New Process Producing Highly Concentrated Polysulfide Liquor
| Autor: | Keigo Watanabe, Tatsuya Andoh, Masahiro Shimizu, Tetsuji Shamohira, Yasunori Nanri |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Thiosulfate
Materials science Waste management Electrolytic cell Mechanical Engineering Pulp (paper) food and beverages General Chemistry engineering.material equipment and supplies Pulp and paper industry Kappa number Sodium sulfide chemistry.chemical_compound Kraft process chemistry Sodium hydroxide Media Technology engineering General Materials Science White liquor |
| Zdroj: | JAPAN TAPPI JOURNAL. 54:52-57 |
| ISSN: | 1881-1000 0022-815X |
| DOI: | 10.2524/jtappij.54.52 |
| Popis: | A new electrolytic oxidation process to produce highly concentrated polysulfide (PS) liquor front the white liquor (WL) has been developed. A specially-designed electrolytic cell makes the system suitable for actual mill operation. The WL, is oxidized to produce PS liquor in the anode compartment. while pure sodium hydroxide is formed in the cathode compartment simultaneously. Since the undesirable thiosulfate formation is easy to control in the electrochemical process, it was possible to produce highly concentrated PS liquor with a good current efficiency. Consequently this process achieves to concentrate sodium sulfide in WL, and produce highly concentrated PS simultaneously, while the sulfur balance in the Kraft pulping process can be maintained. PS with SAQR pulping of hardwoods was evaluated using the oxidized liquor produced by the bench scale cell with the laboratory digester. Then, the large increases of pulp yields and large reductions of kappa number were observed, and modified cooking intensified these effects. A capable case of system closure for the bleached kraft pulp production was also proposed. |
| Databáze: | OpenAIRE |
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