[2] Certain industrial processes, such as petroleum refining, steel milling, and methods for producing carbon black, coke, ammonia, and methanol, discharge enormous amounts of waste gases containing mainly CO and H2 into the atmosphere either directly or through combustion.
Biocatalysts can be exploited to convert these waste gases to chemicals and fuels as, for example, ethanol.
[3] In addition, incorporating nanoparticles has been demonstrated to improve gas-liquid fluid transfer during syngas fermentation.
Syngas fermentation process has advantages over a chemical process since it takes places at lower temperature and pressure, has higher reaction specificity, tolerates higher amounts of sulfur compounds, and does not require a specific ratio of CO to H2.
[2] On the other hand, syngas fermentation has limitations such as: The most common utilized reactor type for syngas fermentation is the stirred-tank reactor in which the mass transfer is influenced by several factors such as geometry of the reactor, impeller configuration, the agitation speed and the gas flow rate.