System and method for carrying out continuous neutralization reaction and application of system and method

Abstract

The invention discloses a system and a method for continuous neutralization reaction and application of the system and the method, and belongs to the technical field of ethyl maltol production. According to the system, a neutralization kettle is additionally arranged on the basis of original process equipment, and automatic accurate control of pH and temperature is realized by interlocking an automatic temperature control and automatic pH adjusting device with a liquid caustic soda adjusting valve and a circulating water cooling valve. Compared with an original single-kettle process, the method has the advantages that automatic control is achieved, operability is high, production is convenient, control is more stable, alkali consumption can be reduced, the process wastewater amount can be reduced, and meanwhile the method plays an important role in improving the yield of the whole maltol product.

Description

Technical Field

[0001] The invention belongs to the technical field of ethyl maltol production, and in particular relates to a system, method and application of a continuous neutralization reaction. Background Art

[0002] The furfural method produces ethyl maltol, which utilizes Grignard reagent to react with furfural in toluene and tetrahydrofuran solvents to generate furfuryl alcohol intermediate, and then uses distillation and vacuum distillation to purify furfuryl alcohol. The furfuryl alcohol is then chlorinated and hydrolyzed to obtain ethyl maltol. The production process is divided into Grignard section, chlorination section, sublimation section, and crystallization section.

[0003] CN117504778A discloses a method for automatic production of maltol in the production of glutamic acid, comprising the following steps: S1 glutamic acid reaction: opening the stirring setting of the glutamic acid kettle, opening the feed valve of the chloroethane metering tank leading to the glutamic acid kettle, and then opening the steam valve of the jacket of the chloroethane metering tank, and the heated chloroethane enters the glutamic acid kettle to carry out the glutamic acid reaction, and the glutamic acid reaction is finished, and the glutamic acid kettle is naturally cooled to the production index; S2 addition reaction: opening the side valve of the glutamic acid kettle, feed liquid 1 enters the addition kettle, and furfural is added dropwise to the addition kettle, and the addition reaction is finished; S3 hydrolysis reaction: opening the discharge valve of the addition kettle, feed liquid 2 enters the hydrolysis kettle, and water is added dropwise to the hydrolysis kettle. After the hydrolysis reaction is finished, filtering, the filtrate enters the intermediate transfer tank, S4 distillation and S5 vacuum distillation. The invention can realize the fully automated production of the glutamic acid section.

[0004] CN104341378A discloses a chlorination hydrolysis production method in the production of ethyl maltol, comprising the following steps: a. after the chlorination reaction is completed, the material in the chlorination kettle is sent to the distillation tower by a circulation pump; b. the circulation pump is turned on, the steam valve is opened, and a plate heat exchanger is used for rapid circulation heat exchange, so that the material is quickly heated up and distilled to recover methanol, and the steam valve is closed when the temperature rises to 90°C; c. the methanol recovered by distillation is sent to the methanol batching tank for repeated use, and the material after distillation in the distillation tower is pumped into the hydrolysis kettle, and the temperature of the hydrolysis kettle is kept between 90 and 95°C for hydrolysis reaction. The present invention realizes the continuity of the chlorination hydrolysis production operation.

[0005] At present, in the production of ethyl maltol, automated operations have been achieved from Grignard to chlorination hydrolysis. However, after the hydrolysis reaction is completed, sodium hydroxide solution needs to be added to the hydrolysis kettle for neutralization reaction. The current neutralization operation adopts manual single-kettle operation. The material temperature is difficult to control during the process, and the rapid adjustment of pH value also affects the material conversion rate. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a system, method and application of a continuous neutralization reaction. A neutralization kettle is added to the original process equipment, and automatic temperature control and automatic pH adjustment devices are interlocked with a liquid alkali regulating valve and a circulating water cooling valve to achieve automatic and precise control of pH and temperature.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] The present invention provides a system for a continuous neutralization reaction, comprising a neutralization kettle, a layering kettle, a mother liquor kettle and a black oil kettle, wherein the neutralization kettle is connected to the layering kettle, the layering kettle is connected to the mother liquor kettle, and the black oil kettle is connected to the neutralization kettle and the layering kettle;

[0009] The upper part of the neutralization kettle is provided with an alkali liquid inlet and a parameter detection inlet, and the bottom is provided with a water bath insulation device;

[0010] The parameter detection port is equipped with an automatic temperature control device and an automatic pH adjustment device, and the automatic temperature control device and the automatic pH adjustment device are interlocked with the liquid alkali regulating valve and the circulating water cooling valve.

[0011] Furthermore, the neutralization kettle comprises a No. 1 neutralization kettle and a No. 2 neutralization kettle connected in series.

