Process for preparing citric acid
Abstract
Abstract A PROCESS FOR PREPARING CITRIC ACID, COMPRISING CARBOXYLATING ACETONE WITH CARBON DIOXIDE IN AN INERT DIPOLAR APROTIC MEDIUM, SELECTED FROM THE GROUP CONSISTING OF N-DIALKYL-SUBSTITUTED AMIDES OF ORGANIC ACIDS, N-ALKYLLACTAMS HAVING UP TO 10 CARBON ATOMS, AND DIMETHYL SULPHOXIDE IN THEPRESENCE OF AT LEAST 4 MOLES OF PHENOL ALKALINE SALTS PER EACH MOLE OF ACETONE, AT A TEMPERATURE BETWEEN 0* AND 60*C. AND AT A SUBSTANTIALLY ATMOSPHERIC PRESSURE, TO YIELD A 3-KETOGLUTARIC ACID ALKALINE SALT. CYANURATING SAID 3-KETOGLUTARIC ACID ALKALINE SALT WITH HCN IN EXCESS WITH RESPECT TO THE THEORETICAL AMOUNT NECESSARY TO OBTAIN THE CYANOHYDRIN OF THE 3-KETOGLUTORIC ACID, AT A TEMPERATURE RANGING FROM 0* TO 20*C. SUBSEQUENTLY HYDROLYZING THE CYANOHYDRIN THUS OBTAINED WITH SULPHURIC ACID IN EXCESS WITH RESPECT TO THE PRESENT ALKALI AND NITROGEN TO YIELD CITRIC ACID. RECOVERING THE CITRIC ACID AS AN ALKALINE EARTH METAL SALT.
Inventors
- 👤 G Bottaccio
- 👤 V Carletti
- 👤 G Chiusoli
- 👤 A Coassolo
Bibliographic Details
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