CN115572246A - Process for preparing benzenesulfonic acid by taking hydrogen chloride gas as acidification reagent - Google Patents

Abstract

The invention provides a process for preparing benzenesulfonic acid by using hydrogen chloride gas as an acidification reagent, which comprises the following steps of acidification, centrifugation, concentration, decolorization, evaporation and the like: the concentration of the anhydrous benzenesulfonic acid product obtained by the method is more than 99.0%, and the yield of the benzenesulfonic acid product is more than 90%, the method takes sodium benzenesulfonate as a raw material, takes high-purity hydrogen chloride gas as an acidifying reagent, carries out acidification synthesis reaction in a pure water solvent, and prepares an anhydrous benzenesulfonic acid finished product by carrying out solid-liquid separation, concentration, decoloration and evaporation on an acidification reaction solution; has the advantages of high product yield, good product quality, little environmental pollution, low raw material cost and the like.

Description

A kind of technology that prepares benzenesulfonic acid with hydrogen chloride gas as acidifying reagent

technical field

The invention relates to the technical field of chemical product preparation technology, in particular to a technology for preparing benzenesulfonic acid by using hydrogen chloride gas as an acidifying reagent.

Background technique

Benzenesulfonic acid, colorless acicular or flaky crystal, molecular formula C ₆ H ₆ O ₃ S. Molecular weight 58.18; benzenesulfonic acid containing 1.5 molecules of crystal water is easy to deliquescence, its melting point is 43-44°C; melting point is 65-66°C (anhydrous), easily soluble in water, easily soluble in ethanol, slightly soluble in benzene, insoluble in ether , carbon disulfide; benzenesulfonic acid is a strong organic acid, the acidity is close to sulfuric acid, Ka=2×10-1 (25°C), and it often turns into sodium salt during separation and storage; it reacts with alkali to form a salt, and -SO ₃ H acts as When the meta-positioning group undergoes electrophilic substitution, the second group enters the meta-position. For example, 72% m-nitrobenzenesulfonic acid can be obtained during nitration, and phenol can be obtained by melting its sodium salt with NaOH; The reaction can generate benzene, which reacts with FeCl ₃ to form an orange precipitate.

The sulfonic acid group of benzenesulfonic acid can be substituted by various groups, and it can be fused with sodium hydroxide to form sodium phenate; it can react with sodium cyanide to produce benzonitrile; it can react with bromine to produce bromobenzene; it can react with nitric acid to produce nitrobenzene; Heat with water to remove the sulfonic acid group. It is used to produce phenol and resorcinol; it is often used as a catalyst and water-absorbing agent in esterification and dehydration reactions. Its advantage is that it is weaker in oxidation than sulfuric acid and can reduce side reactions.

The sulfonic acid group in benzenesulfonic acid is a strongly water-soluble and strongly acidic group, and is a water-soluble and strongly acidic compound. The sulfonic acid group in the benzenesulfonic acid molecule can be replaced by hydroxyl and cyano groups, and it is an important intermediate for the preparation of phenol and nitrile;

The -H part of the benzenesulfonic acid molecule can be substituted by halogen atoms, amino groups, etc., and is very useful in organic synthesis; benzenesulfonic acid can be prepared by the sulfonation reaction of aromatic hydrocarbons or the oxidation reaction of mercaptans; currently benzenesulfonic acid The production method usually has technical disadvantages such as complicated steps, low yield, high cost, and large amount of waste water, and it is difficult to obtain high-purity anhydrous benzenesulfonic acid with a content greater than 99.0% and above electronic grade.

Contents of the invention

Aiming at the deficiencies in the prior art, the present invention provides a process for preparing benzenesulfonic acid using hydrogen chloride gas as an acidifying reagent, which solves the problems of complicated steps, low yield, high cost, and waste water volume in the prior art. Large, limited purity and other issues.

