Propylene decomposition temperature

The formation of Ci - C6 hydrocarbons shows that the main reaction is accompanied with side processes of propylene destruction and dimerization with participation of CHx -species and hydrogen is formed at propylene decomposition. The carbon oxide were detected in some experiments due to the dissociation of CO2 => Oads COads on the specific centers of catalyst surface at high temperatures. 

Most highly polar and ionic species are not amenable to processing with desirable solvents such as carbon dioxide or any other solvent such as water that has a higher critical temperature well above the decomposition temperature of many solutes. In such instances, the combination of the unique properties of supercritical fluids with those of micro-emulsions can be used to increase the range of applications of supercritical fluids. The resulting thermodynamically stable systems generally contain water, a surfactant and a supercritical fluid (as opposed to a non-polar liquid in liquid micro-emulsions). The possible supercritical fluids that could be used in these systems include carbon dioxide, ethylene, ethane, propane, propylene, n-butane, and n-pentane while many ionic and non-ionic surfactants can be used. The major difference between the liquid based emulsions and the supercritical ones is the effect of pressure. The pressure affects the miscibility gaps as well as the microstracture of the micro-emulsion phase. 

In the present work, propane-propylene mixtures with various ratios were pyrolyzed at temperatures near 900°C and at an atmospheric pressure in an annular flow reactor. Hydrogen was used as a diluent. Under these experimental conditions, it was rather difficult to maintain an uniform temperature throughout the reactor since the reaction rate was high, and consequently, thermal effects due to the heat reaction were significant. In this work, therefore, experimental data at the initial stage of decomposition were analyzed using the effective temperature method to obtain kinetic rate parameters, activation energy and frequency factor, for propane and propylene decompositions. From the relations between... 

Using the experimental results of the pyrolysis of propane-propylene mixtures under the conditions of temperatures near 900 C, atmospheric pressure and hydrogen dilution, the relation between the decomposition rate constant of propane or propylene and the ratio of both reactants was obtained. It was found from the results that propylene had an inhibition effect on propane decomposition, and conversely, propane had an acceleration effect on propylene decomposition. 

To obtain Arrhenius kinetic parameters of propane and propylene decompositions in this system, the experimental results with low conversions were analyzed with the effective temperature method. From the relation between propane-propylene ratio in the feed and... 

As shown in Figure 14.1b two maximum decomposition temperatures are observed corresponding to the two different decomposition steps chain scission at 232 °C and unzipping at 251 °C. The final pyrolysates are not carbon dioxide and propylene oxide, but cyclic propylene carbonate and 1,2-propanediol. 

The decomposition of sodium methoxide commences at temperatures above 623 K (Figure 15.14). The gaseous products formed on decomposition were mainly methane (mass 16) with minor quantities of ethane (mass 30) and propylene (mass 42). However, Pfeifer et al. [36] have reported the decomposition temperatures of sodium... 

Ethylbenzene Hydroperoxide Process. Figure 4 shows the process flow sheet for production of propylene oxide and styrene via the use of ethylbenzene hydroperoxide (EBHP). Liquid-phase oxidation of ethylbenzene with air or oxygen occurs at 206—275 kPa (30—40 psia) and 140—150°C, and 2—2.5 h are required for a 10—15% conversion to the hydroperoxide. Recycle of an inert gas, such as nitrogen, is used to control reactor temperature. Impurities ia the ethylbenzene, such as water, are controlled to minimize decomposition of the hydroperoxide product and are sometimes added to enhance product formation. Selectivity to by-products include 8—10% acetophenone, 5—7% 1-phenylethanol, and <1% organic acids. EBHP is concentrated to 30—35% by distillation. The overhead ethylbenzene is recycled back to the oxidation reactor (170—172). 

Polyethylene displays good heat resistance in the absence of oxygen in vacuum or in an inert gas atmosphere, up to the temperature of 290°C. Higher temperature brings about the molecular-chain scission followed by a drop in the molecular-weight average. At temperatures in excess of 360°C the formation of volatile decomposition products can be observed. The main components are as follows ethane, propane, -butane, n-pentane, propylene, butenes and pentenes [7]. 

Sheratte55 reported the decomposition of polyurethane foams by an initial reaction with ammonia or an amine such as diethylene triamine (at 200°C) or ethanolamine (at 120°C) and reacting the resulting product containing a mixture of polyols, ureas, and amines with an alkylene oxide such as ethylene or propylene oxide at temperatures in the range of 120-140°C to convert the amines to polyols. The polyols obtained could be converted to new rigid foams by reaction with the appropriate diisocyanates. 

Fluidized-bed CVD was developed in the late 1950s for a specific application the coating of nuclear-fuel particles for high temperature gas-cooled reactors. PI The particles are uranium-thorium carbide coated with pyrolytic carbon and silicon carbide for the purpose of containing the products of nuclear fission. The carbon is obtained from the decomposition of propane (C3H8) or propylene... 

Terpolymers of maleic anhydride (MA) and PPC could be prepared using a double-metal cyanide (DMC)-type catalyst. The polymer was amorphous like most terpolymers of propylene carbonate [39]. For terpolymers with up to 50 50 (mol/ mol) of PO/CO2 and MA, it could be shown by TGA that the observed degradation temperature was again raised by about 20-30°C and that the maximum rate of decomposition even exceeded 300°C. 

In this paper selectivity in partial oxidation reactions is related to the manner in which hydrocarbon intermediates (R) are bound to surface metal centers on oxides. When the bonding is through oxygen atoms (M-O-R) selective oxidation products are favored, and when the bonding is directly between metal and hydrocarbon (M-R), total oxidation is preferred. Results are presented for two redox systems ethane oxidation on supported vanadium oxide and propylene oxidation on supported molybdenum oxide. The catalysts and adsorbates are stuped by laser Raman spectroscopy, reaction kinetics, and temperature-programmed reaction. Thermochemical calculations confirm that the M-R intermediates are more stable than the M-O-R intermediates. The longer surface residence time of the M-R complexes, coupled to their lack of ready decomposition pathways, is responsible for their total oxidation. 

Baranski and Lu [209] have carried out, applying microelectrodes, voltammetric studies on ammonium amalgam in propylene carbonate solutions at room temperatures. The sweep rates up to 80 V s were appropriate for the analysis of the formation kinetics of this compound. Experimental and numerical simulation results have shown that ammonium amalgam was formed via fast charge-transfer process and its first-order decomposition was characterized by the rate constant of about 0.6 s . Diffusion coefficient of NH4 radical in mercury was estimated to be about 1.8 X 10 cm s k The formal potential of NH4+ (aq)/NH4(Hg) couple was determined as—1.723 V (SHE). 

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