A system for improving carbon monoxide utilization in acetic acid production

Abstract

The utility model discloses a system that improves carbon monoxide utilization rate in acetic acid production, including carbonyl synthesis reactor, tail gas circulation reactor, cooler and gas -liquid separator, the cooler with gas -liquid separator is connected, the tail gas export of carbonyl synthesis reactor with the cooler is connected, the gas export of gas -liquid separator with the bottom of tail gas circulation reactor is connected, the liquid export of gas -liquid separator with carbonyl synthesis reactor is connected, the bottom of carbonyl synthesis reactor with the bottom of tail gas circulation reactor is connected, and carbonyl synthesis reactor sets up product discharge pipe. The utility model has improved carbon monoxide utilization rate significantly, and the resource waste caused by tail gas emission has been reduced.

Description

Technical Field

[0001] This invention belongs to the field of organic chemistry technology, specifically relating to a system for improving the utilization rate of carbon monoxide in acetic acid production. Background Technology

[0002] Acetic acid, also known as acetic acid, is an important basic organic chemical raw material widely used in chemical fibers, pharmaceuticals, food, coatings, and other fields. Currently, the methanol carbonylation method has become the mainstream technology for acetic acid production worldwide due to its high atom economy and high product purity. This process uses methanol and carbon monoxide as core raw materials, and the carbonylation reaction is completed in a reactor under the action of rhodium-based or iridium-based catalysts to produce acetic acid.

[0003] The methanol carbonylation method still has shortcomings. Low carbon monoxide utilization in the reactor is a key bottleneck restricting the economic viability and environmental compliance of this process. From a raw material cost perspective, carbon monoxide, as a core reactant, requires a synthesizer conversion process for industrial production, resulting in significant energy consumption and cost. If a large amount of unreacted carbon monoxide is discharged with the tail gas, it will directly increase the raw material consumption and production cost of acetic acid production. From an environmental and safety perspective, unreacted carbon monoxide is a flammable, explosive, and toxic gas. Carbon monoxide in the tail gas must be incinerated or adsorbed before discharge, increasing investment in environmental protection facilities and posing safety hazards. From a process efficiency perspective, carbon monoxide has limited solubility in the reaction liquid, i.e., the acetic acid-iodomethane system. Insufficient gas-liquid mass transfer can easily lead to insufficient local carbon monoxide concentration in the reactor, not only reducing acetic acid yield but also producing byproducts such as methane and carbon dioxide, affecting product concentration and subsequent separation efficiency.

[0004] Current mainstream processes primarily improve mass transfer by optimizing reaction pressure, temperature, and stirring rate. However, there is still room for improvement in carbon monoxide utilization. Therefore, this invention proposes a system to improve carbon monoxide utilization in acetic acid production, addressing the problem of low carbon monoxide utilization. Utility Model Content

[0005] To solve the above-mentioned technical problems, the purpose of this utility model is to provide a system for improving the utilization rate of carbon monoxide in acetic acid production, which significantly improves the utilization rate of carbon monoxide and reduces the waste of resources caused by tail gas emissions.

[0006] To achieve the above-mentioned objectives, the technical solution adopted by this utility model is as follows:

[0007] A system for improving carbon monoxide utilization in acetic acid production includes a carbonyl synthesis reactor, a tail gas recirculation reactor, a cooler, and a gas-liquid separator.

[0008] The cooler is connected to the gas-liquid separator, the tail gas outlet of the carbonyl synthesis reactor is connected to the cooler, the gas outlet of the gas-liquid separator is connected to the bottom of the tail gas recirculation reactor, the liquid outlet of the gas-liquid separator is connected to the carbonyl synthesis reactor, the bottom of the carbonyl synthesis reactor is connected to the bottom of the tail gas recirculation reactor, and the carbonyl synthesis reactor is equipped with a product discharge pipe.

[0009] Preferably, the top of the carbonyl synthesis reactor is connected to the cooler via a gas phase pipe, and the gas phase pipe is equipped with a regulating valve to control the flow rate of the exhaust gas entering the cooler.

