Chemical plant apparatus for reducing product acidity and method

Abstract

The application discloses a chemical device acidity reducing device and method, and aims at the problem that the existing MMA production device is not completely deacidified, and the product acidity only reaches the qualified product standard. The application sets a molecular sieve system on the pipeline from the MMA product cooling to the product tank, adopts spherical silicate molecular sieve adsorption deacidification, the system can be used in single tank or series connection, through double-tank switching standby and auxiliary line acidity adjustment design, the service life of the adsorbent is prolonged, the application avoids the problems of product yield reduction and equipment blockage caused by chemical neutralization method, can reduce the MMA product acidity to the superior product standard, guarantees long-period full-load operation of the device, significantly improves the economic benefit, and has good popularization value.

Description

Technical Field

[0001] This invention belongs to the field of fine chemical technology, specifically relating to an apparatus and method for reducing the acidity of methyl methacrylate (MMA) products in a chemical plant. Background Technology

[0002] The acidity content of methyl methacrylate (MMA) is a core indicator for measuring product quality. Superior grade requires an acidity ≤50 mg / kg, while qualified grade requires an acidity ≤300 mg / kg. In existing MMA production equipment, due to insufficient process design in the C-1202 deacidification tower, complete deacidification cannot be achieved, resulting in the finished MMA acidity remaining at 200–300 mg / kg, only meeting the qualified grade standard and hindering the improvement of product added value.

[0003] Currently, there are three main methods for deacidification commonly used in the industry: one is to use specialized molecular sieves for deacidification; the second is to introduce ammonia into the deacidification tower for neutralization; and the third is to add organic bases in the refining section for neutralization and deacidification. Among these, the methods of introducing ammonia or adding organic bases consume the reaction intermediate methacrylic acid, affecting the product yield. Furthermore, the salts generated in the reaction are prone to precipitating and clogging pipelines and tower packing, leading to plant shutdowns, which have significant drawbacks. Traditional molecular sieve deacidification technology lacks efficient switching and lifespan extension designs, limiting its application effectiveness. Summary of the Invention

[0004] This invention aims to overcome the shortcomings of existing technologies and provide a device and method for reducing the acidity of MMA products in chemical plants. Without reducing the processing load of the plant, the acidity of MMA products is effectively reduced by optimizing the design of the molecular sieve adsorption system, thereby improving the product quality to the superior grade standard. At the same time, it ensures the long-term stable operation of the plant and improves economic and social benefits.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: This invention discloses a method for reducing the acidity of methyl methacrylate in a chemical plant, comprising the following steps: Step 1) The methyl methacrylate (MMA) produced by the finished product tower is cooled by the finished product cooler E-1308 and then transported to the molecular sieve system through pipeline No. 1. Step 2) After cooling, methyl methacrylate (MMA) is introduced into molecular sieve tank A (S-1606A) or molecular sieve tank B (S-1606B) for adsorption and deacidification treatment. Step 3) After deacidification, methyl methacrylate (MMA) is transported to the finished product tank T-1603A / B through pipeline No. 2. When the adsorbent in the molecular sieve tank in use fails, it is switched to another standby molecular sieve tank. The adsorbent in the failed molecular sieve tank is replaced and then put into standby mode. Step 4) Under the premise of meeting the product quality indicators, adjust the product acidity through the molecular sieve sub-line valve on the molecular sieve pipeline to extend the service life of the adsorbent.

[0006] Preferably, the molecular sieve system includes molecular sieve A tank S-1606A and molecular sieve B tank S-1606B arranged in parallel, and molecular sieve A tank S-1606A and molecular sieve B tank S-1606B are connected to pipeline No. 1 and pipeline No. 2 through a three-way valve.

[0007] Preferably, the molecular sieves in molecular sieve tank A (S-1606A) and molecular sieve tank B (S-1606B) are spherical aluminosilicate molecular sieves with an alkaline pH value.

[0008] Preferably, the composition of the aluminosilicate molecular sieve includes 41-43% Al2O3 and 35-37% SiO2; Alternatively, the composition of the aluminosilicate molecular sieve may include 75-85% 5A zeolite, 15-25% mineral clay, and 0-2% quartz.

[0009] Preferably, the molecular sieve A tank S-1606A and molecular sieve B tank S-1606B can be used individually or in series.

