SU1392072A1 - Method of controlling continuous process of isoprene polymerization - Google Patents

Abstract

The invention relates to the automation of the production of synthetic rubber and can be used in the process of isoprene polymerization. The invention allows to reduce the consumption of catalyst and monomer due to the fact that in the cascade of the isoprene polymerization reactor at a stabilized temperature in the first reactor, changing the flow rate of the complex catalyst minimizes the optical density determined over the length of optical light 600-900 nm, by changing the flow rate of one of the catalyst components by stages of catalyst preparation .. 3 sludge., 3 tab.

Description

The invention relates to the automation of the production of synthetic rubber and can be applied in the process of polymerization of isoprene.

The purpose of the invention is to reduce the specific consumption of catalyst and monomer due to more precise process control.

Example 1 FIG. 1 shows graphs of the dependence of the optical density of the polymer on the ratio of the components.

When an equimolar ratio of the components is reached, which ensures the maximum activity of the catalyst, the optical allomacy of polymerisate reaches the minimum value. The absolute value of optical density depends on the concentration of | polymer in solution (curves 1, | 2, 3 correspond to different values of concentration) and can be associated, for example, with the concentration of isoprene monomer in the initial mixture.

Fig. „2 shows the absorption spectra of the polymer at the same polymer concentration in it, but with a different composition of the catalyst.,.

Curve 1 corresponds to an excess of organo-organic compound,

& curves 2, 3, 4 - excess titanium component | In the spectral regions below J600 nm and Bbmie 900 nm, the absorption from other factors | is observed, which makes the use of these areas of the spectrum unacceptable. ; In the region below 600 nm, there is a noticeable effect of the absorption of the catalyst, and in the region above 900 nm there is a noticeable effect of the absorption of the charge components.

FIG. 3 shows a block diagram of the installation with the control of the proposed method.

The process unit (FIG. 3) contains a polymerisation battery consisting of reactors 1 and 2, pipeline 3 for supplying the charge (isoprene solution), mixer 4 for preparing the catalyst, pipelines 5 and 6 for supplying the catalyst components for displacement, flow meters 7 and 8 and regulating valves 9 and 10 installed on pipelines 5 and 6, respectively, pump 11, catalyst supply pipe 12, flow meter and control valve 14, pipe 12, gauge 15, measuring

optical density detector 16; catalyst controllers 17; and catalyst components 18 consumption. The regulator 18 controls the ratio of components by step search, minimizing the optical density.

The continuous process of polymerization of isoprene is carried out in a cascade (battery) of two reactors 1 and 2. The reactor 1 is fed through pipeline 3 with a flow rate of 30 tons / h. The concentration of isoprene in the mixture is 15 wt.%. The temperature specified in the process mode in the reactor. The initial consumption of the catalyst, set by the regulator 17 to maintain this temperature, is 19.7 l / h, which translates to the ratio of catalyst: monomer is 0.43%. The G6 optical density sensor at the wavelength of the measured light of 800 nm measures the optical density of the polymer at the outlet of the reactor 1 and minimizes the value of the optical density using the regulator 18 using the control valve 9 by changing the flow rate of the organoaluminum component. The maximum duration of the search for a minimum does not exceed 15-20 minutes. The temperature in reactor 1 increases with

this is up

and catalyst consumption.

this is up

supplied through the pipeline 12, additionally adjusted downward until the temperature returns to 45 C. I

The adjustment operations are presented in table. one.

Similar adjustment operations are carried out every hour and for 8 hours (one shift) the specific consumption of catalyst per ton of rubber produced and the specific consumption of isoprene monomer are determined by consumed substances. In this case, the catalyst consumption was 2.1 kg / t, and isoprene, 1.003 t / t.

i

EXAMPLE 2 Isoprene is polymerized continuously as in Example 1, but the optical density is measured at a wavelength of 600 nm and its value is minimized by varying the flow rate of the titanium component using the control valve 10.

The adjustment operations are presented in table. 2

The catalyst consumption in this example was 2.1 kg / ton, and the isoprene monomer was 1.004 ton / ton.

PRI me R 3. A continuous polymerization process is carried out. As in Example 1, but the measurement of the optical density is carried out at a wavelength of 900 nm and minimizes its value by changing the flow rate of the alumina-organic component.

ra 0.5 kg / t, and isoprene monomer - 0.004 t / t.

Claims (1)

Invention Formula ten A method of controlling the continuous polymerization process of isoprene in a cascade of reactors by stabilizing the temperature in the first reactor by varying the consumption of the complex catalyst, characterized in that, in order to reduce the consumption of catalyst and monomer, 15 are minimized. optical density, determined at the wavelength of the emitted light of 600-900 nm, by changing the flow rate of one of the catalyst components at the stage of catalyst preparation. Table 1 The parameters of the process of polymerization of isoprene in the regulation of the consumption of the organoaluminum component according to the minimum optical density at a wavelength of light of 800 nm The adjustment operations are presented in table. 3 The specific consumption of the catalyst in this example was 2.2 kg / t, and that of the isoprene monomer was 1.004 tons / ton. The proposed control method reduces the catalyst consumption by 0.5 kg / ton, and the isoprene monomer, by 0.004 ton / ton. Invention Formula with . ten 15 Table 2. The parameters of the process of polymerization of isoprene in the regulation of the consumption of the titanium component according to the minimum optical density at a wavelength of light of 600 nm Table3 The parameters of the process of polymerization of isoprene in the regulation of the consumption of the organoaluminum component according to the minimum optical density at the wavelength 900 nm 4J 4J m Continuation of table 2 one.& "L m / n - ABB700 800 900 1000 Nm FIG 2 Fig.Z