Reaction Invariant Balances in a System of Units

Let us again consider a system of units such as in Chapter 3. With (4.2.7) introduced into (4.3.1) we have, in the n-th node 

Recall also that according to the Remark to Section 4.4, by (4.4.5) we have 

In the same manner as in Section 4.2, we generally introduce certain additional conditions such as (4.2.14), to obtain the whole set of constraints. 

The equations can be rewritten in different other manners. A simple modification consists in introducing the sets E, as in (4.2.14). TTien the components (n) of vector n(n) read 

Thus the vector equations (4.5.9a) are written for each n e T (nodes that are not splitters). For the splitters s g S, we have the scalar equations (4.5.9 b and c). We take k = I, , K and for each k, write the equations (4.5.9b) only for such s that j, G Ek (the split streams contain component Q) the equations (4.5.9b) are then written for each j g (streams obtained by splitting the input stream ). Finally, for each S we have the equation (4.5.9c). 

---