Abstract: A process is described for producing a high molar mass polylactic acid, which comprises the following steps: a) polycondensation in a reactor (R1) of a lactic acid solution, by heating in the form of temperature gradients and under controlled pressure, resulting in a polylactic acid oligomer within the range of 300 to 5000 g/mol; b) conversion, in reactor (200), of the polylactic acid of low molar mass obtained in step a) to a lactide, in the presence of a depolymerization catalyst; c) separation of the volatile fractions; d) recrystallization of the lactide in the vessel (R3), in order to obtain ethanol; e) polymerization, in a tube reactor (300), of the recrystallized lactide obtained in step d), via ring opening in the presence of the catalyst, producing a high molar mass polylactic acid; f) devolatilization, at (400), of the polymeric mass obtained in step e); and g) recovery of the final polylactic acid product with a high degree of purity, with a molar mass of between 50 000 and 200 000 g/mol and a reac
Abstract: The present invention describes a process for obtaining lactic acid with a high degree of purity from a fermentative liquor (1) containing sodium lactate, with a view to the production of polylactic acid. The process comprises the unitary operations of centrifugation (101), centrifugal decantation (102), microfiltration (103), ultrafiltration (104), primary filtration in an activated charcoal bed (105), conventional electrodialysis (201), ion exchange columns in a chelating resin bed (202), bipolar electrodialysis (203), ion exchange columns (204), primary evaporation under vacuum (302), secondary filtration in an activated charcoal bed (304), liquid-liquid extraction from the aqueous phase to the organic phase (305), back extraction from the organic phase to the aqueous phase (306), and secondary, atmospheric evaporation (402).
Abstract: A system (100, 200) is described for correcting constant volume acidity of fermentative media for the production of organic acids, which comprises a fermenter (1) provided with a pH sensor (P1) a filtration module (2) provided with a filtering element, an addition vessel (3) provided with a main metering element (4), and a heat exchanger (5). Operation of the system (100, 200) is controlled by a controller (CT). As soon as the sensor (P1) detects a reduction in pH to below the ideal values for producing organic acid, the controller (CT) calculates the amount of fermentative medium to be withdrawn from the fermenter (1) and said amount is conveyed to the vessel (3) in order to be alkalinized and returned to the system. Arrangements of the system with more than one fermenter are also described. The process for correcting acidity used by the system (100, 200) of the invention is likewise described.