[0010] Preferably, the cooler is connected to the gas-liquid separator via a first connecting pipe.

[0011] More preferably, an exhaust gas detection component is provided on the first connecting pipe, the exhaust gas detection component including a carbon monoxide concentration detector, a carbon dioxide concentration detector and a methane concentration detector, all of which are provided on the first connecting pipe.

[0012] Preferably, the bottom of the carbonyl synthesis reactor is connected to the bottom of the tail gas recirculation reactor via a liquid phase outlet pipe, and the liquid phase outlet pipe is equipped with a regulating valve to control the flow rate of the reaction liquid input into the tail gas recirculation reactor.

[0013] Preferably, a gas compressor is provided between the gas phase outlet of the gas-liquid separator and the tail gas recirculation reactor. The gas-liquid separator is connected to the gas compressor through a second connecting pipe, and the gas compressor is connected to the tail gas recirculation reactor through a third connecting pipe. A regulating valve is provided on the third connecting pipe.

[0014] More preferably, the third connecting pipe is connected to the raw material gas replenishment pipe, and the connection point between the third connecting pipe and the raw material gas replenishment pipe is located between the regulating valve and the gas compressor.

[0015] More preferably, a pressure control component is provided on the product discharge pipe, and the pressure control component includes a pressure controller.

[0016] More preferably, the pressure controller is electrically connected to the regulating valve of the third connecting pipe.

[0017] Preferably, the exhaust gas recirculation reactor is a static mixing reactor, and a static mixing distributor is provided inside the exhaust gas recirculation reactor, into which the gas phase separated by the gas-liquid separator is input.

[0018] Beneficial effects:

[0019] This invention not only significantly improves the utilization rate of carbon monoxide and reduces resource waste caused by exhaust emissions, but also enhances the continuity and stability of system operation by precisely controlling reactor pressure, while reducing overall energy consumption and optimizing the carbonylation reaction process. It is particularly suitable for acetic acid synthesis reaction systems. Attached Figure Description

[0020] Figure 1 The diagram shown is a schematic diagram of this utility model.

[0021] Figure reference numerals: 1-Carbonyl synthesis reactor, 2-Tail gas recirculation reactor, 3-Cooler, 4-Gas-liquid separator, 5-Gas compressor, 6-Regulating valve, 7-Carbon monoxide concentration detector, 8-Carbon dioxide concentration detector, 9-Methane concentration detector, 10-Pressure controller, 11-Gas phase pipe, 12-First connecting pipe, 13-Second connecting pipe, 14-Third connecting pipe, 15-Product discharge pipe, 16-Raw material gas replenishment pipe, 17-Liquid phase extraction pipe. Detailed Implementation

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the specific implementation methods of this utility model will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of this utility model. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0023] like Figure 1 As shown, this utility model proposes a system for improving the utilization rate of carbon monoxide in acetic acid production, including a carbonyl synthesis reactor 1, a tail gas recirculation reactor 2, a cooler 3, and a gas-liquid separator 4. The cooler 3 is connected to the gas-liquid separator 4, the tail gas outlet of the carbonyl synthesis reactor 1 is connected to the cooler 3, the gas outlet of the gas-liquid separator 4 is connected to the bottom of the tail gas recirculation reactor 2, the liquid outlet of the gas-liquid separator 4 is connected to the carbonyl synthesis reactor 1, the bottom of the carbonyl synthesis reactor 1 is connected to the bottom of the tail gas recirculation reactor 2, and the carbonyl synthesis reactor 1 is equipped with a product discharge pipe 15.

[0024] This invention introduces a portion of the reaction liquid from the carbonyl synthesis reactor 1 into the bottom of the tail gas recirculation reactor 2 as a reaction raw material. The tail gas generated in the carbonyl synthesis reactor 1 passes through the cooler 3 and the gas-liquid separator 4, and the carbon monoxide in the tail gas enters the tail gas recirculation reactor 2 to mix and react with the reaction liquid containing methanol, thereby realizing the recovery and utilization of carbon monoxide in the tail gas. The product in the tail gas recirculation reactor 2 is output through the product discharge pipe 15.

