Daicel Chemical Industries, Ltd.

Etsuo Takemoto

Hiroshi Koyama

Teruhiko Hirabayashi

Yoshiyuki Imagire

Akira Horiguchi

Akihisa Takabe

Toshifumi Kitagawa

Nobuo Nonaka

Yasukazu Murakami

Shinzo Uda

Iwao Abe

Osamu Ohshima

1-aminopropanediol-2,3 containing 2-aminopropanediol-1,3 of less than 0.30% by weight can be prepared by the present purification process, which comprises distilling a 1-aminopropanediol-2,3 containing at least 0.3% of 2-aminopropanediol-1,3 based on the weight of 1-aminopropanediol-2,3 with a distillation column, said distillation column having low pressure loss.

Highly purified 1-aminopropanediol-2,3

Disclosed are a process for the preparation of a dihydroxyamino compound in which water and discoloring ingredients are removed while preventing decomposition of a dihydroxyamino compound by distilling a crude reaction liquid containing an epoxy compound and an amino compound at a specified temperature and pressure, a process for improving a yield of a dihydroxyamino compound having high purity by recirculating an aqueous solution of an amino compound recollected from a crude reaction liquid into a reaction step, and a process in which there are prevented discoloration and a yield decline of a dihydroxyamino compound.

Process for the preparation of a dihydroxyamino compound

1-aminopropanediol-2,3 containing 2-aminopropanediol-1,3 of less than 0.30% by weight can be prepared by the present purification process, which comprises distilling a l-aminopropanediol-2,3 containing at least 0.3% of 2-aminopropanediol-1,3 based on the weight of 1-aminopropanediol-2,3 with a distillation column, said distillation column having low pressure loss.

1-aminopropanediol-2,3 containing 2-aminopropanediol-1,3 of less than 0.30% by weight can be prepared by the present purification process, which involves distilling a 1-aminopropanediol-2,3 containing at least 0.3% of 2-aminopropanediol-1,3 based on the weight of 1-aminopropanediol-2,3 using a distillation column, said distillation column having low pressure loss.

Method for the purification of 1-aminopropanediol-2,3

The present invention provides a process for recovering a tungsten compound from a waste liquor containing a high-boiling organic compound and the tungsten compound, which process comprises the steps of spray-burning said waste liquor at an air ratio of 1.05 or higher under conditions of a temperature and a residence time which lie within the region of a pentagon defined by points A, B, C, D, and E in FIG. 1; quenching the combustion product by immediately bringing it into direct contact with water; and recovering the tungsten compound.

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Hiroshima, Japan

Etsuo Takemoto