Possibility of enlarging "standard specifications" in distillation columns

The use of nonstandard specifications may lead to cumbersome calculations when solving distillation units. This happens in general when algorithms, which carry on a decomposition of the system of equations describing the model, are applied. In order to avoid this situation, the paper presents a simple way of solving material and enthalpy balance equations which enlarges the class of standard specification equations to any set of linear equation containing: total flowrates (liquid, vapor, of internal or side streams or feeds), thermal duties, in whichever tray of the column. © 1982 American Chemical Society.