Process and system for recovering product from residual liquid in production of acetylfuran

Abstract

The invention discloses a process and a system for recovering products from residual liquid in production of acetylfuran, the system comprises a flushing tank and a flushing condenser, a top gas phase outlet of the flushing tank is communicated with the bottom of the flushing condenser, and the flushing tank and the flushing condenser are of an integrated structure; an outlet liquid phase of the flushing condenser enters a receiving tank, and a gas phase of the receiving tank is connected with a vacuum tank; the vacuum tank gas phase is connected with the vacuum pump through a pipeline, vacuum pump tail gas is connected with the tail gas condenser through a pipeline, and the tail gas condenser is connected with the liquid collecting tank through a pipeline. The process is high in automation degree, a temperature and pressure reducing facility is arranged to adjust steam, and the safety and stability of the scouring and distilling process are improved; and the heat exchanger is arranged to cool circulating water into constant-temperature water, so that the possibility of freezing and blocking of the condenser is reduced while the cooling effect is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of furan ammonium salt production, in particular to a product recovery process and a recovery system of acetylfuran production residual liquid. Background Art

[0002] Furan ammonium salt (English name: SMIA) is currently the main raw material for the production of cephalosporin antibiotics cefuroxime and cefuroxime axetil. Cefuroxime was first successfully developed by Glaxo William's and was first launched in the UK, Ireland, Germany and Italy in 1978 and then sold in many countries and regions around the world. The trade name is "Ciliou". It was approved by the US FDA in 1987 and launched in the United States. Due to its definite efficacy, it is widely used to combat various infections caused by sensitive bacteria. In the 1990s, the drug has become the world's best-selling anti-infective drug with good efficacy. Furan ammonium salt, as a new type of pharmaceutical intermediate, is a key intermediate in the synthesis of second-generation cephalosporin drugs such as cefuroxime. Its property state is white or off-white crystalline powder, molecular weight 186.17, boiling point: 284.7℃at760mmHg, trans isomer ≤0.5%, and chemical name is (z)-2-methoxymethylamino-2-(furan-2-yl) ammonium acetate.

[0003] The production process of furan ammonium salt is as follows: acetofuran, sodium nitrite, water, phosphoric acid, hydrochloric acid and the like are mixed to generate keto acid, which is then reacted with methoxyamine to generate oxime acid, which is then reacted with ammonia to obtain crude furan ammonium salt. The crude furan ammonium salt is decolorized with activated carbon and then pumped into a concentration kettle. After concentration, it is centrifugally dried to obtain the finished furan ammonium salt.

[0004] In the industrial production of furan ammonium salt, the main raw material of furan ammonium salt is acetofuran, which accounts for a large proportion of the total cost, so the production cost of acetofuran is the key to determining the entire production cost of furan ammonium salt. The current production process is mainly acylation and distillation. In order to ensure safety during the production process, the final distillation process is relatively conservative, resulting in a small amount of acetofuran not being distilled cleanly, affecting the yield and increasing the cost of treating the residual liquid.

[0005] In order to improve the yield of acetofuran and reduce the production cost of furan ammonium salt, it is urgently necessary to provide a new product recovery process and recovery system from the residual liquid of acetofuran production, so research on this is imminent. Summary of the invention

[0006] In order to solve the problems existing in the above process and ensure that the yield of acetofuran is improved, and at the same time the final residual liquid is easy to be processed at low cost, the present invention provides a product recovery process in the residual liquid of acetofuran production and a recovery system thereof.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A product recovery system in acetofuran production residual liquid includes a distillation tank and a distillation condenser, wherein the gas phase outlet at the top of the distillation tank is connected to the bottom of the distillation condenser and is an integrated structure; the liquid phase at the outlet of the distillation condenser enters a receiving tank, and the gas phase of the receiving tank is connected to a vacuum tank;

[0009] The gas phase of the vacuum tank is connected to the vacuum pump through a pipeline, the tail gas of the vacuum pump is connected to the tail gas condenser through a pipeline, and the tail gas condenser is connected to the liquid collecting tank through a pipeline.

