Ethylene oxide production, steady

Unsteady-State Direct Oxidation Process. Periodic iatermption of the feeds can be used to reduce the sharp temperature gradients associated with the conventional oxidation of ethylene over a silver catalyst (209). Steady and periodic operation of a packed-bed reactor has been iavestigated for the production of ethylene oxide (210). By periodically varyiag the inlet feed concentration of ethylene or oxygen, or both, considerable improvements ia the selectivity to ethylene oxide were claimed. 

Figure 6.4. Examples for the four types of global classical promotion behaviour. Work function increases with the x-axis. (a) Steady-state (low conversion) rates of ethylene oxide (EtO) and C02 production from a mixture of 20 torr of ethylene and 150 torr of 02 for various Cs predosed coverages on Ag(lll) at 563 K19 (b) Rate of water-gas shift reaction over Cu(l 11) as a function of sulphur coverage at 612 K, 26 Torr CO and 10 Torr H202° (c) Effect of sodium loading on NO reduction to N2 by C3H6 on Pd supported on YSZ21 at T=380°C (d) Effect of sodium loading on the rate of NO reduction by CO on Na-promoted 0.5 wt% Rh supported on Ti02(4% W03).22...

Structural Sensitivity. Figure 1 shows the steady-state rates of ethylene oxide (EtO) and CO2 production as a function of temperature, in Arrhenius form, at an ethylene pressure (P-.) of 20 torr and P. 

The nitrogen assumes cationic properties and forms a complex with the dye anion. The non-ionic ethylene oxide condensate portion of the molecule keeps the addition product in a state of solution. The wool has no affinity for the dye anion which is comple.xed with the nitrogen atom at low temperatures. As the liquor becomes hotter the dye anions are gradually released. Not only does it follow that the dye becomes available at a steady and slow rate, but also the release takes place at higher temperatures when the fibre is more swollen and the dye aggregates are broken down. 

A gaseous stream consisting of 60% C2H4, 30% O2, and 10% N2 (by mole) is fed at a rate of 40 mol/min into a flow reactor operating at steady state. If the mole firaction of oxygen in the reactor effluent stream is 0.08, calculate the production rate of ethylene oxide. 

Considerably more progress has been made in the oxidative coupling of methane to form ethane and ethylene (C2 products). Since the early work of Keller and Bhasin [Ref. 3], the steady-state yields of C2 products have improved to a level of about 20%. Among the more effective catalysts are the Group IIA oxides which... 

Fig. 9. Influence of chlorine coverage on the kinetic parameters for selective ethylene oxidation over a Ag(llO) surface. Parameters for both the production of ethylene epoxide (EtO, circles) and the undesired side reaction to full combustion (C02, squares) are presented. Steady-state reaction orders in P02 and Pei and activation energies a versus chlorine coverage near 563 K, Pb = 20 torr, and P02 = 150 torr. From Ref. 118.

This chapter describes our recent advances on the utilization of polymer-modified laccase complexes in aqueous systems towards the oxidation/polymerization of naturally hydro-phobic steroidal compounds, Equilin (EQ) and 17-P-estradiol (P-EST). We elucidate the kinetic and synthetic aspects of the process with the model compoimd 5,6,7,8-tetrahydro-2-naphthol (THN). The nano-reactor system is composed of linear poly(ethylene oxide)-dendritic poly(benzyl ether) diblock copolymer (G3-PE013k) and laccase isolated from Trametes versicolor. Other advantages of the complex in comparison to the native enzyme are its recyclability, enhanced stability, activity, and overall simplicity in product harvesting and isolation. A principle of action of the complex is suggested based on these findings and is further supported by the biphasic solid-liquid nature of the reaction medium, which exhibits continuous influx of starting material and steady solid product expulsion. Comparative experiments with linear-linear poly(styrene)-Woc -poly(ethylene oxide) copolymer under identical conditions do not evince formation of a... 

The logarithmic time dependence of fraction in ethylene oxide, ln(l-ac2H4o) (see inset on Figure 51.6), is convex down, which is characteristic for the mechanism with a buffer step or with parallel ones. Note that isotope responses OCco2(0 and OCc2H4o(0 are close in the character of approaching a new steady state. Thus, slow relaxations for both reaction products are likely determined by the presence of a common buffer step. The observed isotope responses allowed the most probable mechanism to be presented as follows ... 

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