Preparation device and method of monolaurin, control system and method

Abstract

The invention discloses a preparation device and method of monolaurin, and a control system and method. In the preparation device of monolaurin of the invention, a computer uses 14-point temperature acquisition, 8-point pressure acquisition and 1-point pH acquisition, and simultaneously controls the opening of 14 valves. The preparation device of monolaurin has a high level of automation, and the collected data is comprehensive and accurate. It performs multi-dimensional analysis and control of temperature, pressure and pH, thereby improving product quality and production efficiency. The preparation method is a method for preparing monolaurin by esterifying glycerol and lauric acid at high temperature under nitrogen or carbon dioxide conditions. The method does not use a catalyst, and no phosphate is generated during the reaction process, and there is no pollution to the environment. Since the reaction equipment is fully enclosed, it is environmentally friendly, and the generated recycled glycerol is recycled as a reactant for the next reaction, which can reduce production costs.

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthesis, and in particular relates to a preparation device and method of lauric acid monoglyceride, and a control system and method. Background Art

[0002] Lauric acid monoglyceride is also known as lauric acid monoglyceride, with the molecular formula of C 11 H 23 COOCH2CHOHCH2OH is a lipophilic nonionic surfactant and a compound naturally found in some plants. After extraction, it is often added to food, daily necessities or cosmetics as a bactericide and anti-inflammatory agent. Lauric acid monoglyceride with a monoester content of more than 96% has excellent performance in both food preservation and emulsification, and is not limited by pH. It still has a good antibacterial effect under neutral to slightly alkaline conditions. Studies have shown that lauric acid monoglyceride has a good inhibitory effect on bacteria, molds, yeasts, fungi and other microorganisms.

[0003] Among the methods for preparing monoglyceride of lauric acid, esterification reaction is one of the more commonly used methods. The catalysts used for esterification reaction mainly include enzymes, traditional strong acids, ion exchange resins, ionic liquids, etc. When the above catalysts catalyze the esterification reaction, there are problems such as long reaction time, high corrosiveness, environmental pollution, many by-products, and high cost. In addition, in the process of removing alkaline catalysts from the reaction system using traditional strong acids such as H3PO4 and HCL, ionic liquids, and heteropoly acids in traditional industries, the generated phosphates are very polluting to the environment. Therefore, it is of great significance to develop a green, environmentally friendly and efficient method for preparing monoglyceride of lauric acid.

[0004] At present, the most commonly used preparation method is direct esterification, which is to use glycerol and lauric acid under alkali catalysis (such as NaOH, KOH), temperature 160-180°C, reaction time 2-4 hours to obtain a mixture with a monolaurin content of about 50%. Summary of the invention

[0005] In order to solve the shortcomings and deficiencies of the prior art, the primary purpose of the present invention is to provide a preparation device for monoglyceride of lauric acid. Compared with a traditional reactor, the reaction device has a faster reaction speed, a shorter production cycle, fewer by-products, better product quality, lighter color and higher yield, lower production cost, and a reaction time that is half that of a traditional reactor.

[0006] The second object of the present invention is to provide a method for preparing monolaurin, which comprises the following steps: esterifying glycerol and lauric acid at high temperature under nitrogen or carbon dioxide conditions to prepare monolaurin. The method does not use a catalyst, and no phosphate is generated during the reaction, which does not pollute the environment. The method solves the problem that the phosphate generated by the traditional process needs to be discharged and causes environmental pollution. Since the reaction equipment is fully enclosed, the method is environmentally friendly, and the recovered glycerol is recycled as a reactant for the next reaction, which can reduce the production cost.

[0007] The third object of the present invention is to provide a control system for preparing monoglyceride of lauric acid, which adopts a computer-based control system to control the entire control system, and can effectively and accurately control the feed amount of each material in the monoglyceride of lauric acid and the feed amount of cooling water, and can also accurately control the reaction temperature, pressure and pH value.

[0008] The fourth object of the present invention is to provide a control method for preparing lauric acid monoglyceride.

[0009] The primary purpose of the present invention is achieved through the following technical solutions:

[0010] A preparation device for monoglyceride of lauric acid comprises a production device for monoglyceride of lauric acid, a distillation device for monoglyceride of lauric acid and a powder spraying device for monoglyceride of lauric acid.

[0011] The production device of monoglyceride of lauric acid comprises an external circulation heat exchanger, a reaction tank, a condensation component, a loop circulation pump, a valve and a detection device. A loop reaction mixer is arranged in the reaction tank, the top of the external circulation heat exchanger is connected to the loop reaction mixer, the bottom of the external circulation heat exchanger is connected to the bottom of the reaction tank through the loop circulation pump, and the top of the reaction tank is connected to the condensation component; the top of the reaction tank is connected to the external circulation heat exchanger through a pipeline, a feed pipeline and a feed valve are arranged on the top of the reaction tank, and a discharge pipeline and a bottom valve are arranged on the bottom; a pressure detection device and a temperature detection device are arranged on the top, middle and bottom of the reaction tank, and a pH detection device is arranged on the bottom of the reaction tank; the top of the reaction tank forms a gas phase loop (monoglyceride loop) with the external circulation heat exchanger and the condensation component through a pipeline, the external circulation heat exchanger is provided with a temperature detection device, and a temperature detection device and a pressure detection device are arranged on the upper part of the condensation component; the pressure detection device, the temperature detection device and the pH detection device are all electrically connected to a computer.

[0012] Preferably, a gas phase discharge valve is provided on the pipeline connecting the middle part of the reaction tank and the condensation component, a control valve is provided on the external circulation heat exchanger, and a main control valve is provided on the condensation component.

[0013] Preferably, the condensation assembly includes a primary condenser, a secondary condenser, a tertiary condenser, a primary condenser receiving tank, a secondary condenser receiving tank and a tertiary condenser receiving tank; a cooling water outlet is provided at the top of the primary condenser, the top of the primary condenser is connected to the upper condensation water inlet of the secondary condenser receiving tank, a cooling water inlet is provided at the bottom of the primary condenser, and cooling water condenses gas from bottom to top; a cooling water outlet is provided at the top of the secondary condenser, the top of the secondary condenser is connected to the upper condensation water inlet of the tertiary condenser receiving tank, a cooling water inlet is provided at the bottom of the secondary condenser, and cooling water condenses gas from bottom to top; a cooling water outlet is provided at the top of the tertiary condenser, and a cooling water inlet and outlet are provided at the bottom of the tertiary condenser; the upper condensation water inlet of the primary condenser receiving tank is connected to the upper part of the reaction tank.

[0014] Preferably, the reaction tank is provided with a vacuum port, a glycerol inlet and a gas phase outlet at the top, a lauric acid inlet at the upper part, a material outlet at the middle part, and an insulation coil at the bottom; the reaction tank material outlet is connected to the bottom of the secondary condenser receiving tank.

[0015] Preferably, the loop reaction mixer is a spray mixer, a jet mixer or a Venturi mixer.

[0016] The loop reactor of the spray mixer is represented by the gas-liquid contact reactor developed by the Italian company PRESS; the loop reactor of the Venturi mixer is represented by the Bush reactor developed by the Swiss company BUSS.

[0017] Preferably, a heat transfer oil outlet is arranged at the top of the external circulation heat exchanger and a heat transfer oil inlet is arranged at the bottom thereof, the top of the external circulation heat exchanger is connected to the top of the reaction tank, and the bottom of the external circulation heat exchanger is connected to the bottom of the reaction tank.

[0018] Preferably, the preparation device of monoglyceride of lauric acid further comprises a sedimentation separation tank, and the upper part of the sedimentation separation tank is connected to the bottom of the reaction tank through a pipeline and a loop circulation pump.

[0019] Preferably, the distillation device of monoglyceride of lauric acid comprises a distillation process feed pump, a first molecular distillation device, a second molecular distillation device, a third molecular distillation device, a fourth molecular distillation device, a distilled ester discharge pump, and a distilled ester precipitation tank, wherein the first molecular distillation device, the second molecular distillation device, the third molecular distillation device and the fourth molecular distillation device are arranged in sequence.

[0020] Preferably, the first molecular distillation device comprises a primary molecular distillation column, a primary collector, a one-, two-, and three-ester precipitation tank, a one-, two-, and three-ester discharge pump and a storage tank, the top of the primary molecular distillation column is connected to the distillation process feed pump, the upper part of the primary molecular distillation column is connected to the primary collector, the bottom of the primary collector is connected to the one-, two-, and three-ester precipitation tank, and the one-, two-, and three-ester precipitation tank is connected to the storage tank through the one-, two-, and three-ester discharge pump.

[0021] Preferably, the second molecular distillation device comprises a secondary distillation column, a secondary collector, and a di- and tri-ester precipitation tank I, the top of the secondary molecular distillation column is connected to the bottom of the primary molecular distillation column, the lower part of the secondary molecular distillation column is connected to the secondary collector, the bottom of the secondary molecular distillation column is connected to a di- and tri-ester precipitation tank, and the lower part of the secondary molecular distillation column is connected to the di- and tri-ester precipitation tank I.

[0022] Preferably, the third molecular distillation device comprises a three-stage molecular distillation column, a three-stage collector, and a three- and four-ester precipitation tank. The top of the three-stage molecular distillation column is connected to the two- and three-ester precipitation tank I, the three-stage collector is connected to the lower part of the three-stage molecular distillation column, the three- and four-ester precipitation tank is connected to the lower part of the three-stage molecular distillation column, the bottom of the three-stage molecular distillation column is connected to the one-, two- and three-ester precipitation tanks, the two- and three-stage gas cylinders are connected to the three-stage collector, and the two- and three-stage hot oil pumps are connected to the middle of the three-stage molecular distillation column.

[0023] Preferably, the fourth molecular distillation device comprises a four-stage molecular distillation column, a four-stage trap, a booster pump, and an ester distillation buffer tank. The top of the four-stage molecular distillation column is connected to the three- and four-ester precipitation tanks, and the lower part of the distillation column is respectively connected to the four-stage trap and the ester distillation buffer tank.

