Estudo da recuperação de acetonitrila proveniente de um laboratório de análises em bebidas

Abstract

In order to obtain an ecologically correct cycle for acetonitrile, recovery of the solvent is sought as an alternative to the usual treatment through incineration. Acetonitrile is obtained primarily through the production of acrylonitrile, this solvent has uses mainly in the pharmaceutical industries and in laboratories, being widely used as a mobile phase in reversed phase liquid chromatography. Due to the recurrent lack of acetonitrile on the market, there was a search and adaptation of a solvent recovery method through a systematic review. After characterizing the residue and calculating the laboratory's consumption of acetonitrile, the solvent was recovered. The process consists of freezing the initial HPLC residue for 72 hours, filtering the remaining liquid phase, which consists mainly of acetonitrile, adding calcium chloride to it, followed by a new filtration and fractional distillation. Finally, a purity of 95,3% was obtained, confirmed through a calibration curve constructed on the gas chromatograph. The use of acetonitrile with this purity did not present significant differences in the analytical results, despite being below the refinement levels of the commercial solvent. The process has a good cost-benefit ratio when compared to the price per liter in the current market, and because of this, there is room for the insertion of new steps for greater product purity. [resumo fornecido pelo autor]