106 research outputs found
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Fundamental study of ash formation and deposition: Effect of reducing stoichiometry. Final report, April 1, 1993--June 30, 1995
The technical objectives of this project are: (1) To identify the partitioning of inorganic coal constituents among vapor, submicron fume, and fly ash products generated during the combustion of pulverized coal under a variety of combustion conditions. Fuel lean and fuel rich combustion conditions are considered. (2) To identify and quantify the fundamental processes by which the transformations of minerals and organically-associated inorganic species occur. Emphasis is placed on identifying any changes that occur as a result of combustion under sub-stoichiometric combustion conditions. (3) To incorporate the effects of combustion stoichiometry into an Engineering Model for Ash Formation
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Trace element emissions. Semi-annual report, October 1994--February 1995
Many trace elements can exist in raw coal gas either in the form of metallic vapors or gaseous compounds which, besides their action on potentially ``very clean`` advanced power generating systems such as fuel cells and gas turbines, can also be detrimental to plant and animal life when released into the atmosphere. Therefore, volatile trace contaminants from coal which can also be toxic must be removed before they become detrimental to both power plant performance/endurance and the environment. Five trace elements were selected in this project based on: abundance in solid coal, volatility during gasification, effects on downstream systems and toxicity to plant and animal life. An understanding was sought in this investigation of the interactions of these five trace elements (and their high temperature species) with the different components in integrated cleanup and power generating systems, as well as the ultimate effects with respect to atmospheric emissions. Utilizing thermodynamic calculations and various experimental techniques, it was determined that a number of trace contaminants that exist in coal may be substantially removed by flyash, and after that by different sorbent systems. High temperature cleanup of contaminants by sorbents such as zinc titanate, primarily to remove sulfur, can also absorb some metallic contaminants such as cadmium and antimony. Further polishing will be required, however, to eliminate trace contaminant species incorporating the elements arsenic, selemium, lead, and mercury
Pennsylvania Folklife Vol. 38, No. 4
• Celebrating Twenty-Five Years of Quintessential Quilts • The Folk Art of Fraktur • Molding & Spinning Pewter • Kaleidoscopes & Unique Stained Glass • Dolls are Not Just for Children Anymore • Paint Decorated Chests of the Pennsylvania Dutch • Festival Focus • Festival Programs • Tiffany-Style Stained Glass Lamps • Be Aware of What Might be Hiding in Grandma\u27s Attic • The Medicine Show • Pennsylvania Dutch Music & More • A Poor Damsel\u27s Fate • Silk Screening • Long Time Favorite Festival Foodshttps://digitalcommons.ursinus.edu/pafolklifemag/1124/thumbnail.jp
The Lombard effect in singing humpback whales : source levels increase as ambient ocean noise levels increase
Funding: Office of Naval Research (Code 322, Marine Mammals and Biology), Commander, U.S. Pacific Fleet (Code N465JR), and the Naval Facilities Engineering Command Living Marine Resources Program.Many animals increase the intensity of their vocalizations in increased noise. This response is known as the Lombard effect. While some previous studies about cetaceans report a 1 dB increase in the source level (SL) for every dB increase in the background noise level (NL), more recent data have not supported this compensation ability. The purpose of this study was to calculate the SLs of humpback whale song units recorded off Hawaii and test for a relationship between these SLs and background NLs. Opportunistic recordings during 2012-2017 were used to detect and track 524 humpback whale encounters comprised of 83 974 units on the U.S. Navy's Pacific Missile Range Facility hydrophones. Received levels were added to their estimated transmission losses to calculate SLs. Humpback whale song units had a median SL of 173 dB re 1 μ Pa at 1 m, and SLs increased by 0.53 dB/1 dB increase in background NLs. These changes occurred in real time on hourly and daily time scales. Increases in ambient noise could reduce male humpback whale communication space in the important breeding area off Hawaii. Since these vocalization changes may be dependent on location or behavioral state, more work is needed at other locations and with other species.Publisher PDFPeer reviewe
Mercury release and speciation in chemical looping combustion of coal
In the in situ Gasification Chemical Looping Combustion of coal (iG-CLC), the fuel is gasified
in situ in the fuel reactor and gasification products are converted to CO2 and H2O by reaction
with the oxygen carrier. This work is the first study on mercury release in Chemical Looping
Combustion of coal. The fraction of the mercury in coal vaporized in the fuel reactor depended
mainly on the fuel reactor temperature and the coal type. In the fuel reactor, mercury was mainly
emitted as Hg0 in the gas phase and the amount increased with the temperature. In the air reactor,
mercury was mostly emitted as Hg2+. In a real CLC system, mercury emissions to the
atmosphere will decrease compared to conventional combustion as only mercury released in the
air reactor will reach the atmosphere. However, measures should be taken to reduce Hg0 in the
CO2 stream before the purification and compression steps in order to avoid operational problems.The authors thank the Government of Aragón and La Caixa (2012-GA-LC-076 project) and the Spanish Ministry for Science and Innovation (ENE2010-19550 project) for the financial support. P. Gayán thanks CSIC for the financial support of the project 201180E102. The authors also thank to Alcoa Europe-Alúmina Española S.A. for providing the Fe-enriched sand fraction used in this work. G. Galo is acknowledged for his contribution to the experimental results.Peer reviewe
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