[0010] Preferably, a conical steam hood is provided at the top of the connection between the distillation tank and the distillation condenser, a reflux pipe is connected to one side of the bottom of the conical steam hood, and one end of the reflux pipe is connected to the side wall of the distillation tank.

[0011] Preferably, a steam distribution component is provided in the distillation tank, and the steam distribution component includes a stirring main shaft vertically inserted into the bottom of the distillation tank, the stirring main shaft passes through the bottom of the distillation tank, and an upper top plate is horizontally provided at the upward extending end, a plurality of groups of steam plates are equidistantly distributed in a ring at the bottom of the upper top plate, and a lower top plate is provided at the bottom of the steam plate.

[0012] Preferably, a plurality of groups of steam holes are provided on the side wall of the steam plate, and the steam holes are connected to a reduced-pressure steam channel through a shunt pipe arranged in the upper top plate, and the reduced-pressure steam channel penetrates the stirring main shaft and is connected downward.

[0013] Preferably, a steam pipe is inserted into the lower port of the reduced-pressure steam channel, a limit block is sleeved on the outer wall of the steam pipe, the limit block is threadedly connected to the stirring main shaft, and a bearing is sleeved at the connection between the limit block and the steam pipe.

[0014] Preferably, a transmission wheel is sleeved on the outer wall of the lower end of the stirring main shaft, and the transmission wheel is connected to a driving motor via a belt.

[0015] A process for recovering products from residual liquid in the production of acetofuran, comprising the following steps:

[0016] Step S1: The gas phase of the distillation tank enters the distillation condenser through a pipeline, and the condensed mixed liquid enters the receiving tank through a pipeline. The receiving tank is connected to the vacuum tank through a pipeline, and the vacuum tank is connected to the vacuum pump through a pipeline. A pressure regulating valve is provided on the pipeline to control the system pressure to -0.09 to -0.08 MPa;

[0017] Step S2: The distillation tank uses a separately configured reduced-pressure steam with a pressure of 0.3-0.4 MPa;

[0018] Step S3: The distillation condenser is cooled by circulating water, and the circulating water temperature is controlled at 20-30°C; the tail gas condenser uses constant temperature water, the external circulating water is cooled by 0°C water, and a regulating valve is used at the 0°C water inlet to cool the circulating water to constant temperature water of 15-20°C, and the constant temperature water enters the tail gas condenser through a pipeline.

[0019] The tail gas condenser is used to recover acetofuran in the tail gas of the vacuum pump, thereby increasing revenue and reducing the difficulty of tail gas treatment.

[0020] Preferably, in step S2, the 0.5 MPa steam is decompressed to 0.33-0.38 MPa through a pressure reducing valve.

[0021] In the distillation step, the commonly used 0.5MPa steam is cooled and decompressed to maintain the steam temperature between 130 and 140 DEG C. At this temperature, it can be ensured that all the acetofuran in the residual liquid can be distilled out, and the acetofuran residual liquid will not be overheated, which greatly improves the stability and safety of the acetofuran distillation process; and a large number of holes are arranged on the steam insertion pipe of the distillation tank, which can increase the distillation area and make the contact of the entire residual liquid more uniform, so as to achieve a better distillation effect.

[0022] In the process of distillation condensation and tail gas condensation, the present invention selects a suitable cooling medium to cool the tail gas, so as to ensure that the gas phase can be condensed and will not cause freezing and blockage of the pipeline and the condenser. In order to ensure further treatment of the tail gas, a tail gas condenser is added, which can not only collect a small amount of acetofuran, but also make the tail gas liquid purer after treatment, which is convenient for subsequent treatment and reduces the treatment difficulty and treatment cost.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The original process lacks a step of flushing and distillation operation, resulting in a low yield of acetofuran, and the cost and difficulty of treating the residual liquid are relatively high. The existing process can recover all the acetofuran produced by acylation to the maximum extent, which can effectively improve the yield. At the same time, the residual liquid after treatment basically does not contain acetofuran, which is easier to treat;

[0025] 2. The outlet pipe of the vacuum pump is equipped with an exhaust condenser, which can effectively recover the material escaped during the distillation process. At the same time, the treated exhaust gas is relatively pure, which is convenient for further treatment of the exhaust gas;

