JPH10139754A - Temperature control of product of sulfonation reaction - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the quick temperature control of a product of sulfonic reaction and accordingly solve the problems of undesirable coloring of the reaction product. SOLUTION: A reaction product in an amount of about 3 to 30 times the amount which is discharged from a discharging pump 6 is returned to a bottom part of a reaction tank 1 or a separator 2 through a circulating pump 4 and a heat exchanger, in which the temperature of the reaction product is adjusted to a specified temperature. By this mechanism, the temperature of the reaction product can be lowered to a specified temperature quickly after the reaction is completed, and thus the problems of undesirable coloring of the reaction product can be solved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature control method for controlling a sulfonation reaction product produced by a sulfonation reaction within a desired temperature range.

[0002]

2. Description of the Related Art The sulfonation reaction is characterized by a so-called exothermic reaction in which the reaction rate is high and heat is generated by the reaction. Due to the high reaction rate, it is difficult to quickly remove the reaction product from the reaction site without hindering the progress of the reaction, so the heat of the reaction gives the reaction product an undesirable color and adversely affects the product quality The problem arises. To cope with such a problem, Japanese Patent Publication No. 51-28618 proposes an isothermal sulfonation method in which cooling is performed during a sulfonation reaction using a cooling gas containing SO3 and an inert gas. In addition, a method of cooling a reaction surface of a reactor with a refrigerant, a method of cooling a reaction product after gas-liquid separation after reaction to a predetermined temperature, and the like are known.

[0003] When the temperature of the reaction product after the reaction is maintained at a high temperature as described above, it is desirable that the reaction product be brought to a predetermined temperature as quickly as possible because the reaction product produces an undesirable coloring. However, some of the reaction products stay at the bottom of the reactor or at the separator,
With respect to such a residue, the time elapses before the temperature is controlled to the predetermined temperature, and the above-described coloring of the reaction product occurs. In order to solve the above-mentioned problem by increasing the cooling effect, if the temperature of the reaction product is excessively lowered, a problem such as precipitation of the reaction product occurs.

[0004]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a simple configuration which allows reliable and rapid temperature control of the sulfonated reaction product, thereby undesired coloring of the reaction product. Is to eliminate the problem.

[0005]

Means for Solving the Problems The present invention for solving the above problems is specified as follows. That is, the present invention provides a temperature control method for controlling the temperature of a sulfonated reactant within a predetermined range, wherein a gas-liquid mixture containing a sulfonated reactant generated by a sulfonating reaction extracted from the reactor is introduced into a separator. Then, the sulfonated reactant is separated in the separator, the separated sulfonated reactant is controlled at a predetermined temperature by a heat exchanger, and the amount of the sulfonated reactant is 3 to 20 times the amount withdrawn from the reactor. A method of controlling the temperature of a sulfonated reactant, wherein the temperature-controlled sulfonated reactant is refluxed to a lower part of a reactor or the separator.

In a preferred embodiment, the reactor in which the above-mentioned sulfonated reactant is produced is a thin-film reactor which reacts with a sulfonating agent, that is, SO3 gas while flowing the raw material down the wall. . In the lower part of the reactor where the reaction product whose temperature is controlled is returned, the sulfonation reaction in the reactor has been substantially completed, and the gas containing the sulfonation reaction product generated by the sulfonation reaction is contained. A liquid mixture is contained.

[0007]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, first, SO3 gas as a sulfonating agent, dilution air and a predetermined sulfonating raw material are introduced into an upper portion of a sulfonating reactor. In the reactor, the raw materials and the like introduced into the upper part of the reactor undergo a sulfonation reaction while flowing down the wall. The gas-liquid mixture containing the sulfonated reactants is led to the lower part of the reactor, and is taken out from an outlet provided in the lower part.
This gas-liquid mixture is then introduced into a separator, where the desired sulfonated reactant is separated from other gases or liquids by a gas-liquid separation treatment.
Then, the reactant is taken out of the separator via a withdrawal line, and transported for the next step.

