Continuous naphthalene sulfonation process and application thereof

Abstract

The invention provides a continuous naphthalene sulfonation process and application thereof, and particularly relates to the field of chemical synthesis. The continuous naphthalene sulfonation process comprises the following steps: melting naphthalene, and reacting the molten naphthalene with sulfuric acid to generate 2-naphthalene sulfonic acid at the reaction temperature of 150-170 DEG C for 10-30 minutes. According to the continuous naphthalene sulfonation process, the operation intensity of workers can be reduced, and the naphthalene conversion rate and the 2-naphthalene sulfonic acid yield are improved.

Description

Technical Field

[0001] The invention provides a naphthalene continuous sulfonation process and application thereof, and particularly relates to the field of chemical synthesis. Background Art

[0002] The traditional continuous sulfonation process of naphthalene is:

[0003] Pump the molten naphthalene into the naphthalene metering tank, stop the pump when reflux occurs, open the sulfonation naphthalene inlet valve after reflux ends, add all into the sulfonation pot, and measure the volume to 2600L.

[0004] Raise the naphthalene temperature to 135-145°C, add 1100 liters of acid for 20-30 minutes while stirring, add 30% acid in the first half and 70% acid in the second half. During the acid addition process, the temperature of the sulfonation pot gradually and evenly rises. After the acid is added, the temperature in the pot is close to 160°C.

[0005] Then, the material temperature is rapidly raised to 162-168°C and maintained at normal pressure for 2.5-3 hours. After the maintenance, stop stirring and measure the volume to about 3600-3700L, take samples for analysis, adjust the valve, and purge the pipeline with steam.

[0006] The pressure in the pot should be 0.15MPa. After discharging, adjust the valve, purge the discharging pipe, and check that there is no residual material in the pot. Before discharging, the pot should maintain normal pressure, and check the exhaust pipe frequently to ensure smooth flow. Material maintenance operation: start maintenance when the material temperature rises to 163℃-168℃, and the maintenance time shall not be less than 2 hours and 50 minutes (if naphthalene is recovered, it shall not be less than 2 hours and 30 minutes).

[0007] Within 20 minutes before the end of the maintenance, turn off the stirring, open the sampling port valve, and use the sampling cup to take samples. After sampling, close the sampling port valve, turn on the stirring to continue to maintain. When the sampling test results meet the requirements (the sample acidity is required to be 25-27%), 2-naphthalenesulfonic acid is discharged, the naphthalene conversion rate is only 90%, and the 2-naphthalenesulfonic acid yield is 90%.

[0008] The original process used kettle operation, which had a poor working environment, high intensity, low yield of 2-naphthalenesulfonic acid, and many impurities that were difficult to separate. At the same time, the original process had high energy consumption, with 48 tons of naphthalene reacting per day and consuming 3,000 cubic meters of natural gas.

[0009] Chinese patent CN117049947A discloses a 2-naphthol and a preparation method thereof, wherein naphthalene and sulfuric acid are used as raw materials to carry out sulfonation reaction and transposition reaction to obtain a naphthalenesulfonic acid mixture, and 1-naphthalenesulfonic acid in the naphthalenesulfonic acid mixture is separated by melt crystallization to obtain 2-naphthalenesulfonic acid. The sulfuric acid is added dropwise at 54-108 mL / h, which is complicated to operate and inefficient. Summary of the invention

[0010] In order to solve the deficiencies in the prior art, the present invention provides a naphthalene continuous sulfonation process, which adopts a tubular reactor, controls the flow rates of naphthalene and sulfuric acid, adjusts the reaction time, and performs continuous feeding sulfonation reaction, thereby reducing the operation intensity of workers, improving the naphthalene conversion rate and the 2-naphthalenesulfonic acid yield, and reducing energy consumption.

[0011] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0012] In one aspect, the present invention provides a naphthalene continuous sulfonation process, wherein naphthalene is melted, and the molten naphthalene reacts with sulfuric acid to generate 2-naphthalenesulfonic acid;

[0013] Specifically, the reaction temperature is 150-170°C;

[0014] Specifically, the reaction time is 10-30 minutes.

[0015] Preferably, the reaction is carried out in a tubular reactor.

