Hanwha Chemical Corporation

Hanwha Solutions Corporation

Kee Do Han

Young Jo Kim

Bong Sik Jeon

Hyo Suk Kim

Ki Taeg Jung

Hye Won Lee

Shin Beom Lee

Kyong Jun Yoon

Sung Eun Park

Seong Ho Park

Ji Hye Choi

Hyun Cheol Ryu

Seon Jeong Jin

Sang Ho Seo

Chang Mo Chung

Wooyoul Ahan

The invention relates to a method for selective hydrogenation. More specifically, it relates to a method for selective hydrogenation capable of improving selectivity and reaction efficiency in the hydrogenation process of petroleum resin.

Method for selective hydrogenation

The present invention relates to a toluene diisocyanate purification method enabling acquisition of a product having a small amount of dimers in a final product by means of using a reactive dividing wall column during toluene diisocyanate preparation. More particularly, according to the present invention, in order to obtain a product having a small amount of dimers in accordance with a reversible reaction of a monomer and a dimer, a purification procedure is designed by means of applying the temperature, pressure, time of stay and the like of a reactive dividing wall column as appropriate particular conditions, a reboiler having short time of stay and high heat transfer rate is used, and thus a dimerization reaction is inhibited and the purity and yield of the product are enhanced. Therefore, high-purity toluene diisocyanate can be purified and obtained.

Toluene diisocyanate purification method

The present invention relates to a stripping method capable of recovering, by an environmentally friendly method, a high-purity ester-based compound without concern over the oxidation of an ester-based compound from a mixture containing the ester-based compound. The stripping method has advantages of generating no wastewater, enabling equipment costs to be reduced by simplifying the process, removing concern over the oxidation of an ester-based compound during the process, and enabling the reuse of the components recovered in the process.

Stripping method

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Daejeon, South Korea

Kee Do Han