Distillation with secondary reflux and vaporization: A comparative evaluation

Abstract

A novel distillation scheme which makes use of secondary reflux and vaporization to enhance thermal efficiency is presented. Low operating temperatures, close boiling mixture, and tight product specifications appear to favor this scheme over the conventional distillation. Computer simulation indicates a potential utility reduction of 50 to 7594,. SCOPEDistillation is the single most important separation unit operation in the process industry. It is widely used to upgrade feedstocks, separate reaction intermediates, arid purify products in processes ranging from cryogenic separation of oxygen, nitrogen, and helium to the recovery of aromatics from coal tar. In a recent study carried out under the auspices of the Governor's Energy Advisory Council of Texas, the energy usage of some forty-five refineries (in thirty-nine companies) and 226 chemical plants (in 140 companies) was surveyed (Prengle et al., 1974), and distillation was an important energy consumer in almost all of them. In petroleum refineries which are the largest energy consumers on a per plant basis (1.9 X 1016 J/plant), crude and vacuum distillation alone accounts for 22.5 to 51% of the total energy consumption. Any enhancement of efficiency of this important unit operation could have an impact which will significantly benefit a wide cross section of process industries.In the conventional distillation column, heat is sup-

Heat and Mass Transfer of Internally Heat Integrated Distillation Column (HIDiC)

“…The idea of the HIDiC was first proposed by Haselden for energy savings in cryogenic air separation 1) . Later the idea was reintroduced by Mah et al 2) , and the outline of the present design of the HIDiC was established. In Japan, the fundamentals and practical application of the HIDiC have been studied by Takamatsu et al 3) since the 1980's.…”

Recent Advances in Internally Heat-Integrated Distillation Columns (HIDiC) for Sustainable Development

“…e original concept of the HIDiC was proposed by Haselden in 1958 for gas separation (Haselden, 1958). Later, the idea was reintroduced by Mah et al (1977) as the Secondary Re ux Vaporization (SRV) method.…”

Dynamic effects of diabatization in distillation columns

“…In a diabatic distillation column the heat required to perform the separation is added and/or removed throughout the column. An example is the heatintegrated distillation column (HIDiC) which was conceptually introduced by Mah et al (1977). An illustration of a CDiC and a general HIDiC is given in Figure 1.…”