[0024] Preferably, the fourth molecular distillation device further comprises a di-tri-ester precipitation tank II, a di-tri-ester discharge pump and a storage tank, the bottom of the quaternary molecular distillation column is connected to the di-tri-ester precipitation tank II, and the di-tri-ester precipitation tank II is connected to the storage tank via the di-tri-ester discharge pump.

[0025] Preferably, the distillation device of lauric acid monoglyceride includes three fourth molecular distillation devices.

[0026] The powder spraying device of monoglyceride of lauric acid comprises a distilled ester temporary storage tank, a distilled ester circulation tank, a distilled ester circulation pump, a distilled ester standing tank, a distilled ester storage tank, a powder spraying pump, a powder spraying tower and an air cooler, wherein the distilled ester temporary storage tank is connected to the distilled ester discharge pump, the distilled ester circulation tank is respectively connected to the distilled ester circulation pump and the distilled ester standing tank, the distilled ester standing tank is sequentially connected to the distilled ester storage tank, the powder spraying pump and the powder spraying tower, and the air cooler is located at the lower part of the powder spraying tower, and is directed from bottom to top toward the powder spraying tower.

[0027] Preferably, the powder spraying device of monoglyceride of lauric acid further comprises a rotary vibrating screen, and the rotary vibrating screen is used to further screen the produced finished monoglyceride of lauric acid powder.

[0028] The second object of the present invention is achieved by the following technical solutions:

[0029] A method for preparing lauric acid monoglyceride, the specific steps are as follows:

[0030] (1) mixing lauric acid and glycerol in a molar ratio of 1:1 to 3 and preheating the mixture, adding the mixture into a lauric acid monoglyceride preparation device, reacting under nitrogen or carbon dioxide protection conditions to produce a lauric acid monoglyceride primary product containing 50% to 55% of lauric acid monoglyceride;

[0031] (2) subjecting the initial product of monolaurin in step (1) to four-stage molecular distillation to obtain monolaurin with a purity of 96% to 99%.

[0032] Preferably, the specific process flow of step (1) is:

[0033] The lauric acid and glycerol are arranged in a molar ratio of 1:1-3, the gas phase loop of the loop reactor is opened, the nitrogen or carbon dioxide is replaced in the system at least twice, and the nitrogen or carbon dioxide pressure of the entire loop reactor system is maintained at -0.09MPa-0.2MPa, glycerol flows in through the glycerol inlet at the top of the reaction tank, and lauric acid flows in through the lauric acid inlet at the upper part of the reaction tank. Glycerol and lauric acid are mixed and heated in the reaction tank under the action of the loop reaction mixer, and the temperature in the reaction tank is controlled to be 160-240°C; the gas generated in the reaction tank and the unreacted glycerol enter the primary condenser from the upper part of the reaction tank for condensation, the unreacted glycerol returns to the reaction tank to continue to participate in the reaction, and the uncondensed gas passes through the secondary condenser and the tertiary condenser, so that the water in the reaction by-product is collected in the secondary condenser receiving tank and the tertiary condenser receiving tank, and the primary condenser (1001) in the gas phase loop is controlled. The temperature is 100 degrees, the temperature of the secondary condenser (1002) is 60 degrees, and the temperature of the tertiary condenser (1003) is 30 degrees; the glycerol and lauric acid materials at the bottom of the reaction tank are continuously pumped into the external circulation heat exchanger through a loop circulation pump for heat exchange; the gas after heat exchange enters the reaction tank through the top of the reaction tank; the loop reaction time is 2 to 8 hours, and when the pH detection device at the bottom of the reaction tank detects that the acid value of the product is reduced to below 5, the reaction is terminated; the loop circulation pump pumps the crude product of lauric acid monoglyceride at the bottom of the reaction tank into a sedimentation and liquid separation tank, cools the temperature to 160 to 170°C, separates by sedimentation, and filters the supernatant to obtain a primary product of lauric acid monoglyceride containing 50% to 55% of lauric acid monoglyceride.

[0034] Preferably, the heat transfer oil is introduced through the heat transfer oil inlet at the lower part of the external circulation heat exchanger and flows out from the heat transfer oil outlet at the upper part of the external circulation heat exchanger to perform heat exchange.

[0035] Preferably, the glycerol and lauric acid are mixed and reacted under the action of a loop reaction mixer.

[0036] Preferably, in step (1), the molar ratio of lauric acid to glycerol is 1:1, the reaction pressure of the reaction tank is 0.08 MPa, the reaction temperature is 235° C., the reaction time is 5 h, the temperature is lowered to 160° C., and the mixture is separated by sedimentation.

[0037] Preferably, in step (1), the molar ratio of lauric acid to glycerol is 1:1.5, the reaction pressure of the reaction tank is 0.05 MPa, the reaction temperature is 225° C., the reaction time is 6 h, the temperature is lowered to 160° C., and the mixture is separated by sedimentation.

[0038] Preferably, in step (1), the molar ratio of lauric acid to glycerol is 1:2, the reaction pressure of the reaction tank is -0.01 MPa, the reaction temperature is 215° C., the reaction time is 4 h, the temperature is lowered to 160° C., and the mixture is separated by sedimentation.

[0039] Preferably, in step (1), the molar ratio of lauric acid to glycerol is 1:3, the reaction pressure of the reaction tank is -0.08 MPa, the reaction temperature is 205° C., the reaction time is 8 h, the temperature is lowered to 170° C., and the mixture is separated by sedimentation.

[0040] Preferably, the specific process flow of the step (2) of subjecting the initial product of lauric acid monoglyceride to four-stage molecular distillation is as follows:

[0041] The primary molecular distillation process: the primary product of lauric acid monoglyceride separated in the step (1) enters from the top of the primary molecular distillation column through the distillation process feed pump, and dehydration, degassing and glycerin process are carried out in the primary molecular distillation column, wherein the reaction temperature is 130-150° C., the vacuum degree is 200-300 Pa, the gaseous component is condensed by the primary collector, and then enters the monoester, diester and triester precipitation tank through the bottom of the primary collector, and the liquid component enters the secondary molecular distillation column through the bottom of the primary molecular distillation column;

[0042] Secondary molecular distillation process: the crude ester dehydrated and vaporized by the primary molecular distillation column enters the secondary molecular distillation column for further separation of glycerol, wherein the reaction temperature is 150-165°C, the vacuum degree is 150-190Pa, the gaseous components are condensed through the secondary collector, the heavier liquid components enter the monoester, diester and triester precipitation tank through the bottom of the secondary molecular distillation column, and the lighter liquid components enter the diester and triester precipitation tank I through the lower part of the secondary molecular distillation column for precipitation;

[0043] Three-stage molecular distillation process: After the crude glycerol ester is separated by the secondary molecular distillation column, it enters the tertiary molecular distillation column for further separation of fatty acids, wherein the reaction temperature is 165-180°C, the vacuum degree is 30-50Pa, the gaseous components are condensed through the three-stage collector, the lighter liquid phase enters the three- and four-ester precipitation tank through the lower part of the three-stage molecular distillation column, and the heavier liquid phase components enter the one-, two-, and three-ester precipitation tanks from the bottom of the distillation column;

[0044] Four-stage molecular distillation process: After the crude ester of fatty acids is separated by the three-stage molecular distillation column, it enters the four-stage molecular distillation column for further separation of triesters, wherein the reaction temperature is 170-190°C, the vacuum degree is 0-20Pa, the gaseous components enter the four-stage collector, the lighter liquid phase enters the ester distillation buffer tank, and then flows into the diester and triester precipitation tank II, and most of the monolaurin glyceride enters the ester distillation precipitation tank through the bottom of the four-stage molecular distillation column; after the four-stage distillation, monolaurin glyceride with a purity of 96% to 99% is obtained.

[0045] Preferably, the four-stage molecular distillation apparatus includes three groups.

[0046] Preferably, the method for preparing monolaurin further comprises drying the monolaurin; and storing the monolaurin in the ester distillation precipitation tank in a ester distillation temporary storage tank by means of an ester distillation discharge pump for further preparation.

[0047] Preferably, the lauric acid glyceryl ester in the ester distillation temporary storage tank is further dehydrated into the ester distillation circulation tank, and the dehydrated lauric acid monoglyceride is first temporarily stored in the ester distillation static tank, and then the lauric acid monoglyceride in the ester distillation static tank is further dehydrated by the ester distillation circulation pump until the content of lauric acid monoglyceride is less than 1%, and then the lauric acid monoglyceride with a water content of less than 1% is stored in the ester distillation storage tank, sprayed into the top of the powder spraying tower by a powder spraying pump, and further dried under the action of an air cooler to obtain the final product of lauric acid monoglyceride powder.

[0048] The third object of the present invention is achieved through the following technical solutions:

[0049] A control system for preparing monoglyceride of lauric acid comprises a computer, a temperature sensor group, a pressure sensor, a pH sensor group, a solenoid valve group, an external circulation heat exchanger, a reaction tank, a condensation component, a loop circulation pump, a primary molecular distillation device, a secondary molecular distillation device, a tertiary molecular distillation device, a quaternary molecular distillation device, a steamed ester temporary storage tank, a steamed ester circulation tank, a steamed ester static tank, a steamed ester storage tank and a powder spraying tower, wherein the temperature sensor group comprises at least fourteen temperature sensors, the pressure sensor group comprises at least eight pressure sensors, the pH sensor group comprises at least one pH sensor, and the solenoid valve group comprises at least fourteen solenoid valves;

[0050] A temperature sensor, a pressure sensor and a solenoid valve are arranged on the connecting pipe between the top of the reaction tank and the top of the external circulation heat exchanger; a temperature sensor, a pressure sensor, a pH sensor and a solenoid valve are arranged on the connecting pipe between the bottom of the reaction tank and the loop circulation pump; a temperature sensor, a pressure sensor and a solenoid valve are arranged in the middle of the reaction tank and connected to the bottom of the condensation component; a temperature sensor, a pressure sensor and a solenoid valve are arranged on the pipe connecting the condensation component and the top of the reaction tank; a temperature sensor is arranged on the external circulation heat exchanger; a temperature sensor, a pressure sensor and a solenoid valve are arranged on the first-level molecular distillation device; a temperature sensor, a pressure sensor and a solenoid valve are arranged on the second-level molecular distillation device; a temperature sensor, a pressure sensor and a solenoid valve are arranged on the third-level Molecular distillation device; a temperature sensor, a pressure sensor and a solenoid valve are arranged in a four-stage molecular distillation device; a temperature sensor and a solenoid valve are arranged in a steam ester temporary storage tank; a temperature sensor and a solenoid valve are arranged in a steam ester circulation tank; a temperature sensor and a solenoid valve are arranged in a steam ester static tank; a temperature sensor and a solenoid valve are arranged in a steam ester storage tank; a temperature sensor and a solenoid valve are arranged in a powder spraying tower; the computer is respectively connected with the temperature sensor group, the pressure sensor, the pH sensor group, the solenoid valve group, the external circulation heat exchanger, the reaction tank, the condensation component, the loop circulation pump, the first-stage molecular distillation device, the second-stage molecular distillation device, the third-stage molecular distillation device, the fourth-stage molecular distillation device, the steam ester temporary storage tank, the steam ester circulation tank, the steam ester static tank, the steam ester storage tank and the powder spraying tower, and is used to control the entry and exit of materials and the delivery of cooling water and heat transfer oil.

