Estimates of energy consumption and selection of optimal distillation sequence for multicomponent distillation

Abstract

An estimate has been obtained of the energy consumption on 1 mol of separated mixture based on thermodynamic balances for processes that use mechanical and heat energy. Only irreversible losses depend on the order of separation for mixtures in mechanical systems, while for the systems using the heat, the order of separation also affects the reversible energy consumption. In the latter case, in order to obtain a reversible estimate of the heat consumption, one should solve the problem of selecting the order of separation. An algo rithm has been obtained for its solution that enables one to approximately choose the order of separation at the stage of preliminary calculations knowing only the properties of the feed.

Distillation optimization: Parameterized relationship between feed flow rate of a steady‐state distillation column and heat duties of reboiler and condenser

“…Comparing the parameterized load characteristic with the expression (9) shows that the characteristic parameters a, b should depend on the kinetics of the processes, the composition, and properties of the substances to be separated as…”

“…The use of graphical‐analytical methods and algorithmic description of the characteristics of each column makes it impossible to obtain analytical solutions of the optimization problem for a system of interconnected columns. This paper uses the results of the authors' previous work 7–11 on finding a link between the characteristics of product flows in a binary distillation column and heat consumption. It takes into account the irreversibility of the processes occurring (see Berry et al, 12 Tsirlin & Grigorevsky, 13 and Tsirlin & Sukin 14 ) for solving the problem of the optimal distribution of flows in the system of columns with their parallel and sequential structure.…”

Entropic Balance Conditions and Optimization of Distillation Column System

“…At a given heat flow, temperatures T + and T − depend on the selected values of temperature differences in the still and the dephlegmator. When substituting in (8), they also determine σ q .…”

“…There is widespread research devoted to the problems of optimal organization of distillation (see [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20], etc.). Often (see [1], p. 540), "the calculation methods are based on phase equilibrium diagrams and reversible process parameters while introducing empirical corrections" and rules such as (see [2], p. 289): "The most volatile component must be separated first" or "The component with the highest concentration must be separated first".…”