Discrimination among rival Hougen‐Watson models through intrinsic parameters

Abstract

P = pressure, lb.f/sq.fr. Q = heat, B.t.u. R equivalent t = time, sec. T = temperature, OR. V = velocity, ft./sec. W alent z = elevation, ft. p = density, Ib.,/cu.ft. = universal gas constant, B.t.u./(lb.-mole) (OR.) or = work (excluding injection work), ft.1b.f or equiv-Subscripts B = solid blocks GIn attempting to describe rate data from a heteroeneous chemical reaction, the chemical engineer has frequently postulated a set of Hougen-Watson models

Identification of Rate Models for Solid Catalyzed Gaseous Reactions

“…From this example it is obvious that the use of the intrinsic parameter C, can establish the adequacy of a Hougen-Watson model at high levels of conversion and, consequently, provides a more complete test of the model than does the sole use of the intrinsic parameter C,. This fact is well exemplified elsewhere [7,10].…”

“…For the method of Yang and Hougen the best discrimination result would be obtained when the weighted transformed variable (Ri/Yi)' Yi/a2 is plotted against one of the independent variables, say pA. The method of Yang and Hougen has been extended to prepare linear plots of high-conversion data [6,7]. The use of high-conversion data provides a more accurate test of a Hougen-Watson model than does the initial rate alone.…”

“…The estimates of C, can be obtained from experimental observations in s e v e r a l different ways. Detailed discussions concerning the estimation of C, were presented elsewhere [ 7 ] . The simplest method of estimation of the parameter C, would be to employ Eq.…”

Activity performance and kinetics for glycerol carbonylation with urea over Zn‐Co mixed metal oxide catalyst

“…Accordingly, the initial rates were calculated at the beginning of the reaction when the product concentration on the catalyst surface was negligible. [56][57][58][59][60] The models get simplified in terms of reactant concentration and desorption steps (steps IV and V) as the product molecules can be neglected. Thus, the final (simplified) 16 models are considered for further studies and are shown in Table S1.…”

“…The catalytic reaction in the absence of mass transfer resistances follows the adsorption‐reaction‐desorption steps. For the initial rate method, the models derived for the Horuiti–Polanyi mechanism [ 56 ] give similar models as Langmuir–Hinshelwood–Hougen–Watson (LHHW) thus its separate mechanism and models are not considered in this work for further study. Scheme 1 shows glycerol carbonylation using urea with the notations used for the mechanistic models.…”