TABLE OF CONTENTS At sharp distillation with finite reflux, the product points should belong to possible product regions 
and 
at those boundary elements of concentration simplex at which trajectory tear-off regions 
and 
are available. In the tear-off points equilibrium coefficients of absent components j should be smaller (bigger) than those of present components i in the top (bottom) section ( K ri > K rj, K si < K sj). Section trajectories tear off from the boundary elements at the value of the parameter L/ V greater than the values of phase equilibrium coefficients of the absent components ( L/ V > K j) in tear-off point x t.
In the mode of minimum reflux, R min at sharp distillation without distributed components trajectory of the top (bottom) section goes from the product point x D ( x B) to the trajectory tear-off point 
( 
) into the boundary element, containing one additional component referring to product components, that is the closest one by phase equilibrium coefficient, then it goes from point ( ) to the point of trajectory tear-off 
( 
) inside concentration simplex, then it goes from point ( ) to point x f ? 1 ( x f) in the feed cross-section of the column. Along with that, material balance should be valid in the feed cross-section.
Separatrix sharp region of the section trajectories 
passing through product...