[0051] Preferably, the temperature sensor and the pressure sensor are connected to a computer and are arranged in an external circulation heat exchanger, a reaction tank, a condensation assembly, a primary molecular distillation device, a secondary molecular distillation device, a tertiary molecular distillation device, a quaternary molecular distillation device, a distilled ester temporary storage tank, a distilled ester circulation tank, a distilled ester standing tank, a distilled ester storage tank and a powder spraying tower.

[0052] Preferably, the pH sensor is connected to a computer and is disposed in a reaction tank.

[0053] Preferably, the control system for preparing lauric acid monoglyceride further comprises an alarm, and the alarm is connected to a computer.

[0054] The fourth object of the present invention is achieved by the following technical solutions:

[0055] A control method for preparing monoglyceride of lauric acid, wherein a computer is provided with thirteen loops, wherein a control valve for controlling the inlet and outlet of materials in a reaction tank is controlled according to the temperature and pressure value at the top of the reaction tank, a control valve for controlling the inlet and outlet of materials in the reaction tank is controlled according to the pH value at the bottom of the reaction tank, a control valve for controlling the external circulation heat exchanger and a bottom valve of the reaction tank are controlled in linkage according to the pH value at the bottom of the reaction tank, a main control valve for controlling the condenser and a gas phase discharge valve of the middle reaction tank are controlled in linkage according to the temperature and pressure value at the middle of the reaction tank, a heating steam valve for controlling the external circulation heat exchanger is controlled according to the temperature and pressure value at the bottom of the reaction tank, a control valve for controlling the inlet and outlet of materials in a primary molecular distillation column is controlled according to the temperature and pressure value of a primary molecular distillation device, and a control valve for controlling the inlet and outlet of materials in a secondary molecular distillation device is controlled according to the temperature and pressure value of a secondary molecular distillation device. The control valve for the inlet and outlet of the first-stage molecular distillation column materials, the control valve for controlling the inlet and outlet of the third-stage molecular distillation column materials according to the temperature and pressure value of the third-stage molecular distillation device, the control valve for controlling the inlet and outlet of the fourth-stage molecular distillation column materials according to the temperature and pressure value of the fourth-stage molecular distillation device, the control valve for controlling the inlet and outlet of the ester distillation temporary storage tank materials according to the temperature of the ester distillation temporary storage tank, the control valve for controlling the inlet and outlet of the ester distillation circulating tank materials according to the temperature of the ester distillation circulating tank, the control valve for controlling the inlet and outlet of the ester distillation static tank materials according to the temperature of the ester distillation static tank, the control valve for controlling the inlet and outlet of the ester distillation storage tank materials according to the temperature of the ester distillation storage tank, and the control valve for controlling the inlet and outlet of the ester distillation storage tank materials according to the temperature of the powder spraying tower.

[0056] Preferably, the computer control method includes the following steps: first, initialize the computer; set the interrupt mode and interrupt program, and accept the interrupt action according to the program setting; set the count value of the control point; collect the parameters of the control point at regular time intervals, and the computer performs a programmed comparison and judgment on the collected parameters; if it is judged that there is an excess, control the valve opening; if there is no excess, directly execute the next display program; repeat the above control process to dynamically adjust the status of all collection points.

[0057] Preferably, for every 0 to +n degrees Celsius or pressure 0 to +mMPa or PH 0 to +f beyond the allowable temperature, the computer calculates it as a +1 level deviation; for every -n to 0 degrees Celsius or pressure -m to 0MPa or PH-f to 0 beyond the allowable lower limit, it is calculated as a -1 level deviation, wherein n and m are arbitrary values; f is 0 to 14; the computer calculates the temperature, pressure and PH deviations, and according to each level of deviation, it can drive the corresponding original position to produce an upward or downward displacement, thereby changing the size of the controlled valve.

[0058] Preferably, when the control point parameters are for linkage control of multiple valves, the priority controlled valve and the cooperative controlled valve are set; the priority controlled valve is first adjusted in valve size, and its valve opening value is the difference between the total valve opening calculated by the computer and the product of the cooperative controlled valve opening and the relative impact system.

[0059] Preferably, the sampling method of the computer is set to take 1 minute as the sampling period of the control parameter, and perform limiting filtering, and then use median filtering, and repeat this 5 to 10 times, and take the average value as the result of each sampling period.

[0060] Principle of the invention:

[0061] This process uses molecular distillation. The temperature of the distillation process is low. As long as there is a temperature difference, the separation purpose can be achieved; the distillation vacuum degree is high, so the material is not easily oxidized and damaged; the distillation liquid film is thin, the heat transfer efficiency is high, the product energy consumption is small, the heat loss in the entire separation process of molecular distillation is small, the internal pressure is extremely low, and energy consumption can be greatly saved; the material is heated for a short time, and the residence time at the distillation temperature is generally between a few seconds and tens of seconds, which reduces the chance of thermal decomposition of the material; the degree of separation is higher, and molecular distillation can separate conventional substances that are difficult to separate; molecular distillation has no boiling and bubbling phenomenon. Molecular distillation is free evaporation on the surface of the liquid layer, which is carried out under low pressure. There is no dissolved air in the liquid, so the entire liquid cannot be boiled during the distillation process, and there is no bubbling phenomenon; the entire production process is non-toxic, harmless, pollution-free, and residue-free, and pure and safe products can be obtained; the target product can be selectively evaporated, other impurities can be removed, and more than two substances can be separated at the same time through multi-stage separation; the fractionation process of molecular distillation is a physical process, so it can well protect the separated substances from pollution and damage.

[0062] Molecular distillation of monoglyceride laurate is to separate small molecules such as unreacted glycerol and lauric acid from large molecules such as monoglyceride and diglyceride by molecular distillation under high temperature and high vacuum conditions. Then the separated glyceride is subjected to secondary separation to further separate small molecules such as unreacted glycerol and lauric acid, so that monoglyceride and diglyceride are separated under appropriate temperature and vacuum conditions, and then tertiary separation and purification of monoglyceride laurate and diglyceride are carried out. The purity of the monoglyceride obtained after the separation of monoglyceride laurate and diglyceride reaches more than 96%, which not only meets the food grade requirements, but also has excellent antiseptic properties with high purity. It can be used in special products that need to add preservatives, and has broad market prospects.

[0063] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0064] (1) This process adopts a method for preparing monoglyceride of lauric acid without using a catalyst. Its advantage is that no phosphate is produced during the preparation process, which solves the environmental pollution problem caused by phosphate in the current traditional process and can reduce production costs.

[0065] (2) In the reaction process of this process, more than 99.5% nitrogen or high-purity carbon dioxide is used as the protective gas, which is non-toxic, harmless, non-combustible, pollution-free, easy to recover and recycle. It is an environmentally friendly green gas and can effectively prevent the decomposition and darkening of saturated fatty acids at high temperatures, and reduce the odor and smell of the product.

[0066] (3) Conventional alkaline catalyst reactions generally produce phosphate and ester compounds accounting for about 1% of the total material volume, which affects product quality and must be discharged, causing environmental pollution.

[0067] (4) Molecular distillation is a distillation under non-equilibrium conditions, which has advantages that conventional distillation cannot match. Molecular distillation has the advantages of high vacuum, low operating temperature, low vapor pressure, removal of impurities and color in raw materials or products, reduction of thermal damage to heat-sensitive substances, short heating time of separated substances, high product quality and yield, clean and environmentally friendly process, etc. It can solve problems that traditional distillation cannot solve, and has a very broad application prospect.

[0068] (5) The preparation process of the present invention adopts a loop reaction device to replace the traditional stirred tank. The traditional stirred tank is strengthened by mechanical stirring and gas bubbling. The temperature difference between the bottom and top liquid levels of the material in the reactor is usually 7 to 15 degrees, which will cause uneven molecular weight distribution and many by-products. The reaction device of monoglyceride of lauric acid of the present invention adopts a venturi ejector and an external circulation heat exchanger. The venturi ejector is the core of the loop reactor. The material temperature is almost the same, there are few by-products, and the molecular weight distribution is uniform; it solves the problem of mass transfer and heat transfer in the gas-liquid-solid three-phase reaction during the reaction process; further, the loop reactor has a high reaction efficiency, which is about 3 times that of a kettle reaction, and can shorten the production cycle by more than 50%; compared with the reaction Comparison of kettles: Since there is no rotating equipment such as mechanical stirring, leakage is avoided, static electricity will not be generated, and safety performance is good; the traditional stirred kettle is strengthened by mechanical stirring and gas bubbling; the power consumption of the loop reactor is mainly the circulation pump, the reaction mainly occurs in the mixing nozzle, and the close mixing of the reaction zone produces a uniform temperature and concentration distribution; the loop reaction mixer can be any of a spray mixer, a jet mixer or a Venturi mixer; the product obtained by the loop reaction is of good quality, uniform molecular weight distribution, small temperature difference, crude ester content up to 55%, light color, reaction time can be shortened by 50%, and the safety factor is high. The reactor has poor mass transfer effect, many reaction by-products, dark product color, strong odor, and long reaction time.

