Butyl lactate production apparatus

Abstract

The utility model belongs to butyl lactate production equipment technical field relates to a kind of butyl lactate production device, including esterification kettle, is equipped with feeding opening, discharge port, column top backflow port and column bottom backflow port;Rectifying tower, multiple packing sections are equipped with along height, column top connects column top backflow processing unit, middle lower side connects side line backflow processing unit, column bottom is communicated with column bottom backflow port by column bottom pipeline;Column top backflow processing unit includes the column top condenser connected with column top export, column top condenser is sequentially connected oil-water delamination tank, column top backflow tank, column top backflow pump, and column top backflow pump export is communicated with column top import, column top backflow port;Side line backflow processing unit includes the side line backflow tank connected with side export, and side line backflow tank connects side line backflow pump, and the export of side line backflow pump is connected butyl lactate tank and side import.The advantages of having improve material's first conversion rate, reduce esterification system water content, improve reaction speed.

Description

Technical Field

[0001] This utility model belongs to the technical field of butyl lactate production equipment, and particularly relates to a butyl lactate production device. Background Technology

[0002] Butyl lactate (chemical name: butyl 2-hydroxypropionate) is an important organic chemical and green solvent. With increasingly stringent environmental regulations, traditional volatile organic compound (VOC) solvents face greater restrictions; however, butyl lactate has gained widespread attention due to its excellent performance and environmentally friendly properties.

[0003] Industrially, butyl lactate is mainly synthesized through the esterification reaction of lactic acid and n-butanol under the catalysis of an acidic catalyst (such as concentrated sulfuric acid or p-toluenesulfonic acid). This reaction is a typical reversible reaction, and the chemical equation is as follows:

[0004]

[0005] In existing production processes, a separation method using a batch reactor and distillation column is employed. The basic process involves adding lactic acid, n-butanol, and a catalyst to the reactor at once and heating to reflux temperature for reaction. During this process, the generated water and some n-butanol form an azeotrope and are distilled off. After condensation and separation, the oil phase (rich in n-butanol) returns to the reactor, while the aqueous phase is discharged. This shifts the reaction equilibrium to the right, increasing the lactic acid conversion rate.

[0006] However, existing production methods have problems: First, the intermittent operation method causes the reactant concentration to gradually decrease as the reaction proceeds, resulting in a slow reaction rate, long production cycle, and high energy consumption; Second, due to the limitations of chemical equilibrium in the reaction, even with azeotropic dehydration, the final conversion rate in the reactor remains at a low level.

[0007] Faced with the above-mentioned practical difficulties, there is an urgent need to improve the existing butyl lactate production equipment. Utility Model Content

[0008] The present invention provides a butyl lactate production apparatus that can improve the primary conversion rate of materials, reduce the water content in the esterification system, and increase the reaction rate.

[0009] The technical solution of this utility model includes: a butyl lactate production apparatus, comprising: an esterification kettle, the esterification kettle being provided with a feed port, a discharge port, a top reflux port, and a bottom reflux port; a distillation column, the distillation column being provided with multiple packing sections arranged along its height, the top of the distillation column being connected to a top reflux treatment unit, the middle and lower sides of the distillation column being connected to a side reflux treatment unit, and the bottom of the distillation column being connected to the bottom reflux port via a bottom pipeline; the top reflux treatment unit includes components connected to the distillation column... The top outlet is connected to a top condenser, which is connected to an oil-water separator. The oil-water separator is connected to a top reflux tank, which is connected to a top reflux pump. The outlet of the top reflux pump is connected to the top inlet and the top reflux port of the distillation column. The side reflux treatment unit includes a side reflux tank connected to the side outlet of the distillation column. The side reflux tank is connected to a side reflux pump, and the outlet of the side reflux pump is connected to a butyl lactate tank and the side inlet of the distillation column.

[0010] Preferably, the distillation column is provided with a first packing section, a second packing section and a third packing section from top to bottom. The top inlet of the column is connected to the first packing section, the side outlet is located between the second packing section and the third packing section, the side inlet is connected to the third packing section, and the discharge port is connected to the second packing section.