A part of the sulfonation reaction product extracted from the separator is passed through a heat exchanger and exchanges heat with a refrigerant to be cooled to a predetermined temperature. The temperature controlled reactants are then returned to the bottom of the reactor or to the separator. The temperature control of the sulfonation reaction product via the heat exchanger can be controlled by the temperature of the refrigerant or the flow rate of the refrigerant. When the temperature of the refrigerant is low and the reactant solidifies, the temperature is kept constant and controlled by the flow rate. The amount of the sulfonated reaction product returned to the lower part of the reactor is controlled in the range of about 3 to 20 times the amount of the sulfonated reaction product generated in the reactor, that is, the capacity of the reactor.

By refluxing the sulfonation reaction product at a predetermined temperature and amount to the lower part of the reactor, the temperature of the sulfonation reaction product immediately after the reaction can be rapidly cooled to a predetermined temperature range, The problem of undesirable coloring of the sulfonation reaction products described above can be eliminated.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. Referring to FIG. 1, there is shown an overall schematic system diagram of a sulfonation treatment apparatus including a thin-film continuous sulfonation reactor 1 according to one embodiment of the present invention. The sulfonation treatment apparatus of the present invention receives a thin-film type sulfonation reactor 1 and a gas-liquid mixture containing a sulfonation reaction product from the reactor, and converts the desired sulfonation reaction product and other gases and liquids. A gas-liquid separator 2 for separation is provided. In addition, the present sulfonation treatment apparatus controls the circulation system to return to the reactor 1 or the separator 2 after controlling a predetermined temperature by removing a part of the gas-liquid separated reaction product from the separator 2 and performing heat exchange. It has. This sulfonation reaction product circulation system is provided with a heat exchanger 3 for controlling the temperature of the sulfonation reaction product returned to the reactor 1 within a predetermined range.

In order to constitute this circulation system, a return line L1 for returning the sulfonation reaction product in the gas-liquid separator 2 to the lower part of the reactor 1 and / or to the separator 2 is provided. A circulation pump 4 is provided at the outlet side of the separator 2 of the return line L1 to send out a sulfonation reaction product for return. The heat exchanger 3 disposed in the return line L1 is configured to control the temperature of the return sulfonation reaction product by exchanging the temperature of the reactant with the refrigerant. A coolant circulation system is provided for the coolant passed through the heat exchanger, that is, the coolant, and the coolant circulation system includes a coolant line L2 and a coolant circulation pump 5 arranged in the coolant line L2. A suction pump 6 is provided on the suction side of the circulation pump 4 for extracting the sulfonation reaction product from the separator 2 and sending it to the next processing step.

The reactor is also provided with a cooling water circulation system for temperature control for controlling the reaction temperature. A cooling water supply line L3 for supplying cooling water to the reactor 1 is connected to the reactor circulation system. A supply pump 7 for introducing cooling water into the reactor 1 is connected to the cooling water line L3. Is provided. The cooling water line L3 is connected to the reactor 1
A steam line L4 for introducing steam for controlling the temperature of the cooling water to the reactor 1 is connected, and a return line L5 for the cooling water from the reactor 1 is connected. The sulfonation reaction product circulation system includes a line L6 for returning the product to the lower portion of the reactor 1 and a line L7 connected to the separator 2 for returning the product to the separator 2. Each line L6, And L7 are provided with flow control valves 8 and 9 for controlling the flow rate of the sulfonation reaction product.

The heat exchanger 3 is provided with a cooling water line L8 for supplying cooling water as a refrigerant for exchanging heat with reaction products, and the cooling water line L8 has a cooling water line L8. Steam line L9 for adjusting temperature
Is connected. The cooling water line L8 and the steam line L9 are provided with flow control valves 10 and 11 for adjusting the flow rates of the cooling water and the steam, respectively. Further, the cooling water return line L5 is connected to the suction side of the cooling water supply pump 7 in the reactor circulation system. On the suction side, the cooling water line L
3 is provided with a flow control valve 12 for controlling the flow rate of the cooling water, and a flow control valve 13 is also provided on the steam line L4. In addition, the above-mentioned extraction pump 6
Is provided in a sulfonation reaction product withdrawal line L10 branched from the separator 2 of the sulfonation reaction product circulation line L1 and the circulation pump 4, and a pump 6 is provided to adjust the withdrawal amount. A flow regulating valve 18 is provided on the delivery side.

