Patents Assigned to Toa Oil Co., Ltd.
  • Treatment of gas containing hydrogen sulfide
    Patent number: 4118467
    Abstract: An effluent alkali salt solution obtained in the desulfurization of a hydrogen sulfide-containing gas by washing with an alkali wash solution is subjected to a two stage precipitation treatment at different temperatures to recover valuable components such as a vanadium compound, chelating agent, ADA, and active alkali salts while removing inactive salts such as sulfate and thiosulfate.
    Type: Grant
    Filed: March 16, 1978
    Date of Patent: October 3, 1978
    Assignees: Nittetu Chemical Engineering Ltd., Toa Oil Co., Ltd.
    Inventors: Masaru Sano, Koji Kashima