SU1487922A1 - Method of controlling isobutylene-sulfuric acid extraction process - Google Patents

Description

The invention relates to automating the process of extracting isobutylene from the butylene-isobutylene fraction using

2

sulfuric acid, can be used in the chemical and petrochemical industries and allows you to stabilize the performance of the process. The method of controlling the extraction of isobutylene with sulfuric acid consists in controlling the cost ratio of the butylene-isobutylene fraction and sulfuric acid, controlling the level of phase separation in the column by affecting the recovery of isobutyl sulfuric acid, measuring the flow rate and electrical conductivity of isobutyl sulfuric acid, determining the degree of saturation of sulfuric acid with isobutylene, given the actual contact time and a change in isobutylsulfuric acid pumping depending on the difference between the actual and the specified contact time. a. 1 il.

The invention relates to automating the process of extracting isobutylene from the butylene-isobutylene fraction with sulfuric acid and can be 'used in the chemical and petrochemical industry.

The aim of the invention is to increase the productivity of the process.

The drawing shows a block diagram of the device for implementing the method of controlling the process of extraction of isobutylene-sulfuric acid.

Sulfuric acid flows continuously into line 1 through line 2, and the butylene-isobutylene fraction enters line 3. Pumping of isobutyl acid is carried out by line 4. The regulation of the ratio of the costs of butylene-isobutylene fraction and sulfuric acid is carried out using sensors 5 and 6, the regulator 7 of the ratio of costs and the actuator 8.

Izobutilsernoy acid consumption measured by the sensor 9, and its electrical conductivity - the sensor 10. Information from the sensors 9 and 10 are supplied to computing unit 11. This also manually entered target on the sulfuric acid concentration C .5o _nJ <, ^as well as information from the sensor section 12 on level phases in column 1.

Computing unit 11 calculates the current value of the contact time, for example, by the expression

H.

with,

(one)

5TS 1487922

where O is the diameter of the column, m;

H - phase separation level, m;

Usek - consumption of isobutyl acid,

m ³ / s.

Next, using the signal from the sensor 10

electrical conductivity and manual signal about

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the concentration of sulfuric acid computing unit 11 calculates the degree of saturation of sulfuric acid with isobutylene. For the calculation can be used, for example, dependence (within the concentration of sulfuric acid 55-65%)

(2 = 125— (Y — 0.7) +677 (Y — 0.7) ² +5.08 (X-6.174), (2)

where ζ) is conductivity, rel. ed;

Y — the degree of saturation of sulfuric acid ^{1 and} isobutylene,%;

X is the concentration of the original sulfuric acid,%.

Next, determine in advance the contact time TCD using the dependence, which, 15 for example, can be approximated by the expression

* £ ass = 31050-225 W. (3)

The specified contact time depends on the degree of saturation of sulfuric acid with isobutylene. The higher the degree of saturation, 20 the shorter the contact time should be, and vice versa. Therefore, the specified value of the contact time varies inversely with the degree of saturation calculated by expression (2). 25

Computing unit 11 compares the current and specified values of the contact time, and the resulting signal acts on the actuator 13, installed on the line 4 pumping

isobutyl sulfuric acid. As can be seen from expression (1), the regulation of contact time is achieved by simultaneously changing two variables, Acace and N. When the valve is opened, Acace increases and H decreases at the same time, which contributes to an almost instantaneous contact time.

The use of an additional control channel makes it possible to reduce fluctuations in the productivity of the installation of extraction of isobutylene with sulfuric acid by 4-5%.

Claims (1)

Claim The method of controlling the process of extraction of isobutylene with sulfuric acid, which consists in controlling the cost ratio of the butylene-isobutylene fraction and sulfuric acid and regulating the level of phase separation in the column by affecting the recovery of isobutyl sulfuric acid, which also measure the flow rate and electrical conductivity isobutyl sulfuric acid, calculate the degree of saturation of sulfuric acid with isobutylene, set and the actual contact time and change the isobutyl pumping ernoy acid directly proportional to the difference between actual and predetermined contact time.