SU1276349A1 - Method of controlling the process of separaion of isoprene-isoamylene fraction - Google Patents

Abstract

The invention relates to the automation of rectification processes, can be used in the chemical industry and reduces the costs of raw materials and energy resources. The method is implemented by the SAR, which includes the flow control circuit of the raw material of the isoprene-isoamylene fraction — controller 3, the flow control loop of the extractant — controller 4, the reflux flow control loop in column 1 — regulator 5, the flow control loop of distillate in column 1 — regulator torus 6, reflux flow control loop in column 2 — regulator 7, distillate flow control loop in column 2 — regulator 8 with sensor 9, coolant flow control loop in column cube 1 — regulator 10 with sensor 11, circuit controlling the flow rate of coolant to the cube of column 2 — regulator 12, pressure control loop in the upper part of column 1 — regulator 13. sensor 14, level in reflux tank capacity 1, analyzer 15 composition of distilles, fifth column 2, functional blocks 18 — corrections according to t to the level in the reflux tank and 19 to the regul (lyophilization of the concentration of isoprene in the distillate columns 1 and the correction units 20 and 21. 1 sludge.

Description

This invention relates to the automation of rectification processes and can be used in the chemical, petrochemical, and other industries.

The purpose of the invention is to reduce the specific consumption of raw materials and energy.

The drawing shows a schematic diagram of a control system implementing a snozob.

The method is carried out as follows.

The separation of the isoprene-isoamylene fraction in the production of isoprene is carried out in column 1, where the isoamylene fraction in the desorption column 2 is separated, and in the latter the isoprene fraction is separated from the extractant.

The process control system includes a feedstock regulator 3 - isoprenisoamylene fraction, an extractant feed controller 4, a reflux flow controller 5 in column 1, a distiller flow controller 6 for column 1, a reflux rate controller 7 for column 8 s. sensor 9 for the flow rate of distillate columns 2, controller 10 with sensor 11 for supplying coolant (water vapor) to the bottom of column 1, regulator 12 for supplying coolant to the bottom of column 2, pressure regulator 13 in the upper part of column 1, level sensor 14 reflux tank columns 1, the analyzer 15 composition of the dist pp is the column 1 - izoamilenovoy fraction analyzer 16 column distillate composition 2 - isoprene fraction. The diagram also shows the functional blocks 18 and 19 of the correction in the reflux tank and the adjustment of isoprene concentration in the distillate of the column 1, respectively, the correction blocks 20 and 21, implemented in the control microcomputer 17.

With the help of regulators 3 and 4, the feedstock and extractant are supplied respectively to the column 1. Using the regulators 5-8, the flow rates of the reflux and distillate columns 1 and 2 are adjusted. Using the controller 10, the measurement from the sensor 11 regulates the flow of coolant to the cube Column 1, with the help of regulator 12 - supply of coolant to the cube of column 2, and with the help of regulator 13 - pressure in the upper part of column 1 with supply of refrigerant to the heat exchanger.

With the help of block 18, discrete (with the interval TI, the correction of the task to the controller 10 is performed, for example, according to

and, and „+ CHE, + xi К; / е, - + I-J (е, -8 ,,),

NZZ-Yat t

- And, - deviation in the 1st cycle

level in the reflux tank, measured by the sensor 14, from the set value.

Using block 19, discrete (with an interval of T2) control of the concentration of C ' isoprene in the distillate of column 1 measured by the analyzer (chromatograph) 15 is carried out by changing the task to controller 6, for example, according to the PID law:

og og + k: and + t, Oy.n4 (,

La ass

where In is C С, CС is the deviation in the nth step of the concentration of isoprene from a given value;

Gn is the task for the consumption of distillate columns 1.

Using block 20, a discrete fc interval, tc, is used to correct the value C, as follows:

MD

C, „, + D1, if r,;

m

SG-s if r „,;

ass Сш- | -AI, if r, „;

where r ,,, is the average value of the concentration of isoamylenes in the distillate of column 2, determined from information from an analyzer (chromatograph) 16; And - tuning parameter. Using block 21, determined at discrete points in time (with an interval of ts) the actual consumption of the coolant per ton

isoprene:

Fm

where Р, „is the average value of the flow rate of the heat carrier in the cube of column 1, determined from information from sensor 11;

Q «is the average value of the consumption of isoprene in the distillate of the column 2 over the mth cycle.

The consumption of isoprene in the distillate of column 2 is determined as the product of the distillate flow rate measured by sensor 9 by the concentration of isoprene, determined from information from analyzer 16.

Adjust the task to controller 5 as follows

bum

FTP1 | + A2, if a, „a F - i, if a F, - Ar. if a ,,,.

where hell is a setting parameter.

The implementation of discrete actions is carried out using a microcomputer 17.

The calculated values of the tasks U, -,, and Rc are checked for valid limits before being issued to the appropriate controller, and if one of the restrictions is violated, they give the value of this restriction to the controller.

The discreteness of TI is chosen taking into account the inertia of the ER column (t | 5-10 min), the discreteness of T2 is chosen equal to the duration of the chromatograph cycle 15 (t2 "15-20 min), and the discreteness of Tz is set to a multiple of T2 discreteness (Tz":; 5T2).

Claims (1)

Invention Formula The method for controlling the separation of the isoprene-isoamylene fraction in the production of isoprene by adjusting the concentration of isoprene in the distillate of the extractive distillation column by affecting the flow rate of the distillate of this column, controlling the flow of coolant to the cube extractive distillation columns, controlling the consumption of isoprene in the distillation of the desorption column, characterized in that, in order to reduce the specific consumption of raw materials and energy resources, the concentration of isoamylenes in the distillate of the desorption column is additionally measured, depending on which the concentration of extractant in the distillate is corrected rectification, measure the level in the reflux tank and adjust the flow of coolant into the cube of the extractive distillation column according to the level in the reflux tank, adjust the stroke reflux extractive distillation column depending on the flow of the heat medium in the cube of the column and the flow rate of isoprene in the distillate desorption column.