles, along with vehicle powertrain models to assess performance capabilities. Furthermore, the study suggests that a 32 kW fuel cell power system paired with a 49 kWh battery energy storage system and 15 kg of hydrogen storage is a desired option to complete the most demanding parcel and delivery duty cycles.

08 HYDROGEN↗

Ethylene-Forming Enzyme and Bioethylene Production

Worldwide, ethylene is the most produced organic compound. It serves as a building block for a wide variety of plastics, textiles, and chemicals, and a process has been developed for its conversion into liquid transportation fuels. Currently, commercial ethylene production involves steam cracking of fossil fuels, and is the highest CO2-emitting process in the chemical industry. Therefore, there is great interest in developing technology for ethylene production from renewable resources including CO2 and biomass. Ethylene is produced naturally by plants and some microbes that live with plants. One of the metabolic pathways used by microbes is via an ethylene-forming enzyme (EFE), which uses a-ketoglutarate and arginine as substrates. EFE is a promising biotechnology target because the expression of a single gene is sufficient for ethylene production in the absence of toxic intermediates. Here we present the first comprehensive review and analysis of EFE, including its discovery, sequence diversity, reaction mechanism, predicted involvement in diverse metabolic modes, heterologous expression, and requirements for harvesting of bioethylene. A number of knowledge gaps and factors that limit ethylene productivity are identified, as well as strategies that could guide future research directions.

09 BIOMASS FUELS↗

Flexible Opportunity Fuels for Process Heat and Steam Generation

The majority of industrial process heating and steam generation is currently fueled by natural gas or coal. Other fuels that are not used throughout industry, such as biomass, anaerobic digester gas and petroleum coke can potentially supplement or replace natural gas and coal in various process heating and steam generation applications. These non-traditional fuel supply options, also known as opportunity fuels, can enhance energy security for industrial facilities by increasing fuel flexibility and reducing or eliminating reliance on traditional fossil fuels. They can also provide significant economic benefits, by reducing fuel costs and improving profit margins. Some fuels may even be available at a negative cost, as owners seek to dispose of waste products that may have energy content.

Lemar, Jr, Paul L.↗

Laminar burning speed measurements for hydrogen enhanced natural gas in a spherical chamber

This work presents laminar burning speed measurements for natural gas and hydrogen enhanced natural gas in gas-turbine conditions using a spherical combustion chamber at an initial temperature and pressure of 296 K and 10 atm, respectively. Natural gas and hydrogen fuels were prepared and mixed with a synthetic air mixture comprised of oxygen, nitrogen, and helium. The experimental data collected during 10 atm ignition was used to predict the LBS at elevated pressures (30 bar) to approach gas-turbine operating conditions. A significant enhancing effect of combustion pressure on LBS was observed, as well as H2 dilution. This work provides fundamental combustion data relevant to sustainable fuels to reduce economic dependence on carbon-based fossil fuels and reduce anthropogenic climate effects through 2050.

Yovino, Louis↗

Evidence for a single impact at the Cretaceous-Tertiary boundary from trace elements

Not only meteoritic elements (Ir, Ni, Au, Pt metals), but also some patently non-meteoritic elements (As, Sb) are enriched at the K-T boundary. Eight enriched elements at 7 K-T sites were compared and it was found that: All have fairly constant proportions to Ir and Kilauea (invoked as an example of a volcanic source of Ir by opponents of the impact theory) has too little of 7 of these 8 elements to account for the boundary enrichments. The distribution of trace elements at the K-T boundary was reexamined using data from 11 sites for which comprehensive are available. The meteoritic component can be assessed by first normalizing the data to Ir, the most obviously extraterrestrial element, and then to Cl chondrites. The double normalization reduces the concentration range from 11 decades to 5 and also facilitates the identification of meteoritic elements. At sites where trace elements were analyzed in sub-divided samples of boundary clay, namely, Caravaca (SP), Stevns Klint (DK), Flaxbourne River (NZ) and Woodside Creek (NZ), Sb, As and Zn are well correlated with Ir across the boundary implying a common deposition mechanism. Elemental carbon is also enriched by up to 10,000 x in boundary clay from 5 K-T sides and is correlated with Ir across the boundary at Woodside Creek. While biomass would appear to be the primary fuel source for this carbon a contribution from a fossil fuel source may be necessary in order to account for the observed C abundance.