[0010] Preferably, the water content of MMA entering the molecular sieve system needs to be strictly controlled by a moisture detector to ensure the deacidification effect of the adsorbent.

[0011] The present invention relates to a device for reducing the acidity of methyl methacrylate in a chemical plant, comprising a finished product cooler E-1308, a first pipeline, and a molecular sieve system, wherein the finished product cooler E-1308 is connected to the molecular sieve system via the first pipeline. The molecular sieve system includes molecular sieve tank S-1606A (A), molecular sieve tank S-1606B (B), finished product tanks T-1603A / B, a second pipeline, and a molecular sieve pipeline. The outlet of the finished product cooler E-1308 is connected to the inlets of molecular sieve tank S-1606A and molecular sieve tank S-1606B respectively via a first pipeline. The outlets of molecular sieve tank S-1606A and molecular sieve tank S-1606B are connected to the inlet of finished product tank T-1603A / B via a second pipeline. The two ends of the molecular sieve pipeline are connected to the first and second pipelines respectively, and are arranged in parallel between the first and second pipelines. A molecular sieve auxiliary line valve is connected to the molecular sieve pipeline.

[0012] Preferably, the No. 2 pipeline, the No. 1 pipeline, and the pipelines separately connected to the No. 1 pipeline are all equipped with switching valves to control the start-up, shutdown, and series / parallel switching of molecular sieve tank S-1606A and molecular sieve tank S-1606B.

[0013] Preferably, the molecular sieve A container S-1606A and molecular sieve B container S-1606B are filled with spherical aluminosilicate adsorbents with an adsorption capacity of 20-30%.

[0014] Preferably, the No. 1 and No. 2 pipelines are equipped with moisture detectors to monitor the water content of MMA.

[0015] Beneficial effects: Reduced product acidity and improved product quality. Ensured long-term operation of the equipment and high processing load, solved the bottleneck restricting the overall plant processing load, and has significant economic and social benefits. Attached Figure Description

[0016] Figure 1 This is a block diagram illustrating the principle of the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] In the description of the invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0019] The specific content / principle of this invention are as follows: Device Structure: The device of this invention includes a finished product cooler E-1308, a first pipeline, a molecular sieve system, a second pipeline, finished product tanks T-1603A / B, and molecular sieve pipelines. The finished product cooler E-1308 is connected to the molecular sieve system via the first pipeline. The molecular sieve system includes molecular sieve tank A S-1606A and molecular sieve tank B S-1606B. The first pipeline is branched off and connected to the inlets of molecular sieve tank A S-1606A and molecular sieve tank B S-1606B respectively. The outlets of molecular sieve tanks A S-1606A and B S-1606B are collected via the second pipeline and connected to the inlet of finished product tank T-1603A / B. The two ends of the molecular sieve pipeline are connected to the first pipeline and the second pipeline respectively, and are arranged in parallel between the first pipeline and the second pipeline. A molecular sieve sub-line valve is connected to the molecular sieve pipeline. Switching valves are installed on Pipeline 2, Pipeline 1, and the pipeline branching off from Pipeline 1 to control the start-up, shutdown, and series / parallel switching of molecular sieve tanks S-1606A (A) and S-1606B (B). Moisture detectors are installed on Pipelines 1 and 2 to monitor the water content of MMA. Molecular sieve tanks S-1606A (A) and S-1606B (B) are filled with spherical aluminosilicate adsorbents with an adsorption capacity of 20-30%. These molecular sieves are alkaline, possessing both adsorption and neutralization properties, and exhibit excellent crush resistance, preventing contamination of the MMA product. The aluminosilicate molecular sieves consist of two types: one with 41-43% Al₂O₃, 35-37% SiO₂, and 20-24% other components; the other with 75-85% 5A zeolite, 15-25% mineral clay, and 0-2% quartz.

[0020] The method steps of this invention are as follows: methyl methacrylate (MMA) produced by the finished product tower is cooled by the finished product cooler E-1308 and then transported to the molecular sieve system through pipeline No. 1; the cooled MMA enters molecular sieve tank A S-1606A or molecular sieve tank B S-1606B for adsorption and deacidification treatment; the deacidified MMA is then transported to the finished product tanks T-1603A / B through pipeline No. 2. When the adsorbent in the molecular sieve tank in use fails, switch to another standby molecular sieve tank, replace the adsorbent in the failed molecular sieve tank, and put it into standby status; under the premise of meeting the product quality indicators, adjust the product acidity through the molecular sieve sub-line valve on the molecular sieve pipeline to extend the service life of the adsorbent.

