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STUDIES OF COMBUSTION CHARACTERISTICS
OF ALCOHOLS, ALDEHYDES, AND KETONES
by
Peter Surendran Veloo
A Dissertation Present to the
FACULTY OF THE USC GRADUATE SCHOOL
UNIVERSITY OF SOUTHERN CALIFORNIA
In Partial Fulfillment of the
Requirements of the Degree
DOCTOR OF PHILOSOPHY
(MECHANICAL ENGINEERING)
August 2011
Copyright 2011 Peter Surendran Veloo
Object Description
| Title | Studies of the combustion characteristics of alcohols, aldehydes, and ketones |
| Author | Veloo, Peter Surendran |
| Author email | pveloo@gmail.com;pveloo@princeton.edu |
| Degree | Doctor of Philosophy |
| Document type | Dissertation |
| Degree program | Mechanical Engineering |
| School | Viterbi School of Engineering |
| Date defended/completed | 2011-05-02 |
| Date submitted | 2011-07-06 |
| Date approved | 2011-07-06 |
| Restricted until | 2011-07-06 |
| Date published | 2011-07-06 |
| Advisor (committee chair) | Egolfopoulos, Fokion N. |
| Advisor (committee member) |
Wang, Hai Tsotsis, Theodore T. |
| Abstract | The combustion characteristics of oxygenated C₁-C₄ hydrocarbons were investigated both experimentally and numerically in laminar premixed and non-premixed flames. These characteristics included laminar flame speeds and extinction limits. Experimentally, flames were established in the counterflow configuration and flow velocity measurements were made using the digital particle image velocimetry technique. All experiments were conducted at an elevated unburned reactant temperature and at atmospheric pressure. A wide range of fuels were studied including the C₁-C₄ alcohols, C₃-C₄ aldehydes, and C₃-C₄ ketones. Numerically, laminar flame speeds and extinction limits were simulated using quasi-one-dimensional codes which integrated the conservation equations with detailed descriptions of molecular transport and chemical kinetics. ❧ Premixed flames of methanol, ethanol, and n-butanol were initially studied. Experimental results revealed that the laminar flame speeds of methanol/air flames are considerably higher than both ethanol/air and n-butanol/air flames under fuel-rich conditions. Additional measurements were conducted to determine the laminar flame speeds of methane, ethane, and n-butane flames in order to compare the effect of alkane and alcohol molecular structures on high-temperature flame kinetics. It was shown that laminar flame speeds of ethanol/air and n-butanol/air flames are similar to those of their n-alkane counterparts, and that methane/air flames have consistently lower laminar flame speeds than methanol/air flames. Two recently developed detailed chemical kinetic reaction models for n-butanol oxidation were used to simulate n-butanol/air laminar flame speeds and extinction limits. Numerous kinetic differences were revealed between these models regarding the consumption pathways of n-butanol and its intermediates. ❧ The combustion characteristics of premixed flames of the remaining three butanol isomers were then studied. Experimental results revealed that n-butanol/air flames propagate somewhat faster than both sec-butanol/air and iso-butanol/air flames, and that tert-butanol/air flames propagate notably slower compared to the other three isomers. Experiments were simulated using a recently developed chemical kinetic reaction model for the oxidation of the four isomers of butanol. Reaction path analysis of numerical simulations of tert-butanol/air flames revealed iso-butene to be a major intermediate, which subsequently reacts to form the resonantly stable iso-butenyl radical retarding thus the overall reactivity of these flames relatively to the other three isomers. ❧ A study similar to the first two was then conducted in which the combustion characteristics of the two propanol isomers and propane were investigated. Experimental results revealed, as expected, that the laminar flame speeds and extinction limits of n-propanol/air and propane/air flames are close to each other whereas those of iso-propanol/air flames are consistently lower. The chemical kinetic reaction model used in this study was found to overpredict the experimental results for fuel-rich n-propanol/air, iso-propanol, and propane/air flames. Analysis revealed that those discrepancies are most likely caused by deficiencies in the C₃ alkane kinetics. ❧ The final study focused on some of the key oxygenated intermediate species formed during the oxidation of the aforementioned alcohols, namely the C₃-C₄ aldehydes and ketones. Acetone/air flames were determined to propagate notably slower than butanone/air flames. For the aldehydes, between fuel-lean and stoichiometric conditions, propanal and n-butanal/air have very similar laminar flames speeds. For fuel-rich conditions propanal/air flames propagate faster than n-butanal/air flames. For all equivalence ratios considered iso-butanal/air flames propagate the slowest of flames of the aldehydes. It was also observed that flames of the aldehydes propagate significantly faster than their corresponding ketones, although this effect diminishes with increasing carbon chain length. |
| Keyword | laminar flames; alcohols; aldehydes; ketones; flame propagation; flame extinction |
| Language | English |
| Part of collection | University of Southern California dissertations and theses |
| Publisher (of the original version) | University of Southern California |
| Place of publication (of the original version) | Los Angeles, California |
| Publisher (of the digital version) | University of Southern California. Libraries |
| Provenance | Electronically uploaded by the author |
| Type | texts |
| Legacy record ID | usctheses-m |
| Contributing entity | University of Southern California |
| Rights | Veloo, Peter Surendran |
| Physical access | The author retains rights to his/her dissertation, thesis or other graduate work according to U.S. copyright law. Electronic access is being provided by the USC Libraries in agreement with the author, as the original true and official version of the work, but does not grant the reader permission to use the work if the desired use is covered by copyright. It is the author, as rights holder, who must provide use permission if such use is covered by copyright. The original signature page accompanying the original submission of the work to the USC Libraries is retained by the USC Libraries and a copy of it may be obtained by authorized requesters contacting the repository e-mail address given. |
| Repository name | University of Southern California Digital Library |
| Repository address | USC Digital Library, University of Southern California, University Park Campus MC 7002, 106 University Village, Los Angeles, California 90089-7002, USA |
| Repository email | cisadmin@lib.usc.edu |
| Archival file | uscthesesreloadpub_Volume71/etd-VelooPeter-52.pdf |
Description
| Title | Page 1 |
| Contributing entity | University of Southern California |
| Repository email | cisadmin@lib.usc.edu |
| Full text | STUDIES OF COMBUSTION CHARACTERISTICS OF ALCOHOLS, ALDEHYDES, AND KETONES by Peter Surendran Veloo A Dissertation Present to the FACULTY OF THE USC GRADUATE SCHOOL UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Fulfillment of the Requirements of the Degree DOCTOR OF PHILOSOPHY (MECHANICAL ENGINEERING) August 2011 Copyright 2011 Peter Surendran Veloo |