[0069] (6) The preparation device of monoglyceride of lauric acid of the present invention uses a computer to collect temperature at 14 points, pressure at 8 points and pH at 1 point, and simultaneously controls the opening of 14 valves. The preparation device of monoglyceride of lauric acid has a high level of automation, and the collected data is comprehensive and accurate. It performs multi-dimensional analysis and control of temperature, pressure and pH, thereby improving product quality and production efficiency.

[0070] (7) The control system of the present invention adopts multi-point temperature acquisition, multi-point pressure acquisition and PH inspection devices, and adopts a control model of multiple control loops. The valve control between multiple control loops adopts a priority method, sets the influence system between valves, and sets the opening of the priority valve according to the coefficient. This precise control method reduces the mutual influence between the control loops. Compared with a single control loop, the controlled quantity of each control loop achieves high precision, eliminating the influence of a single system control on the overall system. In this way, the purpose of precise control, increased production and optimized product quality can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Figure 1 The process flow chart for preparing the crude product of monoglyceride of lauric acid;

[0072] Figure 2 The process flow chart for preparing 96% to 99% lauric acid monoglyceride;

[0073] Figure 3 It is a production device for monoglyceride of lauric acid;

[0074] Figure 4 The first molecular distillation device to the third molecular distillation device in the distillation device of monoglyceride of lauric acid;

[0075] Figure 5 It is the fourth molecular distillation device in the distillation device of monoglyceride of lauric acid;

[0076] Figure 6 A powder spraying device for lauric acid monoglyceride;

[0077] Figure 7 The present invention is a process flow chart of the control method for preparing monoglyceride of lauric acid.

[0078] Among them, vacuum port-1, glycerol inlet-2, lauric acid inlet-3, cooling water inlet-4, cooling water outlet-5, heat transfer oil outlet-6, heat transfer oil inlet-7, external circulation heat exchanger-8, loop circulation pump-9, first-stage condenser-1001, second-stage condenser-1002, third-stage condenser-1003, first-stage condenser receiving tank-1101, second-stage condenser receiving tank-1102, third-stage condenser receiving tank-1103, loop reaction mixer-12, reaction tank-13, sedimentation separation tank-14, insulation coil-15, distillation process feed pump-16, first-stage molecular distillation column-17, first-stage collector-18, mono-, di- and tri-ester precipitation tank-19, mono-, di- and tri-ester discharge pump -20, the first material storage tank -21, the secondary molecular distillation column -22, the secondary collector -23, the diester and triester precipitation tank I -24, the tertiary molecular distillation column -25, the tertiary collector -26, the triester and tetraester precipitation tank -27, the quaternary molecular distillation column -28, the quaternary collector -29, the ester distillation buffer tank -30, the diester and triester precipitation tank II -31, the diester and triester discharge pump -32, the second material storage tank -33, the ester distillation precipitation tank -34, the ester distillation discharge pump -35, the ester distillation temporary storage tank -36, the flow meter -37, the ester distillation circulation tank -38, the ester distillation circulation pump -39, the ester distillation standing tank -40, the ester distillation storage tank -41, the powder injection pump -42, the powder injection tower -43, the air cooler -44, the rotary vibrating screen -45. DETAILED DESCRIPTION

[0079] The present invention is further described in detail below in conjunction with examples and drawings, but the embodiments of the present invention are not limited thereto.

[0080] The purpose of the present invention is to address the phosphate problem (environmental pollution) caused by the above-mentioned prior art, and to provide a method for preparing monolaurin glyceride by esterifying glycerol and lauric acid at high temperature under nitrogen or carbon dioxide conditions. The method does not use a catalyst, so no phosphate is generated during the reaction process. The reaction equipment is fully enclosed, environmentally friendly, and can reduce production costs. The monoester content detection method of Examples 2 to 5 is determined according to GB1886.65-2015.

[0081] Example 1

[0082] In this embodiment, the preparation device of monoglyceride of lauric acid includes a production device of monoglyceride of lauric acid, a distillation device of monoglyceride of lauric acid and a powder spraying device of monoglyceride of lauric acid.

[0083] like Figure 3The figure shows a production device for monoglyceride of lauric acid, including an external circulation heat exchanger, a reaction tank, a condensation component, a loop circulation pump, a valve and a detection device. A loop reaction mixer (a gas-liquid contact reactor-spray mixer created by the Italian PRESS company) is arranged in the reaction tank. The top of the external circulation heat exchanger is connected to the loop reaction mixer, the bottom of the external circulation heat exchanger is connected to the bottom of the reaction tank through a loop circulation pump, and the top of the reaction tank is connected to the condensation component; the top of the reaction tank is connected to the external circulation heat exchanger through a pipeline, a feed pipeline and a feed valve are arranged on the top of the reaction tank, and a discharge pipeline and a bottom valve are arranged on the bottom; a pressure detection device and a temperature detection device are arranged on the top, middle and bottom of the reaction tank, and a pH detection device is arranged on the bottom of the reaction tank; the top of the reaction tank is connected to the external circulation heat exchanger and the condensation component through a pipeline to form a gas phase loop (monoglyceride of lauric acid loop), the external circulation heat exchanger is provided with a temperature detection device, and the upper part of the condensation component is provided with a temperature detection device and a pressure detection device; the pressure detection device, the temperature detection device and the pH detection device are all electrically connected to the computer.

[0084] In the device of the present invention, a gas phase discharge valve is arranged on the pipeline connecting the middle part of the reaction tank and the condensation component, a control valve is arranged on the external circulation heat exchanger, and a main control valve is arranged on the condensation component; the condensation component comprises a primary condenser, a secondary condenser, a tertiary condenser, a primary condenser receiving tank, a secondary condenser receiving tank and a tertiary condenser receiving tank; a cooling water outlet is arranged on the upper part of the primary condenser, the top of the primary condenser is connected with the upper condensation water inlet of the secondary condenser receiving tank, a cooling water inlet is arranged on the lower part of the primary condenser, and the cooling water condenses the gas from bottom to top; a cooling water outlet is arranged on the upper part of the secondary condenser, the top of the secondary condenser is connected with the upper condensation water inlet of the tertiary condenser receiving tank, a cooling water inlet is arranged on the lower part of the secondary condenser, and the cooling water condenses the gas from bottom to top; a cooling water outlet is arranged on the upper part of the tertiary condenser, and a cooling water inlet and outlet are arranged on the lower part of the tertiary condenser; the condensation water inlet on the upper part of the primary condenser receiving tank is connected to the upper part of the reaction tank.

[0085] The top of the reaction tank of the device of the present invention is provided with a vacuum port, a glycerol inlet and a gas phase outlet, the upper part is provided with a lauric acid inlet, the middle part is also provided with a material outlet, and the bottom is provided with a heat-insulating coil; the material outlet of the reaction tank is connected to the bottom of the secondary condenser receiving tank; the upper part of the external circulation heat exchanger is provided with a heat transfer oil outlet and the lower part is provided with a heat transfer oil inlet, the top of the external circulation heat exchanger is connected to the top of the reaction tank, and the bottom of the external circulation heat exchanger is connected to the bottom of the reaction tank; the preparation device of monoglyceride of lauric acid also includes a sedimentation separation tank, and the upper part of the sedimentation separation tank is connected to the bottom of the reaction tank through a pipeline and a loop circulation pump.

[0086] In this embodiment, Figures 4 to 5As shown, the distillation device of monoglyceride of lauric acid includes a distillation process feed pump, a first molecular distillation device, a second molecular distillation device, a third molecular distillation device, a fourth molecular distillation device, a distilled ester discharge pump, and a distilled ester precipitation tank. The first molecular distillation device, the second molecular distillation device, the third molecular distillation device and the fourth molecular distillation device are arranged in sequence.

[0087] In the device of the present invention, the first molecular distillation device comprises a primary molecular distillation column, a primary trap, a one, two, three ester precipitation tank, a one, two, three ester discharge pump and a storage tank, the top of the primary molecular distillation column is connected to the distillation process feed pump, the upper part of the primary molecular distillation column is connected to the primary trap, the bottom of the primary trap is connected to the one, two, three ester precipitation tank, and the one, two, three ester precipitation tank is connected to the storage tank through the one, two, three ester discharge pump;

[0088] The second molecular distillation device includes a secondary distillation column, a secondary trap, and a di-tri-ester precipitation tank I, wherein the top of the secondary molecular distillation column is connected to the bottom of the primary molecular distillation column, the lower part of the secondary molecular distillation column is connected to the secondary trap, the bottom of the secondary molecular distillation column is connected to the one, two, and three ester precipitation tanks, and the lower part of the secondary molecular distillation column is connected to the di-tri-ester precipitation tank I;

[0089] The third molecular distillation device comprises a three-stage molecular distillation column, a three-stage collector, and a three- and four-ester precipitation tank. The top of the three-stage molecular distillation column is connected to the two- and three-ester precipitation tank I, the three-stage collector is connected to the lower part of the three-stage molecular distillation column, the three- and four-ester precipitation tank is connected to the lower part of the three-stage molecular distillation column, the bottom of the three-stage molecular distillation column is connected to the one-, two- and three-ester precipitation tanks, the two- and three-stage gas cylinders are connected to the three-stage collector, and the two- and three-stage hot oil pumps are connected to the middle of the three-stage molecular distillation column;

[0090] The fourth molecular distillation device includes a four-stage molecular distillation column, a four-stage trap, a booster pump, and an ester distillation buffer tank. The top of the four-stage molecular distillation column is connected to the three- and four-ester precipitation tanks, and the lower part of the distillation column is respectively connected to the four-stage trap and the ester distillation buffer tank;

[0091] Preferably, the fourth molecular distillation device further comprises a di-tri-ester precipitation tank II, a di-tri-ester discharge pump and a storage tank, the bottom of the quaternary molecular distillation column is connected to the di-tri-ester precipitation tank II, and the di-tri-ester precipitation tank II is connected to the storage tank via the di-tri-ester discharge pump.

