CN212348709U

CN212348709U - Continuous esterification equipment

Info

Publication number: CN212348709U
Application number: CN202020308264.4U
Authority: CN
Inventors: 何关印; 陈玉成
Original assignee: Individual
Current assignee: Hunan Chengyouhua Technology Co ltd
Priority date: 2020-03-13
Filing date: 2020-03-13
Publication date: 2021-01-15
Anticipated expiration: 2030-03-13

Abstract

The utility model relates to a continuous esterification device, including mixing the sour storage tank, mix sour measuring pump, heat exchanger, mix sour heater, the tower of esterifying, be equipped with in the tower of esterifying and mix sour distributor, it is equipped with the ripple filler to mix sour distributor below, be equipped with the interior heater of tower between two liang of adjacent ripples fillers, it can with the tower lower part of esterifying under a plurality of towers of intercommunication in turn to be equipped with in the tower below, the cauldron of esterifying has the butanol storage tank through butanol union coupling under the tower, there is first thick ester storage tank through thick ester union coupling, the butanol pipe is last to have connected gradually the butanol measuring pump, the butanol heater, the butanol governing valve, the butanol distributor is located the interior below of the cauldron of esterifying under the tower, top at the butanol distributor is equipped with the stirring. Compared with the prior art, the utility model discloses a continuous vapour-liquid countercurrent mode obtains crude ester semi-manufactured goods to adopted the mode of a plurality of cauldron of esterifying operation in turn, possessed a great deal of advantages such as operation automation, uninterrupted production, efficient, output height, with low costs.

Description

Continuous esterification equipment

Technical Field

The utility model relates to an esterify technical field, in particular to equipment of esterifying in succession.

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 continuous gas-liquid countercurrent mode and an esterification kettle alternative operation mode 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 prior art problem, the utility model provides a continuous esterification device, this equipment adopt continuous gas-liquid countercurrent mode to obtain crude ester semi-manufactured goods, for getting butyl palmitate and butyl oleate and lay the basis down to adopted the mode of a plurality of cauldron of esterifying operation in turn, possessed a great deal of advantages such as operation automation, uninterrupted production, efficient, output height, with low costs.

SUMMERY OF THE UTILITY MODEL

The utility model provides an equipment of esterifying in succession, this equipment adopt continuous gas-liquid countercurrent mode to obtain crude ester semi-manufactured goods, for getting butyl palmitate and butyl oleate and lay the basis down to adopted the mode of a plurality of cauldron of esterifying operation in turn, possessed a great deal of advantages such as operation automation, uninterrupted production, efficient, output high, with low costs.

The technical scheme of the utility model is realized like this:

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 gas 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 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 esterification kettles, a stirring rod is arranged above the butanol distributor, and the esterification tower is provided with a gas outlet positioned above the acid mixing distributor, and the gas outlet is communicated with the heat exchanger.

The utility model relates to an esterification device (replacing the traditional kettle type intermittent method esterification) which continuously esterifies in a gas-liquid countercurrent mode and continuously produces in an esterification kettle alternative operation mode under a tower, and a fractionating device which is used 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 gaseous butanol, the gaseous butanol enters the bottom of an esterification kettle through the butanol distributor, the gaseous butanol on the one hand has an esterification reaction with the 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 gaseous butanol rises into the esterification tower through a gas pipe and is fully and repeatedly contacted with the mixed acid flowing downwards on the surface of the corrugated filler to have the esterification reaction 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, the generated gaseous water and unreacted gaseous butanol continuously rise to the upper part of the esterification tower together and enter an alcohol-water separation device through a gas outlet and a heat exchanger, water is discharged out of the device, and the liquid butanol flows back into a butanol storage tank again to participate in 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 gaseous 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 crude ester mixed acid content index 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 reaches the standard, continuously introducing the gaseous butanol into the esterification kettle under the tower to continue the esterification reaction, and when the crude ester reaches the standard, flowing the crude ester 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, gaseous butanol in the esterification kettle below the tower rises to enter the esterification tower through the check valve, when the gaseous butanol stops rising, the check valve is automatically closed, and the gaseous butanol in the esterification tower cannot flow back into 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 gas pipe is connected with the kettle top of the esterification kettle under the tower, and the other end of the gas pipe is connected with the lower part of the esterification tower; in the esterification tower, the orifice of the gas pipe is higher than that of the liquid pipe.

