Ethylene oxide pyrolysis

The global reactions considered include the conversion by pure pyrolysis of toluene to acetylene and the conversion of isooctane to ethylene, oxidative pyrolysis of the acetylene and ethylene, and partial oxidation of the parent fuels and these hydrocarbon intermediates to CO, H2, and H2O. The specific reactions and rates for this system are given in Table II. Soot formation is assumed to be a function of temperature and oxygen and precursor concentrations. In the present study the soot precursors are taken to be acetylene and toluene, expressed as C2 hydrocarbons. 

Dihydro-2f/-pyran-2-one has been prepared by reductive cycliza-tion of 5-hydroxy-2-pentynoic acid [2-Pentynoic acid, 5-hydroxy-], which is obtained in two steps from acetylene [Ethyne] and ethylene oxide [Oxirane] 3 and by the reaction of dihydropyran [277-Pyran, 3,4-dihydro-] with singlet oxygen [Oxygen, singlet].4,5 2ff-Pyran-2-one has been prepared by pyrolysis of heavy metal salts of coumalic acid [2//-Pyran-5-carboxylic acid, 2-oxo-],8 by pyrolysis of a-pyrone-6-carboxylic acid [211 - Pyran-6-carboxyl ic acid, 2-oxo-] over copper,7 and by pyrolysis of coumalic acid over copper (66-70% yield).8... 

CCOP [Chlorine-catalyzed oxidative pyrolysis] A process for converting methane into a mixture of ethylene and acetylene. Invented by the Illinois Institute of Technology, Chicago, and under development by Dow Chemical Company in 1991. 

Propane s greatest use is not as a fuel but in the petrochemical industry as a feedstock. As an alkane, it undergoes typical alkane reactions of combustion, halogenation, pyrolysis, and oxidation. Pyrolysis or cracking of propane at several hundred degrees Celsius and elevated pressure in combination with metal catalysts result in dehydrogenation. Dehydrogenation is a primary source of ethylene and propylene ... 

Still another decomposition giving rise to ethylene oxide involves die pyrolysis f 0-hydrvjxyethyl -V,N-dialkylaminopolymethylehe carbamates. A specific illustration (Eq. 318) is -hydroxyethyl y-morpho-Kuopropyl carbamate, which on heating at 130-140° yields ethylene xide. carbon dioxide, and a urea derivative.4 Although interesting, this decomposition is of little preparative value in epoxide synthesis. 

Aromatics extractive distillation (3) Ethylene oxide (3) Pyrolysis gasoline... 

Pyrolysis, photolysis, and electronolysis of ethylene oxide (128) yielded similar products (P. Brown et al., 1966). Electron impact-induced fragmentation (129) of the epoxide (51) (P. Brown et al., 1966) was similar to the photochemical behaviour (130) of the epoxide (52) (Kristinsson and Griffin, 1966). Rearrangement of the a,/3-epoxy-ketone to the diketone after ionization (131) has been suggested to account for... 

Automatic recording infrared apparatus can also be used in studying the kinetics of both complex reactions and intermediates if their concentrations are not less than 1 per cent. In this way, ketene, CH2CO, and acetaldehyde, CIIsCHO, have been identified as intermediates in the pyrolysis of ethylene oxide, C2H40. ... 

Spinning of PCS, often with the use of an organic-polymer spinning aid such as poly (ethylene oxide), followed by curing and high-temperature pyrolysis gives black silicon-carbide-like fibers. 

The velocity of the decomposition flame was first measured by Gerstein et al. [62] using upward flame propagation in a tube. The experimental value of 12.5 cm. sec , corrected to 1 atm and room temperature, was in reasonable agreement with values calculated from theories of flame propagation using the Arrhenius parameters obtained by Mueller and Walters [63] for the first-order pyrolysis of ethylene oxide at much lower temperatures. 

The process in rominisoent of the pyrolyaie of cyciobutane to ethylrn . whkdk occurs at about the same temperature, and is quite different, from the pyrolysis of eithu ethylene oxide or tetrahydrofurait. uhidi requires teni2>eraturos of about 400° and ddO°. respectivdy. 

Echols and Pease found that the reaction is partially inhibited by nitric oxide, and a similar result was obtained by Rice and Polly with propene. Evidence against the hypothesis that the uninhibitable reaction is a molecular process was obtained by Steacie and Folkins , who found that small amounts of ethylene oxide could sensitize the maximally-inhibited reaction. They also found that the products of the inhibited reaction were identical with those of the uninhibited reaction. The fact that the maximally-inhibited pyrolysis is not molecular has been firmly established by Kuppermann and Larson, who pyrolyzed a mixture of C4H10 and C4D10. They found that the ratio of CD3H to CD4 in the products was independent of the amount of nitric oxide. They also found that whereas the... 

Several reports are available In literature regarding thermal decomposition of poly(ethylene oxide) not in flash pyrolysis conditions. One such report indicates that at temperatures between 324° C and 363° C, the polymer generates 9.7% of volatile compounds (at 25° C), 3.9% monomer with smaller amounts of CO2, formaldehyde, ethanol, and saturated C1-C7 compounds [4]. Another report indicates that at temperatures between 225° C and 250° C, the polymer generates CO2, HCHO,... 

One more example of pyrolysis results is given for poly(ethylene oxide) with M = 300,000 and is shown in Figure 9.1.5. The Py-GC/MS experiment was done in similar conditions as for other examples (see Table 4.2.2) and peak identification is given in Table 9.1.3. 

Figure 9.1.5. Result for a Py-GC/MS analysis of poly(ethylene oxide) M = 300,000. Pyrolysis done on 0.4 mg material at 60(f C in He, with the separation on a Carbowax type column.

Poly(ethylene glycol) is used in a number of copolymers, such as poly(propylene oxide-co-ethylene oxide), polyethylene-ft/oc/c-poly(ethylene glycol), poly [2,2-propanebis(4-phenyl)carbonate-b/oc/c-poly(ethyIene oxide], as well as in various polymer blends. Several pyrolysis studies were done on these copolymers [9-11]. 

Polyepichlorohydrin pyrolysate is a complex mixture of compounds, somehow similar to that obtained by the pyrolysis of poly(ethylene oxide). The breaking of the C-O bonds is probably easier than that of C-C bonds. However, C-C bonds are more frequently cleaved in pyrolysis of polyepichlorohydrin than in that of poly(propylene oxide). The elimination of HCI (4.7% in the pyrogram) further complicates the pyrogram of this polymer. 

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