SU1474156A1 - Method of controlling oxime isomerization process - Google Patents

Abstract

The invention relates to the field of automation of chemical technology processes, in particular the process of rearrangement of oxime into lactam, and can be used in the chemical industry. The aim of the invention is to reduce the consumption of oleum and the loss of lactam. The method includes measuring the acidity of the rearranged product, regulating the oleum consumption by acidity, measuring the temperature of the reaction mixture in the reaction zone, regulating the flow of oxime by temperature, changing the consumption of oleum with temperature correction. 1 il.

Description

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This invention relates to the automation of chemical technology processes, in particular the process of regrouping oxime into lactam, and can be used in the chemical industry.

The aim of the invention is to reduce the consumption of oleum and the loss of lactam.

The drawing shows a diagram of the device that implements the proposed method.

The scheme contains a rearrangement reactor 1, a temperature sensor 2 installed in the reaction zone, an acidity sensor 3, a control unit 4 according to the temperature sensor readings, an actuator 5, an oxime feed control valve 6, a logic unit 7 with a control device, an actuator 8 and control valve 9.

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The method is carried out as follows.

In the rearrangement reactor 1, oxime and oleum are fed. As a result of the Beckmann rearrangement, the oxime is converted to lactam. In the reaction zone, the temperature t is measured and the error signal DT T - T0 is determined (7G, where Topt is optimal, the pre-set temperature, the acidity of product K rearrangement K is measured at the output and a mismatch signal is received 4K K - K0 g, where K0 ( 7G optimum acidity in the regrouped product.

The signal from temperature sensor 2 DV a {dT enters the control device and, through actuator 8, opens or closes the oxime supply valve. Mismatch signals dT and d K are received in

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the logical block and is converted into a signal dt a24T + a3 /) K, where af, ar and a are weights determined experimentally during adjustment. The signal goes to the actuator 8, which opens or closes the oleum supply valve.

If the temperature rises, a signal is received to reduce the consumption of oxime and at the same time a signal to increase the consumption of oleum, taking into account the acidity signal, as the optimum temperature is reached, the contribution to the signal by the controlling oleum flow rate as the temperature changes decreases, and the contribution to the signal from acidity changes the oleum ray yield increases and is adjusted to the optimum acidity. If the temperature decreases, the consumption of oxime increases and the consumption of oleum decreases when the temperature reaches the optimum one. When the temperature reaches close to optimal, the acidity begins to equalize as the difference D T becomes small and the term a24K in the signal f f becomes decisive.

Example. In reactor 1, sensor 2 detects an increase in temperature exceeding Т.0pt in the reaction zone and at the same time sensor 3 of the acidity of the rearranged product detects an increase in acidity from 59 to 59.5%, which is due to the fact that oleum contains 30 -koleblets from 18 to 23% and also the humidity in the oxime varies from 3 to 57 ,. Sensors 2 and 3 of temperature and acidity record an increase in acidity and temperature. The Lf atuT (a. L) signal, generated by the control unit 4, actuates the actuator 5, which covers the valve 6, and reduces the supply of oxime. At the same time, two signals from sensors 2, 3 are sent to logic block 7, where a2dT and a3dK are multiplied (aЈ 1, and 3 0,6) in multiplication blocks and their summation in an adder, and a 4 m 4-a.dK signal is output actuator 8, actuating valve 9, which

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in parallel, increases the flow rate of oleum, the temperature decreases to TVpg, the contribution of the member to the signal Dta decreases, and the contribution of the member increases and the valve 9 closes, reducing the consumption of oleum.

Example 2. Analogously to example 1, only the acidity increases from 59 to 60.5%, in this case the contribution of the term exceeds the contribution of the member to the signal and valve 9 reduces the consumption of oleum while reducing the consumption of oxime.

Thus, the proposed control method allows the process to be carried out without tarring a part of the lactam because of the high temperature and at the same time without decomposing the part of the lactam due to the high acidity, i.e. to avoid the loss of the most expensive reagent, oxime, and at the same time reduce the consumption of oleum, since the acidity in the process is kept as high as possible (without lactam loss).

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Using the proposed method allows to obtain additional products with a simultaneous decrease in the consumption of oleum.

Claims (1)

Invention Formula A method for controlling the oxime isomerization process, including regulating the supply of oleum to the reactor depending on the acidity of the product at the outlet of the reactor, as well as oxime, characterized in that, in order to reduce the consumption of oleum and lactam loss, the temperature of the reaction mixture in the reactor is also the temperature of the reaction mixture in the reactor with a given value and, when the measured temperature exceeds a specified value, reduces the flow of oxime and increases the flow, oleum to the reactor op, and at a measured temperature lower than the specified value, increase the flow of oxime and reduce the flow of oleum into the reactor. Oksim h Yz Oleun s one} Editor N. Gunko Compiled by G.Ogadzhanov Tehred M.Didyk Order 1839/22 Circulation 352 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5 four n product Proofreader S. Shekmar Subscription