[0021] Molecular sieve tank A (S-1606A) and molecular sieve tank B (S-1606B) can be used individually or in series, with different operating modes achieved through a switching valve. During use, the water content of MMA entering the molecular sieve system is strictly controlled using a moisture detector to ensure the adsorbent's deacidification effect.

[0022] Example 1: The present invention will be further described in detail below with reference to specific examples.

[0023] Equipment configuration: Between the finished product cooler E-1308 and the finished product tanks T-1603A / B of the No. 1 MMA unit of Zhejiang Petrochemical Co., Ltd., pipeline No. 1, pipeline No. 2 and molecular sieve system are installed. The molecular sieve system includes molecular sieve tank S-1606A and molecular sieve tank S-1606B, both with a volume of 5m³.

[0024] The interior is filled with Luoyang Jianlong Micro-Nano JL-MMA type spherical molecular sieves, with a composition of 42% Al2O3, 36% SiO2, and 22% other components, filling to 80% of the tank's internal cavity. Pneumatic switching valves are installed on pipeline 1, pipeline 2, and the pipeline branching off from pipeline 1. A manual molecular sieve auxiliary line valve is installed on the molecular sieve pipeline. Moisture detectors are installed on both pipeline 1 and pipeline 2.

[0025] Process operation: The MMA produced by the finished product tower is cooled to 25°C by the finished product cooler E-1308 and then transported to the molecular sieve system through pipeline No. 1. The moisture detector monitors the water content of the MMA in real time. Open the switching valve of pipeline No. 1 that leads to molecular sieve tank S-1606A, and close the corresponding switching valve of molecular sieve tank S-1606B. MMA enters molecular sieve tank S-1606A for adsorption and deacidification. Methacrylic acid molecules are adsorbed by the molecular sieve. The deacidified MMA enters the finished product tank T-1603A through pipeline No. 2. After 15 days of operation, data from the moisture detector and the acidity test of the finished product showed that the adsorption efficiency of molecular sieve A tank S-1606A had decreased. The corresponding switching valve was closed, and the corresponding switching valve of molecular sieve B tank S-1606B was opened to switch to operation of molecular sieve B tank S-1606B. The failed adsorbent in molecular sieve A tank S-1606A was replaced. After replacement, the relevant valves were closed to put it in standby mode. When the adsorption effect of a single tank cannot meet the requirements, adjust the switching valve to connect molecular sieve tank S-1606A and molecular sieve tank S-1606B in series, extending the adsorption cycle to 25 days. When the acidity test result of the finished product is lower than 30 mg / kg, open the molecular sieve sub-line valve to allow some MMA to enter the finished product tank T-1603A / B directly through the molecular sieve pipeline, and adjust the outlet acidity to 40-50 mg / kg to avoid excessive consumption of adsorbent.

[0026] Operational results: After processing by this device and method, the acidity of the finished MMA product is stable at 40-50 mg / kg, the purity is ≥99.9%, and the water content is ≤400 PPM, fully meeting the standards for superior grade products; the device has been running continuously for 6 months without any blockages or shutdowns, increasing the annual production of superior grade MMA by approximately 46,700 tons and the annual revenue by 7 million yuan.

[0027] In summary, this invention can effectively reduce the acidity of MMA finished product to below 50 mg / kg, meeting the standards for superior grade products, while not affecting the product purity of ≥99.9% and water content of ≤400 PPM. It avoids pipeline blockage and equipment shutdowns caused by alkaline washing or ammonia neutralization, ensuring long-term operation and full-load processing, thus solving the bottleneck in the overall plant's processing capacity. Each ton of superior grade product generates an additional 150 yuan in revenue compared to qualified product, resulting in an annual increase in benefits of 7 million yuan. The dual-tank switching and series design extend the adsorbent's lifespan and reduce operating costs. It has high promotional value, a simple process, low modification difficulty, and is applicable to various MMA production units, demonstrating significant social benefits.

