RU2310666C2 - Method of governing butyl rubber production - Google Patents

Abstract

FIELD: rubber industry.

SUBSTANCE: invention relates to automation of synthetic rubber production processes and can be utilized in production of butyl rubber for different embodiments of process, for instance in production of chemically modified rubbers. Method of governing production of butyl rubber via catalytic copolymerization of isoprene and isobutylene in inert solvent is implemented for a plant comprising mixer, cooler, reactor, degasser, all interconnected by pipelines provided with control circuits including sensors-controller-valves regulating intake of isoprene, isobutylene, inert solvent, reaction charge, catalyst, level and consumption of cooling agent into cooler and into reactor and steam into degasser, reaction charge temperature and concentration sensors, reactor and degasser temperature sensors linked to controllers adjusting consumption of reactants, solvent, cooling agent, and steam. Plant further has: reaction charge supply collector, by means of which a part of reaction charge is used to produce non-modified butyl rubber and the other part to produce modified butyl rubber; total reaction charge consumption transducer; reactor; rubber crumb averaging vessel; vessels for dissolving and vessels for averaging rubber for modification; salt washing-off and neutralization towers and degasser connected with each other and to collector for supplying pulp to recovery assemblies through corresponding lines provided with control circuits controlling uptake of reaction charge, catalyst, averaged rubber crumb, rubber crumb solvent, rubber solution to be modified, modified rubber solution, cooling agent into reactor and steam into degasser; isoprene uptake sensor; modifier sensor; washing water sensor; etc. Specified parameters are the following: total productivity, modified-to-unmodified rubber production ratio, reaction charge/catalyst ratio, temperature control zones in reactors and degassers, modifier/rubber ratio, and rubber unsaturation index.

EFFECT: widened application area for butyl rubber production control and assortment of products, reduced consumption of raw materials due combined production of unmodified and unmodified rubbers.

3 cl, 2 dwg

Description

The invention relates to the field of automation of technological processes for the production of synthetic rubber and can be used in the production of butyl rubber for various processes, for example, upon receipt of modified chemical rubbers.

A known method of controlling the process of synthesis of butyl rubber, carried out in an inert solvent in a reactor with a stirrer. The copolymerization of monomers (isoprene and isobutylene) is carried out in the presence of a catalyst, the charge and catalyst consumption are regulated, the temperature in the reaction zone is measured, the Mooney viscosity is determined by calculation, and the lower drive parameter of the mixer is determined (Pat. RF 2046126, IPC G05D 27 / 00.1993 g.).

The disadvantage is the low quality of the rubber. A known method of controlling the production of butyl rubber during the copolymerization of isoprene and isobutylene in an inert solvent in a batch mixer, a refrigerator, reactors and a degasser using control loops consisting of sensor controllers, charge flow valves, catalysts, isoprene, isobutylene, an inert solvent, steam, temperature sensors and the concentration of the mixture, the temperature in the reactors and degassers, the level and flow rate of ethylene connected to the controllers. When controlling processes, the concentration and temperatures in the reactors and degassers are set and the flow rates of ethylene, isoprene, and steam are adjusted by the action of the corresponding valves (Pat. RF No. 2223284, C08F 210/12, G05D 27/00, 2004).

The disadvantage of this method of controlling the production of butyl rubber is its limited scope, for example, the task of producing modified rubbers was not set, which reduces the assortment of the obtained butyl rubbers, the features of the charge preparation processes, temperature conditions of copolymerization and degassing processes during regulation are not taken into account, which affects the quality of butyl rubber and equipment performance .

The objective is to improve the quality of modified and unmodified butyl rubbers and equipment performance.