[0025] Preferably, the exhaust gas recirculation reactor 2 is a static mixing reactor, equipped with a static mixing distributor inside. The gas input into the exhaust gas recirculation reactor 2 is uniformly dispersed into bubbles of ≤100μm through the static mixing distributor, and distributed in the reaction liquid containing the catalyst. It is easy to understand that the static mixing distributor is a conventional static mixer, a high-efficiency mixing device without moving parts.

[0026] The top of the carbonyl synthesis reactor 1 is connected to the cooler 3 via a gas phase pipe 11. A regulating valve 6 is installed on the gas phase pipe 11 to control the flow rate of the tail gas entering the cooler 3. The gas phase that has not fully participated in the reaction within the carbonyl synthesis reactor 1, as well as some gasified components, enter the cooler 3 through the gas phase pipe 11. In this invention, the regulating valve 6 is preferably an electrically controlled valve, such as a solenoid valve, for easy automatic control of its opening. It is readily understood that in this invention, all electrical components within the system are controlled by a control center, and will not be described in detail further.

[0027] Cooler 3 is connected to gas-liquid separator 4 via first connecting pipe 12. In cooler 3, the exhaust gas is cooled and separated. The liquid and gas phases continue to enter gas-liquid separator 4 through first connecting pipe 12. After being processed by gas-liquid separator 4, the gas phase, which contains carbon monoxide, enters exhaust gas recycling reactor 2 for reuse, while the liquid phase is returned to carbonyl synthesis reactor 1 for reuse.

[0028] This invention achieves the recovery of the liquid phase formed by cooling the tail gas through the cooler 3 and the gas-liquid separator 4, allowing it to be returned to the carbonyl synthesis reactor 1 for reuse, while the carbon monoxide in the tail gas enters the tail gas recirculation reactor 2 to participate in the reaction again.

[0029] Reintroducing the carbon monoxide separated from the tail gas back into the original carbonyl synthesis reactor 1 offers limited improvement in carbon monoxide utilization. This invention avoids reintroducing the tail gas into the carbonyl synthesis reactor 1; instead, it utilizes a tail gas recirculation reactor 2 to recover and reuse the tail gas. In the tail gas recirculation reactor 2, the amount of carbon monoxide is insufficient compared to the reaction liquid, which promotes the forward reaction and improves carbon monoxide utilization. This invention inputs a portion of the reaction liquid from the carbonyl synthesis reactor 1 into the tail gas recirculation reactor 2, where it reacts with the carbon monoxide in the tail gas, ensuring high raw material utilization, reducing production costs, and minimizing waste.

[0030] Furthermore, the bottom of the carbonyl synthesis reactor 1 is connected to the bottom of the tail gas recirculation reactor 2 via a liquid phase outlet pipe 17. The liquid phase outlet pipe 17 is equipped with a regulating valve 6 to control the flow rate of the reaction liquid input into the tail gas recirculation reactor 2.

[0031] Furthermore, a gas compressor 5 is installed between the gas phase outlet of the gas-liquid separator 4 and the tail gas recirculation reactor 2. The gas-liquid separator 4 is connected to the gas compressor 5 through a second connecting pipe 13, and the gas compressor 5 is connected to the tail gas recirculation reactor 2 through a third connecting pipe 14. A regulating valve 6 is installed on the third connecting pipe 14. The non-condensable gas separated by the gas-liquid separator 4 is pressurized by the gas compressor 5 and then input into the tail gas recirculation reactor 2.