[0026] 3. This process has a high degree of automation and is equipped with cooling and pressure reduction facilities to adjust the steam, which improves the safety and stability of the distillation process; a heat exchanger is equipped to cool the circulating water to constant temperature water, which ensures the cooling effect while reducing the possibility of freezing and blocking of the condenser. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 It is a schematic diagram of the system structure flow of the present invention;

[0029] Figure 2 It is a structural schematic diagram of the distillation tank of the present invention;

[0030] Figure 3 This is an enlarged schematic diagram of structure A of the present invention;

[0031] In the figure: distillation tank 1, stirring main shaft 11, upper top plate 12, steam plate 13, lower top plate 14, steam hole 15, reduced pressure steam channel 16, diverter pipe 17, steam pipeline 18, limit block 19, transmission wheel 20, distillation condenser 2, conical steam hood 21, reflux pipe 22, receiving tank 3, vacuum tank 4, vacuum pump 5, tail gas condenser 6, liquid collecting tank 7. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Example 1

[0034] A product recovery system in acetofuran production residual liquid includes a distillation tank 1 and a distillation condenser 2. The top gas phase outlet of the distillation tank 1 is connected to the bottom of the distillation condenser 2 and is an integrated structure. The liquid phase at the outlet of the distillation condenser 2 enters a receiving tank 3, and the gas phase of the receiving tank 3 is connected to a vacuum tank 4.

[0035] The gas phase of the vacuum tank 4 is connected to the vacuum pump 5 through a pipeline, the tail gas of the vacuum pump 5 is connected to the tail gas condenser 6 through a pipeline, and the tail gas condenser 6 is connected to the liquid collecting tank 7 through a pipeline.

[0036] A conical steam cover 21 is provided at the top of the connection between the distillation tank 1 and the distillation condenser 2 , and a reflux pipe 22 is connected to one side of the bottom of the conical steam cover 21 , and one end of the reflux pipe 22 is connected to the side wall of the distillation tank 1 .

[0037] A steam distribution component is arranged in the distillation tank 1, and the steam distribution component includes a stirring main shaft 11 vertically inserted into the bottom of the distillation tank 1. The stirring main shaft 11 passes through the bottom of the distillation tank 1, and an upper top plate 12 is horizontally arranged at the upwardly extending end. A plurality of groups of steam plates 13 are equidistantly distributed in a ring at the bottom of the upper top plate 12, and a lower top plate 14 is arranged at the bottom of the steam plate 13.

[0038] The side wall of the steam plate 13 is provided with a plurality of steam holes 15 , and the steam holes 15 are connected to a reduced pressure steam channel 16 through a shunt pipe 17 disposed in the upper top plate 12 , and the reduced pressure steam channel 16 penetrates the stirring main shaft 11 and is connected downward.

[0039] A steam pipe 18 is inserted into the lower end of the reduced pressure steam channel 16 , and a limit block 19 is sleeved on the outer wall of the steam pipe 18 . The limit block 19 is threadedly connected to the stirring main shaft 11 , and a bearing is sleeved at the connection between the limit block 19 and the steam pipe 18 .

[0040] A transmission wheel 20 is sleeved on the outer wall of the lower end of the stirring main shaft 11, and the transmission wheel 20 is connected to a driving motor through a belt; the driving motor drives the transmission wheel 20 to rotate through the belt, and the transmission wheel 20 drives the stirring main shaft 11 to rotate, so that the stirring structure composed of the upper top plate 12, the steam plate 13, and the lower top plate 14 can fully mix the waste liquid. At this time, the reduced pressure steam enters the reduced pressure steam channel 16 through the steam pipe 18, and then enters the diversion pipe 17 through the reduced pressure steam channel 16, and is sprayed to the waste liquid through the distributed multiple groups of steam holes 15, thereby increasing the area of ​​distillation and making the contact of the entire residual liquid more uniform, which can achieve a better distillation effect.

