CN111253253A - Continuous esterification equipment and method - Google Patents
Continuous esterification equipment and method Download PDFInfo
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- CN111253253A CN111253253A CN202010172794.5A CN202010172794A CN111253253A CN 111253253 A CN111253253 A CN 111253253A CN 202010172794 A CN202010172794 A CN 202010172794A CN 111253253 A CN111253253 A CN 111253253A
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- DCKVNWZUADLDEH-UHFFFAOYSA-N sec-butyl acetate Chemical compound CCC(C)OC(C)=O DCKVNWZUADLDEH-UHFFFAOYSA-N 0.000 claims description 9
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- QSBYPNXLFMSGKH-UHFFFAOYSA-N 9-Heptadecensaeure Natural products CCCCCCCC=CCCCCCCCC(O)=O QSBYPNXLFMSGKH-UHFFFAOYSA-N 0.000 claims description 7
- ZQPPMHVWECSIRJ-UHFFFAOYSA-N Oleic acid Natural products CCCCCCCCC=CCCCCCCCC(O)=O ZQPPMHVWECSIRJ-UHFFFAOYSA-N 0.000 claims description 7
- 239000005642 Oleic acid Substances 0.000 claims description 7
- QXJSBBXBKPUZAA-UHFFFAOYSA-N isooleic acid Natural products CCCCCCCC=CCCCCCCCCC(O)=O QXJSBBXBKPUZAA-UHFFFAOYSA-N 0.000 claims description 7
- ZQPPMHVWECSIRJ-KTKRTIGZSA-N oleic acid Chemical compound CCCCCCCC\C=C/CCCCCCCC(O)=O ZQPPMHVWECSIRJ-KTKRTIGZSA-N 0.000 claims description 7
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 6
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- 239000011265 semifinished product Substances 0.000 abstract description 5
- GLYJVQDYLFAUFC-UHFFFAOYSA-N butyl hexadecanoate Chemical compound CCCCCCCCCCCCCCCC(=O)OCCCC GLYJVQDYLFAUFC-UHFFFAOYSA-N 0.000 description 106
- WIBFFTLQMKKBLZ-SEYXRHQNSA-N n-butyl oleate Chemical compound CCCCCCCC\C=C/CCCCCCCC(=O)OCCCC WIBFFTLQMKKBLZ-SEYXRHQNSA-N 0.000 description 53
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Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C67/00—Preparation of carboxylic acid esters
- C07C67/08—Preparation of carboxylic acid esters by reacting carboxylic acids or symmetrical anhydrides with the hydroxy or O-metal group of organic compounds
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C67/00—Preparation of carboxylic acid esters
- C07C67/48—Separation; Purification; Stabilisation; Use of additives
- C07C67/52—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation
- C07C67/54—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation by distillation
Abstract
The invention relates to continuous esterification equipment and a method, which comprises a mixed acid storage tank, a mixed acid metering pump, a heat exchanger, a mixed acid heater and an esterification tower, wherein the esterification tower is internally provided with a mixed acid distributor, corrugated fillers are arranged below the mixed acid distributor, an in-tower heater is arranged between every two adjacent corrugated fillers, a plurality of under-tower esterification kettles which can be alternately communicated with the lower part of the esterification tower are arranged below the esterification tower, the under-tower esterification kettles are connected with a butanol storage tank through a butanol pipe and connected with a first crude ester storage tank through a crude ester pipe, the butanol pipe is sequentially connected with the butanol metering pump, the butanol heater, a butanol regulating valve and a butanol distributor, the butanol distributor is positioned below the inside of the under-tower esterification kettle, and a stirring rod is arranged above the butanol distributor. Compared with the prior art, the method obtains the crude ester semi-finished product in a continuous vapor-liquid countercurrent mode, adopts a mode of alternately operating a plurality of esterification kettles, and has the advantages of automatic operation, uninterrupted production, high efficiency, high yield, low cost and the like.
Description
Technical Field
The invention relates to the technical field of esterification, in particular to continuous esterification equipment and a continuous esterification method.
Background
The butyl ester product of monomer fatty acid (oleic acid, palmitic acid, stearic acid and the like) is a finished product obtained by esterification of fatty acid (such as oleic acid) and butanol and then deacidification and decoloration; specifically, the conventional production process of butyl oleate (including other fatty acid butyl esters) comprises the steps of heating commercial industrial oleic acid and butanol to 120-140 ℃ under an acid catalyst by using the conventional equipment, reacting for 4-8 hours to reach an esterification end point, neutralizing, washing with water, removing the catalyst, dehydrating, deodorizing and decolorizing to obtain a finished product; therefore, the production process based on the existing equipment has the defects of long flow, intermittent production, low yield, high cost and the like.
At present, the domestic refined edible rice bran oil is about 100-200 ten thousand tons, the byproduct rice bran oil mixed fatty acid generated in the refining process is about 5-10 ten thousand tons, and the byproduct is mainly used for soap making industry and extraction of industrial rice bran oleic acid; the method comprises the steps of directly esterifying mixed fatty acid of rice bran oil, which is a byproduct of the rice bran oil, with butanol, and obtaining a crude ester semi-finished product (mixed fatty acid butyl ester) by adopting a mode of continuous vapor-liquid countercurrent and alternate operation of an esterification kettle during esterification; the crude ester is directly sent into a fractionating tower after the catalyst is removed, and is cut into butyl palmitate and butyl oleate, and the butyl oleate is flashed and condensed to obtain the finished product.
In order to solve the problems of the prior art, the invention provides continuous esterification equipment and a method, the equipment adopts a continuous vapor-liquid countercurrent mode to obtain a crude ester semi-finished product, lays a foundation for obtaining butyl palmitate and butyl oleate, adopts a mode of alternately operating a plurality of esterification kettles, and has the advantages of automatic operation, uninterrupted production, high efficiency, high yield, low cost and the like.
Disclosure of Invention
The invention provides continuous esterification equipment and a method, the equipment adopts a continuous vapor-liquid countercurrent mode to obtain a crude ester semi-finished product, lays a foundation for obtaining butyl palmitate and butyl oleate, adopts a mode of alternately operating a plurality of esterification kettles, and has the advantages of automatic operation, uninterrupted production, high efficiency, high yield, low cost and the like.
