SU1281566A1 - Method for controlling process of polymerization or copolymerization of alpha-olefins in gas phase - Google Patents

Description

ГСхЗ-Q - г1 атй / агагщ j

€ L

to

00

cl

Odd

Gzaz znaic

The invention relates to methods for controlling the polymerization processes of alpha-olefins in the production of polyolefins and can be used in chemical, petrochemical and other industrial complexes.

The aim of the invention is to increase the productivity of the polymerization reactor by reducing the time to forced shutdowns.

The drawing shows a block diagram of a system implementing the proposed control method.

Ethylene, hydrogen and carbon dioxide are fed to the polymerization reactor 1. The circulation of the reaction gas is carried out due to the operation of the compressor 2. The pressure in the reactor is stabilized by the regulator 3 by varying the flow rate of ethylene. The concentration of CO — regulator 4 and the flow rate of hydrogen — regulator 5. The particle size of the polymer, the melt flow index of the MFR, and the concentrations of hydrogen and ethylene in reactor 1 are measured by sensors 6–8, respectively. The measured values are entered into the computing device. 9 The specified values of the particle size of the polymer, g, and the routine value of the activity index are entered here.

catalyst Z

 Max

The method is carried out as follows.

Let, for example, as a result, changes in the purity of the feedstock or the properties of the catalyst reduce the particle size of the polymer formed.

Then the computing device (WU) 9 for a given and measured values determine the new value of the concentration of trace trace CO according to the formula

Г С

h h

 (rr,.) dt:

0.09 J

--K (Z-ZJ-K (,

(one)

de c. and C, and

3

and g

to, cf.

the concentration of micronutrient carbon dioxide required by the average, h, per million; polymer particle size measured and back, mm;

the size of the part of the catalyst measured to average, mm;

,

mean

Max

Kj.Ki

the ash content of the measured, average and maximum polymer produced (the percentage of residual catalyst in the polymer can serve as a measure of catalyst activity),%; coefficients depending on the grade gets the MO polymer:

, 1-0.5 -; K2 5-25;

Kz 10-40,

(at Z $ Z

 ma "

KjO).

If it is impossible to determine the particle size of the supplied catalyst, g is assumed to

The calculated value of the co-concentration of the mass impediment € 0 by the computing device 9 is given as a task to the controller 4. The concentration of hydrogen is regulated depending on the change in the concentration of CO ,, and the MFR;

1 CP

with ..., Ji-a- -k. In SHi-j; (2)

9

PTR

"Y,

0 0

five

0

five

F f

TR CP

),

where and

CH.fpfC Sleep, i

TO.

PTR

 Н5) ТР - К5,} 1ЧС

V

 Ner

-concentration of hydrogen calculated, average and measured, wt.%;

-coefficient K 0,2-0,1

3 ° i

PTR

FTP and

Hjm

FCP Melt Flow Index of the resulting polymer, set and measured, g / 10 min; hydrogen consumption in the reactor is calculated and average, kg / h. The calculated value of C., “issued 2

Ems as a task on the hydrogen consumption controller 5.

For example, let the particle size be rejected and equal to 0.8 mm (given O, 9). And the ash content changed from 0 “01 to 0 ,, ppm,. ,, - 0.025%„

Then the required concentration (at),, 67 hours per million

The concentration of hydrogen should be increased (without taking into account the change in the MFR) in accordance with formula (2):

 s / s

 - “3fp C

; - 3.72% .3 12815664

Thus, the control on the pre-result of this performance

the latency method allows a constant reactor to increase due to an increased support of the particle size in terms of the useful time of the peaxToffa

leamer at their given value, with, (removed stops

where the best way to clean the reactor is to clean it from the heat removal of the exothermic reaction of the polymer with increasing size

(with enlarged particles of heat particles), respectively, decreases

returns are reduced due to a decrease in the rate of consumption of raw materials and electricity, the specific surface area) and

Even the time reduces particle entrainment 0 By increasing the mileage of the co-polymer and their clogging of the pipeline, the consumption norms for production

The circulation gas of the reaction, the improvement of 1 ton of polymer is reduced by 0.6%, and

their fluidization and conditions of reactor performance increase the polymer discharge system. It is 0.15%,

Claims (1)

METHOD FOR CONTROLLING THE POLYMERIZATION OR COPOLYMERIZATION PROCESS OF ALPHA-0 LEFINS IN A GAS PHASE IN THE PRESENCE OF A CATALYST, HYDROGEN AND CARBON DIOXIDE, which consists in regulating the pressure in the reactor ° by changing the flow rate of the monomer and the melt flow rate at different loads by varying the concentration of carbon dioxide and the fact that, in order to increase the productivity of the reactor, the particle size of the resulting polymer is controlled by a directly proportional change in the concentration of microprim If you take carbon dioxide, taking into account the activity indicator of the fed catalyst. • a SU .... 1281566