To solve the task of controlling the production of butyl rubber, obtained by copolymerization of isoprene and isobutylene in an inert solvent in the presence of a catalyst, carried out in an installation including a mixer, refrigerator, reactor, degasser, which are interconnected by pipelines using control loops consisting of sensor controllers, valves expenses of isoprene, isobutylene, inert solvent, charge, catalyst, level and flow rate of refrigerant in the refrigerator and in the reactor and steam in the degasser, dates temperature and concentration of the mixture, temperature in the reactor and degasser, connected to the controllers with the correction of the flow rate of isoprene, isobutylene, inert solvent, refrigerant and steam, additionally contains a charge supply collector, with which part of the charge is used to obtain unmodified butyl rubber, and the other part to obtain a modified butyl rubber, a sensor for the total charge flow rate, a reactor, a container for averaging rubber crumbs, a container for dissolving rubber for modification and a tank for averaging I am a rubber for modification, salt washing and neutralization columns and a degasser, connected to each other and to a pulp supply manifold to separation units and corresponding pipelines with charge and catalyst flow control circuits, averaged rubber crumb and rubber crumb solvent, rubber solution for modification and modified rubber solution refrigerant to the reactor and steam to the degasser; flow sensors of isoprene, modifiers, water for washing and salt washing and neutralization indicators connected to the controllers; at the same time, the total load and the ratio of production of modified and unmodified rubber, the charge-catalyst ratio, temperature control zones in reactors and degassers, the mass ratio of the modifier-rubber and the coefficient of unsaturation of the rubber are set and the charges of the charge and catalyst, refrigerant, steam, rubber crumb solvent are adjusted accordingly , modifiers and isoprene by influencing valve flow control loops. Moreover, the temperature control zone of the copolymerization reaction is in the range (-80) - (-100) ° C and the temperature control zone in the degassers is 85-90 ° C, and the mass modifier-rubber ratio is 1.1 / 1.3: 98, 9 / 98.7 for chlorine and 2.8: 97.2-5.2: 94.8 for bromine and the unsaturation index of the modified rubber is maintained at 1.5-2.2 mol%.

A system that implements a butyl rubber production control method provides for the transfer of information to the upper level of enterprise management.

A study of the production of butyl rubber showed that in order to improve the physicomechanical properties of rubber products, for example, the modulus and strength of rubber at break, increase adhesion to metal, and reduce cold flow, it is necessary to carry out halogenation by adding chlorine and bromine to butyl rubber.

The proposed control method allows to obtain modified and unmodified butyl rubbers, which saves raw materials, energy consumption and increases equipment productivity.

The butyl rubber control method can be used in the copolymerization of isobutylene with isoprene in an inert solvent (isopentane, methyl chloride) in the presence of various catalysts, for example, Friedel-Craft and others.

The following is an example of the copolymerization of isobutylene with isoprene in an inert solvent, methyl chloride.

The essence of the invention is illustrated by the drawing, which shows a schematic diagram of the control of technological processes for the production of butyl rubber (one production line is shown). The control method is illustrated in figure 1 and figure 2.

The scheme includes an installation for producing modified (halogenated) and unmodified butyl rubber and consists of apparatuses and collectors 1-13. The starting monomers (isobutylene and isoprene) and an inert solvent (methyl chloride) are transferred to mixer 1, from where the resulting charge is sent to the refrigerator 2, and after cooling it is sent to the charge supply manifold 3 and then, to obtain unmodified rubber, part of the charge is sent to the reactor 4 and the copolymer to the degasser 5. The other part of the mixture is used to obtain modified rubber (additional isoprene is pre-dosed into this mixture stream) and sent to the reactor 6, averaging capacity of the rubber crumb 7, the capacity for the solution Nia-modifying rubber 8, which also serves solvent (Nefras). Then, in the rubber averaging tank for modification 9, the mixture is averaged and modifiers are added to the output line. Then the rubber mixture is sent to the salt washing column 10, the neutralization column 11, and then the modified rubber enters the degasser 12. After removing the solvent and the remaining monomers, the rubber pulp is sent to the pulp supply manifold 13, where unmodified rubber pulp is also fed. The system with collectors 3 and 13 allows you to get unmodified and modified rubber.

The production process control system is built on the basis of controllers 14 and personal computers 15, which are interconnected by two-way communication. The control system includes control sensors connected to the controllers, control loops 16-60, consisting of sensor controllers, valves. Electric lines of communication of sensors and valves with controllers are not conventionally shown in the drawing. The system includes.