The technical scheme of the invention is realized as follows:
a continuous esterification device comprises a mixed acid storage tank, a mixed acid metering pump, a heat exchanger, a mixed acid heater and an esterification tower which are sequentially communicated through a mixed acid pipe, wherein the upper part in the esterification tower is provided with a mixed acid distributor communicated with the mixed acid heater, a plurality of corrugated fillers which are arranged up and down are arranged below the mixed acid distributor, an in-tower heater is arranged between every two adjacent corrugated fillers, a plurality of under-tower esterification kettles which can be alternately communicated with the lower part of the esterification tower are arranged below the esterification tower, a liquid pipe and a vapor pipe are connected between each under-tower esterification kettle and the esterification tower, the under-tower esterification kettles are connected with a butanol storage tank through butanol pipes, a first crude ester storage tank is connected through the crude ester pipes, the butanol pipes are sequentially connected with butanol metering pumps, butanol heaters, butanol regulating valves and butanol distributors, wherein the butanol distributors are positioned below the under-tower esterification kettles, stirring rods are arranged above the butanol distributors, and a steam outlet positioned above the acid mixing distributor is arranged on the esterification tower and is communicated with the heat exchanger.
The invention relates to an esterification device which continuously esterifies in a vapor-liquid countercurrent mode and continuously produces in an esterification kettle alternative operation mode under a tower (replacing the traditional kettle type intermittent esterification method), and a fractionating device for fractionating and cutting to obtain butyl palmitate and butyl oleate; wherein, the esterification device is characterized in that a mixed acid metering pump pumps mixed acid (rice bran oil mixed fatty acid) in a mixed acid storage tank, the mixed acid sequentially passes through a heat exchanger, a mixed acid heater and a mixed acid distributor to enable the mixed acid to enter an esterification tower and flow downwards along the surface of a corrugated filler, meanwhile, a butanol metering pump pumps butanol in a butanol storage tank, the butanol passes through a butanol heater to be vaporous butanol, the vaporous butanol enters the bottom of an esterification kettle through the butanol distributor, the vaporous butanol on the one hand has an esterification reaction with unreacted rice bran oil mixed fatty acid flowing into the esterification kettle below the tower under the stirring of a stirring rod to improve the esterification rate, on the other hand, the unreacted vaporous butanol rises into the esterification tower through a vapor pipe and is fully and repeatedly contacted with the mixed acid flowing downwards on the surface of the corrugated filler, and the esterification reaction is carried out under the action of a catalyst (the heater in the tower provides reaction temperature for the esterification reaction), the generated crude ester flows into an esterification kettle below the esterification tower through a liquid pipe, continuous esterification is realized through repeated circulation, wherein the generated vaporous water and unreacted vaporous butanol continuously rise to the upper part of the esterification tower together and enter an alcohol-water separation device through a vapor outlet and a heat exchanger, water is discharged out of the device, and the liquid butanol flows back to a butanol storage tank again to participate in the esterification reaction; when the crude ester amount in one esterification kettle under the tower reaches a certain amount, closing a corresponding liquid pipe and a butanol pipe (the on-off of the butanol pipe is realized through a butanol regulating valve) to stop the crude ester and the vaporous butanol from entering the esterification kettle under the tower, simultaneously opening the liquid pipe and the butanol pipe corresponding to the other esterification kettle under the tower with an empty inner part, so that the esterification kettle under the tower is communicated with the esterification tower, the continuity of the esterification is ensured, the production does not need to be stopped, simultaneously detecting the content index of the crude ester mixed acid in the esterification kettle under the tower (a sampling port can be arranged on the esterification kettle under the tower to realize the sampling), if the crude ester mixed acid does not reach the standard, continuously introducing the vaporous butanol into the esterification kettle under the tower to continue the esterification reaction, and when the crude ester reaches the standard, enabling the crude ester to flow into a first crude ester storage tank for standby, thereby effectively improving the product quality.
Preferably, the liquid pipe is connected with a liquid level meter linkage valve, the gas pipe is connected with a check valve, and a liquid level meter is arranged in the esterification kettle below the tower.
The linkage valve in the linkage valve of the liquid level meter is in linkage control with the liquid level meter on the esterification kettle under the tower, and when the crude ester liquid level in the esterification kettle under the tower rises to a preset position, the liquid level meter sends a signal to the linkage valve to automatically close the linkage valve to stop feeding the crude ester; the check valve is a one-way valve, the vaporous butanol in the esterification kettle below the tower rises to enter the esterification tower through the check valve, when the vaporous butanol stops rising, the check valve is automatically closed, and the vaporous butanol in the esterification tower cannot flow back to the esterification kettle below the tower.
Preferably, one end of the liquid pipe is connected with the bottom of the esterification tower, the other end of the liquid pipe is connected with the upper part of the esterification kettle under the tower, one end of the vapor pipe is connected with the kettle top of the esterification kettle under the tower, and the other end of the vapor pipe is connected with the lower part of the esterification tower; in the esterification tower, the nozzle of the gas pipe is higher than that of the liquid pipe.
The pipe orifice of the steam pipe is higher than that of the liquid pipe, so that the vaporous butanol can be ensured to quickly rise in the esterification tower without being interfered by crude ester.
Preferably, an outer heater is arranged on the outer side surface of the esterification kettle below the tower.
The materials in the kettle are heated to provide heat for the esterification reaction.
Preferably, the lower end of the stirring rod is provided with a stirring fan blade.
Ensures the full and rapid esterification reaction between the vaporous butanol and the mixed acid, and has high efficiency and good quality.
Preferably, a crude ester discharge pump is connected to the crude ester pipe.
Crude ester is allowed to enter the first crude ester sump.
Preferably, the oleic acid distributor and the butanol distributor respectively comprise a feeding main pipe and a plurality of branch pipes connected to two sides of the feeding main pipe, the feeding main pipe is communicated with the branch pipes, and the feeding main pipe and the branch pipes are respectively provided with distribution holes with downward openings.
The liquid mixed acid and the vapor butanol flow out of the distribution holes after entering the main feeding pipe and the branch pipes, the liquid mixed acid enters the esterification tower, and the vapor butanol enters the esterification kettle and the esterification tower below the tower.
Preferably, one end of the inner tube pass of the heat exchanger is connected with the mixed acid metering pump through an acid mixing tube, the other end of the inner tube pass of the heat exchanger is connected with the mixed acid heater through the acid mixing tube, one end of the inner shell pass of the heat exchanger is connected with the steam outlet, and the other end of the inner shell pass of the heat exchanger is connected with an alcohol-water separator.
The vaporous butanol is cooled into liquid through a heat exchanger and then enters an alcohol-water separator for alcohol-water stratification, and the mixed acid in the tube pass is heated and then enters a mixed acid heater.
Preferably, the alcohol-water separator comprises an alcohol outlet end and a water outlet end, wherein the alcohol outlet end is communicated with the butanol storage tank.
The alcohol-water separator is a common separation tower structure, butanol dehydrated at the upper layer flows back to a butanol storage tank through an alcohol outlet end to continuously participate in esterification reaction, and water at the lower layer can flow into a water storage tank through the water outlet end to be recycled, so that waste is avoided.
Preferably, a demisting wire mesh is arranged above the acid mixing distributor in the esterification tower, and the steam outlet is positioned above or beside the demisting wire mesh.