[0032] This invention also includes an exhaust gas detection component, comprising a carbon monoxide concentration detector 7, a carbon dioxide concentration detector 8, and a methane concentration detector 9. These detectors are all mounted on the first connecting pipe 12 and are used to detect the concentrations of the corresponding gases in the cooled exhaust gas, facilitating real-time adjustment of the gas-liquid ratio in the exhaust gas circulation reaction. For example, after cooling, the carbon monoxide concentration in the gas phase of the exhaust gas is approximately 85-95%, the methane concentration is controlled at approximately 0.1-2%, and the carbon dioxide concentration is controlled at approximately 1-3%.

[0033] Furthermore, the third connecting pipe 14 can also be connected to the raw material gas supply pipe 16, and the connection point between the third connecting pipe 14 and the raw material gas supply pipe 16 is located between the regulating valve 6 and the gas compressor 5. The raw material gas supply pipe 16 introduces fresh carbon monoxide into the system. The non-condensable gases in the exhaust gas are pressurized and mixed with the fresh carbon monoxide to form a mixed gas, which is then introduced into the exhaust gas recirculation reactor 2. This invention can control the input amount of fresh carbon monoxide based on the carbon monoxide in the exhaust gas to meet the carbon monoxide requirements of the reaction liquid in the exhaust gas recirculation reactor 2.

[0034] Furthermore, this utility model also includes a pressure control component, which includes a pressure controller 10. The pressure controller 10 is disposed on the product discharge pipe 15. The pressure controller 10 is electrically connected to the regulating valve 6 of the third connecting pipe 14. The pressure controller 10 detects the internal pressure of the tail gas circulation reactor 2 and automatically controls the opening of the regulating valve 6 on the third connecting pipe 14 according to the pressure change, thereby dynamically controlling the air intake and accurately stabilizing the pressure inside the tail gas circulation reactor 2.

[0035] The technical solution of this utility model will be described in detail below with specific embodiments.

[0036] The tail gas generated in the carbonyl reactor is cooled by cooler 3, and then non-condensable gas is separated by gas-liquid separator 4. The non-condensable gas, which contains carbon monoxide, is pressurized by gas compressor 5 and mixed with fresh carbon monoxide to form a mixture. The mixture is introduced into the bottom of tail gas recirculation reactor 2 through third connecting pipe 14. At the same time, the carbonyl synthesis reactor 1 inputs reaction liquid into tail gas recirculation reactor 2 through liquid phase outlet pipe 17. The reaction liquid and the mixer fully contact and react in tail gas recirculation reactor 2. After the reaction, the product is output through product outlet pipe 15.

[0037] The tail gas recirculation reactor 2 is a static mixing reactor with an internal static mixing distributor. The mixed gas is uniformly dispersed into bubbles smaller than 100 μm through the static mixing distributor and distributed in the reaction liquid containing iridium and rhodium catalysts, ensuring sufficient contact and reaction between carbon monoxide and methanol. The carbonyl synthesis reactor 1 is equipped with a liquid phase outlet pipe 17, through which the reaction liquid reaches the bottom of the tail gas recirculation reactor 2, and its flow rate is controlled by a regulating valve 6.

[0038] A pressure control component is installed on the product discharge pipe 15 of the tail gas recirculation reactor 2. The pressure control component is electrically connected to the regulating valve 6 on the third connecting pipe 14. It is used to monitor the pressure inside the tail gas recirculation reactor 2 in real time and automatically control the opening of the regulating valve 6 according to the pressure change, thereby controlling the gas phase circulation volume and realizing precise control of the pressure of the tail gas recirculation reactor 2.

[0039] A tail gas detection assembly is installed at the top of the carbonyl synthesis reactor 1 to monitor the concentrations of carbon monoxide, methane, and carbon dioxide in the exhaust gas in real time. The carbon monoxide concentration is controlled at approximately 85-95%, the methane concentration at approximately 0.1-2%, and the carbon dioxide concentration at approximately 1-3%. Unreacted gas phase and vaporized reaction liquid at the top of the carbonyl synthesis reactor 1 are condensed by cooler 3 and then transported to gas-liquid separator 4. The separated gas phase is transported to tail gas recirculation reactor 2 via gas compressor 5, while the condensed reaction liquid is returned to carbonyl synthesis reactor 1. The operating conditions of the carbonyl synthesis reactor 1 are: pressure controlled at 2.3-3.7 MPa and temperature controlled within the range of 170-213℃ to ensure reaction stability.

