Chlorinated recovered methanol purification system in maltol production

Abstract

The utility model provides a chlorination recovery methanol purification system in maltol production, which belongs to the technical field of maltol preparation systems and comprises a reaction unit and a step-by-step separation unit, the reaction unit comprises a soft water inlet pipe, a chlorination hydrolysis recovery methanol pipe and a reactor, the soft water inlet pipe is connected with a first inlet of the reactor, and the step-by-step separation unit is connected with a second inlet of the reactor. The chlorination hydrolysis methanol recovery pipe is connected with a second inlet of the reactor, and an outlet of the reactor is connected with the step-by-step separation unit; methanol in the chlorination hydrolysis recovery methanol pipe and soft water in the soft water inlet pipe are added into the reactor, the chlorination hydrolysis recovery methanol is subjected to a hydrolysis reaction, heavy-phase turbid impurities naturally sink, methanol liquid is on the upper layer, then the methanol liquid is conveyed to the step-by-step separation unit to be separated, and a methanol solution with high purity is obtained; when the methanol solution with high purity is repeatedly used, the impurity content in the methanol solution is low, so that side reactions in the chlorination reaction are reduced, and the yield of the chlorination reaction product is improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of maltol preparation system, and concretely relates to a chlorination recovery methanol purification system in maltol production. BACKGROUND

[0002] The maltol production process is mainly divided into Grignard process, chlorination process, sublimation process, crystallization process and drying and packaging process. The chlorination process includes chlorination reaction, chlorination hydrolysis reaction and neutralization reaction. In the chlorination process, methanol aqueous solution is used as the solvent for chlorination reaction, which is reported in the chlorination hydrolysis production method in maltol production disclosed in publication No. CN106366062A. Therefore, the use of methanol is extensive and in large quantity in the production of maltol.

[0003] In the prior art, the chlorination recovered methanol is usually purified, recovered and then distilled to remove impurities. However, the purity of the purified methanol is low. In the continuous circulation and application process of the methanol aqueous solution, the methanol aqueous solution contains a large amount of impurities, mainly including aldehydes (formaldehyde and acetaldehyde), ketones (acetone), alcohols (ethanol and propanol), esters and organic acids. The existence of the above impurities leads to a large amount of side reactions in the chlorination reaction, and the yield of the reaction product is low. SUMMARY

[0004] Therefore, the utility model provides a chlorination recovery methanol purification system in maltol production for improving the yield of chlorination reaction.

[0005] A chlorination recovery methanol purification system in maltol production, comprising a reaction unit and a step-by-step separation unit. The reaction unit comprises a soft water inlet pipe, a chlorination hydrolysis recovery methanol pipe and a reactor. The soft water inlet pipe is connected with a first inlet of the reactor, and the chlorination hydrolysis recovery methanol pipe is connected with a second inlet of the reactor. The outlet of the reactor is connected with the step-by-step separation unit. The soft water in the soft water inlet pipe and the impurities in the chlorination hydrolysis recovery methanol pipe are hydrolyzed and separated into layers to recover methanol.

[0006] Preferably, the step-by-step separation unit comprises a first separation tank, a second separation tank and a methanol recovery tank. The outlet of the reactor is connected with the inlet of the first separation tank. The outlet of the first separation tank is connected with the inlet of the second separation tank. The outlet of the second separation tank is connected with the inlet of the methanol recovery tank.

[0007] Preferably, the soft water inlet pipe is provided with a first valve, and the chlorination hydrolysis recovery methanol pipe is provided with a second valve.

[0008] Preferably, the reaction unit further comprises a delivery pump, an inlet of the delivery pump is connected with the lower outlet of the reactor, and an outlet of the delivery pump is connected with the lower inlet of the first stratification tank.

[0009] Preferably, an upper portion of the first stratification tank is provided with a first overflow port, an upper portion of the second stratification tank is provided with a second overflow port, the first overflow port is connected with the lower inlet of the second stratification tank, and the second overflow port is connected with the inlet of the methanol recovery tank.

[0010] Preferably, a stirring member is arranged in the reactor.

[0011] Preferably, the step-by-step separation unit comprises three separation assemblies, the three separation assemblies are respectively connected with the bottom outlet of the reactor, the bottom outlet of the first stratification tank and the bottom outlet of the second stratification tank, and each separation assembly comprises a sedimentation tube, a sight glass and a liquid discharge valve.

[0012] Preferably, the sedimentation tube is a cone, and the inlet of the sedimentation tube is one end with a large opening.