To remove entrained liquid sites in the vaporous butanol.
A continuous esterification method for synthesizing mixed fatty acid butyl ester based on the equipment comprises the following steps:
s1: selection of raw materials
Rice bran oil mixed fatty acid: acid value mgKOH/g: not less than 190
Iodine value gI2/100g：95-105
N-butanol: alcohol content%
The catalyst is p-toluenesulfonic acid: sulfuric acid (H) with a content of more than or equal to 95%2SO4)％≤3
S2: stock preparation
a. Adding p-toluenesulfonic acid into the rice bran oil mixed fatty acid, uniformly stirring, pumping into a mixed acid storage tank for later use, and keeping the temperature at 55-65 ℃;
b. n-butanol is reserved in a butanol storage tank (normal temperature);
s3: feeding of the feedstock
a. Uniformly preheating the mixed fatty acid of the rice bran oil to 130-150 ℃ by using a mixed acid metering pump through a heat exchanger and a mixed acid heater, and pumping the mixture into an esterification tower;
b. preheating n-butyl alcohol to 160-165 ℃ at a uniform speed by a butanol metering pump through a butanol heater, and pumping the n-butyl alcohol into the lower part of the lower esterification kettle of the tower;
s4: esterification reaction
a. Uniformly distributing rice bran oil mixed fatty acid on the surface of a corrugated filler through an acid mixing distributor, allowing the rice bran oil mixed fatty acid to flow downwards along the surface of the corrugated filler under the action of gravity, pumping n-butanol into the lower part of an esterification kettle in a tower through a butanol metering pump by virtue of a butanol heater, heating liquid n-butanol to 160-165 ℃ by virtue of the butanol heater to form vapor n-butanol, allowing the vapor n-butanol to rise into the lower part of the esterification tower, then rising along the corrugated filler in the esterification tower, contacting with the rice bran oil mixed fatty acid on the corrugated filler and carrying out esterification reaction, allowing crude ester generated by the reaction to flow downwards along the surface of the corrugated filler to enter the esterification kettle under the tower, continuously repeating the steps, discharging redundant vapor n-butanol and vapor water from a vapor outlet, sequentially entering a heat exchanger and an alcohol-water separator, allowing the liquid butanol to flow back to a butanol storage tank to continuously;
b. if the crude ester flowing into the esterification kettle under the tower contains unreacted rice bran oil mixed fatty acid, the vaporous n-butanol and the rice bran oil mixed fatty acid are subjected to esterification reaction under the stirring of a stirring rod, wherein the unreacted vaporous n-butanol rises to enter the esterification tower;
c. when the crude ester amount in the esterification kettle under the tower reaches a certain amount and reaches the standard, pumping the crude ester into a first crude ester storage tank.
The process method of the invention uses the mixed fatty acid to replace the prior monomer fatty acid (oleic acid, palmitic acid or stearic acid, etc.) to be directly esterified with butanol to obtain the mixed fatty acid butyl ester, adopts vapor-liquid countercurrent continuous esterification and a plurality of under-tower esterification kettles to alternately operate, and has the advantages of high yield, high purity, high quality, low cost, high utilization rate, etc.; the butyl palmitate and butyl oleate in the mixed fat are widely applied in the plastic industry and the lubricating oil industry, and the impurity vegetable pitch can be used as fuel or casting adhesive.
Preferably, in S4, the esterification kettle includes a plurality of esterification kettles, and when the amount of the crude ester in the esterification kettle a reaches a certain amount, the corresponding liquid pipe and butanol pipe are closed, the crude ester and the vaporous n-butanol stop entering the esterification kettle a, and the liquid pipe and butanol pipe of the other esterification kettle B are opened, and the crude ester and the vaporous n-butanol enter the esterification kettle B; simultaneously detecting the content index of mixed acid of the crude ester in the esterification kettle A under the tower, if the mixed acid reaches the standard, pumping the crude ester into a first crude ester storage tank for treatment, and emptying the esterification kettle A under the tower for standby and repeating continuously; if the standard is not met, continuously introducing the vapor-state n-butanol into the esterification kettle A below the tower, and continuously carrying out the esterification reaction until the standard is met.
The esterification kettles under the towers alternately operate, so that uninterrupted production is guaranteed, the yield is effectively improved, and the product quality is also improved.
The beneficial effects of the invention adopting the technical scheme are as follows:
the invention provides continuous esterification equipment and a continuous esterification method, wherein the equipment adopts a continuous vapor-liquid countercurrent mode to obtain a crude ester semi-finished product, lays a foundation for obtaining butyl palmitate and butyl oleate, adopts a mode of alternately operating a plurality of esterification kettles, and has the advantages of automatic operation, uninterrupted production, high efficiency, high yield, low cost and the like. The equipment realizes continuous esterification and continuous operation between the rice bran oil mixed fatty acid and the butanol by a vapor-liquid countercurrent mode and a lower esterification kettle alternative use mode, replaces the traditional kettle type intermittent esterification, and realizes the purposes of continuous feeding and discharging, high yield, high quality, simple operation, full utilization of material heat, low cost, material waste avoidance and the like.
Drawings
FIG. 1 is a schematic view of the overall configuration of an esterification apparatus according to an embodiment;
FIG. 2 is an enlarged view of portion A of FIG. 1;
FIG. 3 is a schematic view showing the overall structure of a fractionation apparatus according to an embodiment;
FIG. 4 is a schematic view of the structure of the material receiving tray of the butyl palmitate material receiver and the butyl oleate material receiver;
FIG. 5 is a schematic diagram of the distributor structures of the acid mixing distributor, the butanol distributor and the crude ester distributor;
reference numerals:
esterification equipment 100, a mixed acid pipe 101, a mixed acid storage tank 102, a mixed acid metering pump 103, a heat exchanger 104, a mixed acid heater 105, an esterification tower 106, a demisting wire net 1061, a vapor outlet 1062, an under-tower esterification kettle 107, a liquid pipe 1071, a level gauge linkage valve 1071A, a vapor pipe 1072, a check valve 1072A, a stirring rod 1073, a stirring fan blade 1074, an out-kettle heater 1075, an alcohol-water separator 108, an alcohol outlet 1081, a water outlet 1082, a water storage tank 109, an automatic pressure regulating valve 110, a butanol pipe 111, a butanol metering pump 1111, a butanol heater 1112, a butanol distributor 1113, a butanol regulating valve 1114, a butanol storage tank 112, a crude ester pipe 113, a crude ester discharge pump 1131, a crude ester regulating valve 1132, a first crude ester storage tank 114, a fractionation device 200, a fractionation pipe 201, a second crude ester storage tank 202, a crude ester metering pump 203, a crude ester heater 204, a fractionation tower 205, a butyl palmitate condenser 2051, a butyl palmitate receiver 2 2052, A butyl palmitate storage tank 2053, a first wire mesh filler 2054 crude ester distributor 2055, a second wire mesh filler 2056, a butyl palmitate heater 2057, a circulating pump 206, a falling film heater 207, a communication port 2071, a flash tower 208, a butyl oleate condenser 2081, a butyl oleate receiver 2082, a butyl oleate storage tank 2083, a third wire mesh filler 2084, a steam recovery pipe 209, an asphalt storage tank 210, a flash pipe 211, a feeding main pipe 301, a branch pipe 302, a distribution hole 303, a material receiving plate 401, a through pipe 402, a steam inlet 403, a cover cap 404, a retainer ring 405 and a discharge tank 406.
