Produção de ácido lático a partir do soro de leite: uma alternativa sustentável para o reaproveitamento de resíduos

Abstract

Lactic acid is a viscous liquid that has two optical isomers, only one of them is biocompatible with the human body (l-lactic acid). This isomer has several areas of activity, those with greater applicability are the pharmaceutical, food and polymer industries. For the production of this optical isomer, it is normally used the fermentation route since it is possible to achieve greater selectivity of which isomer to be produced. However, one of the disadvantages of this route is the high cost of raw materials, such as glucose, in addition to production of waste such as calcium sulfate. In this way, the company STARLACT brings as a proposal the production from an agribusiness residue with low added value, cheese whey. Furthermore, to avoid the production of calcium sulfate in the purification stage, it was decided to use magnesium hydroxide replacing the traditional calcium hydroxide, since it does not generate waste. Through market analysis, it was decided to install the company in the city of Estrela (RS), due to the proximity to suppliers. Finally, the viability of the project was validated, since it presented a positive net present value (NPV) with a payback time of 4 years and 4 months. The project has shown to be viable for an annual production of 378 tons of lactic acid and another 465 tons of by-products, operating 360 days a year.