SU798115A1 - Method of control of solvent purification from impurities during its rectification - Google Patents

Description

(54) METHOD FOR REGULATING THE SOLVENT CLEANING PROCESS FROM GUYMESIA DURING RECTIFICATION

I

The invention relates to the automation of polymerization processes and can be used in the production of synthetic rubber.

There is a method for recollecting the process of purifying a solvent from impurities during the distillation process by adjusting the steam flow rate in the distillation column boiler, stabilizing reflux and vat residue 1.

The known method has limited possibilities with respect to reducing the content of water boiling impurities in the solvent due to the lack of consideration of the concentration of individual or total impurities.

The aim of the invention is to reduce the content of HIGHLY abrasive impurities in the solvent.

This goal is achieved by the fact that in a known method of controlling the solvent purification process from impurities during the distillation process by adjusting the steam flow rate, a distillation column and a stabilizer of reflux and bottom sediment are additionally bypassed from the top of the vapor phase (distillate) flow from the top. distillation, colony, lithium polystyrene is introduced into it, the color is stabilized in the resulting mixture by changing the flow rate of the bypass stream of solvent or lithium polystyrene, changes stroke reflux depending on the solvent flow rate baypasirovannogo stabilize in resid concentration of the solvent distillation column bottoms flow change.

At the same time, the level of the liquid phase in the distillation column can be further stabilized by changing the steam consumption in the distillation column boiler, and if the reflux number exceeds the specified allowable value, the solvent consumption for the distillation column can be further reduced.

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

Claims (3)

Returning solvent is fed to distillation column 1. Steam consumption in the boiler 2 of the distillation column is stabilized by regulator 3, which receives information about the flow rate from sensor 4 and acts on valve 5. From the cube of distillation column 1, labor bottoms 6 output bottoms is stabilized by the regulator 7, receiving information from the flow sensor 8 and acting on the valve 9. On the pipeline 6 a sensor 10 of the return solvent concentration in the bottoms is installed, which provides information controller 11 was concentrated. When this concentration is exceeded by a predetermined value, the controller 11 reduces the task to the controller 7, i.e. reduces the consumption (output) of the bottoms, and as the concentration decreases from the setpoint, the controller 11 increases the reference to the controller 7, i.e. increases the extraction of bottoms. On distillation column 1, a liquid phase level sensor 12 is installed, feeding the formation to a level 13 regulator. When the level of the liquid phase in the distillation column 1 of the specified value is exceeded, the regulator 13 increases the reference to the controller 3, i.e. increases the consumption of steam in the distillation column boiler 1, and when this level decreases from the set value, the controller 13 reduces the task to the controller 3, reducing the steam consumption in the boiler. At the outlet of the column, the vapor phase through line 14 enters the condenser 15, from which the distillate is fed through line 16 for polymerization or for additional azeotropic drying. From this pipeline, part of the distillate is bypassed and used as reflux, the flow of which is stabilized by the regulator 17, receiving information from the flow sensor 18 and acting on the valve 19. Another part of the distillate from the pipeline 16 is bypassed by the pipeline 20 lithium polystyrene is introduced, which is a mixture in a certain ratio of lithium butyl and styrene. Consumption of distillate flow bypassed through pipeline 20 and consumption of lithium polystyrene are stabilized, respectively, by controllers 22 and 23, which receive information from flow sensors 24 and 25 and act on valves 26, 27. A sensor 28 is installed at pipeline 20, measuring the color of the mixture, which gives the corresponding signal to the controller 29, which stabilizes the color of the mixture by changing the task to the controller 22, i.e. by changing the flow rate of the distillate flow that is bypassed through pipeline 20. In an equivalent embodiment, the stabilization of the photoelectric signal can be accomplished by changing the setting of the controller 23, i.e. by changing the consumption of lithium polystyrene, but the distillate bypass flow must be stabilized by the regulator 22. Information about the consumption of the distillate bypass flow from sensor 24 (and equivalently about consumption of Pytistyrene from sensor 25) is fed to regulator 30, which when exceeded This flow rate of a given value corresponding to a certain Ipperal concentration of impurities in the solvent — distillate — reduces the reflux consumption, i.e. reduces the setting of the controller 17, and when this flow rate decreases from a predetermined value, it increases the flow rate of the reflux by increasing the reference to the controller 17. In an equivalent embodiment, when the photoelectric signal is stabilized by changing the flow rate of polystyrene, the flow of the reflux increases, and vice versa. If the current reflux number determined by the computing device. 31 according to information from sensors 18 and 32 of the flow rate (sensor 32 is installed on pipeline 16) exceeds the maximum permissible value, then the solvent supply (load of distillation column 1). adjustable by controller 33, is reduced. Thus, when the fl-1-mon-1 number of each value is calculated, the computational ycrpoiiciBO 3 reduces the reference to the controller 33. The controller 33 will receive information about the flow from the sensor 34 and act on the valve 35. As an option, the Incremental device 31 can change the reference controller 30: when trans. by the phlegmon of the given admissible value, the assignment to the controller 30 is reduced, those. allow a large concentration of impurities in the solvent lillillary. In this case, the load on the distillation column 1, i.e. the task of regulator 33 is not reduced. Thus, the concentration of individual and total impurities in the return solvent is reduced and stabilized, which may lead in the process of shmerization to a decrease in catalyst consumption and to an increase in the quality of commercial polymer. According to preliminary experiments carried out in the production of polybutadiene, by reducing the concentration and impurities in the return solvent according to the method proposed, the consumption of the titanium component of the catalyst during the polymerization process can be reduced by 0.5 mol per ton of rubber. Claim 1. The method of regulating the process of purifying a solvent from impurities in the process of rectification by rschulirona steam consumption in the booster pskti (| ikatsioinoy column, stabilizing the flow of reflux and vat residue, so that In order to reduce the content of high boilers in the solvent, they bypass a portion of the vapor phase (distillate) stream discharged from the top of the distillation column, inject polystyrene into the net, stabilize its color in the resulting mixture by changing the flow rate Single solvent or litiypolistirola. the reflux rate is changed depending on the consumption of the bypass stream of solvent; the concentration of solvent in the bottom residues of the distillation column is stabilized by a change in the consumption of the bottom residues. 6 2. A method according to claim 1, characterized in that the level of the liquid phase in the distillation column is additionally stabilized by changing the steam flow rate into the distillation column distillation column. 3. The method according to p. 1, about tl and h and y and that with the reflux number exceeding the specified allowable value, reduce the consumption of solvent for the distillation column. Sources of information taken into account when examining 1. I. Anisimov. Automatic regulation of the process of rectification, M., Gostekhizdat, 1961, p. 4-6.