Detailed Description
The specific embodiment of the invention is as follows:
the esterification equipment of the invention esterifies the mixed fatty acid to obtain the mixed fatty acid butyl ester, wherein the mixed fatty acid butyl ester is separated into butyl oleate and butyl palmitate, and the equipment can realize fractionation by combining the following fractionation device.
As shown in FIGS. 1 to 5, the device comprises an esterification device 100 and a fractionation device 200.
The esterification device 100 comprises a mixed acid storage tank 102, a mixed acid metering pump 103, a heat exchanger 104, a mixed acid heater 105 and an esterification tower 106 which are sequentially communicated through an acid mixing pipe 101, wherein 2 under-tower esterification kettles 107 which can be alternately communicated with the lower part of the esterification tower 106 are arranged at the bottom of the esterification tower 106.
Further, a demisting wire mesh 1061 (a steam outlet 1062 is arranged above or beside the demisting wire mesh 1061, the steam outlet 1062 is communicated with the heat exchanger 104), an acid mixing distributor 1063 communicated with the acid mixing heater 105, and 3 corrugated packings 1064 arranged up and down are sequentially arranged in the esterification tower 106 from top to bottom, and an in-tower heater 1065 (a shell-and-tube heater is adopted to facilitate the flow of the materials in the esterification tower 106) is arranged between every two adjacent corrugated packings 1064 arranged up and down; one end of an inner tube pass of the heat exchanger 104 is connected with the mixed acid metering pump 103 through the mixed acid tube 101, the other end of the inner tube pass of the heat exchanger 104 is connected with the mixed acid heater 105 through the mixed acid tube 101, one end of an inner shell pass of the heat exchanger 104 is connected with the steam outlet 1062, the other end of the inner shell pass of the heat exchanger 104 is connected with the alcohol-water separator 108, the alcohol-water separator 108 is specifically an alcohol-water separation tower and comprises an alcohol outlet end 1081 and a water outlet end 1082, wherein the alcohol outlet end 1081 is communicated with a butanol storage tank 112, and the water outlet end 1082 is communicated with the water storage. The esterification column 106 is connected to a pressure self-regulating valve 110 for automatically controlling the pressure in the column.
A liquid pipe 1071 and a gas pipe 1072 are connected between each esterification kettle 107 and the esterification tower 106, one end of the liquid pipe 1071 is connected with the bottom of the esterification tower 106, the other end is connected with the upper part of the esterification kettle 107, one end of the gas pipe 1072 is connected with the top of the esterification kettle 107, the other end is connected with the lower part of the esterification tower 106, in the esterification tower 106, the pipe orifice of the gas pipe 1072 is higher than the pipe orifice of the liquid pipe 1071, a liquid level meter linkage valve 1071A is connected on the liquid pipe 1071, a check valve 1072A is connected on the gas pipe 1072 (wherein the linkage valve in the liquid level meter linkage valve 1071A is in linkage control with the liquid level meter on the esterification kettle under the tower, when the crude ester liquid level in the esterification kettle under the tower rises to a preset position, the liquid level meter sends a signal to the linkage valve to automatically close the crude ester to stop feeding, the check valve 1072A is a one-way valve, the vapor butanol in the esterification kettle under the tower rises to enter the esterification tower through the check, when the rising of the vaporous butanol stops, the check valve is automatically closed, and the vaporous butanol in the esterification tower cannot flow back to the esterification kettle below the tower).
In order to facilitate the examination of the content index of the crude ester mixed acid in the esterification kettle 107 under the tower, the esterification kettle 107 under the tower is provided with a sampling port which can be opened and closed. In addition, a crude ester regulating valve 1132 is connected to the crude ester pipe 113 between the crude ester discharge pump 1131 and the outside of the esterification reactor 107 under the tower, so as to control the discharge of the crude ester to the first crude ester storage tank.
Specifically, regarding the esterification apparatus 100, the mixed acid (rice bran oil mixed fatty acid) in the mixed acid storage tank 102 is pumped by the mixed acid metering pump 103, the mixed acid sequentially passes through the heat exchanger 104, the mixed acid heater 105 and the mixed acid distributor 1063, so that the mixed acid enters the esterification tower 106 and flows down along the surface of the corrugated packing 1064, meanwhile, the butanol metering pump 1111 pumps butanol in the butanol storage tank 112, the butanol passes through the butanol heater 1112 to become vaporous butanol, the vaporous butanol passes through the butanol distributor 1113 to enter the bottom of the esterification kettle, the vaporous butanol on one hand undergoes an esterification reaction with the unreacted mixed fatty acid of rice bran oil flowing into the esterification kettle 107 under the tower under the stirring of the stirring rod 1073 (so that the content of the fatty acid in the crude ester is reduced to within 0.2%), and on the other hand, the unreacted vaporous butanol rises into the esterification tower 106 through the vaporous pipe 1072 and fully reacts with the mixed acid flowing down along the surface of the corrugated packing 1064, Repeatedly contacting, carrying out esterification reaction under the action of a catalyst (wherein a heater 1065 in the tower provides reaction temperature for the esterification reaction), enabling the generated crude ester to flow into an esterification kettle 107 below the tower through a liquid pipe 1071, repeatedly circulating to realize continuous esterification, wherein the generated vaporous water and unreacted vaporous butanol continuously rise to the upper part of the esterification tower 106 and enter an alcohol-water separator 108 through a demisting wire 1061, a vaporous outlet 1062 and a heat exchanger 104, discharging the water out of the device, and enabling the liquid butanol to flow back into a butanol storage tank 112 to participate in the esterification reaction; when the amount of the crude ester in the esterification kettle under one tower reaches a certain amount, closing the corresponding liquid pipe and butanol pipe to stop the crude ester and the vaporous butanol from entering the esterification kettle under the tower (because the check valve on the vapor pipe is a one-way valve, the vaporous butanol in the esterification kettle under the tower rises through the check valve to enter the esterification tower, and when the vaporous butanol stops rising, the check valve is automatically closed, and the vaporous butanol in the esterification tower cannot flow back to the esterification kettle under the tower); and simultaneously opening a liquid pipe and a butanol pipe corresponding to the other esterification kettle under the tower, the inner part of which is empty, so that the esterification kettle under the tower is communicated with the esterification tower, the esterification continuity is ensured, the production stop is not needed, simultaneously, the content index of the mixed acid of the crude ester in the esterification kettle under the tower is detected, if the mixed acid content index does not reach the standard, the vaporous butanol is continuously introduced into the esterification kettle under the tower to continue the esterification reaction, and when the mixed acid content index reaches the standard, the crude ester flows into the first crude ester storage tank 114 for standby.
