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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 343 records · Page 19
All sourcesNASA NTRSDOE OSTI
DOE OSTI2012

Recover Heat from Boiler Blowdown - Steam Tip Sheet #10

Heat can be recovered from boiler blowdown by using a heat exchanger to preheat boiler makeup water. Any boiler with continuous blowdown exceeding 5% of the steam rate is a good candidate for the introduction of blowdown waste heat recovery. Larger energy savings occur with high-pressure boilers. This revised AMO tip sheet on recovering heat from boiler blowdown provides how-to advice for improving industrial steam systems using low-cost, proven practices and technologies.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2012

Consider Installing a Condensing Economizer - Steam Tip Sheet #26A

The key to a successful waste heat recovery project is optimizing the use of the recovered energy. By installing a condensing economizer, companies can improve overall heat recovery and steam system efficiency by up to 10%. Many boiler applications can benefit from this additional heat recovery, such as district heating systems, wallboard production facilities, greenhouses, food processing plants, pulp and paper mills, textile plants, and hospitals. Condensing economizers require site-specific engineering and design, and a thorough understanding of the effect they will have on the existing steam system and water chemistry. Use this tip sheet and its companion, Considerations When Selecting a Condensing Economizer, to learn about these efficiency improvements.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2012

Cover Heated, Open Vessels - Steam Tip Sheet #19

This revised AMO steam tip sheet on covering heated, open vessels provides how-to advice for improving industrial steam systems using low-cost, proven practices and technologies.

industry, manufacturing, AMO, cover, heat, open ve↗
DOE OSTI2012

Steam Balancing and Tuning for Multifamily Residential Buildings in Chicagoland

Older heating systems often suffer from mis-investment—multiple contractors upgrading parts of systems in inadequate or inappropriate ways that reduce system functionality and efficiency—or from a lack of proper maintenance. This technical report addresses these barriers to information, contractor resources, and cost-savings. Building off of previous research, CNT Energy conducted a study to identify best practices for the methodology, typical costs, and energy savings associated with steam; system balancing.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2018

Chinese Ink: A Powerful Photothermal Material for Solar Steam Generation

Solar steam generation offers signifcant promise in alleviating fresh water crises, particularly in regions with accessible seawater and abundant insolation. Affordable, efficient, and environmentally friendly photothermal materials are needed to fabricate sunlight-driven evaporation devices. In this work, Chinese ink, a carbon-based paint used in traditional painting and calligraphy, is readily coated on diverse substrates and stabilized by atomic layer deposition (ALD) for solar steam generation. The ALD/Chinese ink coating exhibits strong and broad light absorption from the NIR to UV regions. Both ALD/Chinese-ink-coated membranes and wood display excellent photothermal properties and superior evaporation performance under simulated sunlight. This study demonstrates the potential of ALD/Chinese ink coating to achieve higher evaporation rate and efficiency by utilizing substrates with rough, structured surfaces and low thermal conductivity.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Process Considerations for the Production of Hydrogen via Steam Reforming of Oxygenated Gases from Biomass Pyrolysis and Other Conversion Processes

Abstract In 2021, average CO 2 emissions was 9.7 g CO 2 /g H 2 produced, primarily based on steam methane reforming (SMR) technology that currently dominates hydrogen production. The substitution of natural gas (NG) and other fossil feedstocks in SMRs with renewable gases may be considered as an option for reducing greenhouse gas emissions. This analysis explores process impacts and constraints associated with the potential introduction of biogenic gases into SMRs. The results indicate that replacing NG in the fuel train of the SMR, followed by partial replacement of NG in the feed train may be a feasible approach. For the CO‐ and CO 2 ‐rich gas compositions assumed in this analysis the results indicate that feed train may accommodate up to 25 mole % of biogenic gases using allowances in existing designs and/or with small modifications, while maintaining similar hydrogen output. NG substitution in higher proportions require more major changes because of increased flow rates and heat exchange requirements in the system. Biogenic gases with lower CO 2 and higher calorific values are advantageous for NG substitution, and dry reforming using the CO 2 present in the feed gas can reduce steam consumption and increase process efficiency within limits where coking does not become a new constraint.