According to an embodiment of the present invention, a kind of technology that prepares benzenesulfonic acid with hydrogen chloride gas as acidifying reagent comprises the following steps:

S1. Dissolve sodium benzenesulfonate in water to form a saturated solution, put it into the acidification kettle, pass in excess hydrogen chloride gas while stirring casually, heat and continue the reflux reaction for 10-14h, when the acidification solution passes the analysis, stop the reflux and cool , centrifuging the acidizing solution to separate sodium chloride to obtain dilute acid solution;

S2. Put the dilute acid solution into the concentration tank, heat and stir, gradually increase the temperature and control the temperature to be less than 140°C, cool and recover the separated gas phase, stop heating when the concentration of the solution in the concentration tank is qualified, and naturally cool to below 100°C, remove The material obtains concentrated acid solution;

S3, add the concentrated acid solution to the decolorization kettle, cool down to normal temperature through the cooling system, add activated carbon and stir for decolorization;

S4. Vacuumize the evaporator, then start heating, and continue to put in the decolorized concentrated acid solution, evaporate while feeding, and recycle the separated gas phase after condensation. When the feeding is over, stop feeding and heating and evaporating , After the material concentration in the kettle is tested and passed, the finished acid in the kettle is discharged to the slicer, and the finished product is measured and packed into the warehouse after being sliced.

Further, the heating temperature in the step S1 is 60-70°C, and the temperature after cooling is less than 30°C

Further, the qualified standard for the analysis in the step S1 is that the sodium ion concentration is less than 200ppm.

Further, the dilute acid liquid obtained by centrifugation in the step S1 is first placed in a sedimentation tank for natural sedimentation for more than 2 hours, and then injected into a dilute acid storage tank through a filter for use.

Further, the qualified standard of the concentration in the step S2 is that the mass concentration of the concentrated solution is ≥ 65%.

Further, the normal temperature in the step S3 is 25°C.

Further, the amount of activated carbon added in the step S3 is positively correlated with the color depth of the concentrated acid solution.

Further, the required vacuum degree in the evaporator in the step S4 is below the ultimate vacuum of 3000Pa.

Further, the qualified standard for detection in the step S4 is that the mass concentration of the still liquid is greater than 99.0%.

Further, in the step S4, nitrogen gas is used to press the qualified finished acid to the slicer.

The technical principle of the present invention is: the present invention has utilized the principle of ion dissolution balance in the solution, when continuously feeding hydrogen chloride gas in the saturated sodium benzenesulfonate solution, has introduced chloride ion in the solution; Because the solubility of hydrogen chloride is greater than that of chloride Sodium, when the concentration of chloride ions in the solution increases, it will push the dissolution balance of sodium chloride to move towards the crystallization direction, and when the concentration of chloride ions is saturated, sodium chloride crystals will be precipitated to reduce the concentration of chloride ions in the solution and avoid loss of balance; With the continuous introduction of hydrogen chloride gas, the sodium chloride in the solution is continuously precipitated until all the sodium ions are discharged in the form of precipitation, and only benzenesulfonic acid and hydrogen chloride remain in the solution. At this time, the hydrogen chloride is separated by distillation to obtain High concentration of benzenesulfonic acid.

Compared with the prior art, the present invention has the following beneficial effects:

In the present invention, sodium benzenesulfonate is used as raw material, high-purity hydrogen chloride gas is used as an acidifying reagent, acidification synthesis reaction is carried out in a pure water solvent, the acidification reaction liquid is separated from solid and liquid, concentrated, decolorized and evaporated to obtain anhydrous benzenesulfonic acid finished product ; It has the advantages of high product yield, good product quality, little environmental pollution and low cost of raw materials.

Description of drawings

Fig. 1 is the process flow diagram of the embodiment of the present invention.

detailed description

The technical solutions in the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Example 1:

(1) make solvent with pure water, sodium benzenesulfonate is made into saturated solution, actual mass concentration is 40%, metering is put into acidizing still then, open acidizing reaction still and stir simultaneously, open jacket cooling water import and export valve, and Feed hydrogen chloride gas in metered amount, control the acidification reaction temperature at 60°C for reflux reaction for 14 hours, after the acidification solution passes the central control analysis (sodium ion ≤ 200ppm), stop the reflux reaction and lower the temperature to below 30°C, open the bottom valve to acidify After the solid-liquid centrifugation and separation of sodium chloride, the acidified solution is placed in the settling tank for 2.5 hours to settle naturally, and the acidified solution is pumped into the dilute acid storage tank through a precision filter and used in the next concentration post by a pneumatic diaphragm pump.