Next, the reactant temperature control system will be described. A thermometer 14 for measuring the temperature of the return sulfonation reaction product is provided on the inlet side and / or the outlet side of the heat exchanger 3.
And 16 are provided. Further, the cooling water circulation system is provided with a thermometer 15 for measuring the inlet temperature of the refrigerant, whose temperature has been adjusted by mixing the cooling water and the steam, to the heat exchanger. Further, a thermometer 17 for measuring the temperature of the cooling water to the reactor 1 is provided in the reactor cooling water line L3. Further, in order to control the flow regulating valves 10 and 11 for controlling the flow rates of the cooling water and steam lines L8 and L9, it is preferable to input an output from the thermometer 15 to achieve a predetermined circulating system temperature. A temperature control device including a microcomputer is provided.

Referring to FIG. 2, this temperature control device will be described. The temperature control device includes a monitoring control computer 20 for controlling the entire sulfonation treatment device according to the present invention, and the monitoring control computer sets the temperature of the sulfonation reaction product in the reactor 1 within a predetermined range. Data as various target values necessary for the operation, and inputs information from the thermometer or the flow meter to control the flow regulating valve or the pump so as to achieve the target value. It has become. The temperature control device of this example includes controllers A, B, C, and D for inputting information to the monitoring control computer and controlling various pumps or flow valves in response to instructions from the computer. ing. The controller A controls the flow control valves 10 and 11 to control the temperature of the return sulfonation reaction product. In this case, the controller A operates the flow control valve 10 so that the value of the temperature 15 becomes the set value based on the temperature set value from the controller C or the monitoring control computer.
And 11 are controlled.

The controller B controls the rotation speed of the pump 5 (or the pump 5) based on the setting value from the controller C or the monitoring control computer so that the rotation speed of the pump 5 becomes the set value.
The opening degree of a control valve (not shown) of a bypass pipe provided in the controller is controlled. The controller C controls the set temperature value of the controller A or the set number of rotations of the controller B based on the temperature set value from the monitoring control computer so that the value of the temperature 14 becomes the set value. The controller D controls the flow regulating valve 12 or 13 based on the temperature set value from the monitoring control computer so that the temperature 17 becomes the set value. The supervisory control computer 20 gives the temperature setting values to the controllers C and D, and selects which of the controllers A and B is to be controlled by the controller C,
A fixed set value is given to a controller that is not controlled.

The operation for controlling the opening of the cooling water and steam flow control valves in order to control the reactant temperature to a predetermined value will be described below. First, SO3 gas, dilution air and a sulfonated raw material are introduced into the reactor 1 at predetermined flow rates.
SO3 gas, which is a sulfonating agent, reacts with a sulfonating raw material that sulfides the wall of the thin-film reactor to generate a sulfonated reactant. In this case, heat of reaction is generated by the sulfonation reaction. Next, the reactant generated in the reactor 1 is introduced into the separator 2 from the lower part of the reactor 1 for gas-liquid separation. In the separator 2, the reaction product and gas components such as dilution air and residual reaction gas are separated, and the cooling water introduced for cooling the reactor 1 is separated from the reaction product. The reactant is withdrawn from the separator 2 by a withdrawal pump 6 for the next step.

As described above, in the present invention, in order to quickly cool the temperature of the reaction product to a predetermined temperature and eliminate the problem of undesired coloring, a circulation line L1 for the reaction product is provided separately from the extraction line L10. Is provided. The predetermined amount is preferably about 3 to 20 times the amount of the reaction product withdrawn from the withdrawal pump 6, and the temperature of the reaction product is adjusted to a predetermined temperature through the circulation pump 4 and the heat exchanger 3. Alternatively, it is returned to the separator 2.
As a result, the temperature of the reaction product can be brought to the predetermined temperature immediately after the completion of the reaction, and the problem of undesirable coloring of the reaction product can be solved. In the case where the reaction product is alcohol ethoxy sulfate, alpha olefin sulfonic acid, and α-sulfofatty acid alkyl ester, preferred temperature ranges in the above temperature control are exemplified below.