[0092] As another preferred solution, the distillation device of lauric acid monoglyceride includes three fourth molecular distillation devices.

[0093] In the present embodiment, the powder spraying device of monoglyceride of lauric acid includes a steam ester temporary storage tank, a steam ester circulation tank, a steam ester circulation pump, a steam ester standing tank, a steam ester storage tank, a powder spraying pump, a powder spraying tower and an air cooler. The steam ester temporary storage tank is connected to the steam ester discharge pump, the steam ester circulation tank is respectively connected to the steam ester circulation pump and the steam ester standing tank, the steam ester standing tank is sequentially connected to the steam ester storage tank, the powder spraying pump and the powder spraying tower, and the air cooler is located at the lower part of the powder spraying tower, from bottom to top toward the powder spraying tower.

[0094] Preferably, the powder spraying device of monoglyceride of lauric acid further comprises a rotary vibrating screen, and the rotary vibrating screen is used to further screen the produced finished monoglyceride of lauric acid powder.

[0095] Example 2

[0096] The preparation method of lauric acid monoglyceride in this embodiment, the specific steps are as follows:

[0097] (1) Figures 1 to 6 As shown, lauric acid and glycerol are configured in a molar ratio of 1:1, the gas phase loop of the loop reactor is opened, nitrogen or carbon dioxide is replaced in the system at least twice, and the nitrogen or carbon dioxide pressure of the entire loop reactor system is maintained at 0.08MPa. Glycerol flows in through the glycerol inlet at the top of the reaction tank, and lauric acid flows in through the lauric acid inlet at the upper part of the reaction tank. Glycerol and lauric acid are mixed and heated in the reaction tank under the action of the loop reaction mixer to react, and the temperature in the reaction tank is controlled to be 160~ 240℃; the gas generated in the reaction tank and the unreacted glycerol enter the first-stage condenser from the upper part of the reaction tank for condensation, the unreacted glycerol returns to the reaction tank to continue to participate in the reaction, and the uncondensed gas passes through the second-stage condenser and the third-stage condenser, so that the water in the reaction by-product is collected in the second-stage condenser receiving tank and the third-stage condenser receiving tank, and the temperature of the first-stage condenser in the gas phase loop is controlled to be 100 degrees, the temperature of the second-stage condenser is 60 degrees, and the temperature of the third-stage condenser is 30 degrees; the glycerol and lauric acid materials at the bottom of the reaction tank are continuously pumped into the external circulation heat exchanger for heat exchange through the loop circulation pump; the gas after heat exchange enters the reaction tank through the top of the reaction tank again; the loop reaction time is 5h, and when the pH detection device at the bottom of the reaction tank detects that the acid value of the product is reduced to below 5, the reaction is terminated; the loop circulation pump pumps the crude product of lauric acid monoglyceride at the bottom of the reaction tank into the sedimentation separation tank, cools it to 160℃, sediments and separates, and filters and takes the supernatant to obtain the initial product of lauric acid monoglyceride containing 51.9% of lauric acid monoglyceride.

[0098] (2) then subjecting the primary product of monoglyceride of lauric acid in step (1) to a four-stage molecular distillation, wherein the specific distillation process is a primary molecular distillation process: the primary product of monoglyceride of lauric acid separated in step (1) enters from the top of a primary molecular distillation column through a distillation process feed pump, and undergoes a dehydration, degassing and glycerol process in the primary molecular distillation column, wherein the reaction temperature is 150 to 165° C., the vacuum degree is 150 to 190 Pa, the gaseous component is condensed by a primary collector, and then enters a monoester, a diester and a triester precipitation tank through the bottom of the primary collector, and the liquid component enters a secondary molecular distillation column through the bottom of the primary molecular distillation column;

[0099] Secondary molecular distillation process: the crude ester dehydrated and vaporized by the primary molecular distillation column enters the secondary molecular distillation column for further separation of glycerol, wherein the reaction temperature is 165-180°C, the vacuum degree is 30-50Pa, the gaseous components are condensed through the secondary collector, the heavier liquid components enter the one, two, and three ester precipitation tank through the bottom of the secondary molecular distillation column, and the lighter liquid components enter the two and three ester precipitation tank I through the lower part of the secondary molecular distillation column for precipitation;

[0100] Three-stage molecular distillation process: After the crude glycerol ester is separated by the secondary molecular distillation column, it enters the tertiary molecular distillation column for further separation of fatty acids, wherein the reaction temperature is 170-190°C, the vacuum degree is 0-20Pa, the gaseous components are condensed through the three-stage collector, the lighter liquid phase enters the three- and four-ester precipitation tank through the lower part of the three-stage molecular distillation column, and the heavier liquid phase components enter the one-, two-, and three-ester precipitation tanks from the bottom of the distillation column;

[0101] Four-stage molecular distillation process: After the crude ester of fatty acids is separated by the three-stage molecular distillation column, it enters the four-stage molecular distillation column for further separation of triesters, wherein the reaction temperature is 170-190°C, the vacuum degree is 0-20Pa, the gaseous phase component enters the four-stage collector, the lighter liquid phase enters the ester distillation buffer tank, and then flows into the diester and triester precipitation tank II, and most of the monolaurin glyceride enters the ester distillation precipitation tank through the bottom of the four-stage molecular distillation column; after the four-stage distillation, lauric acid monoglyceride with a purity of 97.2% is obtained (according to GB1886.65-2015).

[0102] Preferably, the four-stage molecular distillation apparatus includes three groups.

[0103] Preferably, the method for preparing monolaurin further comprises drying the monolaurin; and storing the monolaurin in the ester distillation precipitation tank in a ester distillation temporary storage tank by means of an ester distillation discharge pump for further preparation.

[0104] Preferably, the lauric acid glyceryl ester in the ester distillation temporary storage tank is further dehydrated into the ester distillation circulation tank, and the dehydrated lauric acid monoglyceride is first temporarily stored in the ester distillation static tank, and then the lauric acid monoglyceride in the ester distillation static tank is further dehydrated by the ester distillation circulation pump until the content of lauric acid monoglyceride is less than 1%, and then the lauric acid monoglyceride with a water content of less than 1% is stored in the ester distillation storage tank, sprayed into the top of the powder spraying tower by a powder spraying pump, and further dried under the action of an air cooler to obtain the final product of lauric acid monoglyceride powder.

[0105] Example 3

[0106] The preparation method of lauric acid monoglyceride in this embodiment, the specific steps are as follows:

[0107] (1) Figures 1 to 6 As shown, lauric acid and glycerol are configured in a molar ratio of 1:1.5, the gas phase loop of the loop reactor is opened, nitrogen or carbon dioxide is replaced in the system at least twice, and the nitrogen or carbon dioxide pressure of the entire loop reactor system is maintained at 0.05MPa. Glycerol flows in through the glycerol inlet at the top of the reaction tank, and lauric acid flows in through the lauric acid inlet at the upper part of the reaction tank. Glycerol and lauric acid are mixed and heated in the reaction tank under the action of the loop reaction mixer, and the temperature in the reaction tank is controlled to be 225°C; the gas generated in the reaction tank and the unreacted glycerol enter the primary condenser from the upper part of the reaction tank for condensation, and the unreacted glycerol returns to the reaction tank to continue to participate in the reaction. The uncondensed gas passes through the secondary condenser and the tertiary condenser, so that the reaction by-products The water in the reaction tank is collected in the secondary condenser receiving tank and the tertiary condenser receiving tank, and the temperature of the primary condenser in the gas phase loop is controlled at 100 degrees, the temperature of the secondary condenser is 60 degrees, and the temperature of the tertiary condenser is 30 degrees; the glycerol and lauric acid materials at the bottom of the reaction tank are continuously pumped into the external circulation heat exchanger for heat exchange through the loop circulation pump; the gas after heat exchange enters the reaction tank through the top of the reaction tank; the loop reaction time is 6 hours, and when the pH detection device at the bottom of the reaction tank detects that the acid value of the product is reduced to below 5, the reaction is terminated; the loop circulation pump pumps the crude product of monoglyceride of lauric acid at the bottom of the reaction tank into the sedimentation separation tank, cools it to 160°C, separates it by sedimentation, and filters the supernatant to obtain the initial product of monoglyceride of lauric acid containing 53.6% of monoglyceride of lauric acid.

[0108] (2) then subjecting the primary product of monoglyceride of lauric acid in step (1) to a four-stage molecular distillation, wherein the specific distillation process is a primary molecular distillation process: the primary product of monoglyceride of lauric acid separated in step (1) enters from the top of a primary molecular distillation column through a distillation process feed pump, and undergoes a dehydration, degassing and glycerol process in the primary molecular distillation column, wherein the reaction temperature is 130 to 150° C., the vacuum degree is 200 to 300 Pa, the gaseous component is condensed by a primary collector, and then enters a one, two, and three ester precipitation tank through the bottom of the primary collector, and the liquid component enters a secondary molecular distillation column through the bottom of the primary molecular distillation column;

[0109] Secondary molecular distillation process: the crude ester dehydrated and vaporized by the primary molecular distillation column enters the secondary molecular distillation column for further separation of glycerol, wherein the reaction temperature is 150-165°C, the vacuum degree is 150-190Pa, the gaseous components are condensed through the secondary collector, the heavier liquid components enter the monoester, diester and triester precipitation tank through the bottom of the secondary molecular distillation column, and the lighter liquid components enter the diester and triester precipitation tank I through the lower part of the secondary molecular distillation column for precipitation;

[0110] Three-stage molecular distillation process: After the crude glycerol ester is separated by the secondary molecular distillation column, it enters the tertiary molecular distillation column for further separation of fatty acids, wherein the reaction temperature is 165-180°C, the vacuum degree is 30-50Pa, the gaseous components are condensed through the three-stage collector, the lighter liquid phase enters the three- and four-ester precipitation tank through the lower part of the three-stage molecular distillation column, and the heavier liquid phase components enter the one-, two-, and three-ester precipitation tanks from the bottom of the distillation column;

[0111] Four-stage molecular distillation process: After the crude ester of fatty acids is separated by the three-stage molecular distillation column, it enters the four-stage molecular distillation column for further separation of triesters, wherein the reaction temperature is 170-190°C, the vacuum degree is 0-20Pa, the gaseous component enters the four-stage collector, the lighter liquid phase enters the ester distillation buffer tank, and then flows into the diester and triester precipitation tank II, and most of the monolaurin glyceride enters the ester distillation precipitation tank through the bottom of the four-stage molecular distillation column; after the four-stage distillation, lauric acid monoglyceride with a purity of 98.6% is obtained (according to GB1886.65-2015).

