ReviewLecture5b_2014 [read]

Thus rate of producion rate of reacion rc2 h4

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Unformatted text preview: r travel ;me through construc;on zone: 24 min Total ;me approximately equal to the ;me to pass through construc;on! Road construc;on determines the rate limi;ng part of the journey; This is equivalent to the rate limi;ng step in a reac;on sequence. Multiple-Component Adsorption with Surface Reaction (ii) species C2H4, H2 adsorp;on species desorp;on (Cn Hm )ad If the absorp;on steps are in equilibrium, rates of produc;on for each absorp;on/desorp;on step is zero, thus: Adsorp;on of C2H4 : Dissocia;ve adsorp;on of H2: Desorp;on of C2H6: CC2 H4 = K1 CC2 H4 Cv 2 2 CCH = K2 CH2 Cv CC2 H6 = K5 CC2 H6 Cv Ctotal = CC2 H4 + CH + CC2 H6 + Cv Surface concentra;ons related to each other by site balance: Site Balance: Multiple-Component Adsorption with Surface Reaction (iii) species C2H4, H2 adsorp;on species desorp;on (Cn Hm )ad Introduce frac;onal surface coverage : i Ci = Ctotal Solve for vacant sites v 1 = C2 H4 + H + C2 H6 + v 1 + K1 CC2 H4 1 + K1 CC2 H4 = = Determining surface coverage: H = C2 H4 1 + K1 CC2 H4 K2 CH2 p + K2 CH2 + K5 CC2 H6 1 p + K2 CH2 + K5 CC2 H6 p K1 CC2 H4 p + K2 CH2 + K5 CC2 H6 Multiple-Component Adsorption with Surface Reaction (iv) species C2H4, H2 adsorp;on species desorp;on (Cn Hm )ad rate of reacIon: r = r3 = R(C2 H4 )ad = k3 CC2 H4 CH Using the previous expressions for the concentra;ons the overall rate of reac;on is r= 2 k3 Ctotal K1 CC2 H4 (1 + K1 CC2 H4 + p K2 C...
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This document was uploaded on 03/14/2014.

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