[0013] Preferably, the separation assembly further comprises a liquid inlet valve, one end of the liquid inlet valve is connected with the outlet of the sedimentation tube, and the other end of the liquid inlet valve is connected with the sight glass.

[0014] Compared with the prior art, the maltol production chlorination recovery methanol purification system has the following beneficial effects:

[0015] The maltol production chlorination recovery methanol purification system comprises a reaction unit and a step-by-step separation unit, the reaction unit comprises a soft water inlet pipe, a chlorination hydrolysis recovery methanol pipe and a reactor, the soft water inlet pipe is connected with a first inlet of the reactor, the chlorination hydrolysis recovery methanol pipe is connected with a second inlet of the reactor, and an outlet of the reactor is connected with the step-by-step separation unit. In the ethyl maltol production process, chlorination hydrolysis recovery methanol in the chlorination hydrolysis recovery methanol pipe and soft water in the soft water inlet pipe are added into the reactor. BRIEF DESCRIPTION OF DRAWINGS

[0016] Fig. 1 The process flow diagram of the methanol purification system for recovering methanol in chlorination in maltol production.

[0017] Fig. 2 The structural schematic diagram of the separation assembly.

[0018] In the figure: the methanol purification system 10 for recovering methanol in chlorination in maltol production, the reaction unit 100, the soft water inlet pipe 110, the first valve 111, the chlorination hydrolysis methanol recovery pipe 120, the second valve 121, the reactor 130, the stirring part 131, the conveying pump 140, the step-by-step separation unit 200, the first stratification tank 210, the first overflow port 211, the second stratification tank 220, the second overflow port 221, the methanol recovery storage tank 230, the separation assembly 240, the sedimentation pipe 241, the sight glass 242, the liquid discharge valve 243, and the liquid inlet valve 244. DETAILED DESCRIPTION

[0019] The technical scheme and technical effects of the embodiments of the present application are further described in detail below in combination with the drawings of the present application.

[0020] Please refer to Figs. 1-2 A methanol purification system 10 for recovering methanol in chlorination in maltol production, comprising a reaction unit 100 and a step-by-step separation unit 200, the reaction unit 100 comprising a soft water inlet pipe 110, a chlorination hydrolysis methanol recovery pipe 120, and a reactor 130, the soft water inlet pipe 110 being connected with a first inlet of the reactor 130, the chlorination hydrolysis methanol recovery pipe 120 being connected with a second inlet of the reactor 130, and an outlet of the reactor 130 being connected with the step-by-step separation unit 200, so as to hydrolyze and stratify the impurities in the chlorination hydrolysis methanol recovery pipe 120 with the soft water in the soft water inlet pipe 110 and recover methanol.

[0021] The utility model discloses a maltol production chlorination recovery methanol purification system 10, including reaction unit 100, step -by -step separation unit 200, reaction unit 100 includes soft water inlet pipe 110, chlorination hydrolysis recovery methanol pipe 120, reactor 130, soft water inlet pipe 110 with first inlet connection of reactor 130, chlorination hydrolysis recovery methanol pipe 120 with second inlet connection of reactor 130, the outlet of reactor 130 is connected with step -by -step separation unit 200, in the ethyl maltol production process, to reactor 130 in the chlorination hydrolysis recovery methanol pipe 120 in the chlorination hydrolysis recovery of methanol and the soft water in the soft water inlet pipe 110 of adding, because the chlorination hydrolysis recovery methanol is acidic, after adding soft water, the nonpolar ketone, ester impurity in the chlorination hydrolysis recovery methanol hydrolysis reaction occurs under acidic conditions, generates corresponding acid and alcohol, after standing for a period of time, heavy phase turbid impurity natural subsidence, methanol liquid is on the upper layer, then methanol liquid is transported to step -by -step separation unit 200 and is separated, obtains high -purity methanol solution, when high -purity methanol solution is sent into chlorination system again and is used repeatedly, the impurity content in methanol solution is low, makes the side reaction in chlorination reaction reduce, and the chlorination reaction product yield improves.

[0022] Specifically, after the chlorination reaction is finished, the liquid is transferred to the chlorination hydrolysis kettle, first, the methanol is recovered by heating, and then the methanol recovery is finished, and the high-temperature rearrangement is continued by heating; the methanol recovered by first heating is the material in the chlorination hydrolysis recovery methanol pipe 120.

