FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W2004279543> ?p ?o ?g. }

• W2004279543 endingPage "260" @default.
• W2004279543 startingPage "245" @default.
• W2004279543 abstract "Abstract Dimethyl ether (DME) has been proposed to be a promising alternative to conventional diesel fuel because of its favorable compression ignition property (high cetane number) and its soot‐free combustion. A radical chain mechanism for hydrocarbon autoignition has been proposed for DME at low temperatures. In this mechanism, the chain initiation step consists of DME undergoing hydrogen abstraction by a highly reactive species (typically ·OH). The CH 3 O·H 2 created in the initiation step then combines with O 2 ; the subsequent CH 3 OCH 2 OO· radical is involved in a Lindemann‐type mechanism, which can lead to the production of formaldehyde (CH 2 = O) and ·OH. This concludes the chain‐propagating step: the one ·OH produced then sustains the chain‐reaction by creating another CH 3 O·H 2 . A relatively stable intermediate (·CH 2 OCH 2 OOH), formed via isomerization of CH 3 OCH 2 OO· in the chain‐propagation step, can combine with a second O 2 to produce a radical (·OOCH 2 OCH 2 OOH) that can potentially decompose into two ·OH radical (and other products). This path leads to chain‐branching and an exponential increase in the rate of DME oxidation. We have used spin‐polarized density functional theory with the Becke‐3‐parameter Lee—Parr—Yang exchange‐correlation functional to calculate the structures and energies of key reactants, intermediates, and products involved in (and competing with) the chain‐propagating and chain‐branching steps of low‐temperature DME oxidation. In this article, Part I, we consider only the chain‐propagation mechanism and its competing mechanisms for DME combustion. Here, we show that only certain conformers can undergo the isomerization to ·CH 2 OCH 2 OOH. A new transition state has been discovered for the disproportionation reaction ·CH 2 OCH 2 OOH → 2CH 2 O + ·OH in the chain‐propagating step of DME autoignition that is much lower than previous barriers. The key to making this decomposition pathway facile is initial cleavage of the O—O rather than the C—O bond. This renders all transition states along the chain‐propagation potential energy surface below the CH 3 O·H 2 + O 2 reactants. In contrast with the more well‐studied CH 3 ·H 2 (ethyl radical) + O 2 system, the H‐transfer isomerization of CH 3 OCH 2 OO· to ·CH 2 OCH 2 OOH in low‐temperature DME oxidation has a much lower activation energy. This is most likely due to the larger ring strain of the analogous transition state in ethane oxidation, which is a five‐membered ring opposed to a six‐membered ring in dimethyl ether oxidation. Thus low‐temperature ethane oxidation is much less likely to form the ·ROOH (where R is a generic group) radicals necessary for chain‐branching, which leads to autoignition. Three competing reactions are considered: CH 3 O·H 2 → CH 2 O + ·CH 3 ; ·CH 2 OCH 2 OOH → 1,3‐dioxetane + ·OH; and ·CH 2 OCH 2 OOH → ethylene oxide + HOO·. The reaction barriers of all these competing paths are much higher in energy (7–10 kcal/mol) than the reactants CH 3 O·H 2 + O 2 and, therefore, are unlikely low‐temperature paths. Interestingly, an analysis of the highest occupied molecular orbital along the CH 3 O·H 2 decomposition path shows that electronically excited ( 1 A 2 or 3 A 2 ) CH 2 O can form; this can also be shown for ·CH 2 OCH 2 OOH, which forms two formaldehyde molecules. This may explain the luminosity of DME's low‐temperature flames." @default.
• W2004279543 created "2016-06-24" @default.
• W2004279543 creator A5076775259 @default.
• W2004279543 creator A5090200106 @default.
• W2004279543 date "2002-12-01" @default.
• W2004279543 modified "2023-09-29" @default.
• W2004279543 title "A hybrid density functional theory study of the low‐temperature dimethyl ether combustion pathways. I: Chain‐propagation" @default.
• W2004279543 cites W1492476004 @default.
• W2004279543 cites W1970906886 @default.
• W2004279543 cites W1971275758 @default.
• W2004279543 cites W1974700238 @default.
• W2004279543 cites W1984614201 @default.
• W2004279543 cites W1986355909 @default.
• W2004279543 cites W1988557394 @default.
• W2004279543 cites W1998725642 @default.
• W2004279543 cites W2001568684 @default.
• W2004279543 cites W2022333924 @default.
• W2004279543 cites W2023271753 @default.
• W2004279543 cites W2041449670 @default.
• W2004279543 cites W2041864995 @default.
