SU1247075A1 - Method of automatic control of production process with recirculation of gaseous reagent - Google Patents

Description

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The invention relates to a technique for controlling catalytic processes carried out in chemical reactors, and can be used in the chemical, petrochemical, microbiological, and other industries.

The aim of the invention is to increase the depth of selection of the target product.

FIG. 1 is a schematic diagram of the control of the benzene production process by thermal hydrodealkirovanie of toluene; in fig. 2 - diagrams of the change in the technological parameters of the process under the action of perturbations at the maximum permissible molar ratio of raw materials to hydrogen.

The control circuit contains a compressor 1 for supplying hydrogen-containing make-up gas (GAS), a compressor 2 for supplying gaseous reactant (GHS) circulating in addition to the regeneration section, a compressor 3 for supplying GV circulating through the regeneration section GHS to increase the concentration of circulating GHS up to 90 vol.% reaction section 5, in which the mixture of make-up, regenerated and circulating SHG flows is mixed with toluene; separator 6 for separating the reagent stream coming from section p gaseous and liquid phase, primary converter 7 toluene consumption, toluene consumption regulator 8 with a secondary device, control valve 9 on the toluene supply line, total VSG consumption converter Yu, the total consumption of the total flow rate, secondary flow control with a secondary device, control valve 12 on the bypass line

12470752

device, algebraic summing device 21, algebraic summing device 22, signal limiting device 23, primary flow converter 24, make-up flow controller, primary flow converter 25, circulating flow rate generator, 26 primary flow converter 26 flow rate and all flow rates after regeneration section, the primary converter 27 of the VGG flow rate to the regeneration section, the control valve 28 on the VSG line from the regeneration section.

15 The control method is implemented as follows.

With an increase in the discharge of excess GSS (graphs 16-36, Fig. 2) over 500 given by the technological regulations, which occurs, for example, or with an increase in the concentration of the make-up GAS (graph 1a, Fig. 2) or the amount of make-up VSG (graph 2a, fig 2), or the content of toluene in SF (Plot diagram, Fig. 2), the correction signal of the converter 17, the regulator 19 through the limiter 23, the adder 21 will change the reference to the controller 11 and the valve 12

30 will increase the flow rate of the hydrogen-containing gas in addition to section 4 (graphs 1c-3c, fig. 2), and hence the HSG adder (graphs 1d-3g, fig. 2). As a result, an increase in the molar ratio of sphe-hydrogen in the range of 1: 4.5–1: 6 will occur, which leads to an increase in the stability of the reaction process.

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Since, in accordance with the technological regulations, the regulator 18 has a reference of 1000, and the regulator 16 has 60 vol% (the concentration of circulating GAS under initial conditions, as in accordance with the technological regulations, the regulator 18 has a reference of 1000, and the regulator 16 - 60 vol.% (concentration of circulating VSH at the initial conditions of the compressor 2, the primary conversion is 56 vol.% (pressure charts 13 before the reaction section 1e-3e, fig. 2), their output signals, controller 14 by

Petrochem- for measuring concentration-regulator of pressure 14 in front of sec-5 with a secondary device, chromatograph 15, for example, of type EPDM

after the reaction section equipped with an electropneumatic transducer, regulator 16 of the concentration of circulating VSG with a secondary device, primary converter 17 of the VSG excess flow, regulator 18 of the VSG excess flow with a secondary device, regulator 19 of the VSG excess flow with VT50

Came into the chambers of different poles of the adder 22 are equal, and the output signal of the adder 22, determined by the magnitude of the shift signal of the adder itself, does not change, maintaining a stable value of the regenerated VSH consumption (graphs 1d-3d, fig. 2). With a simultaneous increase in the concentration of the make-up GAS and the flow rate of the circulating GFS, the concentration of the total GAS does not change (Figures 1g-3g, Fig. 2). Since loading40

Since, in accordance with the technological regulations, regulator 18 has a reference of 1000, and regulator 16 has a volume of 60 vol.% (The concentration of circulating GAS under initial conditions is 56 vol.% (Graphs 1e-3e, Fig. 2), their output signals

