197-Hydrogen peroxide project distillates heavy aromatic hydrocarbons and TOP’s original wire mesh defoamer baffle demister is transformed into a feather leaf separator

This post was last edited by luoli519 on 2021-9-23 12:54. In recent years, many companies have launched hydrogen peroxide projects, especially those with surplus hydrogen resources. From the perspective of the downstream market of hydrogen peroxide, under the new coronavirus epidemic, low-concentration hydrogen peroxide as a sterilization and disinfectant is safer than medical alcohol in terms of explosion safety, especially in confined space applications, and its usage has increased significantly. Mid- to high-concentration hydrogen peroxide is receiving more and more attention as a green oxidant in the chemical industry. High-concentration hydrogen peroxide is even more essential as a circuit board cleaning agent in the electronics industry and as a space rocket propulsion stage. The application market continues to expand and the market prospects are promising, which has led many companies, especially those with surplus hydrogen resources, to decide to build hydrogen peroxide projects. The scale of a single hydrogen peroxide device launched has also increased from the initial 10,000 tons to the current scale of more than 300,000 tons, which is enough to illustrate the long-term market demand and prospects of hydrogen peroxide projects.

Here is a picture of a company's 300,000-ton hydrogen peroxide device, which is inspiring.

However, whether it is low-concentration medical hydrogen peroxide, medium-to-high-concentration chemical industrial oxidant hydrogen peroxide, or high-concentration hydrogen peroxide for the electronics and aerospace industries, they all impose strict requirements on the residual EAQ, heavy aromatic hydrocarbons, higher fatty alcohols and TOP carried in the production process to avoid these carried impurities from causing harm to medical objects and introducing impurities in chemical reactions. Therefore, the content of the aforementioned carrier substances in the hydrogen peroxide product determines whether the hydrogen peroxide product is qualified and its application fields, and thus also determines the market price of the hydrogen peroxide product and the technical and economic benefits of the hydrogen peroxide device. This is the issue that every hydrogen peroxide production company is most concerned about and has the most troubles with.

This post was last edited by luoli519 on 2021-9-23 13:49 Alkyl anthraquinone, the commonly used 2-ethylanthraquinone EAQ, is the hydrogen carrier in the hydrogenation working solution, and it also has isomers such as alkyl anthraquinone.； Heavy aromatic hydrocarbons HAR is the aromatic solvent in the hydrogenation working fluid. It is provided by the platinum reforming unit of the refining and chemical company. It is mainly C9-C10 heavy aromatic hydrocarbons. ； Higher fatty alcohols and TOP are used as hydroxyl and ester compounds to adjust the polarity of working fluids. ； These heavy compounds have always been present in significant amounts in the hydrogenation process, oxidation process, and extraction process of the hydrogen peroxide production process. Precision vapor-liquid separators must be used in the thin film evaporator and distillation distillation tower device of the deduplication distillation process to efficiently separate and remove the heavy compounds, so that the quality of the resulting hydrogen peroxide or hydrogen peroxide product can meet the usage requirements.

In the traditional hydrogen peroxide production process equipment in the past, especially in the high-vacuum deduplication and concentration process of thin film evaporators and distillation distillation tower devices, wire mesh demisters and baffle demisters were often used to separate and remove the many aforementioned heavy compounds carried by hydrogen peroxide vapor. In actual operation, wire mesh demisters and baffle demisters often have problems such as low operating flexibility, low separation efficiency, high operating pressure drop, and unqualified organic heavy compound content in hydrogen peroxide products, which are difficult to effectively solve. The output and quality of the product hydrogen peroxide cannot stably meet the design requirements, and the owners are very distressed by this!

Why do traditional wire mesh demisters and baffle demisters often have problems such as low operating flexibility, low separation efficiency, high operating pressure drop, and unqualified organic heavy compound content in hydrogen peroxide products that cannot be effectively solved during the degravity and concentration process of hydrogen peroxide devices? As a hydrogen peroxide device engineering process designer, you must have an in-depth understanding of the principles of dynamic gas-liquid separation between hydrogen peroxide vapor and heavy aromatic hydrocarbon droplets and foam, as well as the structural performance of traditional wire mesh demisters and baffle demisters. Do they meet the corresponding dynamic separation requirements? Especially under the special working conditions of hydrogen peroxide de-re-distillation with high vacuum and high steam velocity.