[0011] Preferably, the feed port of the esterification reactor is connected to a raw material tank, the bottom of the esterification reactor is connected to an esterification circulation pump, and the outlet of the esterification circulation pump is connected to a heavy component tank and the feed port.

[0012] Preferably, the shell of the esterification reactor is provided with a heat exchange jacket; and / or, the esterification reactor is provided with a heat exchange coil.

[0013] Preferably, the esterification reactor is equipped with a stirring device.

[0014] Preferably, the bottom reflux port is located on the upper side of the esterification reactor, and the bottom pipeline is equipped with a reactor outflow pump.

[0015] Preferably, the top condenser is connected to a vacuum system.

[0016] The beneficial effects of this invention are as follows: By designing multiple packing sections within the distillation column, and designing a top reflux treatment unit connected to the top of the column and a side reflux treatment unit connected to the middle and lower sides, and coordinating with top and bottom reflux ports in the esterification reactor, the top reflux treatment unit works in conjunction with the upper packing sections. The upper packing sections separate butanol and water from butyl lactate, which then enter the top condenser of the top reflux treatment unit. After passing through an oil-water separation tank, the aqueous phase is collected, and the oil phase butanol is separated... A portion of the reflux pumped from the top of the column returns to the top to form reflux, while the remainder returns to the esterification reactor to continue the esterification reaction. A side-stream reflux treatment unit, in conjunction with the lower packed section, separates heavy components such as butyl lactate and lactic acid. This separated material is then refluxed back to the distillation column via the side-stream reflux tank and pump of the side-stream reflux treatment unit, yielding high-purity butyl lactate. Simultaneously, the bottom material, primarily lactic acid and lactic acid oligomers with a small amount of butyl lactate, is refluxed back to the esterification reactor via the bottom pipeline to continue the reaction. This novel butyl lactate production device improves production efficiency through a continuous process. The reactive distillation method increases the primary conversion rate of the material and removes moisture in real time, reducing the water content in the esterification system. This, in turn, increases the esterification reaction temperature, accelerates the reaction, reduces the overall reaction time, and ultimately improves production efficiency. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of this embodiment.

[0019] in:

[0020] 1. Esterification kettle; 11. Esterification circulating pump; 2. Distillation column; 21. Packing section; 22. Bottom pump; 31. Top condenser; 32. Oil-water separator; 33. Top reflux tank; 34. Top reflux pump; 41. Side reflux tank; 42. Side reflux pump.

[0021] 100. Raw material tank; 200. Heavy component tank; 300. Vacuum system; 400. Butyl lactate tank. Detailed Implementation

[0022] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] In this document, terms such as "above," "below," "left," "right," "inner," and "outer" are established based on the positional relationships shown in the accompanying drawings. Depending on the drawings, these positional relationships may change; therefore, they should not be construed as absolute limitations on the scope of protection. Furthermore, relational terms such as "first" and "second" are merely used to distinguish one component from another with the same name, and do not necessarily require or imply any actual relationship or order between these components. In addition, in embodiments of this utility model, "above," "below," etc., include the stated number.

[0024] Reference Figure 1 The butyl lactate production apparatus of this embodiment includes an esterification reactor 1 and a distillation column 2. The esterification reactor 1 is equipped with a feed port, a discharge port, a top reflux port, and a bottom reflux port. The distillation column 2 has multiple packing sections 21 arranged along its height. A top reflux treatment unit is connected to the top of the distillation column 2, and a side-stream reflux treatment unit is connected to the lower middle side of the distillation column 2. The bottom of the distillation column 2 is connected to the bottom reflux port via a bottom pipeline.

[0025] The top reflux treatment unit includes a top condenser 31 connected to the top outlet of distillation column 2. The top condenser 31 is connected to an oil-water separator 32, which is connected to a top reflux tank 33. The top reflux tank 33 is connected to a top reflux pump 34, the outlet of which is connected to the top inlet of distillation column 2 and the top reflux port of esterification reactor 1. Thus, the top reflux treatment unit can be used in conjunction with the upper packed section. The upper packed section separates butanol and water from butyl lactate, which then enter the top condenser 31 of the top reflux treatment unit. After passing through the oil-water separator 32, the aqueous phase is collected. The oil phase butanol is partially returned to the top of the column via the top reflux pump 34 to form reflux, and partially returned to the esterification reactor 1 to continue participating in the esterification reaction.