[0041] Example 2

[0042] Reference Figure 1-3 A process for recovering products from residual liquid in the production of acetofuran comprises the following steps:

[0043] Step S1: The gas phase of the distillation tank 1 enters the distillation condenser 2 through a pipeline, and the condensed mixed liquid enters the receiving tank 3 through a pipeline. The receiving tank 3 is connected to the vacuum tank 4 through a pipeline, and the vacuum tank 4 is connected to the vacuum pump 5 through a pipeline. A pressure regulating valve is provided on the pipeline to control the system pressure to -0.09MPa;

[0044] Step S2: The distillation tank 1 uses a separately configured reduced-pressure steam with a pressure of 0.33 MPa;

[0045] Step S3: The distillation condenser 2 is cooled by circulating water, and the circulating water temperature is controlled at 20°C; the tail gas condenser 6 uses constant temperature water, the external circulating water is cooled by 0°C water, and a regulating valve is used at the 0°C water inlet to cool the circulating water to constant temperature water of 20°C, and the constant temperature water enters the tail gas condenser 6 through a pipeline.

[0046] The tail gas condenser is used to recover acetofuran in the tail gas of the vacuum pump, thereby increasing revenue and reducing the difficulty of tail gas treatment.

[0047] Example 3

[0048] Reference Figure 1-3 A process for recovering products from residual liquid in the production of acetofuran comprises the following steps:

[0049] Step S1: The gas phase of the distillation tank 1 enters the distillation condenser 2 through a pipeline, and the condensed mixed liquid enters the receiving tank 3 through a pipeline. The receiving tank 3 is connected to the vacuum tank 4 through a pipeline, and the vacuum tank 4 is connected to the vacuum pump 5 through a pipeline. A pressure regulating valve is provided on the pipeline to control the system pressure to -0.08MPa;

[0050] Step S2: The distillation tank 1 uses a separately configured reduced pressure steam with a pressure of 0.35 MPa;

[0051] Step S3: The distillation condenser 2 is cooled by circulating water, and the circulating water temperature is controlled at 25°C; the tail gas condenser 6 uses constant temperature water, and the external circulating water is cooled by 0°C water. A regulating valve is used at the 0°C water inlet to cool the circulating water to constant temperature water of 18°C, and the constant temperature water enters the tail gas condenser 6 through a pipeline.

[0052] The tail gas condenser is used to recover acetofuran in the tail gas of the vacuum pump, thereby increasing revenue and reducing the difficulty of tail gas treatment.

[0053] Example 4

[0054] Reference Figure 1-3 A process for recovering products from residual liquid in the production of acetofuran comprises the following steps:

[0055] Step S1: The gas phase of the distillation tank 1 enters the distillation condenser 2 through a pipeline, and the condensed mixed liquid enters the receiving tank 3 through a pipeline. The receiving tank 3 is connected to the vacuum tank 4 through a pipeline, and the vacuum tank 4 is connected to the vacuum pump 5 through a pipeline. A pressure regulating valve is provided on the pipeline to control the system pressure to -0.08MPa;

[0056] Step S2: The distillation tank 1 uses a separately configured reduced pressure steam with a pressure of 0.38 MPa;

[0057] Step S3: The distillation condenser 2 is cooled by circulating water, and the circulating water temperature is controlled at 30°C; the tail gas condenser 6 uses constant temperature water, and the external circulating water is cooled by 0°C water. A regulating valve is used at the 0°C water inlet to cool the circulating water to constant temperature water of 20°C, and the constant temperature water enters the tail gas condenser 6 through a pipeline.

[0058] The tail gas condenser is used to recover acetofuran in the tail gas of the vacuum pump, thereby increasing revenue and reducing the difficulty of tail gas treatment.

[0059] After three months of continuous and stable operation, the original process has increased the yield of the entire acetofuran production by adding the existing distillation step. At the same time, after this step, the residual liquid produced has a small taste, a faster solidification speed, and is easy to handle. According to testing, the cost of residual liquid treatment after distillation is greatly reduced, reducing the cost of residual liquid treatment; the entire vacuum pump outlet gas phase treatment and constant temperature water system further reflects the considerations of this process in exhaust gas treatment and environmental protection, and has achieved good results.

