PROCESS FOR PRODUCTION OF POLYLACTIC ACID, APPARATUS FOR PRODUCTION OF POLYLACTIC ACID, PROCESS FOR PRODUCTION OF BIODEGRADABLE PLASTIC, AND APPARATUS FOR PRODUCTION OF BIODEGRADABLE PLASTIC

摘要

Disclosed are: a process for producing polylactic acid, which can produce polylactic acid having uniform quality and enables the reduction in time required for the production of polylactic acid; an apparatus for producing polylactic acid; a process for producing a biodegradable plastic; and an apparatus for producing a biodegradable plastic.In a primary fermentation tank (12), a plant-derived raw material is hermetically placed and fermented to produce lactic acid. By a first separation means (13), a fermentation product produced by the fermentation in the primary fermentation tank (12) is separated into a liquid fraction and a solid fraction. In a secondary fermentation tank (15), the liquid fraction of the fermentation product, which has been separated by the first separation means (13), is hermetically placed and re-fermented. By a second separation means (16), a re-fermentation product produced by the re-fermentation in the secondary fermentation tank (15) is separated into a liquid fraction and a solid fraction. By a dehumidification means (17), water is evaporated from the liquid fraction of the re-fermentation product, which has been separated by the second separation means (16), to thereby extract lactic acid. By a polymerization means (18), lactic acid extracted by the dehumidification means (17) is heated and polymerized to thereby produce polylactic acid (2).