[0026] The side-stream reflux treatment unit includes a side-stream reflux tank 41 connected to the side outlet of distillation column 2. This side-stream reflux tank 41 is connected to a side-stream reflux pump 42, the outlet of which is connected to a butyl lactate tank 400 and the side inlet of distillation column 2. Thus, the side-stream reflux treatment unit, in conjunction with the lower packing section, separates heavy components such as butyl lactate and lactic acid. These components are then refluxed back to distillation column 2 via the side-stream reflux tank 41 and the side-stream reflux pump 42, and high-purity butyl lactate is collected and transported to the butyl lactate tank 400 for storage. Simultaneously, the bottom material, mainly lactic acid and lactic acid oligomers with a small amount of butyl lactate, is refluxed back to the esterification reactor 1 via the bottom pipeline to continue the reaction.

[0027] The butyl lactate production apparatus of this embodiment adopts a continuous mode, which can improve production efficiency. The reactive distillation method can improve the primary conversion rate of materials and remove the generated water in real time, thereby reducing the water content in the esterification system, increasing the esterification reaction temperature, increasing the reaction rate, reducing the overall reaction time, and improving production efficiency.

[0028] Specifically, the distillation column 2 is equipped with a first packing section, a second packing section, and a third packing section from top to bottom. The top inlet is connected to the first packing section, the side outlet is located between the second and third packing sections, and the side inlet is connected to the third packing section. The outlet of the esterification reactor 1 is connected to the second packing section. In this way, the top reflux treatment unit, the side reflux treatment unit, and the esterification reactor 1 are respectively connected and coordinated with the three packing sections, which helps to improve the overall effect of the reaction.

[0029] The feed port of the esterification reactor 1 is connected to a raw material tank 100, which contains, for example, butanol, lactic acid, and a catalyst. An esterification circulation pump 11 is connected to the bottom of the esterification reactor 1, and the outlet of the esterification circulation pump 11 is connected to a heavy component tank 200 and a feed port. Mass transfer can then occur under the circulating action of the esterification circulation pump 11. Specifically, a stirring device is provided inside the esterification reactor 1 to enhance the mass transfer effect through the combined action of the stirring device and the esterification circulation pump 11.

[0030] The shell of the esterification vessel 1 is equipped with a heat exchange jacket; and / or, the esterification vessel 1 is equipped with a heat exchange coil, or an external heat exchanger is designed to be connected to the esterification vessel 1, thereby maintaining the temperature of the esterification vessel 1 at the required reaction temperature and improving the production efficiency and reaction effect of the entire device.

[0031] The bottom reflux port is located on the upper side of the esterification reactor 1. The bottom pipeline is equipped with a bottom pump 22, which can improve the material conveying efficiency. Specifically, the top condenser 31 is connected to a vacuum system 300.

[0032] In operation, butanol, lactic acid, and catalyst from the raw material tank 100 are added to the esterification reactor 1 through the feed port. For example, a pump can be used to inject the raw material into the esterification reactor 1. The esterification reactor 1 is equipped with a jacket, internal coil, or external heat exchanger for heat exchange. Mass transfer in the esterification reactor 1 is achieved through stirring and an esterification circulation pump 11. In the esterification reactor 1, lactic acid and butanol undergo an esterification reaction under the catalysis of the catalyst to produce butyl lactate. The reaction products, butyl lactate, water, and a portion of butanol and lactic acid, enter the distillation column 2 through a vacuum gas phase pipeline. The distillation column 2 has three packed sections. The first packed section mainly separates butanol and water from the butyl lactate and then sends them to the top condenser 31. After passing through the oil-water separation tank 32, the aqueous phase is collected. The oil phase butanol is partially returned to the top of the column to form reflux through the top reflux pump 34, and part of it returns to the esterification reactor 1 to continue participating in the esterification reaction. The second and third packed sections primarily separate heavy components such as butyl lactate and lactic acid. The refluxed components are returned to the distillation column 2 via side-stream reflux tank 41 and side-stream reflux pump 42, while high-purity butyl lactate is collected and transported to the butyl lactate tank 400. Simultaneously, the bottom material, mainly lactic acid and lactic acid oligomers with a small amount of butyl lactate, is pumped back to the esterification reactor 1 via bottom pump 22 to continue the reaction.