These x are 56 vol.% (graphs 1e-3e, fig. 2), their output signals,

Came into the chambers of different polarities of the adder 22 are equal, and the output signal of the adder 22, determined by the magnitude of the shift signal of the adder itself, does not change, maintaining a stable value of the flow of the regenerated GSS (graphics 1d-3d, fig. 2). With a simultaneous increase in the concentration of the make-up FGG and the flow rate of the circulating FGG, the concentration of the total FFG does not change (Figures 1g-3g, Fig. 2). Since the raw material loading (toluene, shown in Figures 1 and 3, Fig. 2) and the pressure in the reaction section (Figures 1h-3h, Fig. 2) are at nominal levels, the output signals of the converter 7, multiplier 20 and controller 1A, the output signal of the adder 21 is not affected. Regulators 8 and 14 stabilize

In this case, the SFE – hydrogen ratio is 1: 6, which ensures the maximum depth of the selection of the target product from the raw material.

Such interaction of the elements of the process control system allows, when reaching the concentration of make-up GSS, for example, 85% by volume and the amount of excess discharge

of the process (graphics 1i-3i, 1h-3h, fig. 2) 10 VSG equal to 1200 (fig. 2

As a result, the yield of the target product increases (graphs 1k-3k, Fig. 2).

With a further increase in the concentration of make-up VSG (as shown by the coordinate P, Fig. 2), for example, more than 82 06.% (graphs 1a-3a, Fig. 2), and an increase in the discharge of excess VSG, for example, more than 1000 nm h (graphs 16 -36, fig. 2) limiter 23 leaves the correction signal of regulator 19 at the reached level j regulator 18 through adder 22 increases the output of regenerated hydrogen through section 4 of regeneration (graphs 1d-3d, fig. 2); The regulator 11 reduces the flow rate of the circulating HSG in addition to the section of the VSG regeneration (graphs 1c-3c, fig. 2) to maintain the flow rate of the total GSS at the reached level (corresponding to the highest circulation rate of the total GSS), within the process regulations. As a result, the concentration of the total VSH is increased, for example, to 76 vol%, (graphs 1g-3g, fig. 2) J with increasing concentration of the VSG after the reaction section to 60 vol% (graphs 1e-3e, fig. 2) controller 16 stabilizes the achieved concentration of circulating HAL. Moth

In this case, the SFE – hydrogen ratio is 1: 6, which ensures the maximum depth of the selection of the target product from the raw material.

Such interaction of the elements of the process control system allows, when reaching the concentration of make-up GSS, for example, 85% by volume and the amount of excess discharge

WASH equal to 1200 (Fig. 2

dinata III), to ensure the stabilization of the process parameters at the achieved optimal level and to obtain the maximum yield of the target product.

When the concentration of the make-up VSH is reduced, the process modes are controlled in reverse order.

To prevent the pressure in the reaction section above the predetermined schedule, for example, due to an unacceptable increase in the flow rate of the total VSH, the operation of the regulator 14 is corrected by the interaction, through the spout matrix 21 to the regulator 11. In this case, the matching unit 20 with the gain factor K 1 allows establish the necessary optimal ratio of the costs of raw materials and the total WASH.

The use of this control method provides in a wide range of disturbing influences the maintenance of the maximum molar ratio of raw materials to hydrogen, monitoring and controlling the expenditures of the circulating HSG, the flow rate of the total HSG, the performance of the reaction section, the discharge value of the VSG excess. The yield of the target product can be increased by 6%.

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Compiler G.Ogadzhanov Editor N.Slobod nickname Tehred V. Kadar Proofreader I.Musk

4047/9

Circulation 527 Subscription VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, st. Project, 4

Claims (2)

1. METHOD OF AUTOMATIC CONTROL OF A TECHNOLOGICAL PROCESS WITH RECYCLING OF A GAS REAGENT by adjusting the flow rate of the total gaseous reactant depending on the flow rate of the liquid reagent, characterized in that, in order to increase the depth of selection of the target product, the flow rate of the total gaseous reactant reagent is adjusted by adjusting the flow rate of the total gaseous reactant reagent pressure in the reaction section, as well as depending on the flow rate of the excess gaseous reactant until this value is reached the course of its boundary value. 2. The method according to claim 1, which includes an additional regulation of the flow rate of the gaseous reactant circulating through the regeneration section, depending on the flow of excess gaseous reactant and the concentration of hydrogen in the gaseous reactant after the reaction section. SU ,,,, 1247075 fi> t