Ethene hydrogen-ethane system

If the ethene/ethane ratios are combined with the hydrogen partial pressures, we can demonstrate that the ethene-hydrogen-ethane system is far from thermal equilibrium under the conditions of the experiment shown in Figure 2. The experimental value of c2h6 Pc2h4 Ph2 s comPare< Figure 4 with the value of Keq. Only at temperatures near and above 600°C, at which the C2 evolution rate is negligible, does the ethene/ethane ratio approach equilibrium. Therefore, a nonequilibrium explanation of the observed alkene/alkane ratios is required. 

Figure 14.7 Typical clnomatogram obtained by using the refinery analyser system shown in Figure 14.6. Peak identification is as follows 1, hydrogen 2, Cg+, 3, propane 4, acetylene 5, propene 6, hydrogen sulfide 6, iso-butane 8, propadiene 9, n-butane, 10. iso-butene 11, 1-butene 12, traw-2-butene 13, cw-2-butene 14, 1,3-butadiene 15, iso-pentane 16, w-pen-tane 17, 1-pentene 18, tro 5-2-pentene 19, cw-2-pentene 20, 2-inethyl-2-butene 21, carbon dioxide 22, ethene 23, ethane 24, oxygen + argon, 25, niti Ogen, 26, carbon monoxide.

The kinetics of the pyrolysis of Pb(C2H5)4 have been investigated in a static system over the temperature range 233 to 267 by means of gas chromatography. In the Initial stages, only ethane, ethene, hydrogen, and n-butane are formed. Over the pressure range... 

Problem 1 In a closed system, the following equilibrium can develop between the compounds ethane (C2H6), hydrogen (H2) and ethene (C2H4) ... 

Our objective was to clarify the reaction mechanisms that determine the observed alkene/alkane ratios under various conditions, and the results are reported here. When oil shale is pyrolyzed either isothermally or nonisothermally, the hydrocarbon and hydrogen concentrations are all time dependent. To determine if the alkene-alkane-hydrogen system is at equilibrium, we heated oil shale at a constant rate and measured the C to C3 hydrocarbons and hydrogen over time. We also measured the effect of an inert sweep gas on the time-dependent ethene/ethane and propene/propane ratios and the integral 1-alkene/n-alkane ratios in the oil. We determined that the C2H4-C2H6-H2 system is not at thermal equilibrium and interpret our results in terms of a nonequilibrium free-radical mechanism proposed by Raley (8). 

Pyrolysis of both kerogen and shale oil breaks larger molecules into smaller ones. For the alkene-alkane-hydrogen system to be at equilibrium, the reactions that lead to this equilibrium must be faster than those producing the smaller molecular fragments. To reach equilibrium, the ethene/ethane ratio must satisfy the condition ... 

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