The fractionating device 200 comprises a second crude ester storage tank 202, a crude ester metering pump 203, a crude ester heater 204 and a fractionating tower 205 which are sequentially communicated through a fractionating pipe 201, the fractionating tower 205 is connected with a vacuum pump (not shown) for maintaining a negative pressure state in the fractionating tower 205, a butyl palmitate condenser 2051, a butyl palmitate receiver 2052 (connected with the butyl palmitate storage tank 2053), a first wire mesh filler 2054, a crude ester distributor 2055, a second wire mesh filler 2056 and a butyl palmitate heater 2057 are sequentially arranged in the fractionating tower 205 from top to bottom, wherein the crude ester distributor 2055 is communicated with the crude ester heater 204, the lower part of the fractionating tower 205 is sequentially communicated with a circulating pump 206 (specifically a water vapor injection circulating pump), a falling film heater 207 and a flash tower 208 through a flash pipe 211, a butyl oleate condenser 2081, a butyl oleate receiver 2082 (connected with the butyl oleate storage tank 2083) are sequentially arranged in the flash tower 208 from top to bottom, A third wire mesh packing 2084, wherein a communication port 2071 between the falling film heater 207 and the flash tower 208 is positioned below the third wire mesh packing 2084; wherein the lower portion of the flash column 208 is in communication with the circulation pump 206 through a vapor recovery pipe 209.
The butyl palmitate receiver 2052 and the butyl oleate receiver 2082 are both of a receiver structure, and specifically, as shown in fig. 4, the butyl palmitate receiver 2052 and the butyl oleate receiver 2082 comprise a receiver 401, a through pipe 402 is connected to the receiver 401 in a penetrating manner, the upper side wall of the through pipe 402 is provided with an air inlet 403, the upper end of the through pipe 402 is connected with a cap 404 (cap-shaped structure) which prevents purified liquid butyl palmitate and liquid butyl oleate from flowing into the through pipe 402, the upper periphery of the receiver 401 is provided with an upwardly extending retaining ring 405, and the retaining ring 405 is provided with a discharge chute 406 which is communicated with a butyl palmitate storage tank and a butyl oleate storage tank; taking the butyl palmitate receiver 2052 as an example, the vaporous butyl palmitate rises through the through pipe and the steam inlet and enters the butyl palmitate condenser, the formed liquid butyl palmitate flows into the receiver, and the liquid butyl palmitate cannot flow into the through pipe due to the blocking of the cap 404.
A cleaning storage tank (not shown) is connected between the butyl palmitate receiver 2052 and the butyl oleate receiver first crude ester storage tank 114 and the second crude ester storage tank 202, a feeding pipe is connected between the cleaning storage tank and the second crude ester storage tank 202, and a feeding pump (used for pumping the crude ester in the cleaning storage tank into the second crude ester storage tank 202) is arranged on the feeding pipe.
And a residue outlet is formed at the bottom of the flash tower and is connected with an asphalt storage tank 210.
The first wire mesh packing 2054 and the second wire mesh packing 2056 are stainless wire mesh packing, and have the functions of realizing vapor-liquid exchange and separating different components; the third wire mesh packing 2084 is also a stainless wire mesh packing and is used for separating impurities in the butyl oleate; in addition, butyl oleate is fed in the tube pass of the falling film heater 207, and heat conducting oil is fed outside the tube pass (shell pass), so that the liquid butyl oleate is heated and changed into vapor butyl oleate, and the vapor butyl oleate enters the flash tower 208.
In the fractionation apparatus 200, the crude ester (catalyst-washed crude ester) in the second crude ester storage tank 202 is pumped by the crude ester metering pump 203, and the crude ester passes through the crude ester heater 204 and the crude ester distributor 2055 in sequence to enter the fractionation tower 205, wherein the butyl palmitate is in a vapor state and the butyl oleate is in a liquid state, the vapor butyl palmitate rises upward and enters the first wire mesh packing 2054, passes through the butyl palmitate receiver 2052, enters the butyl palmitate condenser 2051, the condensed vapor butyl palmitate is in a liquid state and flows downward into the butyl palmitate receiver 2052 and then flows out of the fractionation tower 205, wherein the unvaporized butyl palmitate passes downward and passes through the second wire mesh packing 2056 and the butyl palmitate heater 2057, and is vaporized and rises to the butyl palmitate condenser 2051 by the butyl palmitate heater 2057, and the butyl oleate liquid flows downward and passes through the second wire mesh packing 2056, the butyl oleate distributor 2056, the butyl oleate liquid, A butyl palmitate heater 2057 (the boiling point of butyl oleate is higher than that of butyl palmitate, so that butyl oleate is not vaporized) and then sequentially enters the falling film heater 207 (for heating butyl oleate into a vapor state) and the flash tower 208 through the circulating pump 206, the vapor-state butyl oleate sequentially rises in the flash tower 208, passes through the third wire mesh filler 2084, passes through the butyl oleate receiver 2082, enters the butyl oleate condenser 2081, the condensed vapor-state butyl oleate becomes a liquid state, flows downwards into the butyl oleate receiver 2082, then flows out of the fractionating tower 205, enters the butyl oleate storage tank, and the plant asphalt flows out of the tower and enters the asphalt storage tank 210.
The side wall of the mixed acid heater 105, the side wall of the butanol heater 1112 and the side wall of the crude ester heater 204 in the embodiment are all provided with heat conduction oil; the external kettle heater 1075 and the butyl palmitate heater 2057 are heat-conducting oil heating coils.
The acid mixing distributor 1063, the butanol distributor 1113, and the crude ester distributor 2055 in this embodiment are all pressure-type distributors, and specifically include a feeding main pipe 301 connected to a corresponding material and a plurality of branch pipes 302 connected to both sides of the feeding main pipe 301, as shown in fig. 5, the feeding main pipe 301 is communicated with the branch pipes 302, and the feeding main pipe 301 and the branch pipes 302 are both provided with distribution holes 303 for the material to flow out; wherein the acid mixing distributor 1063 and the butanol distributor 1113 only comprise downward-facing distribution holes, and the crude ester distributor 2055 comprises both upward-facing distribution holes and downward-facing distribution holes.
