Organosolv pulping and recovery process
Abstract
Abstract A PROCESS IS PROVIDED FOR PULPING SUBDIVIDED FIBROUS PLANT MATERIAL, USING AS PULPING AGENT A MIXTURE OF WATER AND A WATER MISCIBLE, VOLATILE ORGANIC SOLVENT FOR EXAMPLE ETHANOL. THE DIGESTION IS CARRIED OUT IN A COUNTERCURRENT MANNER, THE SUBDIVIDED FIBROUS PLANT MATERIAL BEING IMMERSED IN THE PULPING LIQUOR AT AN ELEVATED TEMPERATURE AND PRESSURE. THE SPENT COOKING LIQUOR IS RECOVERED FROM THE DIGESTER AND IS CONDUCTED AT APPROXIMATELY THE PULPING CONDITIONS OF TEMPERATURE AND PRESSURE INTO A MULTISTAGE FLASH EVAPORATOR FROM WHICH THE ORGANIC SOLVENT IS RECOVERED CONTINUOUSLY AND CAN BE RECYCLED FOR MAKE-UP OF THE PULPING LIQUOR. THE MULTISTAGE FLASH EVAPORATION ALSO PERMITS RECOVERY OF LIGNIN AND WATER SOLUBLE COMPONENTS CONTAINING SUGARS, OLIGOSACCHARIDES AND ORGANIC ACIDS.
Inventors
- 👤 Theodor N Kleinert
Bibliographic Details
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