[0023] Further, the step-by-step separation unit 200 includes a first layering tank 210, a second layering tank 220, and a methanol recovery storage tank 230. The outlet of the reactor 130 is connected with the inlet of the first layering tank 210. The outlet of the first layering tank 210 is connected with the inlet of the second layering tank 220. The outlet of the second layering tank 220 is connected with the inlet of the methanol recovery storage tank 230. The upper clear liquid containing methanol in the reactor 130 is transported into the first layering tank 210. After standing and layering, the clear liquid containing methanol is transported into the second layering tank 220 for continuous standing and layering. The reactor 130, the first layering tank 210, and the second layering tank 220 are used for continuous three-stage separation, so that the impurities are completely separated, and then the solution in the methanol recovery storage tank 230 has high methanol content and low impurity content.

[0024] Further, the soft water inlet pipe 110 is provided with a first valve 111, and the chlorination hydrolysis recovery methanol pipe 120 is provided with a second valve 121. The opening degree of the first valve 111 and the second valve 121 is controlled to control the volume ratio of the soft water and the material in the chlorination hydrolysis recovery methanol pipe 120 to be 1:3, so that the hydrolysis reaction can be normally performed.

[0025] Further, the reaction unit 100 further comprises a delivery pump 140, an inlet of the delivery pump 140 is connected with a lower outlet of the reactor 130, an outlet of the delivery pump 140 is connected with a lower inlet of the first stratification tank 210, the flow rate of the liquid into the first stratification tank 210 is controlled by the delivery pump 140 so as not to affect the separation in the first stratification tank 210.

[0026] Further, an upper portion of the first stratification tank 210 is provided with a first overflow port 211, an upper portion of the second stratification tank 220 is provided with a second overflow port 221, the first overflow port 211 is connected with a lower inlet of the second stratification tank 220, the second overflow port 221 is connected with an inlet of the methanol recovery tank 230, in the first stratification tank 210, after a long time of standing, the supernatant containing methanol automatically overflows into the second stratification tank 220 through the first overflow port 211 to continue the separation, and the separation efficiency of the supernatant and impurities is improved.

[0027] Further, the height of the second overflow port 221 is higher than the height of the first overflow port 211.

[0028] Further, a stirring member 131 is arranged in the reactor 130 so as to make the hydrolysis reaction sufficient.

[0029] Further, the step-by-step separation unit 200 comprises three separation assemblies 240, the three separation assemblies 240 are respectively connected with a bottom outlet of the reactor 130, the first stratification tank 210 and the second stratification tank 220, the separation assembly 240 comprises a sedimentation pipe 241, a sight glass 242 and a liquid discharge valve 243, an inlet of the sedimentation pipe 241 is connected with the bottom outlet of the reactor 130, the first stratification tank 210 or the second stratification tank 220, an outlet of the sedimentation pipe 241 is connected with the sight glass 242, a lower portion of the sight glass 242 is connected with the liquid discharge valve 243, when a large amount of impurities is deposited at the bottom of the reactor 130, the first stratification tank 210 or the second stratification tank 220, the liquid discharge valve 243 is opened to discharge the heavy phase turbid impurities by observing the sight glass 242.

[0030] Further, the sedimentation pipe 241 is a cone, and one end of the inlet of the sedimentation pipe 241 is an opening, when the amount of impurities is small, the sedimentation pipe 241 is used for standing and separation so as to make the separation thorough.

[0031] Further, the separation assembly 240 further comprises an inlet valve 244, one end of the inlet valve 244 is connected with the outlet of the sedimentation pipe 241, and the other end of the inlet valve 244 is connected with the sight glass 242; when the impurities need to be discharged, the inlet valve 244 is first opened, so that the impurities enter the sight glass 242, then the sight glass 242 is observed, the liquid discharge valve 243 is opened to discharge the impurities, if the amount of impurities is small, the inlet valve 244 can be closed when no impurity flow is observed in the sight glass 242, so as to prevent the required methanol from being discharged; the liquid in the sight glass 242 can be statically placed again, then the sight glass 242 is observed, and the liquid discharge valve 243 is opened to discharge the impurities, so as to prevent the required methanol liquid from being lost.

[0032] The use of the utility model will be introduced through the following examples.

