Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby DK-2800, Denmark.
Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby DK-2800, Denmark.
Bioresour Technol. 2017 Jun;234:310-319. doi: 10.1016/j.biortech.2017.03.055. Epub 2017 Mar 12.
This study evaluates the efficiency of four novel up-flow reactors for ex situ biogas upgrading converting externally provided CO and H to CH, via hydrogenotrophic methanogenesis. The gases were injected through stainless steel diffusers combined with alumina ceramic sponge or through alumina ceramic membranes. Pore size, input gas loading and gas recirculation flow rate were modulated to optimize gas-liquid mass transfer, and thus methanation efficiency. Results showed that larger pore size diffusion devices achieved the best kinetics and output-gas quality converting all the injected H and CO, up to 3.6L/L·d H loading rate. Specifically, reactors' CH content increased from 23 to 96% and the CH yield reached 0.25LL. High throughput 16S rRNA gene sequencing revealed predominance of bacteria belonging to Anaerobaculum genus and to uncultured order MBA08. Additionally, the massive increase of hydrogenotrophic methanogens, such as Methanothermobacter thermautotrophicus, and syntrophic bacteria demonstrates the selection-effect of H on community composition.
本研究评估了四种新型上流式反应器用于沼气体外升级的效率，通过氢营养型产甲烷作用将外部提供的 CO 和 H 转化为 CH。气体通过不锈钢扩散器与氧化铝陶瓷海绵或氧化铝陶瓷膜一起注入。调节孔径、进气负荷和气体循环流速以优化气液传质，从而提高甲烷化效率。结果表明，较大孔径的扩散装置实现了最佳动力学和输出气体质量，可将所有注入的 H 和 CO 转化，H 负荷率高达 3.6L/L·d。具体而言，反应器的 CH 含量从 23%增加到 96%，CH 产率达到 0.25LL。高通量 16S rRNA 基因测序显示，属 Anaerobaculum 和未培养 MBA08 目细菌占优势。此外，氢营养型产甲烷菌（如 Methanothermobacter thermautotrophicus）和共生细菌的大量增加证明了 H 对群落组成的选择作用。
