Journal of Biotechnology & Biomaterials
Open Access

Abstract

Microbial conversion of syngas components (CO, CO2 and H2) is a potential technology for the production of biofuels and biochemicals using coal, lignocellulosic biomass and waste gases from iron and steel works. However, poor Gas-Liquid Mass Transfer (GL-MT) and low productivities limit the scale up and commercialization of the technology. The use of hollow fiber membranes as a micro bubbles generating system make it possible to achieve the highest mass transfer efficiency in the GL-MT applications. However, only a few studies have been reported in which the highest GL-MT is achieved with the aid of high fluid (liquid) circulation. Additional vessels were used to achieve mixing through agitation. These reactor configurations would possibly cause high cost for scale up. Thus, there is a strong need to develop a simple HFMBR configuration capable to produce high GL-MT efficiencies without liquid circulation, substrate gas recycling and mixing by agitation. Owing to the density ratio of syngas components to the water, the pumping cost for fermentation media will be much higher compared with the gaseous feed stocks. In this study, we developed a high GL-MT, HFMBR system (standalone configuration) using micro porous Polyvinyl Fluoride (PVDF) hollow fiber membranes. High CO volumetric mass transfer coefficient (kLa) of 155.16 h-1 was achieved without using pumps and agitators. Finally, CO/CO2 fermentation was conducted using Eubacterium limosum KIST612 to assess the practicality of the HFMBR system under biotic conditions. Lower residence time of the substrate gases in the fermentation medium is a potential drawback that needs to be addressed.

Biography

Email: ischang@gist.ac.kr