(2) Measure the dilute acid liquid from the dilute acid storage tank into the concentration kettle, open the agitation of the concentration kettle and the jacket heat transfer oil inlet and outlet valves, start to heat up, control the distillation temperature to be less than 140°C during the concentration process, control the vacuum degree, and concentrate After the vapor phase of the kettle is condensed by the graphite condenser, it enters the recovery tank for recycling. When the distillation temperature of the concentrated kettle reaches 140°C, take a sample for analysis. After the sampling analysis is qualified (concentrated liquid content ≥ 65%), close the jacket heat transfer oil inlet and outlet valve to stop. Concentrate, and when it naturally cools down to below 100°C, open the discharge bottom valve to pump the concentrated acid solution to the concentrated acid solution decolorization kettle for use.

(3) Turn on the stirring of the concentrated acid decolorization kettle and the jacket cooling water inlet and outlet valves, and start to cool down. When the concentrated acid solution cools down to room temperature 25°C, add an appropriate amount of activated carbon according to the actual appearance and color of the concentrated acid solution for decolorization. After the decolorization treatment, open the discharge bottom valve to press the concentrated acid liquid with compressed air to the high level tank of the concentrated acid liquid through a precision filter for the next evaporation post.

(4) First use the Roots vacuum pump unit of the wiped film evaporator to evacuate the vacuum to below the ultimate vacuum of 3000Pa, then open the heat transfer oil in the jacket of the wiped film evaporator and the steam inlet and outlet valves of the heat preservation system to start preheating, and at the same time open the high level of concentrated acid The tank outlet valve starts to measure the feed through the flow meter. During the evaporation process, the vacuum degree, evaporation temperature and feed amount are strictly controlled, and by adjusting the feed amount of the wiped film evaporator, the vapor phase of the evaporator enters after being condensed by the condenser. The dilute acid recovery tank is used for recycling; when the feed is finished, close the heat transfer oil inlet and outlet valves of the wiper evaporator jacket, and stop evaporation. After the central control sampling and analysis pass (the concentration of the kettle liquid is greater than 99.0%), then open the evaporator The outlet bottom valve presses the finished acid to the slicer with nitrogen pressure, and the finished product is sliced by the slicer and then measured into the finished product packaging barrel for packaging according to the standard, and the finished product is put into storage with a label.

Example 2:

(1) make solvent with pure water, sodium benzenesulfonate is made into saturated solution, actual mass concentration is 40%, metering is put into acidizing still then, open acidizing reaction still and stir simultaneously, open jacket cooling water import and export valve, and Feed hydrogen chloride gas in metered amount, control the acidification reaction temperature at 65°C for reflux reaction for 12 hours, after the acidification solution passes the central control analysis (sodium ion ≤ 200ppm), stop the reflux reaction and lower the temperature to below 30°C, open the bottom valve to acidify After the solid-liquid centrifugation and separation of sodium chloride, the acidified solution is placed in a settling tank for natural settlement for 3 hours, and the acidified solution is pumped into the dilute acid storage tank through a precision filter with a pneumatic diaphragm pump for use in the next concentration post.

(2) Measure the dilute acid liquid from the dilute acid storage tank into the concentration kettle, open the agitation of the concentration kettle and the jacket heat transfer oil inlet and outlet valves, start to heat up, control the distillation temperature to be less than 140°C during the concentration process, control the vacuum degree, and concentrate After the vapor phase of the kettle is condensed by the graphite condenser, it enters the recovery tank for recycling. When the distillation temperature of the concentrated kettle reaches 140°C, take a sample for analysis. After the sampling analysis is qualified (concentrated liquid content ≥ 65%), close the jacket heat transfer oil inlet and outlet valve to stop. Concentrate, and when it naturally cools down to below 100°C, open the discharge bottom valve to pump the concentrated acid solution to the concentrated acid solution decolorization kettle for use.

(3) Turn on the stirring of the concentrated acid decolorization kettle and the jacket cooling water inlet and outlet valves, and start to cool down. When the concentrated acid solution cools down to room temperature 25°C, add an appropriate amount of activated carbon according to the actual appearance and color of the concentrated acid solution for decolorization. After the decolorization treatment, open the discharge bottom valve to press the concentrated acid liquid with compressed air to the high level tank of the concentrated acid liquid through a precision filter for the next evaporation post.