[0033] The butyl lactate production apparatus of this embodiment can improve production efficiency and reduce energy consumption through continuous operation. At the same time, the reactive distillation method can improve the primary conversion rate of materials and reduce the water content in the esterification system, so that the esterification rate can reach more than 90%. Furthermore, the reactive distillation method removes the generated water in real time, reduces the water content in the esterification system, and can increase the esterification reaction temperature, thereby increasing the reaction rate and reducing the overall reaction time.

[0034] Where the embodiments do not contradict each other, at least some of the technical solutions in each embodiment can be recombine to form the essential technical solution of this utility model. Of course, the embodiments can also reference or include each other. Furthermore, it should be noted that adaptive adjustments and modifications made by those skilled in the art when recombinating the technical means described in the embodiments will also fall within the protection scope of this utility model.

[0035] The technical principles of this utility model have been described above in conjunction with specific embodiments. However, it should be noted that these descriptions are merely for explaining the principles of this utility model and should not be construed as limiting the scope of protection of this utility model in any way. Based on this explanation, other specific embodiments or equivalent substitutions of this utility model that can be conceived by those skilled in the art without creative effort will all fall within the scope of protection of this utility model.

Claims

1. A butyl lactate production apparatus, characterized in that, include: Esterification vessel (1), wherein the esterification vessel (1) is provided with a feed port, a discharge port, a top reflux port and a bottom reflux port; A distillation column (2) is provided with multiple packing sections (21) arranged along the height direction. The top of the distillation column (2) is connected to a top reflux treatment unit, and the middle and lower sides of the distillation column (2) are connected to a side reflux treatment unit. The bottom of the distillation column (2) is connected to the bottom reflux port through a bottom pipeline. The top reflux treatment unit includes a top condenser (31) connected to the top outlet of the distillation column (2), the top condenser (31) is connected to an oil-water separation tank (32), the oil-water separation tank (32) is connected to a top reflux tank (33), the top reflux tank (33) is connected to a top reflux pump (34), and the outlet of the top reflux pump (34) is connected to the top inlet of the distillation column (2) and the top reflux port; The side-stream reflux treatment unit includes a side-stream reflux tank (41) connected to the side outlet of the distillation column (2), the side-stream reflux tank (41) is connected to a side-stream reflux pump (42), and the outlet of the side-stream reflux pump (42) is connected to a butyl lactate tank (400) and the side inlet of the distillation column (2).

2. The lactate butyl ester production apparatus according to claim 1, characterized in that: The distillation column (2) is provided with a first packing section, a second packing section and a third packing section from top to bottom. The top inlet of the column is connected to the first packing section. The side outlet is located between the second packing section and the third packing section. The side inlet is connected to the third packing section and the discharge port is connected to the second packing section.

3. The lactate butyl ester production apparatus according to claim 1, characterized in that: The feed port of the esterification reactor (1) is connected to a raw material tank (100), the bottom of the esterification reactor (1) is connected to an esterification circulation pump (11), and the outlet of the esterification circulation pump (11) is connected to a heavy component tank (200) and the feed port.

4. The butyl lactate production apparatus according to claim 3, characterized in that: The shell of the esterification vessel (1) is provided with a heat exchange jacket; and / or, the esterification vessel (1) is provided with a heat exchange coil.

5. The butyl lactate production apparatus according to claim 4, characterized in that: The esterification kettle (1) is equipped with a stirring device.

6. The lactate butyl ester production apparatus according to claim 3, characterized in that: The bottom reflux port is located on the upper side of the esterification reactor (1), and the bottom pipeline is equipped with a reactor outflow pump (22).

7. The butyl lactate production apparatus according to claim 1, characterized in that: The top condenser (31) is connected to a vacuum system (300).

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