Gilmour, Iain↗

Biorefinery for combined production of jet fuel and ethanol from lipid‐producing sugarcane: a techno‐economic evaluation

Abstract Replacing fossil fuels with an economically viable green alternative at scale has proved most challenging in the aviation sector. Recently sugarcane, the most productive crop on the planet, has been engineered to accumulate lipids. This opens the way for production of far more industrial vegetable oil per acre than previously possible. This study performs techno‐economic feasibility analysis of jet fuel production from this new cost efficient and high yield feedstock. A comprehensive process model for biorefinery producing hydrotreated jet fuel (from lipids) and ethanol (from sugars), with 1 600 000 MT yr −1 lipid‐cane processing capacity, was developed in SuperPro Designer. Considering lipid‐cane development is continuing for higher oil concentrations, analysis was performed with lipid‐cane containing 5%, 10%, 15%, and 20% lipids. Capital investments for the biorefinery ranged from 238.1 to 351.2 million USD , with jet fuel capacities of 12.6–50.5 million liters (correspondingly ethanol production of nil to 102.6 million liters). The production cost of jet fuel for different scenarios was estimated $0.73 to $1.79 per liter ($2.74 to $6.76 per gal) of jet fuel. In all cases, the cost of raw materials accounted for more than 70% of total operational cost. Biorefinery was observed self‐sustainable for steam and electricity requirement, because of in‐house steam and electricity generation from burning of bagasse. Minimum fuel selling prices with a 10% discount rate for 20% lipid case was estimated $1.40/L ($5.31/gal), which was lower than most of the reported prices of renewable jet fuel produced from other oil crops and algae. Along with lower production costs, lipid‐cane could produce as high as 16 times the jet fuel (6307 L ha −1 ) per unit land than that of other oil crops and do so using low‐value land unsuited to most other crops, while being highly water and nitrogen use efficient.

09 BIOMASS FUELS↗

Performance and economics of advanced energy conversion systems for coal and coal-derived fuels

The desire to establish an efficient Energy Conversion System to utilize the fossil fuel of the future - coal - has produced many candidate systems. A comparative technical/economic evaluation was performed on the seven most attractive advanced energy conversion systems. The evaluation maintains a cycle-to-cycle consistency in both performance and economic projections. The technical information base can be employed to make program decisions regarding the most attractive concept. A reference steam power plant was analyzed to the same detail and, under the same ground rules, was used as a comparison base. The power plants were all designed to utilize coal or coal-derived fuels and were targeted to meet an environmental standard. The systems evaluated were two advanced steam systems, a potassium topping cycle, a closed cycle helium system, two open cycle gas turbine combined cycles, and an open cycle MHD system.

Corman, J. C.↗

Fuel Sensitivity of Lean Blowout in a RQL Gas Turbine Combustor

Transition from fossil fuels to synthetic drop-in fuels without the need to change existing combustors is the current research topic. The combustor performances such as cold-day ignition limits, lean blow-out (LBO) limits and altitude relight limits are the main focus points. The objective of this work is to evaluate the effect of different fuel candidates on the operability of gas turbines by comparing a conventional petroleum-based fuel with one other alternative fuel candidate. Time filtered Navier-Stokes simulations (TFNS) and K-LES are performed to examine the performance of these fuels at the stable conditions close to blow-out in a referee combustor rig.

Fuel sensitivity↗

Fuel Sensitivity of Lean Blowout in a RQL Gas Turbine Combustor

Transition from fossil fuels to synthetic drop-in fuels without the need to change existing combustors is the current research topic. The combustor performances such as cold-day ignition limits, lean blow-out (LBO) limits and altitude relight limits are the main focus points. The objective of this work is to evaluate the effect of different fuel candidates on the operability of gas turbines by comparing a conventional petroleum-based fuel with one other alternative fuel candidate. Time filtered Navier-Stokes simulations (TFNS) and K-LES are performed to examine the performance of these fuels at the stable conditions close to blow-out in a referee combustor rig.

referee rig↗

An Integrated Sustainability Evaluation of Indirect Liquefaction of Biomass to Liquid Fuels

Developing a more sustainable biofuel production process holds the key for displacing fossil fuels with biofuels for sustainable greenhouse gas emissions and natural resource consumption mitigation. A holistic sustainability analysis for the production of biofuel plays a critical role on the improvement of the overall life cycle sustainability. Once a conceptual conversion process is developed, the next step is to evaluate its overall sustainability, preferably based on a process sustainability evaluation methodology using various indicators. The EPA's GREENSCOPE methodology evaluates processes in four areas: environment, energy, economics, and efficiency. The method develops relative scores for indicators that allow comparisons across various technologies. In this study, we have implemented GREENSCOPE methodology for a sustainability performance assessment of NREL's indirect liquefaction of biomass to high-octane gasoline blendstock by evaluating a range of metrics beyond the typical minimum fuel selling price and greenhouse gas considerations. We applied this methodology to evaluate the sustainability performance of this gate-to-gate conceptual design. One outcome of the sustainability evaluation is to allow researchers to identify process areas in need of sustainability improvement, as well as the challenges and opportunities for achieving the best possible sustainability target.

