초록 ▼

An improved distillation process and apparatus are provided whereby liquid product recovery other than bottom product is maximized and feed stream heating is minimized. Inert gas streams combined with the feed stream and introduced into the distillation tower are controlled whereby feed stream heate

An improved distillation process and apparatus are provided whereby liquid product recovery other than bottom product is maximized and feed stream heating is minimized. Inert gas streams combined with the feed stream and introduced into the distillation tower are controlled whereby feed stream heater residence time and partial pressures of feed stream components are minimized. The temperature of the combined inert gas-feed stream exiting the feed stream heater is controlled at a minimum temperature by establishing signals representative of overflash, bottom product specification and other conditions and comparing such signals whereby the signal which represents the lowest heater outlet temperature is utilized for controlling the heater operation.

대표청구항 ▼

In a distillation process wherein a feed stream containing components to be separated is combined with a first inert gas stream, the combined inert gas-feed stream is passed through a heater whereby it is heated, the heated combined inert gas-feed stream is introduced into a distillation tower where

In a distillation process wherein a feed stream containing components to be separated is combined with a first inert gas stream, the combined inert gas-feed stream is passed through a heater whereby it is heated, the heated combined inert gas-feed stream is introduced into a distillation tower wherein the feed stream is subjected to distillation at a low total tower pressure, a second inert gas stream is introduced into the distillation tower and a liquid bottom product of required specification, one or more sidedraw liquid products and overhead gases are withdrawn from the distillation tower, the improvement whereby the recovery of liquid product other than liquid bottom product is maximized with minimum energy input while meeting the bottom product specification comprising: maintaining the total distillation tower pressure at a low level; controlling the flow rate of said first inert gas stream in proportion to the flow rate of said feed stream and additionally in a ratio therewith such that the residence time of said feed stream in said heater is minimized; controlling the flow rate of said second inert gas stream in proportion to the flow rate of said feed stream and additionally at a total flow rate such that the partial pressures of said feed stream components are minimized in said tower; and controlling the temperature of the combined inert gasfeed stream exiting said heater at the minimum temperature whereby minimum overflash is produced in said tower while maintaining the required bottom product specification and process conditions.