[0012] Furthermore, the No. 1 discharge port of the No. 1 neutralization kettle is connected to the No. 2 feed port of the No. 2 neutralization kettle through a pipeline.

[0013] Furthermore, the automatic temperature control device includes a temperature sensor and / or an online temperature detector.

[0014] Furthermore, the automatic pH adjustment device includes a pH sensor and / or a pH online monitor.

[0015] Furthermore, a drain pipe is provided at the bottom of the neutralization kettle, and the drain pipe is connected to the top of the black oil kettle.

[0016] Furthermore, the liquid alkali regulating valve is arranged on a pipeline connected to the alkali liquid outlet.

[0017] Furthermore, the circulating water cooling valve is arranged on a pipe connected to the water inlet of the water bath insulation device.

[0018] Furthermore, the No. 2 discharge port of the No. 2 neutralization kettle is connected to the feed port of the stratification kettle through a pipeline.

[0019] The present invention provides a method for performing a continuous neutralization reaction, and the neutralization reaction is performed using the above-mentioned system.

[0020] Furthermore, the method comprises the following steps:

[0021] (1) The hydrolyzed liquid enters the No. 1 neutralization kettle, and then enters the No. 2 neutralization kettle from the No. 1 neutralization kettle. The real-time changes in the neutralization kettle are monitored by an automatic temperature control device and an automatic pH adjustment device. The automatic temperature control device and the automatic pH adjustment device are interlocked with the liquid caustic soda regulating valve and the circulating water cooling valve to adjust and control the temperature and pH changes in the neutralization kettle in real time;

[0022] (2) The neutralized liquid enters the layering kettle from the No. 2 neutralization kettle;

[0023] (3) The mother liquor in the upper layer of the stratification kettle enters the mother liquor kettle, and the black oil in the lower layer of the neutralization kettle enters the black oil kettle through the drain pipe.

[0024] Furthermore, the hydrolyzate in step (1) comprises water, methanol and an acidic substance.

[0025] Furthermore, in step (1), the temperature in the neutralization kettle is controlled at 65-90°C, and the pH in the neutralization kettle is controlled at 2.0-3.5; preferably, when the temperature is controlled at 65-75°C, the pH is controlled at 2.5-3.0; when the temperature is controlled at 75-85°C, the pH is controlled at 3.0-3.5.

[0026] The present invention provides application of the aforementioned system or the aforementioned method in the automated production of ethyl maltol.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) Compared with the original single-kettle process, the present invention realizes automatic control, has strong operability, is easy to produce, and has more stable control.

[0029] (2) Compared with the original single-pot process, the present invention reduces the consumption of liquid caustic soda, reduces the cost, and reduces the average amount of liquid caustic soda per pot by about 100 liters, thereby reducing process wastewater. Each pot neutralization reduces the amount of wastewater by about 100 liters.

[0030] (3) The present invention can reduce alkali consumption and the amount of process wastewater, and at the same time plays an important role in improving the yield of the entire maltol product. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of a system for the continuous neutralization reaction of the present invention.

[0032] Among them, 1 is neutralization kettle No. 1, 2 is neutralization kettle No. 2, 3 is stratification kettle, 4 is mother liquor kettle, and 5 is black oil kettle. DETAILED DESCRIPTION

[0033] The following describes the embodiments of the present invention in conjunction with specific examples. Before further describing the specific embodiments of the present invention, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments described below; it should also be understood that the terms used in the embodiments of the present invention are for describing specific embodiments rather than for limiting the scope of protection of the present invention.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. The liquid alkali of the present invention is a NaOH aqueous solution.

[0035] A system for continuous neutralization reaction of the present invention adds a neutralization kettle on the basis of the original process equipment, and realizes automatic and precise control of pH and temperature by interlocking the automatic temperature control and automatic pH adjustment devices with the liquid alkali adjustment valve and the circulating water cooling valve.

[0036] Figure 1 The present invention is a schematic diagram of a system for continuous neutralization reaction, comprising a No. 1 neutralization kettle 1, a No. 2 neutralization kettle 2, a layering kettle 3, a mother liquor kettle 4 and a black oil kettle 5, wherein the No. 2 neutralization kettle 2 is connected to the layering kettle 3, the layering kettle 3 is connected to the mother liquor kettle 4, and the black oil kettle 5 is connected to the No. 1 neutralization kettle 1, the No. 2 neutralization kettle 2 and the layering kettle 3.

[0037] The No. 1 neutralization kettle 1 and the No. 2 neutralization kettle 2 are both provided with an alkali liquid inlet and a parameter detection inlet at the top, and a water bath insulation device at the bottom.

