查看文章

Strategies for extracting organic acids from aqueous solutions using polymeric absorbents are demonstrated and discussed in the context of two-phase partitioning bioreactor (TPPB) design. Experimental data and material balances for the uptake of butyric acid and benzoic acid by a poly(ether-block-amide) copolymer (Pebax 2533) establish the inherent limitations of unreactive absorbents for organic acid bioprocesses that operate at near-neutral pH. Improvements to TPPB performance are achieved by lowering pH temporarily with CO₂ to enhance acid absorption, and removing the solute-rich polymer before restoring pH to fermentative values by releasing the CO₂ pressure. Butyric acid removal by Pebax 2533 improved from 3% to 40% upon acidifying a pH 6 solution with 60 bar of CO₂, while benzoic acid absorption increased from 1% to 80% using this pressure manipulation technique. A reactive extraction …