09 BIOMASS FUELS↗

Synthetic and Biomass Alternate Fueling in Aviation

Worldwide, aviation alone uses 85 to 95 billion gallons of nonrenewable fossil fuel per year (2008). General transportation fueling can accommodate several different fuels; however, aviation fuels have very specific requirements. Biofuels have been flight demonstrated, are considered renewable, have the capacity to become "drop-in" replacements for Jet-A fuel, and solve the CO2 climate change problem. The major issue is cost; current biomass biofuels are not economically competitive. Biofuel feedstock sources being researched are halophytes, algae, cyanobacteria, weeds-to-crops, wastes with contingent restraints on use of crop land, freshwater, and climate change. There are five major renewable energy sources: solar thermal, solar photovoltaic, wind, drilled geothermal and biomass, each of which have an order of magnitude greater capacity to meet all energy needs. All five address aspects of climate change; biomass has massive potential as an energy fuel feedstock.

Hendricks, R.C.↗

Data Driven Fuel Efficient Driving Behavior Feedback for Fleet Vehicles

Dependency of the transport sector on fossil fuels is encouraging a significant amount of research in to improving fuel efficiency in vehicles. Three primary techniques are identified for vehicle fuel efficiency improvement: 1) vehicle technology improvements such as drivetrain improvements, 2) traffic infrastructure improvements such as traffic flow management and route selection, and 3) driver behavior changes such as acceleration and deceleration profiles. Out of the 3 techniques, driver behavior changing has the least implementation cost and is able to provide immediate results. Thus, this paper presents a fuel efficient driving behavior identification and feedback architecture that is specific to fleet vehicles. The presented method utilizes historical data from fleet drivers on specific routes and generates fuel optimal velocity profiles that do not affect travel time. The identified velocity profile is the prompted to the driver via a low-cost plug-and-play style un-obstructive display. The display uses an intuitive and easily understandable visualization to prompt drivers on fuel efficient velocity. The presented architecture was tested on the Idaho National Laboratory (INL) bus fleet in real-world driving conditions and was shown to be able to increase the fuel economy by 9% and 20% in two different driving scenarios.

99 GENERAL AND MISCELLANEOUS↗

Win–Win strategies to promote air pollutant control policies and non-fossil energy target regulation in China

The rapid growth of energy consumption in China has led to increased emissions of air pollutants. As a response, in its 12th Five Year Plan the Chinese government proposed mitigation targets for SO2 and NOx emissions. Herein we have investigated mitigation measures taken in different sectors and their corresponding impacts on the energy system. Additionally, as non-fossil energy development has gained traction in addressing energy and environmental challenges in China, we further investigated the impact of non-fossil energy development on air pollutant emissions, and then explored interactions and co-benefits between these two types of policies. An extended Global Change Assessment Model (GCAM) was used in this study, which includes an additional air pollutant emissions control module coupling multiple end-of-pipe (EOP) control technologies with energy technologies, as well as more detailed end-use sectors in China. We find that implementing EOP control technologies would reduce air pollution in the near future, but with little room left to implement these EOP technologies, other cleaner and more efficient technologies are also effective. These technologies would reduce final energy consumption, increase electricity’s share in final energy, and increase the share of non-fossil fuels in primary energy and electricity consumption. Increasing non-fossil energy usage at China’s proposed adoption rate would in turn also reduce SO2 and NOx emissions, however, the reductions from this policy alone still lag behind the targeted requirements of air pollutant reduction. Fortunately, a combination of air pollutant controls and non-fossil energy development could synergistically help realize the respective individual targets, and would result in lower costs than would addressing these issues separately.

Air pollution↗

Bioconversion of renewable feedstocks by Rhodococcus opacus

The production of fuels and chemicals from renewable feedstocks is necessary for a fossil fuel independent economy. Lignin and other industrial wastes represent sustainable, non-food feedstocks that can be tapped for microbe-based bioproduction. Rhodococcus opacus is a gram-positive bacterium capable of catabolizing a broad range of feedstocks, and recent technological advances have further established its potential for lignin and industrial waste valorization. In the process of developing R. opacus as a platform for bioproduction, metabolic profiling has elucidated its native mechanisms of bioconversion, adaptive evolution has enhanced its tolerance towards inhibitory feedstocks, and genetic engineering has enabled it to produce novel products, such as wax esters, free fatty acids, and long chain hydrocarbons. Furthermore, we present recent examples of broad feedstock utilization and value-added chemical production by R. opacus , demonstrating its potential as an industrially-relevant strain.

09 BIOMASS FUELS↗