[0038] The parameter detection port is equipped with an automatic temperature control device and an automatic pH adjustment device.

[0039] The liquid alkali regulating valves are respectively arranged on the pipelines connecting the No. 1 neutralization kettle 1, the No. 2 neutralization kettle 2 and the corresponding alkali liquid outlets.

[0040] The circulating water cooling valves are respectively arranged on the pipelines connecting the No. 1 neutralization kettle 1, the No. 2 neutralization kettle 2 and the water inlets of the corresponding water bath insulation devices.

[0041] The automatic temperature control device and the automatic pH adjustment device are interlocked with the liquid alkali adjustment valve and the circulating water cooling valve.

[0042] In some embodiments, the automatic temperature control device includes a temperature sensor and / or an online temperature detector; the automatic pH adjustment device includes a pH sensor and / or an online pH monitor.

[0043] In some embodiments, the No. 1 discharge port of the No. 1 neutralization kettle 1 is connected to the No. 2 feed port of the No. 2 neutralization kettle 2 through a pipeline, and the No. 2 discharge port of the No. 2 neutralization kettle 2 is connected to the feed port of the stratification kettle 3 through a pipeline.

[0044] In some embodiments, drain pipes are provided at the bottom of the No. 1 neutralization kettle 1 , the No. 2 neutralization kettle 2 and the layering kettle 3 , and the drain pipes are connected to the top of the black oil kettle 5 .

[0045] Compared with the existing neutralization reaction system, the present invention improves the automation level of the device, realizes automatic control, has strong operability, is easy to produce, and has more stable control.

[0046] Based on the aforementioned system for continuous neutralization reaction and in combination with specific implementation methods, the technical solution of the present invention and the technical effects achieved are described in detail below.

[0047] Example 1 A method for continuous neutralization reaction

[0048] The real-time changes in the neutralization kettle are monitored by an automatic temperature control device and an automatic pH adjustment device, and the automatic temperature control device and the automatic pH adjustment device are interlocked with the liquid alkali regulating valve and the circulating water cooling valve to adjust and control the temperature and pH changes in the neutralization kettle in real time. The temperature control index is 70±5℃, and the pH control index is 2.5-3.0.

[0049] The hydrolyzate (including water, methanol and acidic substances) enters the No. 1 neutralization kettle at a flow rate of 100 liters / minute, and the liquid alkali with a mass concentration of 32% is input into the No. 1 neutralization kettle at a flow rate of 20 liters / minute. The total volume of the liquid alkali is 700 liters. The temperature in the No. 1 neutralization kettle is 83°C and the pressure is normal. The hydrolyzate enters the No. 2 neutralization kettle from the No. 1 neutralization kettle at a flow rate of 100 liters / minute, and the liquid alkali with a mass concentration of 32% is input into the No. 2 neutralization kettle at a flow rate of 20 liters / minute. The volume of the liquid alkali is 700 liters. The temperature in the No. 2 neutralization kettle is 82°C and the pressure is normal.

[0050] The neutralized liquid enters the stratification kettle from the No. 2 neutralization kettle at a flow rate of 100 liters / minute; the mother liquor on the upper layer of the stratification kettle enters the mother liquor kettle. After standing for 30 minutes, the stratification intelligent viewing mirror automatically separates the layers. The black oil is a maltol intermediate, and the mother liquor is a neutralization liquid containing water. The function of the black oil kettle is to store black oil.

[0051] Example 2 A method for continuous neutralization reaction

[0052] The real-time changes in the neutralization kettle are monitored by an automatic temperature control device and an automatic pH adjustment device, and the automatic temperature control device and the automatic pH adjustment device are interlocked with the liquid alkali regulating valve and the circulating water cooling valve to adjust and control the temperature and pH changes in the neutralization kettle in real time. The temperature control index is 80±5℃, and the pH control index is 3.0-3.5.

[0053] The hydrolyzate (including water, methanol and acidic substances) enters the No. 1 neutralization kettle at a flow rate of 100 liters / minute, and the liquid alkali with a mass concentration of 32% is input into the No. 1 neutralization kettle at a flow rate of 20 liters / minute. The total volume of the liquid alkali is 705 liters. The temperature in the No. 1 neutralization kettle is 82°C and the pressure is normal. The hydrolyzate enters the No. 2 neutralization kettle from the No. 1 neutralization kettle at a flow rate of 100 liters / minute, and the liquid alkali with a mass concentration of 32% is input into the No. 2 neutralization kettle at a flow rate of 20 liters / minute. The total volume of the liquid alkali is 705 liters. The temperature in the No. 2 neutralization kettle is 81°C and the pressure is normal.