[0028] Finally, it should be noted that the present invention is not limited to the above embodiments, and many variations are possible. All variations that can be directly derived or conceived by those skilled in the art from the disclosure of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A device and method for reducing the acidity of products in a chemical plant, characterized in that, Includes the following steps: Step 1) The methyl methacrylate (MMA) produced by the finished product tower is cooled by the finished product cooler (E-1308) and then transported to the molecular sieve system through pipeline No. 1; Step 2) After cooling, methyl methacrylate (MMA) is placed in molecular sieve tank A (S-1606A) or molecular sieve tank B (S-1606B) for adsorption and deacidification treatment; Step 3) After deacidification, methyl methacrylate (MMA) is transported to the finished product tank (T-1603A / B) through pipeline No.

2. When the adsorbent in the molecular sieve tank in use fails, it is switched to another standby molecular sieve tank. The adsorbent in the failed molecular sieve tank is replaced and it is put into standby mode. Step 4) Under the premise of meeting the product quality indicators, adjust the product acidity through the molecular sieve sub-line valve on the molecular sieve pipeline to extend the service life of the adsorbent.

2. The apparatus and method for reducing product acidity in a chemical plant according to claim 1, characterized in that, The molecular sieve system includes molecular sieve tank A (S-1606A) and molecular sieve tank B (S-1606B) arranged in parallel. Molecular sieve tank A (S-1606A) and molecular sieve tank B (S-1606B) are connected to pipeline No. 1 and pipeline No. 2 through three-way valves.

3. A chemical plant apparatus and method for reducing product acidity according to claim 1 or 2, characterized in that, The molecular sieves in molecular sieve tank A (S-1606A) and molecular sieve tank B (S-1606B) are spherical aluminosilicate molecular sieves with an alkaline pH value.

4. The apparatus and method for reducing product acidity in a chemical plant according to claim 3, characterized in that, The composition of the aluminosilicate molecular sieve includes 41-43% Al2O3 and 35-37% SiO2. Alternatively, the composition of the aluminosilicate molecular sieve may include 75-85% 5A zeolite, 15-25% mineral clay, and 0-2% quartz.

5. The apparatus and method for reducing product acidity in a chemical plant according to claim 1, characterized in that, The molecular sieve A container (S-1606A) and molecular sieve B container (S-1606B) can be used individually or in series.

6. The apparatus and method for reducing product acidity in a chemical plant according to claim 1, characterized in that, The water content of MMA entering the molecular sieve system must be strictly controlled using a moisture detector to ensure the deacidification effect of the adsorbent.

7. A device for reducing the acidity of products in a chemical plant, characterized in that, It includes a finished product cooler (E-1308), a No. 1 pipeline, and a molecular sieve system. The finished product cooler (E-1308) is connected to the molecular sieve system through the No. 1 pipeline. The molecular sieve system includes molecular sieve A tank (S-1606A), molecular sieve B tank (S-1606B), finished product tank (T-1603A / B), a second pipeline, and a molecular sieve pipeline. The outlet of the finished product cooler (E-1308) is connected to the inlet of molecular sieve A tank (S-1606A) and molecular sieve B tank (S-1606B) respectively via a first pipeline. The outlets of molecular sieve A tank (S-1606A) and molecular sieve B tank (S-1606B) are connected to the inlet of the finished product tank (T-1603A / B) via a second pipeline. The two ends of the molecular sieve pipeline are connected to the first pipeline and the second pipeline respectively, and are arranged in parallel between the first pipeline and the second pipeline. A molecular sieve sub-line valve is connected to the molecular sieve pipeline.

8. A chemical plant device for reducing product acidity according to claim 7, characterized in that, The No. 2 pipeline, the No. 1 pipeline, and the pipelines branched off from the No. 1 pipeline are all equipped with switching valves to control the start-up, shutdown, and series / parallel switching of molecular sieve A tank (S-1606A) and molecular sieve B tank (S-1606B).

9. A chemical plant device for reducing product acidity according to claim 7, characterized in that, The molecular sieve A container (S-1606A) and molecular sieve B container (S-1606B) are filled with spherical aluminosilicate adsorbents, with an adsorption capacity of 20-30%.

10. A chemical plant device for reducing product acidity according to claim 7, characterized in that, Moisture detectors are installed on pipelines No. 1 and No. 2 to monitor the water content of MMA.

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