Analyses of the characteristics of a binary packed distillation column with internal heat integration.

Abstract

Distillation with internal heat integration, in which energy is recovered by heat transfer from the rectifying section to the stripping section, is an effective method for energy saving in distillation columns. This paper analyzes the effects of distillation parameters such as relative volatility, column height and product specification on the energy reducibility of a packed distillation column with internal heat integration. To make the effectiveness of internal heat integration clearer, the stripping section, the rectifying section and the integrated column (consisting of both sections) were analyzed separately.It was found that: 1) energy saving due to internal heat integration of the stripping section is more sensitive than that of the rectifying section; 2) especially for the stripping section, the reduction of the heat duty at the reboiler is greater than the quantity of heat added to the side of the column, provided that the column is short enough; and 3) for the integrated column, the effectiveness of the internal heat integration is comparatively greater when the relative volatility is large and the specification of the product purity is loose.