[0054] The neutralized liquid enters the stratification kettle from the No. 2 neutralization kettle at a flow rate of 100 liters / minute; the mother liquor on the upper layer of the stratification kettle enters the mother liquor kettle. After standing for 30 minutes, the stratification intelligent viewing mirror automatically separates the layers. The black oil is a maltol intermediate, and the mother liquor is a neutralization liquid containing water. The function of the black oil kettle is to store black oil.

[0055] Example 3 A method for continuous neutralization reaction

[0056] The real-time changes in the neutralization kettle are monitored by an automatic temperature control device and an automatic pH adjustment device, and the automatic temperature control device and the automatic pH adjustment device are interlocked with the liquid alkali regulating valve and the circulating water cooling valve to adjust and control the temperature and pH changes in the neutralization kettle in real time. The temperature control index is 80±5℃, and the pH control index is 2.0-3.5.

[0057] The hydrolyzate (including water, methanol, and acidic substances) enters the No. 1 neutralization kettle at a flow rate of 100 liters / minute, and the liquid alkali with a mass concentration of 32% is input into the No. 1 neutralization kettle at a flow rate of 20 liters / minute, the volume of the liquid alkali is 708 liters, and the temperature in the No. 1 neutralization kettle is 81°C and the pressure is normal. The hydrolyzate enters the No. 2 neutralization kettle from the No. 1 neutralization kettle at a flow rate of 100 liters / minute, and the liquid alkali with a mass concentration of 32% is input into the No. 2 neutralization kettle at a flow rate of 20 liters / minute, the volume of the liquid alkali is 708 liters, and the temperature in the No. 2 neutralization kettle is 80°C and the pressure is normal.

[0058] The neutralized liquid enters the stratification kettle from the No. 2 neutralization kettle at a flow rate of 100 liters / minute; the mother liquor on the upper layer of the stratification kettle enters the mother liquor kettle. After standing for 30 minutes, the stratification intelligent viewing mirror automatically separates the layers. The black oil is a maltol intermediate, and the mother liquor is a neutralization liquid containing water. The function of the black oil kettle is to store black oil.

[0059] Comparative Example 1 A method for continuous neutralization reaction

[0060] The difference between this comparative example 1 and example 2 is that this comparative example is a single-pot process, does not contain a No. 2 neutralization pot, and has no automatic temperature control device, automatic pH adjustment device, and liquid alkali regulating valve and circulating water cooling valve interlocking.

[0061] Specifically:

[0062] The hydrolyzate (including water, methanol and acidic substances) enters the No. 1 neutralization kettle at a flow rate of 100 L / min, and the liquid alkali with a mass concentration of 32% is input into the No. 1 neutralization kettle at a flow rate of 10 L / min. The total volume of the liquid alkali is 850 L. The temperature in the No. 1 neutralization kettle is 86°C and the pressure is normal.

[0063] The neutralized liquid enters the stratification kettle from the No. 1 neutralization kettle at a flow rate of 100 liters / minute; the mother liquor on the upper layer of the stratification kettle enters the mother liquor kettle. After standing for 30 minutes, the stratification intelligent viewing mirror automatically separates the layers. The black oil is a maltol intermediate, and the mother liquor is a neutralization liquid containing water. The function of the black oil kettle is to store black oil.

[0064] Comparative Example 2 A method for continuous neutralization reaction

[0065] The difference between this comparative example and Example 2 is that the temperature and pH controlled by the automatic temperature control device, the automatic pH adjustment device, the liquid caustic soda regulating valve and the circulating water cooling valve are different.

[0066] The real-time changes in the neutralization kettle are monitored by an automatic temperature control device and an automatic pH adjustment device, and the automatic temperature control device and the automatic pH adjustment device are interlocked with the liquid alkali regulating valve and the circulating water cooling valve to adjust and control the temperature and pH changes in the neutralization kettle in real time. The temperature control index is 90±5℃, and the pH control index is 4.0-5.0.

[0067] The hydrolyzate (including water, methanol, and acidic substances) enters the No. 1 neutralization kettle at a flow rate of 100 liters / minute, and the liquid alkali with a mass concentration of 32% is input into the No. 1 neutralization kettle at a flow rate of 20 liters / minute, the volume of the liquid alkali is 780 liters, and the temperature in the No. 1 neutralization kettle is 83°C and the pressure is normal. The hydrolyzate enters the No. 2 neutralization kettle from the No. 1 neutralization kettle at a flow rate of 100 liters / minute, and the liquid alkali with a mass concentration of 32% is input into the No. 2 neutralization kettle at a flow rate of 20 liters / minute, the volume of the liquid alkali is 780 liters, and the temperature in the No. 2 neutralization kettle is 82°C and the pressure is normal.

