OPP Key Process Technology And Innovation

The production technology of o-phenylphenol has the following key technologies and innovations:

1. The cyclohexanone condensation adopts the super strong solid acid catalyst and the continuous technology of multiple reactors in series

In general patent documents, concentrated sulfuric acid is used as catalyst for cyclohexanone condensation reaction. The reaction temperature is 120 ℃, the one-way conversion rate is about 50%, and the total yield is 85%. After the reaction, alkali is used to neutralize the reaction solution. The equipment is severely corroded, and there is a large amount of wastewater, causing serious environmental pollution.

A super solid acid is used as catalyst for o-phenylphenol, the dosage is 2-3%, the reaction temperature is about 120 ℃, the one-way conversion rate is 60%, and the total yield is more than 90%. The catalyst can be reused, and it is a clean production process, which solves the problem of wastewater generation.

The multi kettle series connection continuous technology is adopted to overcome the disadvantages of troublesome production operation and large equipment investment, which can realize full automatic continuous.

2. Efficient dehydrogenation catalyst

Dehydrogenation catalyst uses platinum as the main catalyst, and 2-3 cocatalysts are added. One of them is rare earth element. Pt 0.5% - rare earth 5% catalyst is carried on a special carrier. Hydrogen is used as the carrier gas, and the reaction temperature is 350-370 ℃. Under the high load of dimer liquid phase space velocity of 0.2-0.4h-1, the dimer conversion rate is 98%, the selectivity is more than 93%, and the yield of o-phenylphenol is more than 90% after continuous operation for more than 5000 hours. However, according to domestic patent data, the catalyst load is 0.2h-1, and the efficiency of o-phenylphenol has decreased significantly after 200 hours of continuous operation.

3. Continuous product refining technology

The cyclohexanone condensation product is refined by thin film evaporation+two tower continuous distillation.

Dehydrogenation products adopt high vacuum molecular distillation technology and continuous recrystallization technology. Continuous recrystallization combines recrystallization, centrifugal separation, drying and packaging into a continuous system to meet the requirements of product purity, production safety and automation.

4. High purity products

The purity of o-phenylphenol can reach more than 99.5%, meeting the needs of export and the fields of sterilization, mildew prevention and fresh-keeping agent.

5. Specially made product stabilizer

The refined product is added with 0.05-0.2% of the special stabilizer to ensure the color of the white flake crystal and meet the export needs. Without the above stabilizer, the product will turn light red after being placed for less than a month.