[0112] Preferably, the four-stage molecular distillation apparatus includes three groups.

[0113] Preferably, the method for preparing monolaurin further comprises drying the monolaurin; and storing the monolaurin in the ester distillation precipitation tank in a ester distillation temporary storage tank by means of an ester distillation discharge pump for further preparation.

[0114] Preferably, the lauric acid glyceryl ester in the ester distillation temporary storage tank is further dehydrated into the ester distillation circulation tank, and the dehydrated lauric acid monoglyceride is first temporarily stored in the ester distillation static tank, and then the lauric acid monoglyceride in the ester distillation static tank is further dehydrated by the ester distillation circulation pump until the content of lauric acid monoglyceride is less than 1%, and then the lauric acid monoglyceride with a water content of less than 1% is stored in the ester distillation storage tank, sprayed into the top of the powder spraying tower by a powder spraying pump, and further dried under the action of an air cooler to obtain the final product of lauric acid monoglyceride powder.

[0115] Example 4

[0116] The preparation method of lauric acid monoglyceride in this embodiment, the specific steps are as follows:

[0117] (1) Figures 1 to 6 As shown, lauric acid and glycerol are configured in a molar ratio of 1:2, the gas phase loop of the loop reactor is opened, nitrogen or carbon dioxide is replaced in the system at least twice, and the nitrogen or carbon dioxide pressure of the entire loop reactor system is maintained at -0.01MPa. Glycerol flows in through the glycerol inlet at the top of the reaction tank, and lauric acid flows in through the lauric acid inlet at the upper part of the reaction tank. Glycerol and lauric acid are mixed and heated in the reaction tank under the action of the loop reaction mixer, and the temperature in the reaction tank is controlled to be 215°C; the gas generated in the reaction tank and the unreacted glycerol enter the primary condenser from the upper part of the reaction tank for condensation, and the unreacted glycerol returns to the reaction tank to continue to participate in the reaction. The uncondensed gas passes through the secondary condenser and the tertiary condenser, so that the reaction by-products The water is collected in the secondary condenser receiving tank and the tertiary condenser receiving tank, and the temperature of the primary condenser in the gas phase loop is controlled at 100 degrees, the temperature of the secondary condenser is 60 degrees, and the temperature of the tertiary condenser is 30 degrees; the glycerol and lauric acid materials at the bottom of the reaction tank are continuously pumped into the external circulation heat exchanger for heat exchange through the loop circulation pump; the gas after heat exchange enters the reaction tank through the top of the reaction tank; the loop reaction time is 4 hours, and when the pH detection device at the bottom of the reaction tank detects that the acid value of the product is reduced to below 5, the reaction is terminated; the loop circulation pump pumps the crude product of lauric acid monoglyceride at the bottom of the reaction tank into the sedimentation separation tank, cools the temperature to 160°C, settles and separates, and filters the supernatant to obtain the initial product of lauric acid monoglyceride containing 54.8% of lauric acid monoglyceride.

[0118] (2) then subjecting the primary product of monoglyceride of lauric acid in step (1) to a four-stage molecular distillation, wherein the specific distillation process is a primary molecular distillation process: the primary product of monoglyceride of lauric acid separated in step (1) enters from the top of a primary molecular distillation column through a distillation process feed pump, and undergoes a dehydration, degassing and glycerol process in the primary molecular distillation column, wherein the reaction temperature is 130 to 150° C., the vacuum degree is 200 to 300 Pa, the gaseous component is condensed by a primary collector, and then enters a one, two, and three ester precipitation tank through the bottom of the primary collector, and the liquid component enters a secondary molecular distillation column through the bottom of the primary molecular distillation column;

[0119] Secondary molecular distillation process: the crude ester dehydrated and vaporized by the primary molecular distillation column enters the secondary molecular distillation column for further separation of glycerol, wherein the reaction temperature is 150-165°C, the vacuum degree is 150-190Pa, the gaseous components are condensed through the secondary collector, the heavier liquid components enter the monoester, diester and triester precipitation tank through the bottom of the secondary molecular distillation column, and the lighter liquid components enter the diester and triester precipitation tank I through the lower part of the secondary molecular distillation column for precipitation;

[0120] Three-stage molecular distillation process: After the crude glycerol ester is separated by the secondary molecular distillation column, it enters the tertiary molecular distillation column for further separation of fatty acids, wherein the reaction temperature is 165-180°C, the vacuum degree is 30-50Pa, the gaseous components are condensed through the three-stage collector, the lighter liquid phase enters the three- and four-ester precipitation tank through the lower part of the three-stage molecular distillation column, and the heavier liquid phase components enter the one-, two-, and three-ester precipitation tanks from the bottom of the distillation column;

[0121] Four-stage molecular distillation process: After the crude ester of fatty acids is separated by the three-stage molecular distillation column, it enters the four-stage molecular distillation column for further separation of triesters, wherein the reaction temperature is 170-190°C, the vacuum degree is 0-20Pa, the gaseous phase component enters the four-stage collector, the lighter liquid phase enters the ester distillation buffer tank, and then flows into the diester and triester precipitation tank II, and most of the monolaurin glyceride enters the ester distillation precipitation tank through the bottom of the four-stage molecular distillation column; after the four-stage distillation, monolaurin glyceride with a purity of 98.9% is obtained (the content detection method is based on GB1886.65-2015).

[0122] Preferably, the four-stage molecular distillation apparatus includes three groups.

[0123] Preferably, the method for preparing monolaurin further comprises drying the monolaurin; and storing the monolaurin in the ester distillation precipitation tank in a ester distillation temporary storage tank by means of an ester distillation discharge pump for further preparation.

[0124] Preferably, the lauric acid glyceryl ester in the ester distillation temporary storage tank is further dehydrated into the ester distillation circulation tank, and the dehydrated lauric acid monoglyceride is first temporarily stored in the ester distillation static tank, and then the lauric acid monoglyceride in the ester distillation static tank is further dehydrated by the ester distillation circulation pump until the content of lauric acid monoglyceride is less than 1%, and then the lauric acid monoglyceride with a water content of less than 1% is stored in the ester distillation storage tank, sprayed into the top of the powder spraying tower by a powder spraying pump, and further dried under the action of an air cooler to obtain the final product of lauric acid monoglyceride powder.

[0125] Example 5

[0126] The preparation method of lauric acid monoglyceride in this embodiment, the specific steps are as follows:

[0127] (1) Figures 1 to 6 As shown, lauric acid and glycerol are configured in a molar ratio of 1:3, the gas phase loop of the loop reactor is opened, nitrogen or carbon dioxide is replaced in the system at least twice, and the nitrogen or carbon dioxide pressure of the entire loop reactor system is maintained at -0.08MPa, glycerol flows in through the glycerol inlet at the top of the reaction tank, and lauric acid flows in through the lauric acid inlet at the upper part of the reaction tank. Glycerol and lauric acid are mixed and heated in the reaction tank under the action of the loop reaction mixer, and the temperature in the reaction tank is controlled to be 205°C; the gas generated in the reaction tank and the unreacted glycerol enter the primary condenser from the upper part of the reaction tank for condensation, and the unreacted glycerol returns to the reaction tank to continue to participate in the reaction. The uncondensed gas passes through the secondary condenser and the tertiary condenser, so that the reaction by-products The water is collected in the secondary condenser receiving tank and the tertiary condenser receiving tank, and the temperature of the primary condenser in the gas phase loop is controlled at 100 degrees, the temperature of the secondary condenser is 60 degrees, and the temperature of the tertiary condenser is 30 degrees; the glycerol and lauric acid materials at the bottom of the reaction tank are continuously pumped into the external circulation heat exchanger for heat exchange through the loop circulation pump; the gas after heat exchange enters the reaction tank through the top of the reaction tank; the loop reaction time is 8 hours, and when the pH detection device at the bottom of the reaction tank detects that the acid value of the product is reduced to below 5, the reaction is terminated; the loop circulation pump pumps the crude product of monoglyceride of lauric acid at the bottom of the reaction tank into the sedimentation and separation tank, cools it to 170°C, separates it by sedimentation, and filters the supernatant to obtain the initial product of monoglyceride of lauric acid containing 53.5% of monoglyceride of lauric acid.

