SU1407926A1 - Method of controlling process of hydrogenating acetylide compounds in parallel-operating reactors - Google Patents

Abstract

The invention relates to methods for controlling the hydrogenation process and can be used in the chemical and petrochemical industry in automating olefin plants. The aim of the invention is to increase the productivity of the process by increasing the turnaround time of the reactors. The scheme for implementing the method includes reactors (P) 1, 2, flow sensors (D) 3 and 4, D 5 and 6 pressure differential, regulator 7, valves 8 and 9, analyzer (A) 11 of the fraction to the reactors, A 13 and 15 of the composition of the fraction after P 1 and 2, functional block (FB) 16 for calculating the loss of olefins, FB 17 for calculating the ratio of hydraulic resistance of reactors and FB 18 for calculating the control actions. 1 il. (L

Description

h

about IND

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MsoOi is related to cnocof); iM controls the hydrogenation process and can be used in chemical and petrochemical industry in the automation of olefin plants.

The purpose of the invention is to increase the productivity of the process by increasing the turnaround time.

The drawing shows the principle of a process control scheme implementing the proposed method.

The scheme for implementing the method includes reactors 1 and 2, flow sensors 3 and 4, pressure differential sensors 5 and 6, regulator 7, control valve 8 (or 9) for feeding the fraction to reactor 1 (or 2), unit 10 for manual setting and analyzer 11 of the fraction before the reactors, the task block 12 and the analyzer 13 of the fraction after reactor 1, the block 14 of the task and the analyzer 15 of the fraction after the reactor 2. The control system also contains functional blocks 16-18 and cross-linking blocks 19- 21,

The method is carried out as follows.

According to information from flow analyzers 11, 13, and 15, or from laboratory analysis (blocks 10, 12, and 14), depending on the state of switching blocks 19-21, block 16 calculates the loss of olefins R, R at reactors 1 and 2,

Due to the relatively small amount of hydrogen supplied after the sampling point of the analyzer 11 (or unit 10) to reactors 1 and 2 (about 30–50 kg / g with an olefin fraction flow rate of 10–15 t / g to the reactor), it is considered that its supply practically does not change the specific olefin content in the stream to the reactor. With this interpretation, the calculation of the loss of olefins R, R in reactors 1 and 2 is carried out as follows:

R, Cf

R with - With

- determined by the analyzer 11 or introduced into block 10 the olefin content in the input streams of reactors, 55

wt.%; - olefin content after

reactor 2, measured by anaCl

whether .1Т (rum 13 or n block 14 introduced, wt., С, is the olefin content after

reactor 1, measured by the analyzer 13 or entered in block 12 of the task, wt.%. In block 17, a value A is calculated that characterizes the ratio of the hydraulic resistances of reactors 1 and 2 according to the following formula:

BUT

DR, LR,

G

GI

where LR ,, ДР - the values of pressure drop Len1sh on reactors 1 and 2, measured by sensors 5 and 6, respectively, kg / cm J G ,, With the magnitude of the loads in

reactors 1 and 2, measured by sensors 3 and 4, respectively, t / h. In function block 18, the control valve 8 (or 9) is set to controller 7, which is formed depending on the sign of magnitude A as follows.

Calculation of controls for R,: R ,:

K A, if A 0;

 , P

ifA 0:

 - y

if A 0;

G -

Oq

35

Q

0

five

0

five

Calculation of controls for R2, R,:

f WQtC

„P JG - к-А, if А 0 ;. (c if A g 0;

G G - C g G,

P p

where G ,, Gj is the calculated mixture flow rates in

reactors 1 and 2; „AGIM

O, G, respectively, the maximum and minimum limit on the flow of the mixture in each reactor;

G G, GJ - total consumption of the mixture per unit of hydrogen and i

K - coefficient chosen experimentally in the range of 1-10 -5 10. In the case when the selectivity of the catalyst in reactor 1 is higher than in reactor 2 (the ratio of olefin loss R, «c Rj), the flow rate of the mixture in reactor 1 is taken as a maximum of,

I’ll continue (, if its hydraulic resistance (i.e., amberness) does not exceed the hydraulic resistance in reactor 2 (AiO), and decreases relative to an amount proportional to their difference A, if the hydraulic resistance in reactor 1 is greater than in reactor 2 (A 0). At the same time, the real range of variation of the total consumption of the mixture G is such that the calculated value of the consumption of the mixture in reactor 2 (G GG) always exceeds the minimum limit.