[0016] Preferably, the tubular reactor is a dynamic tubular reactor.

[0017] Specifically, the flow rate of naphthalene is 33.3-58 L / min.

[0018] Preferably, the flow rate of naphthalene is 42-50 L / min.

[0019] Preferably, the flow rate of naphthalene is 50 L / min.

[0020] Specifically, the flow rate of the sulfuric acid is 33.3-58 L / min.

[0021] Preferably, the flow rate of the sulfuric acid is 33.3-50 L / min.

[0022] Preferably, the flow rate of the sulfuric acid is 50 L / min.

[0023] Specifically, the sulfuric acid is concentrated sulfuric acid.

[0024] Preferably, the concentrated sulfuric acid is 98% sulfuric acid.

[0025] Preferably, the reaction temperature is 150°C-170°C.

[0026] Preferably, the reaction temperature is 150°C-160°C.

[0027] Preferably, the reaction temperature is 150°C.

[0028] Specifically, the reaction is a normal pressure reaction.

[0029] Preferably, the reaction time is 15-30 min.

[0030] Preferably, the reaction time is 30 min.

[0031] On the other hand, the present invention provides an application of a naphthalene continuous sulfonation process in improving the naphthalene conversion rate.

[0032] The beneficial effects of the present invention are:

[0033] (1) The present invention adopts a tubular reactor and weighing and metering equipment, which effectively reduces the operating intensity of workers and improves efficiency.

[0034] (2) The present invention achieves the effect of improving the conversion rate and quality of naphthalene by measuring the flow rates of naphthalene and sulfuric acid and adjusting the reaction time.

[0035] (3) The present invention saves energy consumption and reduces costs by measuring the flow rates of naphthalene and sulfuric acid and adjusting the reaction time. DETAILED DESCRIPTION

[0036] To better illustrate this patent, the following examples are listed. The following examples are intended to enable the industry personnel to understand the present invention in more detail, or to make some non-essential improvements and adjustments based on the content of the present invention. However, the scope of the present invention is not limited by these examples.

[0037] Example 1

[0038] After industrial naphthalene is melted, it is maintained at 90°C in the storage tank. After naphthalene is metered by a metering pump, it is fed into the dynamic tubular reactor at 33.3L / min. After sulfuric acid is metered by a metering pump, it is fed into the dynamic tubular reactor at 42L / min. The two streams of materials undergo sulfonation reaction inside the dynamic tubular reactor at a reaction temperature of 170°C to generate 2-naphthalenesulfonic acid. The reaction time is 10 minutes. Under normal pressure, the naphthalene conversion rate is 95%, and the 2-naphthalenesulfonic acid yield is 98%. 1,740 cubic meters of natural gas are used every day.

[0039] Example 2

[0040] After industrial naphthalene is melted, it is maintained at 90°C in the storage tank. After naphthalene is metered by a metering pump, it is fed into the dynamic tubular reactor at 42L / min. After sulfuric acid is metered by a metering pump, it is fed into the dynamic tubular reactor at 33.3L / min. The two streams of materials undergo sulfonation reaction inside the dynamic tubular reactor at a reaction temperature of 160°C to generate 2-naphthalenesulfonic acid. The reaction time is 15 minutes. Under normal pressure, the naphthalene conversion rate is 98%, and the 2-naphthalenesulfonic acid yield is 98%. 1,770 cubic meters of natural gas are used every day.

[0041] Example 3

[0042] After industrial naphthalene is melted, it is maintained at 90°C in a storage tank. Naphthalene is metered by a metering pump and fed into a dynamic tubular reactor at 50L / min. Sulfuric acid is metered by a metering pump and fed into a dynamic tubular reactor at 50L / min. The two streams of materials undergo sulfonation reaction inside the dynamic tubular reactor at a reaction temperature of 150°C to generate 2-naphthalenesulfonic acid. The reaction time is 30 minutes. The naphthalene conversion rate is 99% and the 2-naphthalenesulfonic acid yield is 98% under normal pressure. 1,800 cubic meters of natural gas are used every day.