The pipe orifice of the gas pipe is higher than that of the liquid pipe, so that the gaseous butanol can not be interfered by the crude ester and can quickly rise in the esterification tower.

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.

Ensuring full and rapid esterification reaction between the gaseous butanol and the mixed acid, 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 acid mixing 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.

And the liquid mixed acid and the gaseous 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 gaseous butanol enters the lower esterification kettle and the esterification 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 gas outlet, and the other end of the inner shell pass of the heat exchanger is connected with the alcohol-water separator.

And the gaseous butanol is cooled into a liquid state 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 gas outlet is positioned above or beside the demisting wire mesh.

To remove entrained liquid sites in the gaseous butanol.

Adopted above-mentioned technical scheme the beneficial effects of the utility model are that:

the utility model provides a continuous esterification equipment, this equipment adopt continuous gas-liquid countercurrent mode to obtain crude ester semi-manufactured goods, for getting butyl palmitate and butyl oleate and lay the basis down to adopted the mode of a plurality of cauldron of esterifying operation in turn, possessed a great deal of advantages such as operation automation, uninterrupted production, efficient, output high, with low costs. The equipment realizes continuous esterification and continuous operation between the rice bran oil mixed fatty acid and the butanol by a gas-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 gas outlet 1062, an under-tower esterification kettle 107, a liquid pipe 1071, a level gauge linkage valve 1071A, a gas pipe 1072, a check valve 1072A, a stirring rod 1073, a stirring fan 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 heater 204, a fractionation tower 205, a butyl palmitate condenser 2051, a butyl palmitate receiver 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 vapor 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, an air inlet 403, a cover cap 404, a retainer ring 405 and a discharge tank 406.

Detailed Description

The specific implementation manner of the utility model is as follows:

the utility model discloses an equipment of esterifying is esterified the mixed fatty acid and is obtained mixed fatty acid butyl ester, and wherein mixed fatty acid butyl ester separates into butyl oleate, butyl palmitate and can combine following fractionating device to realize that equipment realizes fractionating.

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 gas outlet 1062 is arranged above or beside the demisting wire mesh 1061, the gas 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 gas 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. The esterification column 106 is connected to a pressure self-regulating valve 110 for automatically controlling the pressure in the column.

Esterification kettle 107 is connected with butanol storage tank 112 through butanol pipe 111 under the tower, is connected with first crude ester storage tank 114 through crude ester pipe 113, butanol pipe 111 is last to connect gradually butanol measuring pump 1111, butanol heater 1112, butanol governing valve 1114 (realize feeding gaseous butanol to esterification kettle's control under the tower), butanol distributor 111, wherein butanol distributor 1113 is located esterification kettle 107 under the tower below in, be equipped with the stirring rod 1073 that the lower extreme is stirring fan blade 1074 in butanol distributor 1113's top, be equipped with cauldron external heater 1075 on the lateral surface lower part of esterification kettle 107 under the tower, be connected with crude ester ejection of compact pump 1131 on crude ester pipe 113.