- isoprene flow control loop 16-14-17 (sensor 16, valve 17 connected by input and output to controller 14; hereinafter, controllers 14 are not conditionally mentioned in the control loops);

- a flow control loop of isobutylene 18.19 and an inert solvent (methyl chloride) 20, 21;

- a circuit for regulating the level of refrigerant (propane) 22, 23 in the refrigerator 2;

- temperature sensor of the charge 24, the concentration of the charge 25 and the sensor of the total consumption of the charge 26;

- loop control flow of the charge 27, 28 and catalyst 29, 30;

- a temperature sensor 31 in the reactor 4 and a refrigerant (ethylene) flow control loop 32, 33;

- a temperature sensor 34 in the degasser 5 and the steam flow control loop 35, 36;

- loop control flow of the charge 37, 38 and catalyst 39, 40;

- a temperature sensor 41 in the reactor 6 and a refrigerant flow control loop 42, 43;

- isoprene flow sensor (rubber unsaturation regulator) 44;

- a flow control loop of the averaged rubber crumb 45, 46 and the rubber crumb solvent 47, 48;

- a rubber solution control loop for modification 49, 50;

- flow sensors of modifiers (chlorine and bromine) 51, 52;

- water flow sensor 53 for washing in the column 10;

- salt and neutralization indicators 54, 55;

- sensors regulating the flow rate of the solution of the modified rubber 56, 57;

- a temperature sensor 58 in the degasser 12 and a steam control loop 59, 60.

A method of controlling the production of butyl rubber is as follows:

- set from the computer 15 the total load and the ratio of production of modified and unmodified rubber;

- set the initial ratio “charge - catalyst”, the catalyst in this case determines the beginning of the copolymerization of monomers;

- set the temperature control zones in reactors 4 and 6 and in degassers 5 and 12;

- set the ratio "modifier - rubber";

- set the indicator of unsaturation of rubber.

Information is input from controllers 14 from sensors 16, 18, 20, 22 24, 25, 26, 27, 29, 31, 32, 34, 35, 37, 39, 41, 42, 44, 45, 47, 49, 51, 52, 53, 54, 55, 56, 58, 59. Isobutylene consumption (control loop 18, 19) is determined from the information of the sensor 18 and, for a given ratio of isoprene-isobutylene flow rates, isoprene consumption (control loop 16, 17); for a given ratio of "isoprene - isobutylene - methyl chloride", the methyl chloride consumption is changed (control loop 20, 21), the components of the initial charge in the mixer 1 are mixed, the concentration of the charge is controlled according to the sensor 25 and sent to the refrigerator 2, where the charge is cooled to a predetermined value with using the temperature sensor of the charge 24 and the control loop of propane 22, 23 and serves in the collector of the charge charge 3. Monitor the total charge flow according to the information of the sensor 26 and direct the charge to the devices, depending on the set accordingly making modified and unmodified rubber.

Part of the charge is sent to the reactor 4 to obtain unmodified rubber using the control loop 27, 28, and for the initial charge-catalyst ratio, the catalyst is fed using the control loop 29, 30. The temperature in the reactor 4 is controlled and corrected for a given temperature control zone the flow rate of the refrigerant (ethylene) using the temperature sensor 31 and the control loop 32, 33. Then, the copolymer solution is fed to the degasser 5 (the stage of catalyst deactivation is not shown conventionally) and for this control zone is adjusted using a temperature sensor 34 and a steam control loop 35, 36. After removing the residual monomers and solvent (introduction of an anti-agglomerator of rubber crumb is not shown), the rubber pulp is sent to the pulp supply manifold 13 and then to the unmodified rubber separation units.