This post was last edited by luoli519 on 2024-4-8 16:27 Let’s take a look at the wire mesh demister. The picture below is a picture of a wire mesh demister. 1. From the perspective of the structure of the wire mesh demister, it intercepts and separates the droplets and foam carried in the airflow through the "pores" formed by "bridging" the fibers. ； The size of the "pores" formed by "bridging" the fiber filaments to each other ranges from a few microns to hundreds of microns. * * Small or small, droplets of the same size in an airflow, such as droplets of 23 microns, will be intercepted when they encounter relatively smaller "hole grids" such as 3 microns, 10 microns, and 15 microns. However, if they encounter relatively larger "hole grids" such as 30 microns, 50 microns, and 100 microns, they will cross and escape. 2. The wire mesh demister has only a single one-stage separation unit in structure, and lacks more classification stages to capture and separate the escaped heavy aromatic droplets again. 3. From the perspective of the separation process, when the droplets and droplets carried in the airflow enter the "pores" of the wire mesh demister, they have the characteristic of "shape-changing" due to their significant surface tension. When the droplets and droplets pass through the "pores" of the wire mesh demister, their equivalent size will shrink and deform. After passing through the "pores", the equivalent size of the droplets and foam will change back to its original size. Therefore, when wire mesh, filter screen, filter element, filter material, etc. are used to effectively intercept and separate the carried matter in the air flow through "hole grids", it is effective for the situation where the equivalent size of solid particles such as dust does not "change with the shape", but it is not efficient for the separation of droplets and liquid foam that have "conformity change" in size such as droplets and liquid foam. 4. The airflow direction before and after the airflow and its carried matter enter the wire mesh demister, and the flow direction of the airflow and the carried matter is either in the same direction or in the opposite direction, causing the gas and liquid to be easily backmixed and carried twice, and even form "liquid flooding" and "liquid surge" during the gas-liquid separation process, which is not conducive to gas-liquid separation.

This post was last edited by luoli519 on 2021-9-23 15:25 Let’s take a look at the baffle demister? The picture below is a picture of a baffle demister. 1. The baffle demister also belongs to the gas-liquid separator, that is, the category of dynamic separation technology. Its structure and configuration design must be completed through an internationally authoritative precision dynamic separation technology calculation and configuration design system platform to complete a systematic plan. Non-professional dynamic separation technology companies cannot rely on experience, "rough estimates" or even "brain" to deal with owners. Otherwise, the separation efficiency in actual applications will deviate greatly from the owner's process and technical requirements. 2. The baffle demister has a single structure and lacks a pre-distribution coalescing structure to pre-distribute the mixed fluid before entering the baffle demister. The prevailing flow pattern and parameter distribution characteristics of the mixed fluid cannot meet the prerequisites for dynamic separation required for efficient and accurate operation of dynamic separation, resulting in poor separation effect. 3. The inner parts of the baffle demister are simple in structure, and the flow direction of the airflow and the carried matter before and after entering the baffle demister is similar to that of the wire mesh demister, either in the same direction or in the opposite direction, causing the gas and liquid to be easily mixed back and carried twice, and the gas-liquid separation efficiency is low. 4. The baffle demister lacks an independent heavy-phase carrier mass discharge system, which causes the separated liquid to be carried back into the airflow, increasing the workload of the baffle demister, repeating itself in a vicious cycle. The typical Chevron baffle demister structure and its operating efficiency are as follows::

The following is an in-depth analysis and discussion of the technical upgrade and transformation of the original demister of a high-concentration hydrogen peroxide concentration distillation device of a hydrogen peroxide device as an example. In the customer's hydrogen peroxide project high vacuum distillation tower, the produced gas carries liquid droplets and foam. Under the conditions of working temperature 55-60°C and working absolute pressure 8kPaA, it passes through the original wire mesh demister and baffle demister at a flow rate of 155kg/h, and then is discharged to the downstream cooling liquid collection system through a nominal diameter 125mm pipeline at high speed. Because the original demister uses a wire mesh demister and a Chevron light plate baffle demister, and the supplier does not have a precise dynamic separation technology calculation and configuration design system platform, the demister technical solution it provides is designed and manufactured based on experience and "rough estimates." The original demister has a simple structure, low gas-liquid separation performance, and small operating flexibility. It cannot meet the requirements for efficient and stable separation of the gas produced from the high vacuum distillation tower under changing working conditions, and the product cannot stably meet the requirements of the buyer.

In view of the fact that the gas flow produced from the high vacuum distillation tower contains liquid droplets and liquid foam carriers, and its operating temperature, pressure and fluid flow pattern may cause unstable fluctuations in variable operating conditions during actual operation. NOVEL company learned through the operation of its precise dynamic separation technology calculation platform: Under the above working conditions, the maximum size of residual droplets carried by the produced gas after treatment by the original wire mesh demister and Chevron light plate baffle demister is still up to 38.74 microns. The residual amount of droplets and foam is large, making it difficult for the product to meet the requirements. In order to efficiently capture the liquid droplets carried by the air flow in the high vacuum distillation tower of the hydrogen peroxide project, NOVEL recommended the owner from the perspective of professional dynamic gas-liquid separation technology: Feather leaf separators are used to technologically upgrade the original simple wire mesh and Chevron light plate baffle demisters to improve their gas-liquid separation processing performance under variable working conditions, so as to meet technical requirements such as high operational flexibility, efficient and stable separation under fluctuating working conditions, and effectively capture droplets and foam carried by the gas produced from the high vacuum distillation tower.