[0033] In the production process of ethyl maltol, the chlorinated hydrolysis recovered methanol in the chlorinated hydrolysis recovery methanol pipe 120 and the soft water in the soft water inlet pipe 110 are added into the reactor 130, the volume ratio of the soft water to the chlorinated hydrolysis recovered methanol is controlled to be 1:3 through the first valve 111 and the second valve 121, since the chlorinated hydrolysis recovered methanol is acidic, after the soft water is added, the nonpolar ketone impurities in the chlorinated hydrolysis recovered methanol hydrolyze under the acidic condition, the stirring is carried out through the stirring piece 131, so that the hydrolysis reaction is sufficient, the corresponding acid and alcohol are generated, after a period of static placement, the heavy phase turbid impurities naturally sink, the methanol liquid is in the upper layer, the heavy phase turbid impurities are discharged, then the methanol liquid is conveyed to the first separation tank 210 through the conveying pump 140, in the first separation tank 210, after a long time of static placement, the upper layer clear liquid containing methanol automatically overflows to the second separation tank 220 through the first overflow port 211 to continue separation, after a period of static placement in the second separation tank 220, the upper layer clear liquid containing methanol automatically overflows to the methanol recovery storage tank 230 through the second overflow port 221, so that the continuous three-stage separation is carried out through the reactor 130, the first separation tank 210 and the second separation tank 220, so that the impurities are completely separated, and then the methanol content in the solution in the methanol recovery storage tank 230 is high, the impurity content is low, and the purity of the methanol solution is high, when the methanol solution is repeatedly used in the chlorination system, the impurity content in the methanol solution is low, the methanol content is increased from 54% to 65%, so that the side reaction in the chlorination reaction is reduced, and the yield of the chlorination reaction product is increased.

[0034] The above only discloses the preferred embodiments of the utility model, of course, cannot be used to limit the scope of the utility model, and the person skilled in the art can understand that all or part of the processes of the above embodiments are implemented, and equivalent changes are made according to the utility model claims, which still belong to the range covered by the utility model.

Claims

1. A system for chlorination recovery and methanol purification in maltol production, characterized in that, The system includes a reaction unit and a step-by-step separation unit. The reaction unit includes a soft water inlet pipe, a chlorination hydrolysis methanol recovery pipe, and a reactor. The soft water inlet pipe is connected to the first inlet of the reactor, the chlorination hydrolysis methanol recovery pipe is connected to the second inlet of the reactor, and the outlet of the reactor is connected to the step-by-step separation unit. The system allows for the hydrolysis and stratification of soft water in the soft water inlet pipe with impurities in the chlorination hydrolysis methanol recovery pipe to recover methanol.

2. The chlorination recovery and methanol purification system for maltol production as described in claim 1, characterized in that, The step-by-step separation unit includes a first layer tank, a second layer tank, and a methanol recovery storage tank. The outlet of the reactor is connected to the inlet of the first layer tank, the outlet of the first layer tank is connected to the inlet of the second layer tank, and the outlet of the second layer tank is connected to the inlet of the methanol recovery storage tank.

3. The chlorination recovery and methanol purification system in maltol production as described in claim 1, characterized in that, The soft water inlet pipe is equipped with a first valve, and the chlorination hydrolysis methanol recovery pipe is equipped with a second valve.

4. The chlorination recovery and methanol purification system in maltol production as described in claim 2, characterized in that, The reaction unit also includes a delivery pump, the inlet of which is connected to the lower outlet of the reactor, and the outlet of which is connected to the lower inlet of the first stratification tank.

5. The chlorination recovery and methanol purification system for maltol production as described in claim 2, characterized in that, The first layered tank is provided with a first overflow port at its upper part, and the second layered tank is provided with a second overflow port at its upper part. The first overflow port is connected to the lower inlet of the second layered tank, and the second overflow port is connected to the inlet of the methanol recovery storage tank.

6. The chlorination recovery and methanol purification system for maltol production as described in claim 1, characterized in that, The reactor is equipped with a stirring element.

7. The chlorination recovery and methanol purification system for maltol production as described in claim 2, characterized in that, The step-by-step separation unit includes three separation components. The three separation components are respectively connected to the bottom outlets of the reactor, the first stratification tank, and the second stratification tank. Each separation component includes a sedimentation tube, a sight glass, and a drain valve. The inlet of the sedimentation tube is connected to the bottom outlet of the reactor, the bottom outlet of the first stratification tank, or the bottom outlet of the second stratification tank. The outlet of the sedimentation tube is connected to the sight glass, and the lower part of the sight glass is connected to the drain valve.

8. The chlorination recovery and methanol purification system for maltol production as described in claim 7, characterized in that, The deposition tube is a cone, and the inlet of the deposition tube is the end with the larger opening.

9. The chlorination recovery and methanol purification system for maltol production as described in claim 7, characterized in that, The separation assembly also includes a liquid inlet valve, one end of which is connected to the outlet of the deposition tube, and the other end of which is connected to the sight glass.

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