(4) First use the Roots vacuum pump unit of the wiped film evaporator to evacuate the vacuum to below the ultimate vacuum of 3000Pa, then open the heat transfer oil in the jacket of the wiped film evaporator and the steam inlet and outlet valves of the heat preservation system to start preheating, and at the same time open the high level of concentrated acid The tank outlet valve starts to measure the feed through the flow meter. During the evaporation process, the vacuum degree, evaporation temperature and feed amount are strictly controlled, and by adjusting the feed amount of the wiped film evaporator, the vapor phase of the evaporator enters after being condensed by the condenser. The dilute acid recovery tank is used for recycling; when the feed is finished, close the heat transfer oil inlet and outlet valves of the wiper evaporator jacket, and stop evaporation. After the central control sampling and analysis pass (the concentration of the kettle liquid is greater than 99.0%), then open the evaporator The outlet bottom valve presses the finished acid to the slicer with nitrogen pressure, and the finished product is sliced by the slicer and then measured into the finished product packaging barrel for packaging according to the standard, and the finished product is put into storage with a label.

Example 3:

(1) make solvent with pure water, sodium benzenesulfonate is made into saturated solution, actual mass concentration is 40%, metering is put into acidizing still then, open acidizing reaction still and stir simultaneously, open jacket cooling water import and export valve, and Feed hydrogen chloride gas in metered amount, control the acidification reaction temperature at 70°C for reflux reaction for 10 hours, after the acidification solution passes the central control analysis (sodium ion ≤ 200ppm), stop the reflux reaction and lower the temperature to below 30°C, open the bottom valve to acidify After the liquid is centrifuged to separate sodium chloride from solid and liquid, it is placed in the settling tank for natural settlement for 5 hours, and the acidified liquid is pumped into the dilute acid storage tank through the precision filter and used in the next concentration post by using a pneumatic diaphragm pump.

(2) Measure the dilute acid liquid from the dilute acid storage tank into the concentration kettle, open the agitation of the concentration kettle and the jacket heat transfer oil inlet and outlet valves, start to heat up, control the distillation temperature to be less than 140°C during the concentration process, control the vacuum degree, and concentrate After the vapor phase of the kettle is condensed by the graphite condenser, it enters the recovery tank for recycling. When the distillation temperature of the concentrated kettle reaches 140°C, take a sample for analysis. After the sampling analysis is qualified (concentrated liquid content ≥ 65%), close the jacket heat transfer oil inlet and outlet valve to stop. Concentrate, and when it naturally cools down to below 100°C, open the discharge bottom valve to pump the concentrated acid solution to the concentrated acid solution decolorization kettle for use.

(3) Turn on the stirring of the concentrated acid decolorization kettle and the jacket cooling water inlet and outlet valves, and start to cool down. When the concentrated acid solution cools down to room temperature 25°C, add an appropriate amount of activated carbon according to the actual appearance and color of the concentrated acid solution for decolorization. After the decolorization treatment, open the discharge bottom valve to press the concentrated acid liquid with compressed air to the high level tank of the concentrated acid liquid through a precision filter for the next evaporation post.

(4) First use the Roots vacuum pump unit of the wiped film evaporator to evacuate the vacuum to below the ultimate vacuum of 3000Pa, then open the heat transfer oil in the jacket of the wiped film evaporator and the steam inlet and outlet valves of the heat preservation system to start preheating, and at the same time open the high level of concentrated acid The tank outlet valve starts to measure the feed through the flow meter. During the evaporation process, the vacuum degree, evaporation temperature and feed amount are strictly controlled, and by adjusting the feed amount of the wiped film evaporator, the vapor phase of the evaporator enters after being condensed by the condenser. The dilute acid recovery tank is used for recycling; when the feed is finished, close the heat transfer oil inlet and outlet valves of the wiper evaporator jacket, and stop evaporation. After the central control sampling and analysis pass (the concentration of the kettle liquid is greater than 99.0%), then open the evaporator The outlet bottom valve presses the finished acid to the slicer with nitrogen pressure, and the finished product is sliced by the slicer and then measured into the finished product packaging barrel for packaging according to the standard, and the finished product is put into storage with a label.