Similarly, provided that the selectivity of the catalyst in reactor 2 is higher than in reactor 1 (,), the flow rate of the mixture in reactor 2 is stabilized at the maximum limit of max.

G, if its hydraulic resistance does not exceed the hydraulic resistance of the reactor 1

20

The proposed method allows the hydrogenation process to be carried out in such a way that the resinification of the catalyst in the reactors, characterized by their hydraulic resistance, is uniform, which makes it possible to simultaneously stop the reactors for cleaning and catalyst overload and thereby increase the overhaul of the reactor unit as a whole by 20%.

(A 0), and decreases relative to the invention.

g max

B on size

their differences are A, otherwise

()

Example 1. Initial data:, 1 wt.% G, 13,500 t / h Gf 77.3 wt.% Gj 12.5 t / h

With "aks, /

, 0 t / h 1-103

Compare the loss of olefin reactors 1 and 2:

R, 0.8 wt.%

thirty

С® 77,0 May .; & P, 2.0 kg / cm LE, "1.6 kg / cm

35

The method of controlling the process of acetylene compounds in parallel operating reactors, including the distribution of loads between reactors by feeding the reactor the maximum allowable consumption of raw materials, characterized in that, in order to increase the productivity of the process by increasing the mean overhaul time of the reactors, reactors on the consumption of raw materials in the reactors and pressure drops in the reactors, calculate the ratio of the hydraulic resistance of the reactors, and the distribution loads between the reactors are additionally adjusted by the calculated ratio of the hydraulic resistance of the reactors,

R

J 1.1 wt.%

R,

Value A 7.3.10 Calculation of controls:

 j, 27 t / h

G (G, -t-G) -G 10.73 t / h G

Example 2. Baseline data;

C 78.1 wt.%, 8 wt.%

G, 13.5 t / h, 5 t / h

five

WITH; 77.0 wt.% (G 40.0 t / h iF, 2.0 kg / cm C 7.0 t / h, 6 kg / cm. K) Compare the losses of olefia at reactors 1 and 2: R, 1, 3 wt.% R 1.1 wt.% A 7.3-S-O,

R, -: K ,;

0

.P / max

Calculation of controls: 16.0 t / h, Gf (G, + Gj), 0.

The proposed method allows the hydrogenation process to be carried out in such a way that the resinification of the catalyst in the reactors, characterized by their hydraulic resistance, is uniform, which makes it possible to simultaneously stop the reactors for cleaning and catalyst overload and thereby increase the overhaul of the reactor unit as a whole by 20%.

The method of controlling the process of acetylene compounds in parallel operating reactors, including the distribution of loads between reactors by feeding the reactor the maximum allowable consumption of raw materials, characterized in that, in order to increase the productivity of the process by increasing the mean overhaul time of the reactors, reactors on the consumption of raw materials in the reactors and pressure drops in the reactors, calculate the ratio of the hydraulic resistance of the reactors, and the distribution loads between the reactors are additionally adjusted by the calculated ratio of the hydraulic resistance of the reactors,

Claims (1)

Claim Example 1 ^C = 78.1 wt.% G? ^"K = 77,3 wt.% C ^BL" = 77.0 wt.% & F = 2.0 kg / cm ² = 1.6 kg / cm ² Initial data G, = 13.500 t / h G ₂ = 12.5 t / h _g mskc _{= 16> 0 t / h} G * ^nH = 7.0 t / h K = 1 -10 ³ Loss of olefin in reactors 1 and 2 is compared: R, = 0.8 wt.% = 3> R ₍ <R ₂ . R ₂ = 1.1 wt.% The value of A = 7.3 · 10 ”*> 0. Calculation of controls: _g p _{= g} m "" _ _{к а = 15>} 27 t / h G ^ = (G, + G ₂ ) -G _a = 10.73 t / h> σ '” ¹ Example 2. Initial data : C ”= 78.1 wt.% G, = 13.5 t / h C® ^s * = 76.8 wt.% G ₄ = 12.5 t / h A method for controlling the process of hydrogenation of acetylenic compounds in parallel reactors, including the distribution of loads between reactors by supplying the reactor with the maximum allowable consumption of raw materials, characterized in that, in order to increase the productivity of the process by increasing the overhaul mileage of the reactors, the pressure drop across the reactors is additionally measured raw materials in reactors and pressure drops on reactors, the ratio of hydraulic resistance of reactors is calculated, and the distribution of load the cut between the reactors is further adjusted according to the calculated ratio of the hydraulic resistances of the reactors,