PRODUCTION OF ACID AND ALKALI

• Main Authors: NOMA YOSHIAKI, MAEHASHI TATSUYA
• Format: Patent
• Language: English
• Published: 16.05.1995
• Edition: 6
• Subjects: APPARATUS THEREFOR; CHEMISTRY; CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION ORPROCESSING OF GOODS; COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM,RUBIDIUM, CAESIUM, OR FRANCIUM; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; INORGANIC CHEMISTRY; METALLURGY; PAPER-MAKING; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; PRODUCTION OF CELLULOSE; PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCESFROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; SEPARATION; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE; TEXTILES; TRANSPORTING

PURPOSE:To reuse caustic soda and sodium hydrogensulfide as a kraft liquor by recovering caustic soda, a carbonic acid gas and sulfuric acid from a smelt solution in a pulp production process. CONSTITUTION:A smelt solution 1 in a pulp production process is supplied to an electrodialyzer 1 alternately arranged with a cation exchange membrane and a monovalent anion selectively permeable membrane to recover a mixed aqueous solution 2 of sodium carbonate and sodium sulfate, and then, the mixed aqueous solution is fed to an electrodialyzer II using a highly porous membrane to produce caustic soda, sulfuric acid and a carbon dioxide gas.