Concentrating second-generation lactic acid from sugarcane bagasse via hybrid short path evaporation: Operational challenges.

Highlights • Separation of lactic acid from 5-carbon sugars is more difficult than from 6-carbon sugars. • Lactic acid concentration is influenced by internal condenser temperature, evaporator temperature, and feed flow rate. • Presence of sugars from fermentation hinder lactic acid separation via hybrid short path evaporation. Abstract Production of lactic acid (LA) from lignocellulosic materials has become increasingly prominent in the market. However, for industrial scale to be reached, several challenges in second-generation lactic acid production must be overcome. Besides obstacles such as the hydrolysis process, one of the major challenges of the lactic acid industry is the separation and purification process. This study evaluates the separation of lactic acid produced from hemicellulose hydrolysate from sugarcane bagasse using a Hybrid Short Path Evaporation (HSPE) system. Results showed that a lactic acid concentration of 3.1 times the feed concentration (27.85 g/L) is achievable. Three operational parameters were studied: evaporator temperature, internal condenser temperature and feed flow rate. Maximum lactic acid concentration was 86.69 g/L with an evaporator temperature of 120 °C, condenser temperature of 13 °C, and feed flow rate of 8.27 mL/min. Separation of LA from hemicellulosic sugars using HSPE was a more difficult process than separation of LA from 6-carbon sugars. [ABSTRACT FROM AUTHOR]