RU35600U1 - Installation for the production of styrene by liquid-phase dehydration of methylphenylcarbinol - Google Patents

Description

PLANT FOR PRODUCING STYROL

Liquid phase dehydration

Methylphenylcarbinol

The utility model relates to the petrochemical and chemical industries and is designed to produce styrene by liquid-phase dehydration of methylphenylcarbinol.

It is known to use distillation columns as a rectifier reactor, especially in the preparation of ethers, for example methyl tert-butyl ether, tert-amyl ether and so on (RF Patent No. 2151624, IPC B 01 D 3/14, publ. 27.06.2000; RF patent No. 2157714 , IPC B 01 D 3/14, publ. 20.10.2000). But such reactors are not suitable for styrene production processes.

Known installation for producing styrene vapor phase dehydration

methylphenylcarbinol in an adiabatic solid catalyst reactor,

including a tube furnace, methylphenylcarbinol dehydration reactors, a heater, a superheater, a column, boilers, a heat exchanger, a scrubber, air and water condensers, a separator, a settler and tanks (P.A. K1FPICHNIKOV, V.V. Berestnev, L.M. Popova "Album technological schemes of the main industrial production of synthetic rubber industry. L., Chemistry, 1986, pp. 109-110). The described installation is designed to operate on a solid catalyst in the vapor phase.

Closest to the proposed one is a plant for the preparation of styrene by liquid-phase dehydration of methylphenylcarbinol, containing a device for heating raw materials, a methylphenylcarbinol dehydration reactor, a condenser, and a distillation column containing at least three theoretical plates using at least three theoretical plates parts device for outputting bottoms product and connected to a device for heating raw materials, which is equipped with devices for a, vstroengoo gg-f 4-h z of raw materials and the catalyst.

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MPC B 01 D 3/14, C 07 C 15/46 X n to the bottom of the device for heating raw materials or to the circulation line of the still product, in the upper part of the column there is a device for feeding reflux and a pipe connecting the column with a condenser, a settling tank for separation products of dehydration to the water and hydrocarbon layers and the vacuum system (RF Certificate No. 23233, IPC B 01 D 3/14, publ. 06.10.2002). A distillation column used as a methylphenylcarbinol dehydration reactor may contain a device for removing product from the bottom plate and a styrene polymerization inhibitor feed system. The described installation does not provide a high conversion of raw materials due to insufficient heat supply to the reaction zone under the conditions of an endothermic reaction, such as the methylphenylcarbinol dehydration reaction. The objective of the utility model is to create a plant for the production of styrene, which allows to achieve high conversion of raw materials in the process of liquid-phase dehydration of methylphenylcarbinol. To solve this problem, a plant for producing styrene by liquid phase dehydration of methylpheylcarbinol containing a device for heating sfia, a methylphenylcarbinol dehydration reactor, which is a distillation column, feed, output and circulation lines for bottoms product, a catalyst supply line connected to the bottom products circulation line, and a withdrawal line, is proposed top product, connecting the reactor with a condenser, sump to separate the products of dehydration into water and hydrocarbon the bottom layers and a vacuum system, while the reactor further comprises a distribution plate connected to the supply line, a built-in tube-type heat exchanger located below the supply line, and a heat-exchange cutter that heats the bottom of the reactor. The bottom part of the reactor can be equipped with a level gauge and a distribution device for introducing gas. The bottoms liquid circulation line can be connected to a feed line equipped with an intensive mixing device.

In addition, the installation may include a catalyst preparation unit connected to the bottoms circulation line directly or through an intensive mixing device; devices for feeding a styrene thermopolymerization inhibitor located on the circulation line of the bottoms product and / or on the discharge line of the bottoms product and / or on the output line of the top product, and devices for introducing a neutralizing agent located on the lines of the bottoms and top products.

The installation for producing styrene by liquid-phase dehydration of methylphenylcarbinol can be made of both stainless and carbon steel.

The methylphenylcarbinol dehydration reactor (MPC) can have plates of any design or a top nozzle. Upper limit of quantity

theoretical plates is limited by economic feasibility and the temperature necessary to maintain the reaction medium in a liquid state. Power, catalyst feed, product lines, etc. can be connected through flanges, by welding or in any other way,

providing tightness in the given conditions. The number of devices for heating raw materials and condensers depends on the load on raw materials and heat transfer of the structures used. As devices for heating raw materials, heat exchangers, furnaces, heat electric heaters, etc. can be used. As a device for introducing sulfur and catalyst, pipes, pipes with a mixer, etc. can be used. As a vacuum system, a steam ejector installation can be used, oil pump, etc. .. As devices for supplying an styrene thermopolymerization inhibitor, a system of nozzles with mixers or separation plates can be used to supply the inhibitor to bottom, middle and lower part of the reactor, as well as in a device for heating raw materials, a condenser and a sump.