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, the pipe orifice of the gas pipe 1072 is higher than the pipe orifice of the liquid pipe 1071 in the esterification tower 106, 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 linkage valve to stop the crude ester feeding, the check valve 1072A is a one-way valve, and the gaseous butanol in the esterification kettle under the tower rises to, when the gaseous butanol stops rising, the check valve is automatically closed, and the gaseous 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 gaseous butanol, the gaseous butanol passes through the butanol distributor 1113 to enter the bottom of the esterification kettle, the gaseous butanol on the one hand and the unreacted rice bran oil mixed fatty acid flowing into the esterification kettle 107 under the tower are subjected to esterification reaction under the stirring of the stirring rod 1073 (so that the content of the fatty acid in the crude ester is reduced to be within 0.2%), on the other hand, the unreacted gaseous butanol rises into the esterification tower 106 through the gas pipe 1072 and is sufficiently mixed acid flowing down with 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 gaseous water and unreacted gaseous butanol continuously rise to the upper part of the esterification tower 106 and enter an alcohol-water separator 108 through a demisting wire net 1061, a gas outlet 1062 and a heat exchanger 104, discharging 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 gaseous butanol from entering the esterification kettle under the tower (because the check valve on the gas pipe is a one-way valve, the gaseous butanol in the esterification kettle under the tower rises through the check valve and enters the esterification tower, and when the gaseous butanol stops rising, the check valve is automatically closed, and the gaseous 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 gaseous 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 line 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) for preventing 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 for communicating the butyl palmitate storage tank and the butyl oleate storage tank; taking the butyl palmitate receiver 2052 as an example, the gaseous butyl palmitate rises to enter the butyl palmitate condenser after passing through the through pipe and the air inlet, the formed liquid butyl palmitate flows into the receiving tray, 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 gas-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 side of the falling film heater 207, and heat conducting oil is fed outside the tube side (shell side), so that the liquid butyl oleate is heated and changed into gaseous butyl oleate, and the gaseous 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 gaseous state, the butyl oleate is in a liquid state, the gaseous 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 gaseous butyl palmitate is in a liquid state, 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, 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 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 gasified) and then sequentially enters the falling film heater 207 (for heating butyl oleate into gas state) and the flash tower 208 through the circulating pump 206, the gas butyl oleate sequentially rises in the flash tower 208, passes through the third wire mesh filler 2084, passes through the butyl oleate receiver 2082 and enters the butyl oleate condenser 2081, the condensed gas butyl oleate is in a liquid state, flows downwards into the butyl oleate receiver 2082 and then flows out of the fractionating tower 205 to enter a butyl oleate storage tank, and the plant asphalt flows out of the tower to enter 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 size of esterifying tower 106 is with being related to output, and under the prerequisite of esterifying tower 106 high definite, its diameter is big more, and the feed volume is more, but the diameter is big, and the material distributes inequality easily, and contact, reaction number of times descend, and the esterification rate reduces on the contrary, consequently, the utility model discloses a diameter is comparatively suitable for 0.3 ~ 2m, guarantees the esterification rate.

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:

comprises an esterification kettle A under the tower and an esterification kettle B under the tower, each of which has a volume of 10m³The kettle body is made of 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 esterification equipment and synthesizing butyl oleate and butyl palmitate based on a fractionating device,

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, the liquid n-butanol is heated to 160 ℃ through the butanol heater 1112 to be in a gaseous state, the gaseous 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 in contact 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, and the redundant gaseous n-butanol and gaseous water, 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 gaseous 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 gaseous n-butanol rises to enter the esterification tower 106;

c. when the amount of the crude ester in the esterification kettle 107 under the tower reaches a certain amount and reaches the standard, pumping the crude ester into a first crude ester storage tank 114;

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 gaseous 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 gaseous 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 gas pipe is a one-way valve, the gaseous butanol in the esterification kettle under the tower rises through the check valve to enter the esterification tower, but when the gaseous butanol stops rising, the check valve is also automatically closed, the gaseous butanol in the esterification tower cannot flow back into 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, and if the mixed acid content index meets the standard, the crude ester is pumped into, 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 gaseous n-butanol into the esterification kettle A under the tower, continuously carrying out esterification reaction for 1-2 hours under stirring, and continuously carrying out 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 gaseous butyl palmitate, liquid butyl oleate and plant asphalt;

b. the gaseous butyl palmitate rises upwards, enters a butyl palmitate condenser and is condensed into liquid, the liquid butyl palmitate flows out of the fractionating tower, then flows into a butyl palmitate receiver 2052, and then enters a butyl palmitate storage tank, the monomer purity is more than or equal to 95%, 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 gasified,

the gaseous 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 the unvaporized plant asphalt flows out of the tower bottom 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 catalyst of the mass ratio of mixed fatty acid of rice bran oil and butanol on the esterification rate (based on the mass of 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 acids: 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: influence 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

TABLE 5

Acid mixing: alcohol 100:53, esterification temperature: 140 ℃, catalyst: 0.5 percent.

Claims

1. A continuous esterification apparatus, characterized in that: 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 gas 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 the 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, wherein the butanol distributor is positioned below the under-tower esterification kettle, and a stirring rod is arranged above the butanol, and the esterification tower is provided with a gas outlet positioned above the acid mixing distributor, and the gas 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 gas pipe is connected with the top of the esterification kettle under the tower, and the other end of the gas pipe is connected with the lower part of the esterification tower; in the esterification tower, the orifice 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: mix acid distributor, butanol distributor all include the feeding and be responsible for and connect in a plurality of branch pipes of feeding person in charge both sides, the feeding is responsible for and branch pipe intercommunication, and the feeding is responsible for and all opens the distributing hole that the opening is 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 tube, the other end of the heat exchanger inner tube pass is connected with the mixed acid heater through the mixed acid tube, one end of the heat exchanger inner shell pass is connected with the gas 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 6, 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, gas outlet is located defogging silk screen's top or side.