National Research Council, Biotechnology Research Institute, 6100 Royalmount Avenue, Montreal, Quebec H4P 2R2, Canada.
Environ Sci Technol. 2011 Mar 1;45(5):2006-12. doi: 10.1021/es102728m. Epub 2011 Feb 3.
Gasification of biomass produces a mixture of gas (mainly carbon monoxide (CO), carbon dioxide (CO(2)), and hydrogen (H(2))) called synthesis gas, or syngas, by thermal degradation without combustion. Syngas can be used for heat or electricity production by thermochemical processes. This project aims at developing an alternative way to bioupgrade syngas into biogas (mainly methane), via anaerobic fermentation. Nonacclimated industrial granular sludge to be used as reactor inoculum was initially evaluated for mesophilic carboxydotrophic methanogenesis potential in batch tests at 4 and 8 mmol CO/g VSS.d, in the absence and presence of H(2) and CO(2), respectively. Granular sludge was then introduced into a 30 L gas-lift reactor and supplied with CO, to study the production of methane and other metabolites, at different gas dilutions as well as feeding and recirculation rates. A maximal CO conversion efficiency of 75%, which was gas-liquid mass transfer limited, occurred at a CO partial pressure of 0.6 atm combined with a gas recirculation ratio of 20:1. The anaerobic granule potential for methanogenesis from CO was likely hydrogenotrophic, combined with CO-dependent H(2) formation, either under mesophilic or thermophilic conditions. Thermophilic conditions provide the anaerobic granules with a CO-bioconversion potential significantly larger (5-fold) than under mesophilic conditions, so long as the gas-liquid transfer is alleviated.
生物质的气化通过无燃烧的热降解产生一种称为合成气（或合成气）的气体混合物，主要由一氧化碳（CO）、二氧化碳（CO(2)）和氢气（H(2)）组成。合成气可以通过热化学过程用于热能或电能的生产。本项目旨在开发一种替代方法，通过厌氧发酵将合成气生物升级为沼气（主要是甲烷）。最初，在 4 和 8 mmol CO/g VSS.d 的分批测试中，在没有和存在 H(2)和 CO(2)的情况下，评估了非驯化的工业颗粒污泥用于中温羧基营养型产甲烷的潜力。然后，将颗粒污泥引入 30 L 气升式反应器中，并供应 CO，以研究在不同气体稀释度以及进料和回流率下甲烷和其他代谢物的生产。在 0.6 大气压的 CO 分压下，发生了最大的 CO 转化效率为 75%，这是气体-液体传质限制的。在 20:1 的气体回流比下，可能是氢营养型的厌氧颗粒具有从 CO 中进行产甲烷的潜力，同时伴随着 CO 依赖性的 H(2)形成，无论是在中温条件下还是在高温条件下。只要缓解气体-液体传递，高温条件就为厌氧颗粒提供了比中温条件大 5 倍的 CO 生物转化潜力。
