Development of a sustainable process for the production of polymer grade lactic acid

Abstract

Lactic acid is a commonly occurring substance in nature, ranging from existence in micro-organisms to the human body. Traditionally, lactic acid has applications in industries such as food, chemicals, pharmaceuticals and textiles. In this work, a sustainable process for the production of polymer grade lactic acid (99 wt. % on dry basis) from crude lactic acid was simulated. The simulation was performed using Aspen Plus® version 8.2. The thermodynamic model used for the process was NRTL -Hayden O'Connell due to the polar nature and non-ideal behavior of the species involved. The process was carried out in three stages. First, crude lactic acid was obtained by reacting calcium lactate with sulfuric acid. The second stage consisted of esterification of lactic acid by reactive distillation. A RadFrac column was used for this purpose which also facilitated easy separation of methyl lactate from methanol and water. Pure methyl lactate obtained from the second stage was then hydrolyzed in the third stage using pure lactic acid as an auto-catalyst to obtain the desired product. Use of pure lactic acid as an auto-catalyst helped to achieve the required purity as it minimized contamination. The process was optimized using sensitivity analysis in Aspen Plus®.

Commodity chemical production from third‐generation biomass: a techno‐economic assessment of lactic acid production

“…The final stage of the process is to separate the lactic acid from the fermentation broth and to purify it to its polymer grade variant (99 wt% dry basis 30 ). The components that reach this stage are mainly lactic acid and water.…”

“…Thus, several methods such as crystallization, solvent extraction, evaporation, adsorption, electrodialysis, membrane separation, and reactive distillation have been applied to facilitate this separation. Although all of them present advantages and disadvantages, the two‐step process consisting of esterification of lactic acid with alcohol followed by the separation of the lactate ester by distillation and its hydrolysis to lactic acid is a good option to obtain high purity lactic acid 29,30 . The process depicts a configuration chosen by current commercial player Purac® (now Corbion®, Netherlands) hence, further warranting this selection 49 .…”

“…28 Lactic acid (LA), in particular, is an important and widely used organic acid around the world, due to its wide range of industrial applications 29,30 . Traditionally, lactic acid production was oriented towards food and pharmaceutical industry but, lately, its demand has been growing due to an interest in producing bioplastics using the bio‐compostable and biodegradable 30 poly‐lactic acid (PLA). Presently, with 15 major players active in the production of LA, the current production capacity is estimated to be 814 300 t per annum (see Appendix S2).…”

Life cycle analysis of corn‐stover‐derived polymer‐grade l‐lactic acid and ethyl lactate: greenhouse gas emissions and fossil energy consumption

“…In the DSP section, calcium lactate in the fermentation broth chemically transforms to crude dilute lactic acid, which is subsequently separated and purified to PGLA. We based the development of this portion of the process model on two studies . The DSP process consists of three primary stages.…”

Industrial Processes Management for a Sustainable Society: Global Research Analysis

“…Companies with highly effective resources and materials management improve their performance and logistics when prioritizing regional production. Sustainability in management also encourage firms to minimize waste and scrap production and through control and review processes, to choose partner companies that have sustainable certifications and standards joining the socially responsible approach [66].…”