Effect of Operating Conditions and Split Ratio for Lactic Acid Purification by Short Path Evaporation System

• Main Authors: Andrea Komesu, Johnatt Oliveira, Luiza Martins, Rubens Maciel Filho, Regina Wolf Maciel Maria
• Format: Article
• Language: English
• Published: AIDIC Servizi S.r.l. 2018-10-01
• Series: Chemical Engineering Transactions
• Online Access: https://www.cetjournal.it/index.php/cet/article/view/9224

An increasing interest for discovery new environment-friendly sources of chemicals has been observed due to the current concerns related to the cost and environmental impact of fossil-based chemicals. One important technological platform is the production of bio-based chemicals by fermentation, such as lactic acid (LA). In this work, LA was produced by fermentation using sugarcane molasses without pretreatment as carbon source and Lactobacillus plantarum inoculum. Traditionally, several steps are needed after fermentation to produce the final LA product. By not using organic solvents and not produce gypsum, short path evaporation system (SPE) is an alternative separation process to purify the LA. Evaporator temperature (from 116 to 164 °C) and condenser temperature (from 13 to 22 °C) were studied aiming to determine the best operating conditions for SPE. This evaluation to obtaining maximum LA purity and recovery can be made either in the distillate or in the residue stream. In the range of study, the product obtained at the distillate stream using evaporator temperature of 141 °C and condenser temperature of 17.6 °C presented the richest lactic acid fraction (~70 wt%) with recovery of ~55 %. Using split ratio (mass of residue/ mass of distillate) of 1.5, the residue stream presented ~22 wt% of LA fraction with ~52 % of recovery. In addition, results were compared with previous works using different distillation processes. The comparison was performed based on Purification Performance Index (PPI).