[0040] This invention, through the aforementioned system, not only significantly improves the utilization rate of carbon monoxide and reduces resource waste caused by exhaust emissions, but also enhances the continuity and stability of system operation by precisely controlling reactor pressure, while reducing overall energy consumption and optimizing the carbonylation reaction process. It is particularly suitable for acetic acid synthesis reaction systems.

[0041] The embodiments provided by this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The descriptions of the embodiments above are only for the purpose of helping to understand the core ideas of this utility model. It should be noted that those skilled in the art can make several improvements and modifications to this utility model without departing from the principles of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

Claims

1. A system for improving carbon monoxide utilization in acetic acid production, characterized in that, It includes a carbonyl synthesis reactor (1), a tail gas recirculation reactor (2), a cooler (3), and a gas-liquid separator (4); The cooler (3) is connected to the gas-liquid separator (4), the tail gas outlet of the carbonyl synthesis reactor (1) is connected to the cooler (3), the gas outlet of the gas-liquid separator (4) is connected to the bottom of the tail gas recirculation reactor (2), the liquid outlet of the gas-liquid separator (4) is connected to the carbonyl synthesis reactor (1), the bottom of the carbonyl synthesis reactor (1) is connected to the bottom of the tail gas recirculation reactor (2), and the carbonyl synthesis reactor (1) is provided with a product discharge pipe (15).

2. The system according to claim 1, characterized in that, The top of the carbonyl synthesis reactor (1) is connected to the cooler (3) via a gas phase pipe (11), and the gas phase pipe (11) is equipped with a regulating valve (6) to control the flow rate of the tail gas entering the cooler (3).

3. The system according to claim 1, characterized in that, The cooler (3) is connected to the gas-liquid separator (4) via the first connecting pipe (12).

4. The system according to claim 3, characterized in that, An exhaust gas detection assembly is provided on the first connecting pipe (12). The exhaust gas detection assembly includes a carbon monoxide concentration detector (7), a carbon dioxide concentration detector (8), and a methane concentration detector (9). The carbon monoxide concentration detector (7), the carbon dioxide concentration detector (8), and the methane concentration detector (9) are all located on the first connecting pipe (12).

5. The system according to claim 1, characterized in that, The bottom of the carbonyl synthesis reactor (1) is connected to the bottom of the tail gas recirculation reactor (2) via a liquid phase outlet pipe (17). The liquid phase outlet pipe (17) is equipped with a regulating valve (6) to control the flow rate of the reaction liquid input into the tail gas recirculation reactor (2).

6. The system according to claim 1, characterized in that, A gas compressor (5) is provided between the gas phase outlet of the gas-liquid separator (4) and the tail gas recirculation reactor (2). The gas-liquid separator (4) is connected to the gas compressor (5) through a second connecting pipe (13). The gas compressor (5) is connected to the tail gas recirculation reactor (2) through a third connecting pipe (14). A regulating valve (6) is provided on the third connecting pipe (14).

7. The system according to claim 6, characterized in that, The third connecting pipe (14) is connected to the raw material gas replenishment pipe (16), and the connection point between the third connecting pipe (14) and the raw material gas replenishment pipe (16) is located between the regulating valve (6) and the gas compressor (5).

8. The system according to claim 6, characterized in that, A pressure control component is provided on the product discharge pipe (15), and the pressure control component includes a pressure controller (10).

9. The system according to claim 8, characterized in that, The pressure controller (10) is electrically connected to the regulating valve (6) of the third connecting pipe (14).

10. The system according to any one of claims 1-9, characterized in that, The tail gas recirculation reactor (2) is a static mixing reactor. The tail gas recirculation reactor (2) is equipped with a static mixing distributor inside. The gas phase separated by the gas-liquid separator (4) is input into the static mixing distributor.

Images