Jet-nozzle based improvement of dissolved H2 concentration for efficient in-situ biogas upgrading in an up-flow anaerobic sludge blanket (UASB) reactor

Abstract

Improvement of dissolved concentration and mass transfer coefficient (KLa) of H2 is a main strategy for efficient biogas upgrading process. In this study, Jet nozzle reactor (JNR) was applied to improve dissolved H2 (DH2) concentration and KLa for successful in-situ biogas upgrading in an up-flow anaerobic sludge blanket (UASB) reactor. JNR could improve the DH2 concentration and KLa to 1.71 and 1.72 times higher than those of control reactor, respectively. Increased DH2 concentration and KLa contributed to increase CH4 content to 96.1% in UASB combined with JNR (JN-UASB). JN-UASB achieved maximum H2 conversion efficiency of 97.9% and minimum H2 content of 3.9% in biogas. Community of hydrogenotrophic methanogens and efficiency of H2 conversion in JN-UASB were 1.1 and 1.3 times higher than those in control UASB (C-UASB), respectively. This study confirmed that DH2 concentration and KLa increased by JNR affected the improvement of H2 methanation efficiency via rapid hydrogenotrophic methanogenesis. The findings of this study provide technical strategy and further research direction to upgrade biogas.