Another part of the charge from the collector 3 is sent to obtain a modified rubber in the reactor 6. For this, for the given value of the unsaturation of the rubber, isoprene is supplied according to the information of the sensor 44. For a given initial charge-catalyst ratio (taking into account the additional supply of isoprene), the charge and catalyst are fed into the reactor 6 using a control loop 37, 38 and a catalyst control loop 39, 40. To achieve a given temperature in the reaction zone, the flow rate of the refrigerant (ethylene) is adjusted ) using a temperature sensor 41 and a control loop 42, 43. Then the copolymer solution is sent to the averaging tank of rubber crumb 7 to effectively dissolve the rubber crumb. Next, the wet crumb of rubber is sent to dissolve in the tank 8 using the control loop 45, 46 and for a given ratio of "crumb rubber-solvent" using the loop 47, 48, solvent (nefras) is fed into the tank 8. The mixture is stirred for a predetermined time and sent to the averaging tank 9, where the solution is circulated to avoid stagnant zones and to improve the averaging of the solution in composition, and thus a rubber solution for halogenation is prepared. Then, for a given ratio “modifier - rubber”, solutions of modifiers (solution of bromine or chlorine in nephras) are supplied from batchers (conventionally not shown) to the pipeline of an averaged copolymer solution at the outlet of tank 10 according to the information of sensors 51 and 52, which are also adjusted depending on the given rubber unsaturation rate. Next, the solution (control loop (49, 50) of the modified rubber is fed into the column 10, where, according to the information of the sensor 53, water is supplied for mixing with the rubber solution and the output of hydrobromic acid or hydrochloric acid. The washing quality is controlled by pH values of 2-4 units using sensor information 54. The solution of the washed modified rubber then enters the column 11 of the catalyst, where it is monitored by the sensor 55. The pH is maintained within 6-8 units (using sodium hydroxide solution). rubberized rubber enters the degasser 12 (using the control loop 56, 57), where the specified temperature control zone is supported using temperature sensors 58 and the steam control loop 59-60. After removal of residual monomers and solvent, the rubber pulp is fed into the pulp collector 13 and further on allocation aggregates.

Example

- set the total load of 25375 kg / h from computer 15 and distribute it in a ratio of 2.34: 1 for modified (17707 kg / h - halogenated) and unmodified rubber (7568 kg / h);

- set the initial ratio of “charge - catalyst", 0, 04;

- set the temperature control zone in the reactor 4 (-85) - (- 86) ° C and in the reactor 6 (-94) - (- 99) ° C;

- set the temperature control zone in the degasser 5 85-87 ° C and in the degasser 12 85-90 ° C. Moreover, the temperature control ranges in the reactors (-80) - (-100) ° C and in the degassers 85-90 ° C are traditional in obtaining modified and unmodified rubber;

- set the mass ratio "modifier-rubber" of 1.3: 98.7 for chlorine and 4.6: 95.4 for bromine;

- set the unsaturation of the modified rubber 2% ± 0.15 mol.%;

- determine from the information of the sensor 18 the current consumption of isobutylene 6835 kg / h and for a given ratio of "isoprene - isobutylene" determine the consumption of isoprene 180 kg / h, which is set by valve 16 (circuit 16, 17);

- for a given ratio of "isobutylene-isoprene-methyl chloride" determine the consumption of methyl chloride, which is set at 19260 kg / h (circuit 20, 21). The resulting mixture in an amount of 26275 kg / h is controlled by the sensor 25 and sent to the refrigerator 2, where it is cooled from +1 to -42 ° C (circuit 22, 23).

Part of the charge using isobutylene = 1665 kg / h, isoprene 47.7 kg / h and methyl chloride = 5860 kg / h (as 97.2 and 2.8% by weight, determined by the charge flow sensor 26) are sent to reactor 4, where its consumption is determined (circuit 27, 28) and, for the initial charge – catalyst ratio, the catalyst consumption is determined as 0.04 * 1665 = 66.6 kg / h (circuit 29, 30, dosage is carried out on isobutylene). The temperature in the reactor 4 (-85) - (- 86) ° C is maintained using a temperature sensor 31 and a control loop 32 and 33. Then, in the degasser 5, 85-87 ° C is maintained using steam supplied at a temperature of 34 and steam sensors 35, 36. Then the rubber is fed into the collector 13 and then to the separation units (the collector 13 has access to other allocation units).

