Mitsubishi Paper Mills Limited

Mitsubishi Heavy Industries Limited

Shinichi Hara

Masayuki Suzuki

Munekazu Nakamura

Takeo Ono

Yoshihiro Ohguchi

Fumihiko Ishizuka

Kuniaki Kimura

Nobuo Onuma

Akira Osawa

Akira Fukuzawa

A method of treating an aqueous sodium sulfide solution, such as white liquor in kraft pulping systems, for the oxidation of the sulfide with oxygen in the presence of a specific activated carbon catalyst which is (a) a particulate activated carbon catalyst having an average particle diameter of 0.2-4 mm, a pore volume of at least 0.25 cc/g in pores with diameters of not smaller than 100 .ANG. and a pore volume of at least 35% of the total pore volume in pores with diameters of not smaller than 100 .ANG. or (b) a fibrous activated carbon catalyst having a specific surface area of 300-2500 m.sup.2 /g and an outer surface area of 0.1-5 m.sup.2 /g.

Method of oxidizing sulfide-containing liquor

A method for oxidizing and removing remaining sodium sulfide as well as generated sulfur compounds by introducing oxygen into cooking liquor at high temperature and high pressure in the end stage of kraft cooking.

Method for oxidizing malodorous sulfur compounds in kraft cooking liquor

Growing community of inventors

Hachinohe, Japan

Shinichi Hara