Department of Civil and Environmental Engineering, 127C, Hudson Hall, Box 90287, Duke University, Durham, NC, 27708-0287, USA.
Department of Civil and Environmental Engineering, 127C, Hudson Hall, Box 90287, Duke University, Durham, NC, 27708-0287, USA.
Bioresour Technol. 2019 Oct;290:121780. doi: 10.1016/j.biortech.2019.121780. Epub 2019 Jul 9.
This study investigated the hydrogen mass transfer limitations in a biotrickling filter inoculated with hydrogenotrophic methanogens for biogas upgrading. A highly sensitive dissolved hydrogen probe allowed measuring concentrations in real-time. Experiments were conducted to test the mass transfer resistance in the gas and liquid films. Results demonstrated that the main resistance resides in the trickling liquid film and that promoting direct gas-biofilm mass transfer could improve upgrading performance by about 20%. Increasing the gas velocity (keeping a constant gas contact time) lowered the upgrading capacity. This was explained by the lowering of the concentration to the average concentration throughout the bed, which resulted a lower reaction rate. At extended gas contact times, the bioreactor shifted from microbial to diffusion limitation, causing lower upgrading capacities. Methane-containing biogas mimics (H/CH/CO) were successfully upgraded to natural gas pipeline standards (>97% methane) with only minor performance reduction compared to upgrading just a H/CO mixture.
本研究调查了接种氢营养型产甲烷菌的生物滴滤器中氢的传质限制，用于沼气升级。高灵敏度的溶解氢探头允许实时测量浓度。进行了实验以测试气体和液膜中的传质阻力。结果表明，主要阻力存在于滴滤液体膜中，促进直接气-生物膜传质可以将升级性能提高约 20%。增加气体速度（保持恒定的气体接触时间）会降低升级能力。这可以通过降低整个床层的平均浓度来解释，从而导致反应速率降低。在延长的气体接触时间下，生物反应器从微生物限制转变为扩散限制，导致升级能力降低。含甲烷的沼气模拟物（H/CH/CO）成功升级到天然气管道标准（>97%甲烷），与仅升级 H/CO 混合物相比，性能仅略有降低。