The parameters of the esterification column 106, the in-column heater 1065, the under-column esterification reactor 107, the fractionating column 205, and the flash column 208 in this embodiment are as follows:
esterification column 106:
the diameter DN is 0.3-2 m, preferably DN1.2m; the height is 10-30 m, preferably 20m, the height is divided into three sections, each section is 6m (the corrugated packing is 1064 sections are 5m), and the height of each section is 1m at the top and the bottom of the tower; the wall thickness of the tower body is 8-12 mm, preferably 10mm, the tower body is made of 316L stainless steel lining polytetrafluoroethylene plates, and the corrugated packing 1064 is made of ceramic; the pressure resistance of the tower body is more than or equal to 2.5MPa, and the operating pressure is 0.1-0.35 MPa; the diameter of the esterification tower 106 is related to the yield, on the premise that the height of the esterification tower 106 is determined, the larger the diameter is, the more the feeding amount is, but the diameter is large, the materials are easy to be distributed unevenly, the contact and reaction times are reduced, and the esterification rate is reduced on the contrary, so that the diameter of 0.3-2 m is suitable, and the esterification rate is ensured.
In-tower heater 1065:
the diameter DN is matched with the diameter DN1.2m of the esterification tower 106, and the material is 316L stainless steel coated with polytetrafluoroethylene;
esterification kettle under column 107:
the esterification reaction kettle comprises an esterification kettle A under the tower and an esterification kettle B under the tower, wherein each esterification kettle A and each esterification kettle B has a volume of 10m3, the material of a kettle body is 316L stainless steel-lined polytetrafluoroethylene, the pressure resistance of the kettle body is more than or equal to 2.5MPa, and the operating pressure is 0.1-0.35 MPa;
fractionating column 205:
the diameter DN is 0.6-2.5 m, preferably 1.5 m; the height is 8-15 m, preferably 14m, and the device is divided into two sections, wherein the upper section is a fractionation section of 6m, and the lower section is a stripping section of 8 m; the wall thickness is 8-10 mm, preferably 8mm, the material is 304L stainless steel, and the first wire mesh filler 2054 and the second wire mesh filler 2056 are stainless steel; negative pressure of-0.1 MPa in vacuum state; the temperature of the top of the fractionating tower 205 is controlled at 190 ℃, and the temperature of the bottom of the fractionating tower is controlled at 230 ℃;
the flash column 208:
the diameter DN 1-3 m, preferably 2 m; a height of 3 m; the wall thickness is 8-10 mm, preferably 10mm, and the material is 304L stainless steel; negative pressure of-0.1 MPa in vacuum state; the falling film heater 207 is a square meter of 90 square meters and is made of 304L stainless steel; the butyl oleate condenser 2081 is a square meter of 60 square meters and is made of 304L stainless steel.
A process method for synthesizing mixed fatty acid butyl ester based on the equipment and synthesizing butyl oleate and butyl palmitate based on the mixed fatty acid butyl ester,
esterification:
fractional distillation:
the method specifically comprises the following steps:
s1: selection of raw materials
Rice bran oil mixed fatty acid: acid value mgKOH/g: not less than 190
Iodine value gI2/100g：95-105
N-butanol: national standard, alcohol content ≧ 99.5
The catalyst is p-toluenesulfonic acid: sulfuric acid (H) with a content of more than or equal to 95%2SO4)％≤3
S2: stock preparation
a. Adding p-toluenesulfonic acid into the rice bran oil mixed fatty acid, uniformly stirring, pumping into a mixed acid storage tank 102 for later use, and keeping the temperature at 60 ℃;
b. n-butanol is kept in the butanol storage tank 112 for standby (normal temperature);
s3: feeding of the feedstock
a. Preheating the mixed fatty acid of rice bran oil with a mixed acid metering pump 103 at the uniform speed of 1000 kg per hour to 130 ℃ through a heat exchanger 104 and a mixed acid heater 105, and pumping the mixture into an esterification tower 106;
b. preheating n-butanol to 160 ℃ by a butanol heater 1112 at an even speed of 530 kg per hour by a butanol metering pump 1111, and pumping the n-butanol into the lower part of the esterification kettle 107 under the tower;
s4: esterification reaction
a. The mixed fatty acid of the rice bran oil is uniformly distributed on the surface of a corrugated filler 1064 through an acid mixing distributor 1063, and flows downwards along the surface of the corrugated filler 1064 under the action of gravity, n-butanol is pumped into the bottom in an esterification kettle in the tower through a butanol heater 1112 through a butanol metering pump 1111, liquid n-butanol is heated to 160 ℃ through the butanol heater 1112 to be in a vapor state, the vapor state n-butanol rises to enter the lower part of the esterification tower 106 and then rises along the corrugated filler 1064 in the esterification tower 106 to be contacted with the mixed fatty acid of the rice bran oil on the corrugated filler 1064 to carry out esterification reaction, wherein the reaction temperature is between 130 and 150 ℃ (the heat required by the esterification reaction is provided by two heaters 1065 in the tower), the crude ester generated by the reaction flows downwards along the surface of the corrugated filler 1064 to enter the esterification kettle 107 in the tower and is repeated continuously, and the redundant vapor state n-butanol and vapor state water are discharged from a, The alcohol-water separator 108, wherein the liquid butanol flows back to the butanol storage tank 112 to continuously participate in the esterification reaction, and the liquid water is discharged out of the device;
b. if the crude ester flowing into the esterification kettle 107 under the tower contains unreacted rice bran oil mixed fatty acid, the steam n-butanol and the rice bran oil mixed fatty acid are subjected to esterification reaction under the stirring of the stirring rod 1073, wherein the unreacted steam n-butanol rises to enter the esterification tower 106;
c. when the amount of the crude ester in the esterification kettle under the tower reaches a certain amount and reaches the standard, pumping the crude ester into a first crude ester storage tank;
d. the esterification kettle under the tower 107 comprises 2, when the crude ester amount in the esterification kettle under the tower A in use reaches a certain amount (for example, 80 percent of the volume), the corresponding liquid pipe and butanol pipe are closed, the crude ester and the vaporous n-butanol stop entering the esterification kettle under the tower A, and the liquid pipe and butanol pipe of the esterification kettle B under the other tower are opened, the crude ester and the vaporous n-butanol enter the esterification kettle B under the tower, so that the automatic switching between the esterification kettle A under the tower and the esterification kettle B under the tower is realized (the check valve on the vapor pipe is a one-way valve, the vaporous butanol in the esterification kettle under the tower rises and enters the esterification tower through the check valve, but when the vaporous butanol stops rising, the check valve is also automatically closed, the vaporous butanol in the esterification tower cannot flow back to the esterification kettle under the tower, simultaneously the mixed acid content index of the crude ester in the esterification kettle A under the tower is detected, if the mixed acid content index reaches the standard, the crude ester is pumped into the first crude ester storage, at the moment, the esterification kettle A under the tower is emptied for standby and is continuously repeated; if the standard is not met, continuously introducing the vaporous n-butanol into the esterification kettle A under the tower, continuously carrying out the esterification reaction for 1-2 hours under stirring, and continuously carrying out the esterification reaction until the standard is met; (generally, each kettle works for about 8 hours, and the total time of the supplementary esterification of the esterification kettle 107 below the tower is not more than 3 hours)
S5: the crude ester in the first crude ester storage tank 114 is washed by clean water to remove the catalyst and then pumped into a second crude ester storage tank 202 for standby;
s6: fractional distillation
a. Pumping the crude ester in the second crude ester storage tank 202 into a fractionating tower 205 by a crude ester metering pump 203 at a uniform speed of 1200L per hour through a crude ester heater 204, controlling the temperature of the crude ester heater 204 at 210 ℃, and separating out vaporous butyl palmitate, liquid butyl oleate and plant asphalt;
b. the vaporous butyl palmitate rises upwards and enters a butyl palmitate condenser to be condensed into liquid, the liquid butyl palmitate flows out of the fractionating tower and then flows into a butyl palmitate receiver 2052, then the liquid butyl palmitate enters a butyl palmitate storage tank, the monomer purity is not less than 95 percent, and the liquid butyl oleate and the plant asphalt flow out of the lower part of the distillation tower;
c. the effluent liquid butyl oleate and the plant asphalt pass through a circulating pump 206 and a falling film heater 207 and then enter a flash tower 208; the falling film heater 207 controls the temperature to 240 ℃, the vacuum residual pressure of the flash tower 208 is less than 1 mm Hg, so that the liquid butyl oleate is vaporized,
the vaporous butyl oleate rises upwards and enters a butyl oleate condenser 2081 to be condensed into liquid, the liquid butyl oleate flows out of the flash tower 208 and then flows into a butyl oleate receiver, and then enters a butyl oleate storage tank 2083, and unvaporized plant asphalt flows out of the bottom of the tower and enters an asphalt storage tank 210.