[0043] Example 4

[0044] After industrial naphthalene is melted, it is maintained at 90°C in the storage tank. Naphthalene is metered by a metering pump and fed into the dynamic tubular reactor at 58L / min. Sulfuric acid is metered by a metering pump and fed into the dynamic tubular reactor at 58L / min. The two streams of materials undergo sulfonation reaction inside the dynamic tubular reactor at a reaction temperature of 160°C to generate 2-naphthalenesulfonic acid. The reaction time is 15 minutes. The naphthalene conversion rate is 96% and the 2-naphthalenesulfonic acid yield is 97% under normal pressure. 1,740 cubic meters of natural gas are used every day.

[0045] Comparative Example 1

[0046] After industrial naphthalene is melted, it is maintained at 90°C in a storage tank. Naphthalene is metered by a metering pump and fed into a dynamic tubular reactor at 66L / min. Sulfuric acid is metered by a metering pump and fed into a dynamic tubular reactor at 66L / min. The two streams of materials undergo sulfonation reaction inside the dynamic tubular reactor at a reaction temperature of 150°C to generate 2-naphthalenesulfonic acid. The reaction time is 30 minutes. The naphthalene conversion rate is 90% under normal pressure, and the 2-naphthalenesulfonic acid yield is 90%. 1,890 cubic meters of natural gas are used every day.

[0047] Comparative Example 2

[0048] After industrial naphthalene is melted, it is maintained at 90°C in a storage tank. Naphthalene is metered by a metering pump and fed into a dynamic tubular reactor at 50L / min. Sulfuric acid is metered by a metering pump and fed into a dynamic tubular reactor at 50L / min. The two streams of materials undergo sulfonation reaction inside the dynamic tubular reactor at a reaction temperature of 150°C to generate 2-naphthalenesulfonic acid. The reaction time is 40 minutes. The naphthalene conversion rate is 92% under normal pressure, and the 2-naphthalenesulfonic acid yield is 90%. 1,950 cubic meters of natural gas are used every day.

[0049] The naphthalene conversion rate of Examples 1-4 is 95%-99%, the 2-naphthalenesulfonic acid yield is 97%-98%, and 1740-1800 cubic meters of natural gas are used every day; the flow rates of naphthalene and sulfuric acid in Comparative Example 1 are not within the protection scope of the present invention, the naphthalene conversion rate is 90%, the 2-naphthalenesulfonic acid yield is 90%, and 1890 cubic meters of natural gas are used; the reaction time of Comparative Example 2 is not within the protection scope of the present invention, the naphthalene conversion rate is 92%, the 2-naphthalenesulfonic acid yield is 90%, and 1950 cubic meters of natural gas are used.

[0050] The naphthalene conversion rate and 2-naphthalenesulfonic acid yield of Comparative Example 1-2 are lower than those of Example 1-4; the energy consumption of Comparative Example 1-2 is higher than that of Example 1-4.

[0051] The present invention is described in detail above. The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the present invention and its core ideas. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A naphthalene continuous sulfonation process, characterized in that, Melting naphthalene, and reacting the molten naphthalene with sulfuric acid to generate 2-naphthalenesulfonic acid; The reaction temperature is 150-170°C; The reaction time is 10-30 min.

2. The continuous sulfonation process of naphthalene according to claim 1, characterized in that: The flow rate of the naphthalene is 33.3-58 L / min.

3. The continuous sulfonation process of naphthalene according to claim 2, characterized in that: The flow rate of the naphthalene is 42-50 L / min.

4. The continuous sulfonation process of naphthalene according to claim 1, characterized in that: The flow rate of the sulfuric acid is 33.3-58 L / min.

5. The continuous sulfonation process of naphthalene according to claim 4, characterized in that: The flow rate of the sulfuric acid is 33.3-50 L / min.

6. The continuous sulfonation process of naphthalene according to claim 1, characterized in that: The sulfuric acid is concentrated sulfuric acid.

7. The continuous sulfonation process of naphthalene according to claim 1, characterized in that: The reaction temperature is 150-160°C.

8. The continuous sulfonation process of naphthalene according to claim 1, characterized in that: The reaction time is 15-30 min.

9. The continuous sulfonation process of naphthalene according to claim 8, characterized in that: The reaction time is 30 min.

10. Application of the continuous sulfonation process of naphthalene as claimed in any one of claims 1 to 9 in improving the conversion rate of naphthalene.