[0128] (2) then subjecting the primary product of monoglyceride of lauric acid in step (1) to a four-stage molecular distillation, wherein the specific distillation process is a primary molecular distillation process: the primary product of monoglyceride of lauric acid separated in step (1) enters from the top of a primary molecular distillation column through a distillation process feed pump, and undergoes a dehydration, degassing and glycerol process in the primary molecular distillation column, wherein the reaction temperature is 130-150° C., the vacuum degree is 200-300 Pa, the gaseous component is condensed by a primary collector, and then enters a monoester, a diester and a triester precipitation tank through the bottom of the primary collector, and the liquid component enters a secondary molecular distillation column through the bottom of the primary molecular distillation column;

[0129] Secondary molecular distillation process: the crude ester dehydrated and vaporized by the primary molecular distillation column enters the secondary molecular distillation column for further separation of glycerol, wherein the reaction temperature is 150-165°C, the vacuum degree is 150-190Pa, the gaseous components are condensed through the secondary collector, the heavier liquid components enter the monoester, diester and triester precipitation tank through the bottom of the secondary molecular distillation column, and the lighter liquid components enter the diester and triester precipitation tank I through the lower part of the secondary molecular distillation column for precipitation;

[0130] Three-stage molecular distillation process: After the crude glycerol ester is separated by the secondary molecular distillation column, it enters the tertiary molecular distillation column for further separation of fatty acids, wherein the reaction temperature is 165-180°C, the vacuum degree is 30-50Pa, the gaseous components are condensed through the three-stage collector, the lighter liquid phase enters the three- and four-ester precipitation tank through the lower part of the three-stage molecular distillation column, and the heavier liquid phase components enter the one-, two-, and three-ester precipitation tanks from the bottom of the distillation column;

[0131] Four-stage molecular distillation process: After the crude ester of fatty acids is separated by the three-stage molecular distillation column, it enters the four-stage molecular distillation column for further separation of triesters, wherein the reaction temperature is 170-190°C, the vacuum degree is 0-20Pa, the gaseous phase component enters the four-stage collector, the lighter liquid phase enters the ester distillation buffer tank, and then flows into the diester and triester precipitation tank II, and most of the monolaurin glyceride enters the ester distillation precipitation tank through the bottom of the four-stage molecular distillation column; after the four-stage distillation, monolaurin glyceride with a purity of 97.5% is obtained (the content detection method is based on GB1886.65-2015).

[0132] Preferably, the four-stage molecular distillation apparatus includes three groups.

[0133] Preferably, the method for preparing monolaurin further comprises drying the monolaurin; and storing the monolaurin in the ester distillation precipitation tank in a ester distillation temporary storage tank by means of an ester distillation discharge pump for further preparation.

[0134] Preferably, the lauric acid glyceryl ester in the ester distillation temporary storage tank is further dehydrated into the ester distillation circulation tank, and the dehydrated lauric acid monoglyceride is first temporarily stored in the ester distillation static tank, and then the lauric acid monoglyceride in the ester distillation static tank is further dehydrated by the ester distillation circulation pump until the content of lauric acid monoglyceride is less than 1%, and then the lauric acid monoglyceride with a water content of less than 1% is stored in the ester distillation storage tank, sprayed into the top of the powder spraying tower by a powder spraying pump, and further dried under the action of an air cooler to obtain the final product of lauric acid monoglyceride powder.

[0135] Example 6

[0136] like Figures 3 to 6 The preparation device of monoglyceride of lauric acid shown in the figure, the control system for preparing monoglyceride of lauric acid described in this embodiment, includes a computer, a temperature sensor group, a pressure sensor, a pH sensor group, a solenoid valve group, an external circulation heat exchanger, a reaction tank, a condensation component, a loop circulation pump, a first-level molecular distillation device, a second-level molecular distillation device, a third-level molecular distillation device, a fourth-level molecular distillation device, a steam ester temporary storage tank, a steam ester circulation tank, a steam ester standing tank, a steam ester storage tank and a powder spraying tower, the temperature sensor group includes at least fourteen temperature sensors, the pressure sensor group includes at least eight pressure sensors, the pH sensor group includes at least one pH sensor, and the solenoid valve group includes at least fourteen solenoid valves.

[0137] A temperature sensor, a pressure sensor and a solenoid valve are arranged on the connecting pipe between the top of the reaction tank and the top of the external circulation heat exchanger; a temperature sensor, a pressure sensor, a pH sensor and a solenoid valve are arranged on the connecting pipe between the bottom of the reaction tank and the loop circulation pump; a temperature sensor, a pressure sensor and a solenoid valve are arranged in the middle of the reaction tank and connected with the bottom of the condensation component; a temperature sensor, a pressure sensor and a solenoid valve are arranged on the pipe connecting the condensation component and the top of the reaction tank; a temperature sensor is arranged on the external circulation heat exchanger; a temperature sensor, a pressure sensor and a solenoid valve are arranged on the first-level molecular distillation device; a temperature sensor, a pressure sensor and a solenoid valve are arranged on the second-level molecular distillation device; a temperature sensor, a pressure sensor and a solenoid valve are arranged on the third-level molecular distillation device; a temperature sensor, a pressure sensor and a solenoid valve are arranged on the fourth-level molecular distillation device; a temperature sensor and a solenoid valve are arranged on the ester distillation temporary storage tank; a temperature sensor and a solenoid valve are arranged on the ester distillation circulation tank; a temperature sensor and a solenoid valve are arranged on the ester distillation static tank; a temperature sensor and a solenoid valve are arranged on the ester distillation storage tank; a temperature sensor and a solenoid valve are arranged on the powder spraying tower.

[0138] The computer is respectively connected with a temperature sensor group, a pressure sensor, a pH sensor group, a solenoid valve group, an external circulation heat exchanger, a reaction tank, a condensation component, a loop circulation pump, a first-level molecular distillation device, a second-level molecular distillation device, a third-level molecular distillation device, a fourth-level molecular distillation device, a distilled ester temporary storage tank, a distilled ester circulation tank, a distilled ester static tank, a distilled ester storage tank and a powder spraying tower, and is used to control the entry and exit of materials and the delivery of cooling water and heat transfer oil.

[0139] Preferably, the temperature sensor and the pressure sensor are connected to a computer and are arranged in an external circulation heat exchanger, a reaction tank, a condensation assembly, a primary molecular distillation device, a secondary molecular distillation device, a tertiary molecular distillation device, a quaternary molecular distillation device, a distilled ester temporary storage tank, a distilled ester circulation tank, a distilled ester standing tank, a distilled ester storage tank and a powder spraying tower.

[0140] Preferably, the pH sensor is connected to a computer and is disposed in a reaction tank.

[0141] Preferably, the control system for preparing lauric acid monoglyceride further comprises an alarm, and the alarm is connected to a computer.

[0142] Example 7

[0143] The control method for preparing lauric acid monoglyceride in this embodiment is as follows: Figure 7 As shown, the computer is provided with 4 loops, which control the control valve for the material in and out of the reaction tank according to the temperature and pressure value at the top of the reaction tank, control the control valve of the external circulation heat exchanger and the bottom valve of the reaction tank according to the pH value at the bottom of the reaction tank, control the main control valve of the condenser and the gas phase discharge valve of the middle reaction tank according to the temperature and pressure value in the middle of the reaction tank, and control the heating steam valve of the external circulation heat exchanger according to the temperature and pressure device at the bottom of the reaction tank.

[0144] In this embodiment, the computer control method includes the following steps:

[0145] First, initialize the computer; set the interrupt mode and interrupt program, and accept the interrupt action according to the program settings; set the count value of the control point; collect the parameters of the control point at regular time intervals, and the computer performs a programmed comparison and judgment on the collected parameters; if it is judged that there is an out-of-tolerance, control the valve opening; if there is no out-of-tolerance, directly execute the next step of the display program; repeat the above control process to dynamically adjust the status of all collection points.

[0146] For every 0~+n degrees Celsius or pressure 0~+mMPa or PH 0~+f beyond the allowable temperature, the computer calculates it as +1 level of deviation; for every -n~0 degrees Celsius or pressure -m~0MPa or PH-f~0 beyond the allowable lower limit, it is calculated as -1 level of deviation, where n, m are arbitrary values ​​and f is 0~14; the computer calculates the temperature, pressure and PH deviations, and according to each level of deviation, it can drive the corresponding original position to produce an upward or downward displacement, thereby changing the size of the controlled valve.

[0147] When the control point parameters are for linkage control of multiple valves, set the priority control valve and the cooperative control valve; the priority control valve is first adjusted, and its valve opening value is the difference between the total valve opening calculated by the computer and the product of the cooperative control valve opening and the relative impact system.

[0148] The computer sampling method is set to take 1 minute as the sampling period of the control parameter, and perform limiting filtering, then use median filtering, and repeat this 5 to 10 times, taking the average value as the result of each sampling period.