d. Within the fractionator, the unvaporized liquid butyl palmitate passes down through a second wire mesh packing 2056, a butyl palmitate heater 2057, the butyl palmitate heater 2057 vaporizing the liquid butyl palmitate.
Further explaining the content index of mixed acid in S4, when the esterification rate is required to reach 99.5% (the acid value index of the product is less than 0.1), further supplementary esterification is needed, in general, the esterification rate of the crude ester flowing out from the bottom of the esterification tower 106 is about 99% and not less than 98.5%, and after refining, the crude ester meets the requirements of conventional products, and when the acid value index is less than 0.1, further supplementary esterification is needed, so that the esterification rate of the crude ester reaches about 99.5%.
The products obtained by the above process are shown in table 1 below;
TABLE 1
The butyl palmitate (about 15 percent), the butyl oleate (about 80 percent) and the plant asphalt are obtained by fractionating and cutting through a fractionating tower, the butyl palmitate and the butyl oleate are widely applied in the plastic industry and the lubricating oil industry, wherein the butyl oleate has light color and high purity, the flash point reaches over 180 ℃, the technical index of a lubricating oil additive is completely met, and the plant asphalt can be used as fuel or a casting binder.
In addition, the following tables 2 to 5 are used to respectively illustrate the influence of the mass ratio of the mixed fatty acid of rice bran oil and n-butanol on the esterification rate, the influence of the esterification temperature on the esterification rate, the influence of the catalyst dosage on the esterification rate, and the influence of the height of the esterification tower section on the esterification rate, so as to facilitate the realization of a better esterification reaction scheme.
Table 2: influence of mass ratio of mixed fatty acid of rice bran oil and butanol on esterification rate
Catalyst (based on the mass of the mixed acid): 0.5%, esterification temperature: 140 ℃, esterification column height: 15m
| Alcohol: acid(s) | 100:26.5 | 100:40 | 100:53 | 100:64 | 100:74 | 100:83 | 100:95 |
| Esterification rate% | 73.5 | 92.7 | 98.3 | 98.5 | 98.7 | 98.9 | 98.9 |
TABLE 2
Table 3: effect of esterification temperature on esterification Rate
Mixed acid: butanol 100:53, catalyst: 0.5%, esterification column height: 15m
| Esterification temperature C | 125 | 130 | 135 | 140 | 145 | 150 | 155 |
| Esterification rate% | 61.5 | 82.3 | 92.1 | 98.2 | 98.5 | 98.6 | 98.6 |
TABLE 3
Table 4: effect of catalyst amount on esterification Rate
Acid: alcohol 100:53, esterification temperature: 140 ℃, esterification column height: 15m
TABLE 4
Table 5: effect of esterification column height on esterification Rate
Acid mixing: alcohol 100:53, esterification temperature: 140 ℃, catalyst: 0.5 percent
TABLE 5
Claims (10)
1. A continuous esterification apparatus, characterized in that: a mixed acid storage tank, a mixed acid metering pump, a heat exchanger, a mixed acid heater and an esterification tower which are sequentially communicated through an acid mixing pipe, wherein the upper part in the esterification tower is provided with a mixed acid distributor communicated with the mixed acid heater, a plurality of corrugated fillers which are arranged up and down are arranged below the mixed acid distributor, an in-tower heater is arranged between every two adjacent corrugated fillers, a plurality of under-tower esterification kettles which can be alternately communicated with the lower part of the esterification tower are arranged below the esterification tower, a liquid pipe and a vapor pipe are connected between each under-tower esterification kettle and the esterification tower, the under-tower esterification kettle is connected with a butanol storage tank through a butanol pipe, a first crude ester storage tank is connected through a crude ester pipe, the butanol pipe is sequentially connected with a butanol metering pump, a butanol heater, a butanol regulating valve and a butanol distributor, wherein the butanol distributor is positioned below the under-tower in the esterification kettle, a stirring rod is arranged above the butanol distributor, a vapor outlet positioned above the mixed acid distributor is arranged on the esterification tower, the steam outlet is communicated with the heat exchanger.
2. A continuous esterification apparatus according to claim 1, wherein: the liquid pipe is connected with a liquid level meter linkage valve, the gas pipe is connected with a check valve, and a liquid level meter is arranged in the esterification kettle below the tower.
3. A continuous esterification apparatus according to claim 1 or 2, wherein: one end of the liquid pipe is connected with the bottom of the esterification tower, the other end of the liquid pipe is connected with the upper part of the esterification kettle under the tower, one end of the vapor pipe is connected with the kettle top of the esterification kettle under the tower, and the other end of the vapor pipe is connected with the lower part of the esterification tower; in the esterification tower, the nozzle of the gas pipe is higher than that of the liquid pipe.
4. A continuous esterification apparatus according to claim 1, wherein: and the crude ester pipe is connected with a crude ester discharging pump.
