Electrolytic Membrane Extraction Enables Production of Fine Chemicals from Biorefinery Sidestreams

详细信息    查看全文

• 作者：Stephen J. Andersen ; Tom Hennebel ; Sylvia Gildemyn ; Marta Coma ; Joachim Desloover ; Jan Berton ; Junko Tsukamoto ; Christian Stevens ; Korneel Rabaey
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：June 17, 2014
• 年：2014
• 卷：48
• 期：12
• 页码：7135-7142
• 全文大小：296K
• 年卷期：v.48,no.12(June 17, 2014)
• ISSN：1520-5851

文摘

Short-chain carboxylates such as acetate are easily produced through mixed culture fermentation of many biological waste streams, although routinely digested to biogas and combusted rather than harvested. We developed a pipeline to extract and upgrade short-chain carboxylates to esters via membrane electrolysis and biphasic esterification. Carboxylate-rich broths are electrolyzed in a cathodic chamber from which anions flux across an anion exchange membrane into an anodic chamber, resulting in a clean acid concentrate with neither solids nor biomass. Next, the aqueous carboxylic acid concentrate reacts with added alcohol in a water-excluding phase to generate volatile esters. In a batch extraction, 96 卤 1.6% of the total acetate was extracted in 48 h from biorefinery thin stillage (5 g L^鈥? acetate) at 379 g m^鈥? d^鈥? (36% Coulombic efficiency). With continuously regenerated thin stillage, the anolyte was concentrated to 14 g/L acetic acid, and converted at 2.64 g (acetate) L^鈥? h^鈥? in the first hour to ethyl acetate by the addition of excess ethanol and heating to 70 掳C, with a final total conversion of 58 卤 3%. This processing pipeline enables direct production of fine chemicals following undefined mixed culture fermentation, embedding carbon in industrial chemicals rather than returning them to the atmosphere as carbon dioxide.