Examples of specific implementation. l p 1 - IFC dehydration reactor; 2- a device for heating raw materials; 3- co-identifier; 4- sedimentation tank for the separation of dehydration products into aqueous and carbon layers; 5- capacity for collecting the hydrocarbon layer; 6- capacity for collecting the water layer; 7- vacuum system; 8- catalyst preparation unit; 9, 10 - mixing devices for intensive mixing; 11 - heat transfer device for maintaining the temperature of 1 subwoofer; 12 - distribution plate; 13 - tubular heat exchanger; 14- distillation plates; 15- heat exchange rubapps; 16-gas distribution device; 17 - level gauge device; 18- capacity for collecting bottoms product; 19 - feed line of the IFC fraction to the dehydration unit; 19a - reactor power line; 20 - line supply fraction IFC to the site of preparation of the catalyst; 21 - feed line for the preparation of the catalyst; 22 - catalyst feed line to the MPC dehydration reactor; 23 - output line of the upper product; 24- line connecting the unit to the vacuum system; 25- line of the entrance of the water layer; 26 - line output hydrocarbon layer; 27- line vyshoda cubic product; 28- gas supply line; 30, 31, 32 - feed lines of a neutralizing agent; 33, 34, 35 — devices for supplying a styrene temopolymerization inhibitor. Installation for the production of styrene by liquid-phase dehydration of methylphenylcarbinol works as follows. To the dehydration unit through line 19, the MFC fraction 2 is preheated in a device for heating raw materials (heat exchanger). A portion of the MFC fraction heated in the heat exchanger 2 is fed through line 20 to the catalyst preparation unit 8, to which sfie is also fed through line 21 to prepare the catalyst. The resulting catalyst in LINE 22 is fed to the lower part of reactor 1. It is possible to mix the bottoms product discharged through line 27 and further along lines 29 and 29a with the catalyst supplied via line 22 directly in line 22 or in the mixing device 10 and the resulting solution can be fed to the lower part of the reactor 1. The MPC fraction through the supply line 19a enters the reactor 1 on the distribution plate 12, passes through the built-in tubular heat exchanger 13, where it is additionally heated, and enters the heated external heat exchange pipe 1 5 the cubic part of the reactor, where it is in contact with the catalyst with inert gas supplied through line 28 using device 16. The liquid level in the reactor cube is determined using the level gauge 17. The bottoms product is discharged from the reactor through line 27 and circulates through the heat exchange device 11, a container 18 through line 29 and / or 29a through an intensive mixing device U and / or through line 29 to the lower part of the reactor and / or through line 296 through an intensive mixing device 9 and through a feed line Nia 19a is supplied to the distributor plate 12 of the reactor. Part of the bottoms liquid from the tank 18 is introduced for further processing. The reaction products formed during dehydration in the reactor cube (styrene and water) evaporate under the influence of temperature and rise to the upper part of the reactor, where they are separated from raw materials and heavy impurities on distillation trays 14. The pressure in the reactor is regulated by a vacuum system 7 connected to the reactor by

lines 23 and 24. The obtained MFC dehydration products (catalysis) through a device located in the upper part of the reactor (not shown in the diagram), are passed through line 23 to a condenser 3, and then to a settling tank 4 for separation of the dehydration products into aqueous and hydrocarbon layers, from where the hydrocarbon layer through line 26 is fed into the tank 5, from which it is discharged to the warehouse, and the water layer through line 25 enters the tank 6, from which it is diverted for further processing. Devices for introducing a neutralizing agent 30, 31 and 32 are installed on the shields 25, 26, and 27. Devices for supplying a thermopolymerization inhibitor 33, 34, and 35 are located on the output line of bottoms product 27 and / or on the circulation line of bottoms product 29 and / or output lines of the upper product 23.

The proposed installation for the production of styrene by liquid-phase dehydration of methylphenylcarbinol allows the reaction to be carried out with higher selectivity, since the design of the reactor allows the reaction products to be removed from the contact zone with the catalyst, which reduces the formation of by-products - esters and allows the reaction to be carried out at a lower temperature, which reduces the formation of polymer .

Claims (6)

1. Installation for the production of styrene by liquid-phase dehydration of methylphenylcarbinol, containing a device for heating raw materials, a methylphenylcarbinol dehydration reactor, which is a distillation column, a feed line, a withdrawal and circulation of a still product, a catalyst supply line connected to the circulation line of a still product, an output line of the upper product, connecting the reactor with a condenser, a sump for the separation of dehydration products into water and hydrocarbon layers and a vacuum system, characterized the fact that the reactor further comprises a distribution plate connected to the supply line, a built-in tube-type heat exchanger located below the supply line, and a heat exchange jacket that heats the bottom of the reactor. 2. Installation according to claim 1, characterized in that the still part of the reactor is equipped with a level gauge and a distribution device for introducing gas. 3. Installation according to claims 1 and 2, characterized in that the circulation line of the still product is connected to a power line equipped with an intensive mixing device. 4. Installation according to claims 1 to 3, characterized in that it comprises a catalyst preparation unit connected to the circulation line of the still product directly or through an intensive mixing device. 5. Installation according to claims 1 to 4, characterized in that it contains devices for supplying a styrene thermopolymerization inhibitor located on the circulation line of the still product, and / or on the output line of the still product, and / or on the output line of the top product. 6. Installation according to claims 1-5, characterized in that it contains devices for introducing a neutralizing agent located on the output lines of bottoms and top products.