• W2004279543 cites W2043531986 @default.
• W2004279543 cites W2046412723 @default.
• W2004279543 cites W2050403045 @default.
• W2004279543 cites W2051554285 @default.
• W2004279543 cites W2056744044 @default.
• W2004279543 cites W2058179787 @default.
• W2004279543 cites W2062357655 @default.
• W2004279543 cites W2069167687 @default.
• W2004279543 cites W2094642658 @default.
• W2004279543 cites W2143981217 @default.
• W2004279543 cites W2148284063 @default.
• W2004279543 cites W2173812745 @default.
• W2004279543 cites W3022748265 @default.
• W2004279543 cites W81990881 @default.
• W2004279543 cites W95991938 @default.
• W2004279543 doi "https://doi.org/10.1560/yqm7-5e5m-523q-aqg2" @default.
• W2004279543 hasPublicationYear "2002" @default.
• W2004279543 type Work @default.
• W2004279543 sameAs 2004279543 @default.
• W2004279543 citedByCount "25" @default.
• W2004279543 countsByYear W20042795432012 @default.
• W2004279543 countsByYear W20042795432013 @default.
• W2004279543 countsByYear W20042795432014 @default.
• W2004279543 countsByYear W20042795432015 @default.
• W2004279543 countsByYear W20042795432016 @default.
• W2004279543 countsByYear W20042795432020 @default.
• W2004279543 countsByYear W20042795432021 @default.
• W2004279543 countsByYear W20042795432023 @default.
• W2004279543 crossrefType "journal-article" @default.
• W2004279543 hasAuthorship W2004279543A5076775259 @default.
• W2004279543 hasAuthorship W2004279543A5090200106 @default.
• W2004279543 hasConcept C105923489 @default.
• W2004279543 hasConcept C111998727 @default.
• W2004279543 hasConcept C126661725 @default.
• W2004279543 hasConcept C139066938 @default.
• W2004279543 hasConcept C147597530 @default.
• W2004279543 hasConcept C147789679 @default.
• W2004279543 hasConcept C152365726 @default.
• W2004279543 hasConcept C15920480 @default.
• W2004279543 hasConcept C161790260 @default.
• W2004279543 hasConcept C166940927 @default.
• W2004279543 hasConcept C168931907 @default.
• W2004279543 hasConcept C178790620 @default.
• W2004279543 hasConcept C185592680 @default.
• W2004279543 hasConcept C206175624 @default.
• W2004279543 hasConcept C2779300417 @default.
• W2004279543 hasConcept C38087914 @default.
• W2004279543 hasConcept C44710219 @default.
• W2004279543 hasConcept C521977710 @default.
• W2004279543 hasConcept C64127748 @default.
• W2004279543 hasConcept C65024703 @default.
• W2004279543 hasConcept C75473681 @default.
• W2004279543 hasConcept C81022585 @default.
• W2004279543 hasConceptScore W2004279543C105923489 @default.
• W2004279543 hasConceptScore W2004279543C111998727 @default.
• W2004279543 hasConceptScore W2004279543C126661725 @default.
• W2004279543 hasConceptScore W2004279543C139066938 @default.
• W2004279543 hasConceptScore W2004279543C147597530 @default.
• W2004279543 hasConceptScore W2004279543C147789679 @default.
• W2004279543 hasConceptScore W2004279543C152365726 @default.
• W2004279543 hasConceptScore W2004279543C15920480 @default.
• W2004279543 hasConceptScore W2004279543C161790260 @default.
• W2004279543 hasConceptScore W2004279543C166940927 @default.
• W2004279543 hasConceptScore W2004279543C168931907 @default.
• W2004279543 hasConceptScore W2004279543C178790620 @default.
• W2004279543 hasConceptScore W2004279543C185592680 @default.
• W2004279543 hasConceptScore W2004279543C206175624 @default.
• W2004279543 hasConceptScore W2004279543C2779300417 @default.
• W2004279543 hasConceptScore W2004279543C38087914 @default.
• W2004279543 hasConceptScore W2004279543C44710219 @default.
• W2004279543 hasConceptScore W2004279543C521977710 @default.
• W2004279543 hasConceptScore W2004279543C64127748 @default.
• W2004279543 hasConceptScore W2004279543C65024703 @default.
• W2004279543 hasConceptScore W2004279543C75473681 @default.
• W2004279543 hasConceptScore W2004279543C81022585 @default.
• W2004279543 hasIssue "2-3" @default.
• W2004279543 hasLocation W20042795431 @default.
• W2004279543 hasOpenAccess W2004279543 @default.

• next