Reactive mass

The hydrocarbon can be in either the liquid or vapour phase and the silicon is finely divided. The inclusion of certain solid catalysts in the reactive mass may in some instances greatly facilitate the reaction. A mixture of powdered silicon and copper in the ratio 90 10 is used in the manufacture of alkyl chlorosilanes. 

Srinivas, B. K. and El-Halwagi, M. M. (1994), Synthesis of reactive mass-exchange networks with general nonlinear equilibrium functions. AlChE J., 40(3), 463-472. 

CHAPTER EIGHT Synthesis of reactive mass-exchange networks... 

Given a number Nr of waste (rich) streams and a number Ns of lean streams (physical and reactive MSAs), it is desired to synthesize a cost-effective network of physical and/or reactive mass exchangers which can preferentially transfer a certain undesirable species. A, from the waste streams to the MSAs whereby it may be reacted into other species. Given also are the flowrate of each waste stream, G/, its supply (inlet) composition, yf, and target (outlet) composition, yj, where i = 1,2,..., Nr. In addition, the supply and target compositions, Xj and x j, are given for each MSA, where j = 1,2, Ns. TTie flowrate of any lean stream, Ly, is unknown but is bounded by a given maximum available flowrate of that stream, i.e.. 

The first step in synthesizing a REAMEN is to establish the conditions for which the reactive mass exchange is thermodynamically feasible. This issue is covered by the next section. 

Corresponding composition scales for reactive mass exchange... 

The fundamentals of reactive mass exchange, design of individual units, chemical equilibrium and kinetics are covered in the literature (e.g., Fogler, 1992 Friedly, 1991 Ei-Halwagi, 1990 Kohl and Reisenfeld, 1985 Westerteip et ai, 1984 Astaritae/a/., 1983 Smith and Missen, 1982 Espenson, 1981 Levenspiel, 1972 El-Halwagi, 1971). This section presents the salient basics of these systems. 

In order to establish the conditions for thermodynamic feasibility of reactive mass exchange, it is necessary to invoke the basic principles of mass transfer with chemical reactions. Consider a lean phase j that contains a set Bj = z —... 

Fi re S.3a a leacdve mass exchanger with convex equilibrium (El-Halwagi and Snnivas, Synthesis of reactive mass-exchange networks, C/iem. Eng. 5ci.,47(8), p.2113,Copyright 1992, with kind permission from Elsevier Science Ltd., The Boulevard, Langford Lane, Kidlington 0X5 1GB, UK). 

Synthesis of Combined Heat and Reactive Mass-Exchange Networks... 

Combined heat- and reactive mass-exchange networks "CHARMEN"... 

A universal method of handling the problem is mathematical modelling, i.e., a quantitative description by means of a set of equations of the whole complex of interrelated chemical, physical, fluiddynamic, and thermal processes taking place concurrently or consecutively in a reactor. Constants of these equations are determined in laboratory experiments. If the range of determining factors (reactive mass compositions, temperature, reaction rates, and so on) in an actual process lie within or only slightly outside the limits studied in laboratory experiments, the solution of the determining set of equations provides a reliable idea of the process operation. 

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