Measuring rate constants and product branching for reactions relevant to combustion and atmospheric chemistry
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Chemical Engineering, 2018.
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| Format: | Thesis |
| Language: | eng |
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Massachusetts Institute of Technology
2018
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| Online Access: | http://hdl.handle.net/1721.1/117862 |
| _version_ | 1826199952270819328 |
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| author | Buras, Zachary J. (Zachary James) |
| author2 | William H. Green. |
| author_facet | William H. Green. Buras, Zachary J. (Zachary James) |
| author_sort | Buras, Zachary J. (Zachary James) |
| collection | MIT |
| description | Thesis: Ph. D., Massachusetts Institute of Technology, Department of Chemical Engineering, 2018. |
| first_indexed | 2024-09-23T11:28:25Z |
| format | Thesis |
| id | mit-1721.1/117862 |
| institution | Massachusetts Institute of Technology |
| language | eng |
| last_indexed | 2024-09-23T11:28:25Z |
| publishDate | 2018 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/1178622019-04-12T23:21:54Z Measuring rate constants and product branching for reactions relevant to combustion and atmospheric chemistry Buras, Zachary J. (Zachary James) William H. Green. Massachusetts Institute of Technology. Department of Chemical Engineering. Massachusetts Institute of Technology. Department of Chemical Engineering. Chemical Engineering. Thesis: Ph. D., Massachusetts Institute of Technology, Department of Chemical Engineering, 2018. Cataloged from PDF version of thesis. Includes bibliographical references (pages [383]-406). Over the last century there have been countless experimental measurements of the overall reaction kinetics of gas-phase radicals, often with the aid of lasers. In more recent decades, ab initio predictions of product branching using quantum chemical calculations combined with modem rate theories have become common. However, there are few experimental measurements against which to validate predicted product branching, even for an important reaction system such as hydroxyl radical addition to acetylene that is critical to oxidation chemistry both in the atmosphere and in combustion. As a result, many of the kinetic parameters that appear in commonly used combustion mechanisms are based purely on predictions. The few experiments that do attempt to quantify product branching generally fall into two categories, each with unique advantages/disadvantages: crossed molecular beams (CMB) that simulate single collision conditions, or end-product analysis of a complex, thermalized process, such as pyrolysis. Laser flash photolysis (LFP) with molecular beam mass spectrometry (MBMS) offers a compromise between CMB and end-product experiments: the reaction conditions are thermalized but still simple enough that primary products can be quantified with confidence. This thesis describes a unique apparatus, and the improvements made to it, that combines LFP and MBMS for primary product branching quantification, as well as multiple-pass laser absorbance spectrometry (LAS) for accurate measurements of overall kinetics. The full capability of this LFP/MBMS/LAS apparatus is demonstrated for the chemically interesting phenyl radical + propene reaction system, which has been implicated as a potential source of second aromatic ring formation under combustion conditions. Overall kinetic measurements are also reported in this work either for systems that involve a newly discovered reactive species (various cycloaddition reactions of the simplest Criegee Intermediate formed in atmospheric ozonolysis) or that was disputed in the literature (vinyl radical + 1,3-butadiene, which has been implicated as a potential source of benzene in combustion). Finally, this thesis shows how detailed chemical insights made either experimentally or theoretically can be translated into applications via the Reaction Mechanism Generator (R4G). The application discussed is natural gas high temperature pyrolysis for the production of C2 commodity chemicals. by Zachary J. Buras. Ph. D. 2018-09-17T15:47:33Z 2018-09-17T15:47:33Z 2018 2018 Thesis http://hdl.handle.net/1721.1/117862 1051189805 eng MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission. http://dspace.mit.edu/handle/1721.1/7582 406 pages application/pdf Massachusetts Institute of Technology |
| spellingShingle | Chemical Engineering. Buras, Zachary J. (Zachary James) Measuring rate constants and product branching for reactions relevant to combustion and atmospheric chemistry |
| title | Measuring rate constants and product branching for reactions relevant to combustion and atmospheric chemistry |
| title_full | Measuring rate constants and product branching for reactions relevant to combustion and atmospheric chemistry |
| title_fullStr | Measuring rate constants and product branching for reactions relevant to combustion and atmospheric chemistry |
| title_full_unstemmed | Measuring rate constants and product branching for reactions relevant to combustion and atmospheric chemistry |
| title_short | Measuring rate constants and product branching for reactions relevant to combustion and atmospheric chemistry |
| title_sort | measuring rate constants and product branching for reactions relevant to combustion and atmospheric chemistry |
| topic | Chemical Engineering. |
| url | http://hdl.handle.net/1721.1/117862 |
| work_keys_str_mv | AT buraszacharyjzacharyjames measuringrateconstantsandproductbranchingforreactionsrelevanttocombustionandatmosphericchemistry |