The specific parameters of the benzenesulfonic acid product obtained in the above-mentioned embodiment are as table 1:

Table 1

As can be seen from Table 1, the concentration of the anhydrous benzenesulfonic acid product of the present invention is greater than 99.0%, and the yield of benzenesulfonic acid product is greater than 90%, which has the advantages of high product yield and good product quality.

Finally, it is noted that the above embodiments are only used to illustrate the technical solutions of the present invention without limitation. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be carried out Modifications or equivalent replacements without departing from the spirit and scope of the technical solution of the present invention shall be covered by the claims of the present invention.

Claims (10)

1. A process for preparing benzenesulfonic acid by using hydrogen chloride gas as an acidifying reagent is characterized by comprising the following steps of:

s1, dissolving sodium benzenesulfonate in water to prepare a saturated solution, putting the saturated solution into an acidification kettle, stirring while introducing excessive hydrogen chloride gas, heating and continuously refluxing for 10-14 hours, stopping refluxing and cooling after the acidification liquid is analyzed to be qualified, and centrifuging the acidification liquid to separate sodium chloride to obtain a dilute acid liquid;

s2, putting the dilute acid solution into a concentration kettle, heating and stirring, gradually heating, controlling the temperature to be lower than 140 ℃, cooling and recovering the separated gas phase, stopping heating when the concentration of the solution in the concentration kettle is qualified, and naturally cooling to be lower than 100 ℃ to remove the material to obtain concentrated acid solution;

s3, adding the concentrated acid solution into a decoloring kettle, cooling to normal temperature through a cooling system, and adding activated carbon to stir for decoloring;

s4, vacuumizing the evaporator, heating, continuously adding decolored concentrated acid liquid, feeding while evaporating, condensing separated gas phase, recycling, stopping feeding and heating evaporation after feeding is finished, discharging finished product acid in the kettle to a slicing machine after the concentration of the material in the kettle is detected to be qualified, and measuring, packaging and warehousing the finished product after the finished product is sliced.

2. The process of claim 1 for the preparation of benzenesulfonic acid using hydrogen chloride gas as acidifying reagent, wherein: in the step S1, the heating temperature is 60-70 ℃, and the temperature is less than 30 ℃ after cooling.

3. The process of claim 1 for the preparation of benzenesulfonic acid using hydrogen chloride gas as acidifying agent, wherein: the standard that the analysis in the step S1 is qualified is that the concentration of sodium ions is less than 200ppm.

4. The process of claim 1 for the preparation of benzenesulfonic acid using hydrogen chloride gas as acidifying agent, wherein: and (2) placing the dilute acid solution obtained by centrifugal separation in the step (S1) into a sedimentation tank for natural sedimentation for more than 2 hours, and injecting the dilute acid solution into a dilute acid storage tank for later use through a filter.

5. The process of claim 1 for the preparation of benzenesulfonic acid using hydrogen chloride gas as acidifying agent, wherein: the qualified concentration standard in the step S2 is that the mass concentration of the concentrated solution is more than or equal to 65 percent.

6. The process of claim 1 for the preparation of benzenesulfonic acid using hydrogen chloride gas as acidifying agent, wherein: the normal temperature in the step S3 is 25 ℃.

7. The process of claim 1 for the preparation of benzenesulfonic acid using hydrogen chloride gas as acidifying agent, wherein: the amount of the activated carbon added in the step S3 is positively correlated with the color depth of the concentrated acid solution.

8. The process of claim 1 for the preparation of benzenesulfonic acid using hydrogen chloride gas as acidifying agent, wherein: and in the step S4, the required vacuum degree in the evaporator is below 3000 Pa.

9. The process of claim 1 for the preparation of benzenesulfonic acid using hydrogen chloride gas as acidifying agent, wherein: and the qualified detection standard in the step S4 is that the mass concentration of the kettle liquid is more than 99.0%.

10. The process of claim 1 for the preparation of benzenesulfonic acid using hydrogen chloride gas as acidifying agent, wherein: and in the step S4, the qualified finished product is pressed to a slicing machine by using nitrogen.

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