Temperature effects oxidation

TABLE 5. Oxidation Temperature Effects on the 3-Point Flexure Properties of SiOC Nextel 312 BN... 

Oxidation Temperature Effects on Flexure Strength of SiOC N312 BN 2-D Composites (5X infiltrations)... 

In the pyrolysis of pure amine oxides, temperature has a significant effect on the ratio of products obtained (22). The principal reaction during thermal decomposition of /V,/V-dimetby11 amyl amine oxide [1643-20-5] at 80—100°C is deoxygenation to /V,/V-dimetby11 amyl amine [112-18-5] (lauryl = dodecyl). 

Zinc oxide is effective in removing H2S, mercaptans, and, to some extent, chlorides. At temperatures above 350 °C, mercaptans decompose to hydrocarbons and H2S which then reacts with the 2inc oxide to form 2inc sulfide. 

The devitrification rate is extremely sensitive to both surface and bulk impurities, especially alkah. Increased alkah levels tend to increase the devitrification rate and lower the temperature at which the maximum rate occurs. For example, a bulk level of 0.32 wt % soda increases the maximum devitrification rate 20—30 times and lowers the temperature of maximum devitrification to approximately 1400°C (101). The impurity effect is present even at trace levels (<50 ppm) and can be enhanced with the addition of alumina. The devitrification rate varies inversely with the ratio of alumina-to-alkah metal oxide. The effect is a consequence of the fact that these impurities lower glass viscosity (102). 

Based on detailed kinetic investigations, a tentative mechanism for this asymmetric oxidation was proposed (Scheme 2) according to which optically active sulphoxides may be formed by two pathways external attack on the sulphur atom by the chiral titanium hydroperoxide (path A) or coordination of sulphur to titanium prior to the oxidation step (path B). Although paths A and B could not be distinguished experimentally, the temperature effect was tentatively ascribed to a change of the mechanism, path A being predominant above — 20 °C and path B becoming competitive at lower temperatures (or vice versa). 

Schmidt TJ, Behm RJ, Grgur BN, Markovic NM, Ross PN. 2000a. Formic acid oxidation on pure and Bi-modified Pt(lll) Temperature effects. Langmuir 16 8159-8166. 

From the coverage made thus far, it may be of interest to record in one place the different factors which influence the rate of chemical reactions. The rate of chemical reaction depends essentially on four factors. The nature of reactants and products is one. For example, certain physical properties of the reactants and products govern the rate. As a specific example in this context mention may be of oxidation of metals. The volume ratio of metallic oxide to metal may indicate that a given oxidation reaction will be fast when the oxide is porous, or slow when the oxide is nonporous, thus presenting a diffusion barrier to the metal or to oxygen. The other two factors are concentration and temperature effects, which are detailed in Sections. The fourth factor is the presence of catalysts. 

Oxidation-reduction Partly The deep-well environment tends to be more reducing than the near-reduction surface environment, but equally reducing conditions occur in the near-surface. Some adjustments may be required for pressure/temperature effects. 

Ravi, V., Mok, Y.S., Rajanikanth, B.S. et al. (2003) Temperature effect on hydrocarbon-enhanced nitric oxide conversion using a dielectric barrier discharge reactor, Fuel Processing Technology 81, 187-99. 

The self-heating temperature (effectively the AIT) of a 50 50 mixture of ethylene oxide and air is reduced from 456°C on passage through various thermal insulation (lagging) materials to 251-416°C, depending on the particular material (of which 13 were tested). 

In a review of the course and mechanism of the catalytic decomposition of ammonium perchlorate, the considerable effects of metal oxides in reducing the explosion temperature of the salt are described [1], Solymosi s previous work had shown reductions from 440° to about 270° by dichromium trioxide, to 260° by 10 mol% of cadmium oxide and to 200°C by 0.2% of zinc oxide. The effect of various concentrations of copper chromite , copper oxide, iron oxide and potassium permanganate on the catalysed combustion of the propellant salt was studied [2], Similar studies on the effects of compounds of 11 metals and potassium dichromate in particular, have been reported [3], Presence of calcium carbonate or calcium oxide has a stabilising effect on the salt, either alone or in admixture with polystyrene [4],... 

Continuous Multicomponent Distillation Column 501 Gas Separation by Membrane Permeation 475 Transport of Heavy Metals in Water and Sediment 565 Residence Time Distribution Studies 381 Nitrification in a Fluidised Bed Reactor 547 Conversion of Nitrobenzene to Aniline 329 Non-Ideal Stirred-Tank Reactor 374 Oscillating Tank Reactor Behaviour 290 Oxidation Reaction in an Aerated Tank 250 Classic Streeter-Phelps Oxygen Sag Curves 569 Auto-Refrigerated Reactor 295 Batch Reactor of Luyben 253 Reversible Reaction with Temperature Effects 305 Reversible Reaction with Variable Heat Capacities 299 Reaction with Integrated Extraction of Inhibitory Product 280... 

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