08 HYDROGEN↗
DOE OSTI2020

Steam-Induced Coarsening of Single-Unit-Cell MFI Zeolite Nanosheets and Its Effect on External Surface Brønsted Acid Catalysis

Commonly used methods to assess crystallinity, micro-/mesoporosity, Brønsted acid site density and distribution (in micro- vs. mesopores), and catalytic activity suggest nearly invariant structure and function for aluminosilicate zeolite MFI two-dimensional nanosheets before and after superheated steam treatment. Yet, pronounced reaction rate decrease for benzyl alcohol alkylation with mesitylene, a reaction that cannot take place in the zeolite micropores, is observed. Transmission electron microscopy images reveal pronounced changes in nanosheet thickness, aspect ratio and roughness indicating that nanosheet coarsening and the associated changes in the external (mesoporous) surface structure are responsible for the changes in the external surface catalytic activity. Finally, superheated steam treatment of hierarchical zeolites can be used to alter nanosheet morphology and regulate external surface catalytic activity while preserving micro- and mesoporosity, and micropore reaction rates.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2013

Minimizing the formation of coke and methane on Co nanoparticles in steam reforming of biomass-derived oxygenates

Fundamental understanding and control of chemical transformations are essential to the development of technically feasible and economically viable catalytic processes for efficient conversion of biomass to fuels and chemicals. Using an integrated experimental and theoretical approach, we report high hydrogen selectivity and catalyst durability of acetone steam reforming (ASR) on inert carbon supported Co nanoparticles. The observed catalytic performance is further elucidated on the basis of comprehensive first-principles calculations. Instead of being considered as an undesired intermediate prone for catalyst deactivation during bioethanol steam reforming (ESR), acetone is suggested as a key and desired intermediate in proposed two-stage ESR process that leads to high hydrogen selectivity and low methane formation on Co-based catalysts. The significance of the present work also sheds a light on controlling the chemical transformations of key intermediates in biomass conversion such as ketones. We gratefully acknowledge the financial support from U. S. Department of Energy (DOE), Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences, and the Laboratory directed research and development (LDRD) project of Pacific Northwest National Laboratory (PNNL). Computing time was granted by the William R. Wiley Environmental Molecular Sciences Laboratory (EMSL). The EMSL is a U.S. DOE national scientific user facility located at PNNL, and sponsored by the U.S. DOE’s Office of Biological and Environmental Research.

biomass↗
DOE OSTI2017

Evaluation of Radioactive Aerosol Precipitation on the Inner Surfaces of Steam-Water Lines in Beyond Design Basis Accidents at NPP with RBMK

The results of modeling performed with the MELCOR code of the transport and precipitation of fission product aerosols in the steam-water lines of RBMK during beyond design basis accidents are presented. It is shown that the precipitation of fission product aerosols on the inner surfaces of steam-water lines depends on the course of the accident and can be an effective mechanism for lowering their atmospheric emissions.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2013

Evaluation of the Effectiveness of a New Technology for Extraction of Insoluble Impurities from Nuclear Power Plant Steam Generators with Purge Water

An experimental technology for the removal of insoluble impurities from a horizontal steam generator with purge water during planned shutdowns of the power generating unit is improved through a more representative determination of the concentration of impurities in the purge water ahead of the water cleanup facility and a more precise effective time for the duration of the purge process. Tests with the improved technique at power generating unit No. 1 of the Rostov Nuclear Power Plant show that the efficiency with which insoluble impurities are removed from the steam generator volume was more than two orders of magnitude greater than under the standard regulations.

