Have you seen the last issue of Separations Savvy, “Fermentation in Your Process?”, which generated a lot of discussion among our biotech and pharmaceutical readers. We discussed the Whens and Whys of using Liquid-Liquid Extraction to recover low concentrations of high boiling organic chemicals generated in the fermentation step of biomass processing and heard from readers who wanted to see a specific example.
Carboxylic Acid from Aqueous Fermentation Broth
When extracting carboxylic acids from an aqueous fermentation broth generated in a cellulosic ethanol process, using ethyl acetate as the solvent of choice, initial attempts by the end user to develop the LLE process step in a rotating disc contactor (RDC) proved to be unsatisfactory. Poor product recovery (< 90%) and a high solvent to feed ratio required (≥ 1.7) were not acceptable. The end user knew that the process had a high tendency towards emulsification. Armed with this information, Koch Modular tested the process in a 25 mm diameter KARR® Column. The KARR® Column demonstrated excellent operability, generating fine dispersion of the solvent phase at low agitation speed as expected for systems which tend to emulsify.
• The solvent to feed ratio was improved to 1.5.
• The acid recovery was increased to 98-99% at slightly elevated temperature (40-45 oC).
With many more stories to share and solve for our clients, we are always happy to hear from you! If you’ve got a difficult separations problem, please contact us at firstname.lastname@example.org or call +1 201 267 8670.