Concentrating lactate-carbon flow on medium chain carboxylic acids production by hydrogen supply. (November 2019)

• Record Type: Journal Article
• Authors: Wu, Qinglian; Guo, Wanqian; You, Shijie; Bao, Xian; Luo, Haichao; Wang, Huazhe; Ren, Nanqi
• Is Part Of: Bioresource technology. Volume 291(2019)
• Publication Date: 2019-11
• Subjects: Chain elongation -- Medium chain carboxylic acids -- Caproate -- Heptylate -- Lactate; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2019.121573
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: H2 concentrated lactate-carbon on medium chain carboxylic acids (MCCAs) production. Mechanism of enhanced MCCAs yield by H2 supply was revealed for the first time. H2 supply improved the electron efficiency and electron donating capacity. H2 supply facilitated the reutilization of dispersive lactate-carbon flow. Abstract: Upgrading lactate/carbohydrate-rich waste biomass into medium-chain carboxylic acids (MCCAs) by chain elongation (CE) technology exhibits economic and environmental benefits. However, the largely dispersive lactate-carbon-flow decreases MCCAs yield. This work discovered appropriate H2 supply could significantly reduce lactate-carbon-flow loss and improve MCCAs production (∼1.65 times) when the system is not operated according to well-defined operating conditions, and revealed corresponding mechanism. Hydrogen (H2 ) supply largely enhanced electron efficiency and electron transfer capacity, and H2 could reduce propionate (from competing acrylate pathway, which should be prevented, but when not possible, the carbon recovery from propionate is possible) to propanol, which was used as electron donor to elongate acetate and propionate. Moreover, H2 could react with CO2 (from CE process) to sequentially generate acetate and ethanol, which further contributed to caproate/caprylate generation. Comparing with non-H2 -supplemented test, the lactate-carbon-flow used for MCCAs production was enhanced by ∼28.4% after H2 supply, and Clostridium spp. were the key discriminative microorganisms.