[0060] Since the start of operation, there have been many cases of spontaneous combustion of acetofuran due to high-boiling polymerization. The main reason is that the acetofuran in the residual liquid has not been completely recovered. During the operation of the new process, the amount of residual liquid produced is small, the solidification speed is faster, and it is not easy to polymerize after heating, which reduces the safety risk.

[0061] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A product recovery system in acetofuran production residual liquid, characterized in that: It comprises a distillation tank (1) and a distillation condenser (2), wherein the gas phase outlet at the top of the distillation tank (1) is connected to the bottom of the distillation condenser (2) and is an integrated structure; the liquid phase at the outlet of the distillation condenser (2) enters a receiving tank (3), and the gas phase of the receiving tank (3) is connected to a vacuum tank (4); The gas phase of the vacuum tank (4) is connected to the vacuum pump (5) through a pipeline, the tail gas of the vacuum pump (5) is connected to the tail gas condenser (6) through a pipeline, and the tail gas condenser (6) is connected to the liquid collecting tank (7) through a pipeline.

2. A product recovery system in acetofuran production residual liquid according to claim 1, characterized in that: A conical steam cover (21) is arranged at the top of the connection between the distillation tank (1) and the distillation condenser (2), and a reflux pipe (22) is connected to one side of the bottom of the conical steam cover (21), and one end of the reflux pipe (22) is connected to the side wall of the distillation tank (1).

3. A product recovery system in acetofuran production residual liquid according to claim 1, characterized in that: A steam distribution assembly is arranged in the distillation tank (1), and the steam distribution assembly comprises a stirring main shaft (11) vertically plugged into the bottom of the distillation tank (1), the stirring main shaft (11) passes through the bottom of the distillation tank (1), and an upper top plate (12) is horizontally arranged at the end extending upward, a plurality of groups of steam plates (13) are equidistantly distributed in an annular manner at the bottom of the upper top plate (12), and a lower top plate (14) is arranged at the bottom of the steam plate (13).

4. A product recovery system in acetofuran production residual liquid according to claim 3, characterized in that: The side wall of the steam plate (13) is provided with a plurality of steam holes (15), the steam holes (15) are connected to a reduced pressure steam channel (16) through a shunt pipe (17) arranged in the upper top plate (12), and the reduced pressure steam channel (16) penetrates the stirring main shaft (11) and is connected downward.

5. A product recovery system in acetofuran production residual liquid according to claim 4, characterized in that: A steam pipe (18) is inserted into the lower end of the reduced-pressure steam channel (16); a limit block (19) is sleeved on the outer wall of the steam pipe (18); the limit block (19) is threadedly connected to the stirring main shaft (11); and a bearing is sleeved at the connection between the limit block (19) and the steam pipe (18).

6. The product recovery system in the acetofuran production residual liquid according to claim 3, characterized in that: The outer wall of the lower end of the stirring main shaft (11) is sleeved with a transmission wheel (20), and the transmission wheel (20) is connected to a driving motor via a belt.

7. A process for recovering products from acetofuran production residual liquid, using the system for recovering products from acetofuran production residual liquid as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: Step S1: The gas phase of the distillation tank (1) enters the distillation condenser (2) through a pipeline, and the condensed mixed liquid enters the receiving tank (3) through a pipeline. The receiving tank (3) is connected to the vacuum tank (4) through a pipeline, and the vacuum tank (4) is connected to the vacuum pump (5) through a pipeline. A pressure regulating valve is provided on the pipeline to control the system pressure to -0.09 to -0.08 MPa; Step S2: the distillation tank (1) uses a separately configured reduced-pressure steam with a pressure of 0.3-0.4 MPa; Step S3: The distillation condenser (2) is cooled by circulating water, and the temperature of the circulating water is controlled at 20-30°C; the tail gas condenser (6) uses constant temperature water, and the external circulating water is cooled by 0°C water. A regulating valve is used at the 0°C water inlet to cool the circulating water to constant temperature water of 15-20°C, and the constant temperature water enters the tail gas condenser (6) through a pipeline.

8. A process for recovering products from acetofuran production residual liquid according to claim 7, characterized in that: In the step S2, the 0.5 MPa steam is decompressed to 0.33-0.38 MPa by a pressure reducing valve.

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