(643a) Recovery of Bio-Based 2,3-Butanediol Using Wiped Film Distillation

The transition from fossil-based energy sources towards more sustainable alternatives is a growing trend within the realms of scientific and industrial research. Among these, 2,3-Butanediol (BDO), a monomer derived from biomass through biochemical pathways with high yields, stands out as a key candidate for the production and subsequent refinement into various chemical products and fuels¹. However, a primary obstacle in leveraging BDO as a precursor is the effective separation and isolation of this molecule from the fermentation broth. Due to its high boiling point, traditional distillation processes for BDO separation prove to be highly energy-demanding and, consequently, economically burdensome. Moreover, elevated temperatures involved in distillation are conducive to the formation of oligomers, necessitating further processing through hydrogenation to achieve the desired purity levels². As such, the quest for alternative BDO recovery methodologies remains a focal point of contemporary research³. Recent studies suggest the hybrid approach, combining solvent extraction and distillation, could be an efficient strategy to separate BDO, presenting a promising direction for future investigations⁴.

In this talk, the efficacy of a Wiped Film Evaporator (WFE)—a specialized variant of short path distillation apparatus—for the separation of BDO from extraction solvents, namely oleyl alcohol and n-hexanol, is thoroughly explored. The influence of experimental parameters including BDO feed concentration, evaporator temperature, condensation temperature, feed flow rate, and wiper speed were rigorously evaluated employing the Response Surface Methodology (RSM). The primary aim was to enhance the concentration and recovery rates of BDO. Furthermore, process optimization and performance forecasting were undertaken utilizing an Artificial Neural Network (ANN). This investigation covers both simulated BDO and actual BDO broth after fermentation. Findings indicate that the concentration of BDO in the feedstock and the temperature of the evaporator markedly impact the purity and yield of the resultant product. Remarkably, by employing oleyl alcohol as the extraction solvent under finely tuned conditions, the process achieved a BDO recovery rate exceeding 95% and a solvent recovery rate above 85% in a single stage of separation.

Reference

1. Tan, E. C., Economic and Sustainability Assessment on Bio-based 2, 3-BDO Separation Approaches for Sustainable Aviation Fuel Production. 2023.
2. Rajale, T.; Yang, X.; Judge, E. J.; Moore, C. M.; Martinez, A.; Guo, M. F.; Ramasamy, K. K.; Elander, R.; Sutton, A. D., Separation, recovery and upgrading of 2, 3‐butanediol from fermentation broth. Biofuels, Bioproducts and Biorefining 2023, 17 (4), 1003-1011.
3. Kubic Jr, W. L.; Tan, E. C., Reactive Extraction Process for Separating 2, 3-Butanediol from Fermentation Broth. Industrial & Engineering Chemistry Research 2023, 62 (12), 5241-5251.
4. Gawal, P. M.; Mudgil, D.; Subudhi, S., Hybrid extraction distillation for downstream purification of 2, 3-butanediol, and ethanol from fermentation broth. Bioresource Technology Reports 2023, 24, 101649.