Hydrogen peroxide production technology

1. technical background:

Hydrogen peroxide is a green chemical product. There is almost no pollution during its production and use, so it is called a “clean” chemical product. The production of hydrogen peroxide by the anthraquinone method is currently one of the most mature production methods in this industry in the world. Domestic and foreign manufacturers basically use the anthraquinone method to produce hydrogen peroxide.

There are more than ten technological methods for producing hydrogen peroxide, but currently the only methods that can be industrialized are electrolysis, isopropyl alcohol auto-oxidation, anthraquinone, and oxygen cathode reduction. The anthraquinone method is currently the most important method for producing hydrogen peroxide in the world. According to the different types of hydrogenation reactors, it is divided into fixed bed and fluidized bed processes.

At present, the industrial production of hydrogen peroxide in the world basically adopts the anthraquinone method (this method was started by DuPont in 1953), which uses alkyl anthraquinone as the working carrier.
The working carrier alkyl anthraquinone in my country mainly uses 2-ethylanthraquinone (EAQ). EAQ is dissolved in an organic solvent (generally composed of heavy aromatic hydrocarbons and trioctyl phosphate (TOP) in a certain proportion) to form a working solution. Then hydrogenation and oxidation reactions are carried out under the action of a catalyst (palladium catalyst) to generate hydrogen peroxide (H2O2), and then H2O2 is extracted from the working solution with pure water to obtain hydrogen peroxide with an H2O2 content of 27.5%, which is concentrated and reprocessed. For other specifications of hydrogen peroxide.
The entire anthraquinone production process is mainly divided into: hydrogenation, oxidation, extraction, purification and post-treatment. In order to reduce the decomposition of hydrogen peroxide and ensure the stability of the product, a small amount of phosphoric acid is added as a stabilizer during the oxidation and extraction process. Approximately 0.3 kg of phosphoric acid is added per ton of hydrogen peroxide (27.5% basis).

2. Reaction principle:

Step 1: The hydrogenation
carrier ethyl anthraquinone reacts with hydrogen in the hydrogenation reactor and is reduced to 2-ethyl hydroanthraquinone under the catalysis of the catalyst. Part of the hydroanthraquinone is further hydrogenated to tetrahydroethyl hydroanthraquinone. Quinone. When the hydrogenation reaction is carried out, the pressure at the top of the hydrogenation reactor is 0.1~0.5 MPa G and the temperature is lower than 60°C. The theoretical heat of formation of hydrogen peroxide is 188.7 KJ/mol. The heat generated by the reaction can be removed by a cooler. A filter is installed at the reactor outlet.

Step 2: Oxidize
the hydrogenated liquid to remove the catalyst through filtration or other methods, and react with air to obtain hydrogen peroxide. The oxidation process uses a countercurrent reaction of gas and liquid in a sieve plate tower. The working fluid enters at the top of the oxidation tower, and the compressed air enters the tower under the bottom sieve plate. In order to more effectively separate the working fluid and exhaust gas, special packing is installed on the top of the oxidation tower. The top pressure of the oxidation tower is controlled at about 0.2~0.5 MPa G.

Step 3: Extract
the hydrogen peroxide generated during the oxidation process, and perform countercurrent extraction and recovery with pure water in the extraction tower.

Step 4: Solvent recovery:
The solvents from each solvent intermediate tank, intermediate equipment and solvent recovery equipment are separated into water and oil phases through the coalescer, and the solvent is recovered and reused in production.

Step 5: Working fluid preparation and regeneration
The working fluid is prepared intermittently in the working fluid preparation tank. Quantitative heavy aromatics, TBU, and anthraquinone are mixed and dissolved into the solution under heating (about 50°C) conditions.
In order to maintain effective anthraquinone concentration and catalyst activity, the contents of anthraquinone, anthrone and epoxide must be controlled. This can be accomplished by removal or regeneration. The anthraphenones and epoxy compounds are regenerated by contact with activated alumina.

Industrial Grade Hydrogen Peroxide Product Specifications

3. Technical advantages:

Although the domestic hydrogen peroxide industry has developed rapidly in recent years and the level of production technology has also improved, they are all optimized and improved on the basis of the fixed-bed hydrogenation process. Compared with the domestic anthraquinone-based hydrogen peroxide production technology, the fluidized bed technology has obvious advantages. Features and Benefits:

1. Larger production scale

Several foreign companies with the largest hydrogen peroxide production have developed their own unique production technology and have supporting production equipment. They basically adopt the fluidized bed hydrogenation process, and the scale of a single set of equipment is large. The hydrogen peroxide production scale can reach 330,000 tons (within 100% concentration meter, hydrogenation efficiency 18g/L).

2. Higher production efficiency

For example, Hubei Sanli Liquidambar Technology Co., Ltd. uses high-capacity working fluids, fluidized bed hydrogenation and other advanced processes. The hydrogenation efficiency reaches 12.5g/l-15g/L or more, which is higher than the hydrogenation efficiency of domestic hydrogen peroxide technology (generally 7.5- 8.5g/L) is 50% higher, that is, the working fluid production capacity per unit volume in each cycle is increased by 50%, which greatly improves the production efficiency of the device and reduces the consumption of circulating working fluid; it can directly produce hydrogen peroxide with a concentration of 35-43%; the total process income The rate is high.

3. The process is simpler, the production is safer, and the products are of higher quality.

There are no K2CO3 drying towers and related control issues in the production process, so the process is greatly simplified; the safety hazard of hydrogen peroxide decomposing in the production system due to alkalinity is essentially eliminated. The product quality is higher, and the product does not contain acid-base neutralized inorganic salts and Other impurities brought by potassium carbonate have wider uses and are beneficial to the further production of high-purity hydrogen peroxide, such as food-grade and electrical-grade hydrogen peroxide.

4. Significant energy saving and consumption reduction, effectively reducing production costs
5. Less investment. Both equipment investment and the working fluid and palladium catalyst required for initial production have been reduced. Taking Hubei Sanli Liquidambar Technology Co., Ltd.’s 70,000 tons/year (100%) [250,000 tons/year (5%) scale production equipment as an example, the investment is 150 million yuan.

For more detailed hydrogen peroxide process information, please contact us. Hubei Sanli Liquidambar Technology Co., Ltd. specializes in providing hydrogen peroxide process technology.