Carboxylic Acid Concentration in Downstream Bioprocessing Using High-Pressure Reverse Osmosis

Area of Science:

• Biochemical Engineering
• Separation Processes
• Sustainable Chemistry

Background:

• Product separation is a costly bottleneck in bio-based chemical production due to low bioproduct concentrations.
• Conventional methods like reverse osmosis (RO) have limitations in achieving high concentration factors.

Purpose of the Study:

• To investigate the integration of high-pressure reverse osmosis (HPRO) for concentrating butyric acid from fermentation broth.
• To evaluate the impact of HPRO on downstream extraction efficiency, cost, and environmental footprint.

Main Methods:

• Experimental measurements and process modeling to determine HPRO performance.
• Integration of HPRO with liquid-liquid extraction and distillation for butyric acid purification.
• Comparison of HPRO-integrated process with conventional RO-integrated process.

Main Results:

• HPRO achieved a concentration factor of 4.0 for butyric acid, exceeding conventional RO membranes (2.6-3.2).
• Integration of HPRO into an in situ product recovery (ISPR) process increased final butyric acid concentration by over 5-fold.
• A 76% reduction in organic solvent usage was observed with the HPRO-integrated ISPR process.

Conclusions:

• HPRO is a highly effective technology for concentrating dilute bioproducts like butyric acid.
• Integrating HPRO into ISPR processes significantly reduces production costs (53%) and greenhouse gas emissions (46%).
• HPRO enables more economical and sustainable recovery of bio-based chemicals from aqueous streams.