[0149] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for preparing lauric acid monoglyceride, characterized in that: The preparation device of lauric acid monoglyceride is used, and the specific steps are as follows: (1) mixing lauric acid and glycerol in a molar ratio of 1:1 to 3 and preheating the mixture, adding the mixture into a lauric acid monoglyceride preparation device, reacting under nitrogen or carbon dioxide protection conditions to produce a lauric acid monoglyceride primary product containing 50% to 55% of lauric acid monoglyceride; (2) subjecting the primary product of lauric acid monoglyceride in step (1) to four-stage molecular distillation to obtain lauric acid monoglyceride with a purity of 96% to 99%; The specific process flow of step (1) is as follows: The lauric acid and glycerol are configured in a molar ratio of 1:1-3, the gas phase loop of the loop reactor is opened, the nitrogen or carbon dioxide is replaced in the system at least twice, and the nitrogen or carbon dioxide pressure of the entire loop reactor system is maintained at -0.09MPa-0.2MPa, glycerol flows in through the glycerol inlet at the top of the reaction tank, and lauric acid flows in through the lauric acid inlet at the upper part of the reaction tank. Glycerol and lauric acid are mixed and heated in the reaction tank under the action of the loop reaction mixer, and the temperature in the reaction tank is controlled to be 160-240°C; the gas generated in the reaction tank and the unreacted glycerol enter the primary condenser from the upper part of the reaction tank for condensation, and the unreacted glycerol returns to the reaction tank to continue to participate in the reaction, and the uncondensed gas passes through the secondary condenser and the tertiary condenser to make the reaction by-products The water in the reaction tank is collected in the secondary condenser receiving tank and the tertiary condenser receiving tank, and the temperature of the primary condenser in the gas phase loop is controlled to be 100 degrees, the temperature of the secondary condenser is 60 degrees, and the temperature of the tertiary condenser is 30 degrees; the glycerol and lauric acid materials at the bottom of the reaction tank are continuously pumped into the external circulation heat exchanger through the loop circulation pump for heat exchange; the gas after heat exchange enters the reaction tank through the top of the reaction tank; the loop reaction time is 2 to 8 hours, and when the pH detection device at the bottom of the reaction tank detects that the acid value of the product is reduced to below 5, the reaction is terminated; the loop circulation pump pumps the crude product of lauric acid monoglyceride at the bottom of the reaction tank into the sedimentation separation tank, cools the temperature to 160 to 170°C, separates by sedimentation, and filters the supernatant to obtain the initial product of lauric acid monoglyceride containing 50% to 55% of lauric acid monoglyceride; The specific process flow of the step (2) of subjecting the primary product of lauric acid monoglyceride to four-stage molecular distillation is as follows: The primary molecular distillation process: the primary product of lauric acid monoglyceride separated in the step (1) enters from the top of the primary molecular distillation column through the distillation process feed pump, and dehydration, degassing and glycerin process are carried out in the primary molecular distillation column, wherein the reaction temperature is 130-150° C., the vacuum degree is 200-300 Pa, the gaseous component is condensed by the primary collector, and then enters the monoester, diester and triester precipitation tank through the bottom of the primary collector, and the liquid component enters the secondary molecular distillation column through the bottom of the primary molecular distillation column; Secondary molecular distillation process: the crude ester dehydrated and vaporized by the primary molecular distillation column enters the secondary molecular distillation column for further separation of glycerol, wherein the reaction temperature is 150-165°C, the vacuum degree is 150-190Pa, the gaseous components are condensed through the secondary collector, the heavier liquid components enter the monoester, diester and triester precipitation tank through the bottom of the secondary molecular distillation column, and the lighter liquid components enter the diester and triester precipitation tank I through the lower part of the secondary molecular distillation column for precipitation; Three-stage molecular distillation process: After the crude glycerol ester is separated by the secondary molecular distillation column, it enters the tertiary molecular distillation column for further separation of fatty acids, wherein the reaction temperature is 165-180°C, the vacuum degree is 30-50Pa, the gaseous components are condensed through the three-stage collector, the lighter liquid phase enters the three- and four-ester precipitation tank through the lower part of the three-stage molecular distillation column, and the heavier liquid phase components enter the one-, two-, and three-ester precipitation tanks from the bottom of the distillation column; Four-stage molecular distillation process: After the crude ester of fatty acid is separated by the three-stage molecular distillation column, it enters the four-stage molecular distillation column for further separation of triesters, wherein the reaction temperature is 170-190°C, the vacuum degree is 0-20Pa, the gaseous phase component enters the four-stage collector, the lighter liquid phase enters the ester distillation buffer tank, and then flows into the diester and triester precipitation tank II, and most of the monolaurin glyceryl enters the ester distillation precipitation tank through the bottom of the four-stage molecular distillation column; after the four-stage distillation, the monolaurin glyceryl with a purity of 96% to 99% is obtained; The preparation device of monoglyceride of lauric acid comprises a production device of monoglyceride of lauric acid, a distillation device of monoglyceride of lauric acid and a powder spraying device of monoglyceride of lauric acid; The production device of monoglyceride of lauric acid comprises an external circulation heat exchanger, a reaction tank, a condensation component, a loop circulation pump, a valve and a detection device. A loop reaction mixer is arranged in the reaction tank. The top of the external circulation heat exchanger is connected to the loop reaction mixer. The bottom of the external circulation heat exchanger is connected to the bottom of the reaction tank through a loop circulation pump. The top of the reaction tank is connected to the external circulation heat exchanger through a pipeline. A feed pipeline and a feed valve are arranged on the top of the reaction tank, and a discharge pipeline and a bottom valve are arranged on the bottom. A pressure detection device and a temperature detection device are arranged on the top, middle and bottom of the reaction tank, and a pH detection device is arranged on the bottom of the reaction tank. The top of the reaction tank forms a gas phase loop with the external circulation heat exchanger and the condensation component through a pipeline. The external circulation heat exchanger is provided with a temperature detection device, and a temperature detection device and a pressure detection device are arranged on the upper part of the condensation component. The pressure detection device, the temperature detection device and the pH detection device are all electrically connected to a computer. The condensation assembly includes a primary condenser, a secondary condenser, a tertiary condenser, a primary condenser receiving tank, a secondary condenser receiving tank and a tertiary condenser receiving tank; a cooling water outlet is provided on the upper portion of the primary condenser, the top of the primary condenser is connected to the upper condensation water inlet of the secondary condenser receiving tank, a cooling water inlet is provided on the lower portion of the primary condenser, and cooling water condenses gas from bottom to top; a cooling water outlet is provided on the upper portion of the secondary condenser, the top of the secondary condenser is connected to the upper condensation water inlet of the tertiary condenser receiving tank, a cooling water inlet is provided on the lower portion of the secondary condenser, and cooling water condenses gas from bottom to top; a cooling water outlet is provided on the upper portion of the tertiary condenser, and a cooling water inlet and outlet are provided on the lower portion of the tertiary condenser; the upper condensation water inlet of the primary condenser receiving tank is connected to the upper portion of the reaction tank; The distillation device of monoglyceride of lauric acid comprises a distillation process feed pump, a first molecular distillation device, a second molecular distillation device, a third molecular distillation device, a fourth molecular distillation device, a distilled ester discharge pump, and a distilled ester precipitation tank, wherein the first molecular distillation device, the second molecular distillation device, the third molecular distillation device and the fourth molecular distillation device are arranged in sequence.

2. The method for preparing lauric acid monoglyceride according to claim 1, characterized in that: A preparation device for monoglyceride of lauric acid and a control system for preparing monoglyceride of lauric acid are used, wherein the control system for preparing monoglyceride of lauric acid specifically comprises a computer, a temperature sensor group, a pressure sensor, a pH sensor group, a solenoid valve group, an external circulation heat exchanger, a reaction tank, a condensation component, a loop circulation pump, a primary molecular distillation device, a secondary molecular distillation device, a tertiary molecular distillation device, a quaternary molecular distillation device, a steam ester temporary storage tank, a steam ester circulation tank, a steam ester static tank, a steam ester storage tank and a powder spraying tower, the temperature sensor group comprises at least fourteen temperature sensors, the pressure sensor group comprises at least eight pressure sensors, the pH sensor group comprises at least one pH sensor, and the solenoid valve group comprises at least fourteen solenoid valves; A temperature sensor, a pressure sensor and a solenoid valve are arranged on the connecting pipe between the top of the reaction tank and the top of the external circulation heat exchanger; a temperature sensor, a pressure sensor, a pH sensor and a solenoid valve are arranged on the connecting pipe between the bottom of the reaction tank and the loop circulation pump; a temperature sensor, a pressure sensor and a solenoid valve are arranged in the middle of the reaction tank and connected to the bottom of the condensation component; a temperature sensor, a pressure sensor and a solenoid valve are arranged on the pipe connecting the condensation component and the top of the reaction tank; a temperature sensor is arranged on the external circulation heat exchanger; a temperature sensor, a pressure sensor and a solenoid valve are arranged on the first-level molecular distillation device; a temperature sensor, a pressure sensor and a solenoid valve are arranged on the second-level molecular distillation device; a temperature sensor, a pressure sensor and a solenoid valve are arranged on the third-level Molecular distillation device; a temperature sensor, a pressure sensor and a solenoid valve are arranged in a four-stage molecular distillation device; a temperature sensor and a solenoid valve are arranged in a steam ester temporary storage tank; a temperature sensor and a solenoid valve are arranged in a steam ester circulation tank; a temperature sensor and a solenoid valve are arranged in a steam ester static tank; a temperature sensor and a solenoid valve are arranged in a steam ester storage tank; a temperature sensor and a solenoid valve are arranged in a powder spraying tower; the computer is respectively connected with the temperature sensor group, the pressure sensor, the pH sensor group, the solenoid valve group, the external circulation heat exchanger, the reaction tank, the condensation component, the loop circulation pump, the first-stage molecular distillation device, the second-stage molecular distillation device, the third-stage molecular distillation device, the fourth-stage molecular distillation device, the steam ester temporary storage tank, the steam ester circulation tank, the steam ester static tank, the steam ester storage tank and the powder spraying tower, and is used to control the entry and exit of materials and the delivery of cooling water and heat transfer oil.

3. The method for preparing lauric acid monoglyceride according to claim 2, characterized in that: The temperature sensor and the pressure sensor are connected to a computer and are arranged in an external circulation heat exchanger, a reaction tank, a condensation component, a primary molecular distillation device, a secondary molecular distillation device, a tertiary molecular distillation device, a quaternary molecular distillation device, a steamed ester temporary storage tank, a steamed ester circulation tank, a steamed ester static tank, a steamed ester storage tank and a powder spraying tower.

4. The method for preparing lauric acid monoglyceride according to any one of claims 2 or 3, characterized in that: The computer is provided with thirteen loops, which control the control valve for materials entering and exiting the reaction tank according to the temperature and pressure value at the top of the reaction tank, control the control valve of the external circulation heat exchanger and the bottom valve of the reaction tank according to the pH value at the bottom of the reaction tank, control the main control valve of the condenser and the gas phase discharge valve of the middle reaction tank according to the temperature and pressure value at the middle of the reaction tank, control the heating steam valve of the external circulation heat exchanger according to the temperature and pressure value at the bottom of the reaction tank, control the control valve for materials entering and exiting the primary molecular distillation column according to the temperature and pressure value of the primary molecular distillation device, control the control valve for materials entering and exiting the secondary molecular distillation column according to the temperature and pressure value of the secondary molecular distillation device Control valves for the inlet and outlet of materials, control valves for controlling the inlet and outlet of materials of the third-stage molecular distillation column according to the temperature and pressure value of the third-stage molecular distillation device, control valves for controlling the inlet and outlet of materials of the fourth-stage molecular distillation column according to the temperature and pressure value of the fourth-stage molecular distillation device, control valves for controlling the inlet and outlet of materials of the ester distillation temporary storage tank according to the temperature of the ester distillation temporary storage tank, control valves for controlling the inlet and outlet of materials of the ester distillation circulation tank according to the temperature of the ester distillation circulation tank, control valves for controlling the inlet and outlet of materials of the ester distillation static tank according to the temperature of the ester distillation static tank, control valves for controlling the inlet and outlet of materials of the ester distillation storage tank according to the temperature of the ester distillation storage ... and control valves for controlling the inlet and outlet of materials of the ester distillation storage tank according to the temperature of the powder spraying tower.

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