42 ENGINEERING↗
DOE OSTI2016

Flare Temperature and Nitrogen Oxide Emission Reduction and Heat Transfer in the TGMP-314I Steam Boiler Firebox

Asolution is given to the problem of heat transfer in the firebox of a steam boiler, taking account of the radiation from all quadrillions of atoms constituting the flare. An innovative firebox for a steam boiler is proposed: the lower part of the firebox is a rectangular parallelepiped and the upper part a four-sided pyramid. The calculations show that in the proposed firebox the nonuniformity of the heat-flux distribution is diminished along the height and perimeter of the walls and nitrogen oxide emissions are reduced.

42 ENGINEERING↗
DOE OSTI2019

Corrosion Mechanism and Applicability Assessment of N80 and 9Cr Steels in CO{sub 2} Auxiliary Steam Drive

Corrosion tests were conducted in a high-temperature high-pressure (HTHP) autoclave to simulate the conditions of CO{sub 2} auxiliary steam drive in gas injection wells. Weight loss tests were performed with the sheets of N80 and 9Cr steels under the testing conditions. The morphology and composition of corrosion products were explored by SEM, EDS, XRD and XPS. The corrosion resistance of 9Cr steel was better than that of N80 steel under the testing conditions. The corrosion rates of N80 and 9Cr met the application requirements in CO{sub 2} auxiliary steam drive. The results broke the constraint in ISO-15156 standards. The corrosion process of N80 steel was mainly affected by the flow velocity. However, the corrosion process of 9Cr steel was mainly affected by temperature. The corrosion resistance of 9Cr steel depended on the FeCO{sub 3} content of Cr-rich layer, which was closely related to temperature. The low flow velocity influenced the diffusion process of N80 steel corrosive ions, whereas the high flow velocity influenced the integrity of corrosion scales. Considering the influence of flow velocity on the corrosion of tubing and casing, in the gas injection well, 9Cr steel and N80 steel were, respectively, selected as the materials of tubing and casing.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Oxidation Kinetics of Ferritic Alloys in High-Temperature Steam Environments

High-temperature isothermal steam oxidation kinetic parameters of several ferritic alloys were determined by thermogravimetric analysis. We measured the oxidation kinetic constant (k) as a function of temperature from 900°C to 1200°C. The results show a marked increase in oxidation resistance compared to reference Zircaloy-2, with kinetic constants 3–5 orders of magnitude lower across the experimental temperature range. Our results of this investigation supplement previous findings on the properties of ferritic alloys for use as candidate cladding materials and extend kinetic parameter measurements to high-temperature steam environments suitable for assessing accident tolerance for light water reactor applications.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Low-Coordinated Pd Catalysts Supported on Zn 1 Zr 1 O x Composite Oxides for Selective Methanol Steam Reforming

Highly dispersed palladium on nanoscale Zn 1 Zr 1 O x mixed oxides was prepared by incipient wetness impregnation. H 2 pretreatment tuned the structure of the catalysts and, hence the catalytic performance in the steam reforming of methanol. Based on catalyst evaluation by XRD, XPS and EXAFS/XANES, it is found that high reduction temperature (400 °C) leads to the formation of PdZn β alloy, which breaks the Pd-Pd bonds in the metallic Pd phase and forms low-coordinated Pd species in the domain of the metal oxides. These low-coordinated Pd species are responsible for the exclusive selectivity to CO 2 as the carbon product. Methyl formate as the reaction intermediate was detected on Pd/Zn 1 Zr 1 O x -R400 catalyst by in situ methanol-DRIFTS and methanol-TPSR, proving the methanol dehydrogenation and coupling reaction pathway on the low-coordinated Pd active sites. The incorporation of ZrO 2 facilitates the dispersion of ZnO and Pd species and stabilizes Pd species against growth, with better stability than monometallic palladium. This work effectively shows how to prepare active and selective Pd catalysts for dehydrogenation and steam reformimg of methanol not suffering from the typical poor selectivity of metallic palladium.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