The second yield using isobutylene = 4170 kg / h, isoprene = 137 kg / h and methyl chloride 13400 kg / h (both 96.8 and 3.2 wt.%) Is used for halogenated butyl rubber. To do this, before entering the reactor 6 serves isoprene flow rate = 50 kg / h (sensor 44). Then, for a given ratio “charge - catalyst” (control loop 37, 38 and control loop 39, 40), the catalyst flow rate is determined as 0.04 * 4170 = 166.8 kg / h (dosage is carried out on isobutylene). The temperature in the reactor 6 (-94) - (- 99) ° C is maintained using the sensor 41 and the control circuit 42, 43. Then the copolymer solution flows into the averaging tank of the rubber crumbs 7, where the solution is averaged and sent through the control circuit 45 and 46 to a container for dissolving rubber for modification 8, where nefras is also directed (control loop 47, 48), where it is averaged when feeding 300 kg / h of isobutylene as 4.170 * 300 = 1251 kg / h. Then the copolymer solution prepared for halogenation (control loop 49, 50) is sent to the rubber averaging tank for modification 9, where it is averaged and the modifier chlorine, sensor 51, is added at 1.3 wt.% On isobutylene as 4170 * 0.013 * 0.8 = 43.4 kg / h, where 80 wt.% Is the conversion of copolymerization monomers. Bromine is also detected here (sensor 52). In addition, rubber unsaturation (2 wt.%) Is also determined here, which is corrected according to the information of the sensor 44. Then, in the salt washing column 10, where water is supplied to neutralize hydrochloric acid (solution 53) (the solution is defined as pH 2-4 units. ) and further to the neutralization column 11, where the quality of the pH is 7-8 units. (when applying a solution of caustic soda). Then, along the transfer line (control loop 56, 57), they are pumped into the degasser 12, the specified control zone of 85-90 ° C is supported by a temperature sensor 58 and a steam control loop 59, 60 and then to the pulp supply manifold 13 to the extraction units.

Thus, we obtain halobutyl rubber HBK-150 with a capacity of 3445 kg / h and a rubber unsaturation of 2.0 mol% and BK-2080 with a productivity of 1370 kg / h and a rubber unsaturation of 1.6 mol%.

By carrying out a separate supply of the charge and components, we produce modified and unmodified butyl rubber, we achieve their joint production (or separate), and thus we obtain rubber ХЕК-139, 150 and ББК - 232, 239, 246 and БК - 1675, 2075, 2080.

By supporting the dynamics of the process of preparing the mixture, the concentration of the mixture and preparing the processes for preparing the modified and unmodified rubber, we save the costs of preparing the mixture, copolymerization, degassing and isolation of rubber, so the cost-based implementation saves up to 5 million per year. The implementation of the control method is scheduled for 2 square meters. 2005 in the city of Nizhnekamsk.

Claims (3)

1. A method of controlling the production of butyl rubber, obtained by copolymerization of isoprene and isobutylene in an inert solvent, in the presence of a catalyst, carried out in an installation including a mixer, a refrigerator, a reactor, a degasser, which are interconnected by pipelines using control loops consisting of sensor controllers, valves expenses of isoprene, isobutylene, an inert solvent, charge, catalyst, level and flow rate of refrigerant to the refrigerator and to the reactor, and steam to the degasser, temperature sensors and the concentration of the mixture, the temperature in the reactor and the degasser, connected to the controllers with the correction of the flow rate of isoprene, isobutylene, an inert solvent, refrigerant and steam, characterized in that the installation further comprises a charge supply manifold, with which part of the mixture is used to produce unmodified butyl rubber, and the other part - to receive modified butyl rubber, a sensor for the total charge flow rate, a reactor, a container for averaging rubber crumbs, a container for dissolving rubber for modification, and a container unification of rubber for modification, salt washing and neutralization columns, and a degasser connected to each other and to the pulp supply collector to separation units by appropriate pipelines with control loops, charge flow, catalyst, averaged rubber crumb and rubber crumb solvent, rubber solution for modification and modified solution rubber, refrigerant to the reactor and steam to the degasser, flow sensors of isoprene, modifiers, washing water and indicators of salt washing and neutralization indicators, connected e to the controllers, while setting the total load and the ratio of production of modified and unmodified rubber, the charge-catalyst ratio, temperature control zones in reactors and degassers, the mass ratio of rubber-modifier and the coefficient of unsaturation of rubber, and respectively adjust the charge and catalyst consumption, refrigerant consumption , steam, modifiers and isoprene by influencing the valve control loops. 2. The method according to claim 1, characterized in that the temperature control zone of 6 reactors is in the range of -80 - (-100 ° C), the temperature control zone in degassers is 85-90 ° C, the modifier-rubber mass ratio is 1.1 : 98.9-1.3: 98.7 for chlorine and 2.8: 97.2-5.2: 94.8 for bromine, and the index of unsaturation of the modified rubber is 1.5-2.2 mol%. 3. The method according to claim 1 or 2, characterized in that the system that implements the method for managing the production of butyl rubber, provides for the transfer of information to the upper level of enterprise management.

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