[0068] The neutralized liquid enters the stratification kettle from the No. 2 neutralization kettle at a flow rate of 100 liters / minute; the mother liquor on the upper layer of the stratification kettle enters the mother liquor kettle. After standing for 30 minutes, the stratification intelligent viewing mirror automatically separates the layers. The black oil is a maltol intermediate, and the mother liquor is a neutralization liquid containing water. The function of the black oil kettle is to store black oil.

[0069] Compared with the original single-pot process, the present invention reduces the consumption of liquid alkali, reduces the cost, reduces the average neutralization of each pot by about 100 liters, reduces process wastewater, and reduces wastewater by about 100 liters per pot. At the same time, the present invention has strong operability, high automation level, more stable control, and compared with the single-pot process, the maltol yield is increased by more than 25%.

[0070] The above is a further description of the present invention in conjunction with specific embodiments, but these embodiments are merely exemplary and do not constitute any limitation on the scope of the present invention. It should be understood by those skilled in the art that the details and forms of the technical solution of the present invention may be modified or replaced without departing from the spirit and scope of the present invention, but these modifications and replacements all fall within the scope of protection of the present invention.

Claims

1. A system for a continuous neutralization reaction, characterized in that: It comprises a neutralization kettle, a layering kettle, a mother liquor kettle and a black oil kettle, wherein the neutralization kettle is connected to the layering kettle, the layering kettle is connected to the mother liquor kettle, and the black oil kettle is connected to the neutralization kettle and the layering kettle; The neutralization kettle is provided with an alkali liquid inlet and a parameter detection inlet at the top and a water bath insulation device at the bottom; The parameter detection port is equipped with an automatic temperature control device and an automatic pH adjustment device, and the automatic temperature control device and the automatic pH adjustment device are interlocked with the liquid alkali regulating valve and the circulating water cooling valve; The neutralization kettle comprises a No. 1 neutralization kettle and a No. 2 neutralization kettle connected in series.

2. The system according to claim 1, characterized in that The No. 1 discharge port of the No. 1 neutralization kettle is connected to the No. 2 feed port of the No. 2 neutralization kettle through a pipeline; the No. 2 discharge port of the No. 2 neutralization kettle is connected to the feed port of the stratification kettle through a pipeline.

3. The system according to claim 1, characterized in that The automatic temperature control device includes a temperature sensor and / or an online temperature detector; the automatic pH adjustment device includes a pH sensor and / or an online pH monitor.

4. The system according to claim 1, characterized in that The liquid alkali regulating valve is arranged on a pipeline connected to the alkali liquid port; the circulating water cooling valve is arranged on a pipeline connected to the water inlet of the water bath insulation device.

5. The system according to claim 1, characterized in that A drain pipe is provided at the bottom of the neutralization kettle, and the drain pipe is connected to the top of the black oil kettle.

6. A method for a continuous neutralization reaction, characterized in that: Using the system of any one of claims 1 to 5 to carry out a neutralization reaction; The steps include: (1) The hydrolyzed liquid enters the No. 1 neutralization kettle, and then enters the No. 2 neutralization kettle from the No. 1 neutralization kettle. The real-time changes in the neutralization kettle are monitored by an automatic temperature control device and an automatic pH adjustment device. The automatic temperature control device and the automatic pH adjustment device are interlocked with the liquid caustic soda regulating valve and the circulating water cooling valve to adjust and control the temperature and pH changes in the neutralization kettle in real time; (2) The neutralized liquid enters the layering kettle from the No. 2 neutralization kettle; (3) The mother liquor in the upper layer of the stratification kettle enters the mother liquor kettle, and the black oil in the lower layer of the neutralization kettle enters the black oil kettle through the drain pipe.

7. The method according to claim 6, characterized in that The hydrolyzate in step (1) comprises water, methanol and an acidic substance.

8. The method according to claim 6, characterized in that In step (1), the temperature in the neutralization kettle is controlled at 65-90° C., and the pH in the neutralization kettle is controlled at 2.0-3.

5.

9. The method according to claim 8, characterized in that When the temperature is controlled at 65-75°C, the pH is controlled at 2.5-3.0; when the temperature is controlled at 75-85°C, the pH is controlled at 3.0-3.

5.

10. Use of the system according to any one of claims 1 to 8 or the method according to any one of claims 9 to 10 in the automated production of ethyl maltol.

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