(1) Alcohol ethoxy sulphate Temperature after reactor reaction: 60 to 80 ° C Circulation line temperature: 20 to 40 ° C Refrigerant temperature: 5 to 25 ° C (2) Alpha olefin sulfonic acid Temperature after reactor reaction: 60 to 80 ℃ Circulating line temperature: 30 to 40 ° C. Refrigerant temperature: 25 to 30 ° C. (If the temperature is too low, sticking to the heat exchanger surface and precipitation occur.) (3) α-Sulfo fatty acid alkyl ester Temperature immediately after reactor reaction: 70-90 ° C. Circulation line temperature: 80 ° C. (fixed to 80 ° C. from coloring and reaction because aging reaction is required) Refrigerant temperature: 60-90 ° C. The temperature difference before and after heat exchanger 3 is 1-5 ° C. A range is preferred. The monitoring control computer 20 performs the following control to obtain the above temperature range. In the circulation line L1, the temperature of the heat medium supplied to the heat exchanger 3 is controlled by the injection amount of the cooling water or the injection amount of the steam so that the indication of the thermometer 14 falls within the target temperature range. The refrigerant is basically circulated by the pump 5, and an excess amount is extracted to the outside by injection of cooling water or steam. The set value of the temperature of the refrigerant is set based on the difference between the indicated value of the thermometer 14 and the set value and the fluctuation history. (Performs PID control based on deviation, differential value, and integral value.) The temperature range is set for each type of sulfonated material as described above, and is controlled within the upper and lower limits of the temperature.

When the temperature reaches the lower limit or the upper limit, the flow rate of the refrigerant is controlled by the rotation speed of the pump 5 (or a flow control valve attached to a bypass line). This temperature control is performed based on thermometers 14 and 16 at the inlet and outlet of the heat exchanger 3. Next, the control at the time of switching the raw materials of the sulfonation reaction will be described. When the reaction raw material is switched, the reaction product before the switching is extracted from the separator 2, but slightly remains in the lower part of the reactor even after the switching. In order to remove the reaction products remaining in the lower part of the reactor as soon as possible and to quickly cool the reactor, the return flow rate control valve 8 to the reactor is closed, the return flow rate control valve 9 to the separator is opened, and a predetermined amount is applied to the separator 2. It is intended to return the reactants cooled to the temperature.

Although the temperature can be slightly adjusted as compared with the case of returning to the lower part of the reactor, the residue at the lower part of the reactor is quickly extracted. After a lapse of a predetermined time, the separator circulation system is closed, the reactor circulation system is opened, and the reaction product circulation line is switched so as to go around the lower part of the reactor to continue the operation.

[0022]

According to the present invention, the sulfonated product obtained by the sulfonation reaction in the reactor is mixed with the reaction product cooled to a predetermined temperature which is returned from the separator to the lower portion of the reactor by the circulation line. Cools quickly. As a result, the problem that coloring proceeds due to being maintained at a high temperature for a long time can be effectively solved. The present invention is advantageous in terms of cost because it can be configured by adding a circulation system to an existing device.

[Brief description of the drawings]

FIG. 1 is an overall system diagram of a sulfonation apparatus according to the present invention,

FIG. 2 is a control system diagram relating to temperature control of a sulfonation device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reactor 2 Separator 3 Heat exchanger 4 Circulation pump 5 Circulation pump 6 Extraction pump.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuaki Powdera 1-3-7 Honjo, Sumida-ku, Tokyo Inside Lion Corporation (72) Inventor Toshihiko Ichikawa 1-3-7 Honjo, Sumida-ku, Tokyo No. Lion Corporation

Claims (1)

[Claims] 1. A temperature control method for controlling the temperature of a sulfonated reactant within a predetermined range, comprising: introducing a gas-liquid mixture containing a sulfonated reactant generated by a sulfonating reaction extracted from the reactor into a separator. Separating the sulfonated reactant in the separator, controlling the separated sulfonated reactant to a predetermined temperature by a heat exchanger, and removing the sulfonated reactant from the reactor by 3 to 20 times the amount withdrawn from the reactor. A method for controlling the temperature of a sulfonated reactant, comprising refluxing the temperature-controlled sulfonated reactant to a lower part of a reactor or the separator.