5. A continuous esterification apparatus according to claim 1, wherein: oleic acid distributor, butanol distributor all include the feeding and are responsible for and connect in a plurality of branch pipes of feeding person in charge both sides, and the feeding is responsible for and branch pipe intercommunication, and the feeding is responsible for and all opens the opening distributing hole down on the branch pipe.
6. A continuous esterification apparatus according to claim 1, wherein: one end of the heat exchanger inner tube pass is connected with the mixed acid metering pump through the mixed acid pipe, the other end of the heat exchanger inner tube pass is connected with the mixed acid heater through the mixed acid pipe, one end of the heat exchanger inner shell pass is connected with the steam outlet, and the other end of the heat exchanger inner shell pass is connected with the alcohol-water separator.
7. A continuous esterification apparatus according to claim 8, wherein: the alcohol-water separator comprises an alcohol outlet end and a water outlet end, wherein the alcohol outlet end is communicated with the butanol storage tank.
8. A continuous esterification apparatus according to claim 1, wherein: in the esterification tower, the top of mixing acid distributor is equipped with the defogging silk screen, the vapour outlet is located defogging silk screen's top or side.
9. A continuous esterification method for synthesizing mixed fatty acid butyl ester based on the device of claim 1, which is characterized by comprising the following steps:
s1: selection of raw materials
Rice bran oil mixed fatty acid: acid value mgKOH/g: not less than 190
Iodine value gI2/100g：95-105
N-butanol: alcohol content%
The catalyst is p-toluenesulfonic acid: sulfuric acid (H) with a content of more than or equal to 95%2SO4)％≤3
S2: stock preparation
a. Adding p-toluenesulfonic acid into the rice bran oil mixed fatty acid, uniformly stirring, pumping into a mixed acid storage tank for later use, and keeping the temperature at 55-65 ℃;
b. n-butanol is reserved in a butanol storage tank (normal temperature);
s3: feeding of the feedstock
a. Uniformly preheating the mixed fatty acid of the rice bran oil to 130-150 ℃ by using a mixed acid metering pump through a heat exchanger and a mixed acid heater, and pumping the mixture into an esterification tower;
b. preheating n-butyl alcohol to 160-165 ℃ at a uniform speed by a butanol metering pump through a butanol heater, and pumping the n-butyl alcohol into the lower part of the lower esterification kettle of the tower;
s4: esterification reaction
a. Uniformly distributing rice bran oil mixed fatty acid on the surface of a corrugated filler through an acid mixing distributor, allowing the rice bran oil mixed fatty acid to flow downwards along the surface of the corrugated filler under the action of gravity, pumping n-butanol into the lower part of an esterification kettle in a tower through a butanol metering pump by virtue of a butanol heater, heating liquid n-butanol to 160-165 ℃ by virtue of the butanol heater to form vapor n-butanol, allowing the vapor n-butanol to rise into the lower part of the esterification tower, then rising along the corrugated filler in the esterification tower, contacting with the rice bran oil mixed fatty acid on the corrugated filler and carrying out esterification reaction, allowing crude ester generated by the reaction to flow downwards along the surface of the corrugated filler to enter the esterification kettle under the tower, continuously repeating the steps, discharging redundant vapor n-butanol and vapor water from a vapor outlet, sequentially entering a heat exchanger and an alcohol-water separator, allowing the liquid butanol to flow back to a butanol storage tank to continuously;
b. if the crude ester flowing into the esterification kettle under the tower contains unreacted rice bran oil mixed fatty acid, the vaporous n-butanol and the rice bran oil mixed fatty acid are subjected to esterification reaction under the stirring of a stirring rod, wherein the unreacted vaporous n-butanol rises to enter the esterification tower;
c. when the crude ester amount in the esterification kettle under the tower reaches a certain amount and reaches the standard, pumping the crude ester into a first crude ester storage tank.
10. A continuous esterification process for the synthesis of mixed fatty acid butyl esters according to claim 9, characterized in that: in S4, the esterification kettle under the tower comprises a plurality of esterification kettles, when the amount of the crude ester in the esterification kettle A under the tower reaches a certain amount, the corresponding liquid pipe and the butanol pipe are closed, the crude ester and the vapor-state n-butanol stop entering the esterification kettle A under the tower, the liquid pipe and the butanol pipe of the esterification kettle B under the other tower are opened, and the crude ester and the vapor-state n-butanol enter the esterification kettle B under the tower; simultaneously detecting the content index of mixed acid of the crude ester in the esterification kettle A under the tower, if the mixed acid reaches the standard, pumping the crude ester into a first crude ester storage tank for treatment, and emptying the esterification kettle A under the tower for standby and repeating continuously; if the standard is not met, continuously introducing the vapor-state n-butanol into the esterification kettle A below the tower, and continuously carrying out the esterification reaction until the standard is met.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010172794.5A CN111253253A (en) | 2020-03-13 | 2020-03-13 | Continuous esterification equipment and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010172794.5A CN111253253A (en) | 2020-03-13 | 2020-03-13 | Continuous esterification equipment and method |
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| CN111253253A true CN111253253A (en) | 2020-06-09 |
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| CN101948384A (en) * | 2010-10-14 | 2011-01-19 | 谢仁华 | Device and method for preparing medium and high-carbon aliphatic ester by continuous etherification method |
| CN105062696A (en) * | 2015-04-16 | 2015-11-18 | 彭才文 | Single-tower countercurrent supercritical non-catalytic continuous esterification process method |
| CN105693514A (en) * | 2016-03-18 | 2016-06-22 | 江苏雷蒙化工科技有限公司 | Continuous production system and production method of polyalcohol low-carbon carboxylate ester |
| CN110790667A (en) * | 2019-11-14 | 2020-02-14 | 海盐县精细化工有限公司 | Continuous esterification process for synthesizing isooctyl oleate |
| CN212348709U (en) * | 2020-03-13 | 2021-01-15 | 何关印 | Continuous esterification equipment |
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101948384A (en) * | 2010-10-14 | 2011-01-19 | 谢仁华 | Device and method for preparing medium and high-carbon aliphatic ester by continuous etherification method |
| CN105062696A (en) * | 2015-04-16 | 2015-11-18 | 彭才文 | Single-tower countercurrent supercritical non-catalytic continuous esterification process method |
| CN105693514A (en) * | 2016-03-18 | 2016-06-22 | 江苏雷蒙化工科技有限公司 | Continuous production system and production method of polyalcohol low-carbon carboxylate ester |
| CN110790667A (en) * | 2019-11-14 | 2020-02-14 | 海盐县精细化工有限公司 | Continuous esterification process for synthesizing isooctyl oleate |
| CN212348709U (en) * | 2020-03-13 | 2021-01-15 | 何关印 | Continuous esterification equipment |
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