Introduction to Quaternary Catalysts for CBDO Synthesis

CBDO is an important raw material for polyester synthesis. The synthesized polyester material can not only maintain the advantages of copolyester, but also increase the glass transition temperature of the product. CBDO is mainly used to prepare copolyester materials and improve the performance of traditional polyesters. In addition, CBDO also acts as a bacteriostatic agent. So far, the most typical and mature method for synthesizing CBDO in the world is to collect and polymerize dimethyl ketene after cracking of ANIB or AIB into TMCD, and then perform hydrogenation to obtain CBDO. The catalyst preparation in the existing literature is complicated, the cost is higher, the hydrogenation process requires a solvent to dissolve, and there are many side reactions. CN105732329B patent introduces a quaternary component catalyst(Copper Oxide - Zinc Oxide -Alumina-Chromium Oxide) including copper, zinc, aluminum and chromium elements. The parts by weight of copper, zinc, aluminum and chromium in terms of oxides are:

Copper oxide accounts for 50-60 parts in the total weight of the catalyst;

Zinc oxide accounts for 15-25 parts in the total weight of the catalyst;

Alumina accounts for 15-20 parts in the total weight of the catalyst;

Chromium oxide accounts for 5-10 parts in the total weight of the catalyst.

The catalyst is to dissolve the soluble salts of copper, zinc and aluminum in water according to the above ratio to make a mixed solution, and then neutralize the mixed solution to a pH value of about 7 to form a precipitate, which is washed, dried and shaped. The catalyst is reduced with hydrogen before use, and the reduction temperature is 100-300°C.

The raw material TMCD and the solvent are passed through the reactor together, contact with the catalyst and undergo hydrogenation reaction, and react under hydrogen conditions,The reactor pressure is 2.0Mpa to 8.0Mpa, the temperature is 140℃ to 200℃, the reaction space velocity is 2-5 hours, and the hydrogen- hydrocarbon molar ratio is 100-350.

The quaternary component catalyst is used in the TMCD hydrogenation reaction, and the result is that the conversion rate of TMCD is 87.7%, and the selectivity of CBDO is 85.8%.

References

CN105732329B A kind of synthetic method of 2,2,4,4-tetramethyl-1,3- cyclobutanediol.