FLASH HYDROGENATION OF COAL.
Item
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Title
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FLASH HYDROGENATION OF COAL.
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Identifier
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AAI8212186
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identifier
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8212186
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Creator
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CHEN, WEI-YIN.
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Contributor
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Robert A. Graff
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Date
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1982
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Language
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English
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Publisher
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City University of New York.
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Subject
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Engineering, Chemical
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Abstract
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Flash hydrogenation is a process approach for converting coal to liquid and gaseous fuels. It is distinguished from other conversion techniques in that raw coal is contacted with hydrogen at elevated pressure under conditions of rapid heating and control of vapor product residence time. The objective of this dissertation is to expand the experimental base for evaluating the potential of the approach and guiding pilot scale development.;This dissertation begins with a review of previous work on flash hydrogenation, in particular the effects of coal nature and process variables on yield structure. Prospects for kinetic modeling, reactor design, and catalysis are discussed.;In this dissertation, experimental studies using the flash tube reactor system developed at City College have been carried out. A ten to twenty milligram batch sample of ground coal was rapidly heated in flowing hydrogen at pressure up to 100 atmospheres. Yields of compounds up to xylene were determined with an on-line mass spectrometer.;A comparative study was carried out with a suite of eight coals selected as broadly representive of the U.S. spectrum. These were augmented by data for three additional coals from other sources. A very high degree of variability was observed, particularly in total volatiles yield and total liquids yield. Using dmmf carbon content as an index of rank proved wholly inadequate for the purpose of correlating yields. The correlation with oxygen and aliphatic hydrogen was found to fit not only the flash hydrogenation yield, but also the vacuum pyrolysis and some liquefaction data. Two variable empirical equations were also developed for the prediction of yield of individual product. A more detailed comparison was made of the performance of two bitminous coals.;In the study of two stage hydrogenation, no advantage was found over single stage, in terms of maximum attainable yield of single ring aromatics. Single stage data was successfully modeled using an exponential decay function for the residuence time distribution of bubbles within a caking coal particle.;Finally, the effects of hydrogen pressure and various additions on the yields were briefly examined and reported.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
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Program
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Chemical Engineering
