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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 595 records · Page 33
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Understanding the trade-offs of national municipal solid waste estimation methods for circular economy policy

Policies embracing circular economy concepts have taken hold in national legislation around the world. As the number of governments and organizations adopting circular economy policies increases, so does the need for accurate and timely measurement of material resource flows. Since many countries do not have access to centrally reported municipal solid waste (MSW) data, estimation and modeling are critical in evaluating circular economy policy effectiveness. The purpose of this paper is to examine three modeling approaches estimating national MSW data in the United States, including industry-based material flow analysis, waste-extended input-output modeling, and aggregated regional waste reporting. We establish five criteria to guide the analysis through the context of policy monitoring (data quality, flow totality, update frequency, sensitivity to disruption, and product granularity) and use these criteria to analyze and score each model. We then use a literature search to identify five, internationally-implemented options for circular economy policy and determine the data and modeling components that are most helpful in evaluating policy effectiveness. Finally, we provide a crosswalk of the model scores and policy needs to inform the suitability of model selection by policy type. We found that data quality and update frequency are identified as critical components for evaluating circular economy policies within the models evaluated, and can both be fulfilled by aggregated regional waste reporting. Flow totality, sensitivity to disruption, and product granularity requirements vary by both model and policy types. While none of the evaluated models satisfy the combination of requirements for any of the five policies, industry-based material flow analysis offers flow totality for extended producer responsibility, landfill bans, and recycling rate target policies that typically require it. Here, the waste-extended input-output model can provide disruption sensitivity and product granularity as needed for policies like minimum recycled content and market restrictions. Policy developers in areas where strong centralized data collection is not an option should design policy action(s) with modeling tradeoffs in mind, including the potential hybridization of modeling approaches that may provide the most accurate national MSW estimates.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2019

Multimode jetting unlocks a trade-off between nanostructure morphology and composition in focused electron beam induced deposition

An ability to accelerate the growth rate while simultaneously controlling shape and composition of deposits is fundamental to expanding the utility of electron beam assisted deposition for “direct write” nanostructure fabrication from gas phase precursors. Here, we report on novel tunable mode of Focused Electron Beam Induced Deposition (FEBID) as enabled by the switchable use of reactive (O2) and inert (Ar) “assist” gases directed at high impingement energy and momentum to a deposition site concurrently with a supply of a precursor in a dual-nozzle FEBID arrangement. Organometallic molecules introduced into a deposition chamber in a free-molecular flow regime through a conventional gas injection nozzle, yielding a broad uniform substrate coverage by the precursor in a quasi-equilibrium adsorbed state. Simultaneously, a supersonic micro-jet from a micron-scale capillary placed in close proximity to a deposition site produces a low Knudsen number continuous flow impingement of energized “assist” gas, which perturbs the precursor state to facilitate different chemical reaction pathways. This process offers modulation of deposition outcomes, e.g., enhanced vertical growth rate (aspect ratio) of nanostructures when using argon micro-jet while locally removing parasitic carbonaceous by-products of organometallic precursor decomposition reaction by e-beam through interactions with oxygen micro-jet. Such in-situ/in operando (during growth and on-demand switchable) modulation of FEBID allows for rapid and precisely controllable deposition for a desired outcome, such as tuning metal-to-carbon composition and maintaining shape fidelity in fabricating high-aspect ratio composite nanostructures, which extends the capabilities of FEBID as a robust multi-dimensional, multi-purpose nanoscale 3D printing tool.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2010

Implications of carbon cap-and-trade for electricity rate design, with examples from Florida

The price of CO{sub 2} emissions allowances affects the structure of the utility's costs, which has implications for rate design and load management programs. Depending on the design of the program to recover these costs, utility total revenue requirements - and the rate design utilized to recover these requirements - may be impacted. A new way to think about rate design may be required. (author)

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2018

General Equilibrium Analysis of the Cobenefits and Trade-Offs of Carbon Mitigation on Local Industrial Water Use and Pollutants Discharge in China

Carbon mitigation strategies have been developed without sufficient consideration of their impacts on the water system. Here, our study evaluates whether carbon mitigation strategies would decrease or increase local industrial water use and water-related pollutants discharge by using a computable general equilibrium (CGE) model coupled with a water withdrawals and pollutants discharge module in Shenzhen, the fourth largest city in China. To fulfill China’s Nationally Determined Contributions (NDC) targets, Shenzhen’s GDP and welfare losses are projected to be 1.6% and 5.6% in 2030, respectively. The carbon abatement cost will increase from 56 USD/t CO2 in 2020 to 274 USD/t CO2 in 2030. The results reveal that carbon mitigation accelerates local industrial structure upgrading by restricting carbon-, energy-, and water-intensive industries, e.g., natural gas mining, nonmetal, agriculture, food production, and textile sectors. Accordingly, carbon mitigation improves energy use efficiency and decreases 55% of primary energy use in 2030. Meanwhile, it reduces 4% of total industrial water use and 2.2–2.4% of two major pollutants discharge, i.e., CODCr and NH3–N. Carbon mitigation can also decrease petroleum (2.2%) and V-ArOH (0.8%) discharge but has negative impacts on most heavy metal(loid)s pollutants discharge (increased by -0.01% to 4.6%). These negative impacts are evaluated to be negligible on the environment. This study highlights the importance of considering the energy–water nexus for better-coordinated energy and water resources management at local and national levels.

Su, Qiong↗
DOE OSTI2014

Siting algae cultivation facilities for biofuel production in the United States: trade-offs between growth rate, site constructability, water availability, and infrastructure

Locating sites for new algae cultivation facilities is a complex task. The climate must support high growth rates, and cultivation ponds require appropriate land and water resources as well as key utility and transportation infrastructure. We employ our spatiotemporal Biomass Assessment Tool (BAT) to select promising locations based on the open-pond cultivation of Arthrospira sp. and a strain of the order Desmidiales. 64,000 potential sites across the southern United States were evaluated. We progressively apply a range of screening criteria and track their impact on the number of selected sites, geographic location, and biomass productivity. Both strains demonstrate maximum productivity along the Gulf of Mexico coast, with the highest values on the Florida peninsula. In contrast, sites meeting all selection criteria for Arthrospira were located along the southern coast of Texas and for Desmidiales were located in Louisiana and southern Arkansas. Site selection was driven mainly by the lack of oil pipeline access in Florida and elevated groundwater salinity in southern Texas. The requirement for low salinity freshwater (<400 mg L-1) constrained Desmidiales locations; siting flexibility is greater for salt-tolerant species such as Arthrospira. Combined siting factors can result in significant departures from regions of maximum productivity but are within the expected range of site-specific process improvements.

Algae Biofuel↗