Syngas Fermentation to Alcohols: Reactor Technology and Application Perspective

Abstract

One approach of Power-to-X is the coupling of the energy and chemical sector, using electrolysis for syngas generation and microbial gas conversion for the production of biochemicals. On the verge of commercialization, known challenges of gas fermentation technology are poor mass transfer of syngas, low cell concentration and productivity. These problems can be addressed by an intelligent reactor design. Thus, this article provides an overview on the current state of the art for reactor technology in syngas fermentation and discusses possible concepts with regard to an application at industrial scale.

Towards continuous industrial bioprocessing with solventogenic and acetogenic clostridia: challenges, progress and perspectives

“…In this section, we pay special attention to the different operation strategies for continuous fermentations, their properties and potential as a powerful tool to develop solvent production towards industrial implementation. For the design of a new economical process, the choice of the reactor type and the operation strategy are the two major criteria, mostly affecting the formation and activity of biocatalyst, conversion rate, volumetric productivity and downstream processing [ 179 , 275 , 314 ].…”

“…There also exist other models of large-scale bubble column fermentation where the biology was modeled with a fundamental set of reactions [ 269 ] or with a biothermodynamics approach [ 7 ]. Considering the industrial importance of bubble column reactors for gas fermentation [ 39 , 275 , 284 ], the rise of these models supports further scale-up and industrialization of gas fermentation.…”

“…Gasification yields accessible carbon even from the complex lignin fraction that accounts for up to 40% of the plant biomass [ 278 ]. Other sources of syngas include industrial waste streams such as exhaust gas of the steel and oil industry [ 270 ] and even gas mixtures obtained electrochemically from CO 2 and H 2 O [ 104 , 275 ].…”

“…Biofuels such as butanol and ethanol are needed in high quantities and their market shows a steady growth [ 164 , 261 , 270 , 275 ]. While ethanol is already used worldwide for biofuel applications, a 50% higher energy density, lower vapor pressure, lower water absorption, lower corrosivity, better blending abilities and the possible use in unmodified combustion engines and existing infrastructure make butanol a promising alternative [ 41 , 58 , 161 , 211 ].…”

Production and Use of Sustainable C2‐C4 Alcohols – An Industrial Perspective

“…The first gas fermentations were developed in the 1980s. Ineos BIO, Coskata and LanzaTech have developed the works of Datta, Zeikus and Gaddy from lab and pilot scale to demonstration and commercialization scale over the past two decades [59]. The production of ethanol and butanol by gas fermentation is mainly based on anaerobic, acetogenic microorganisms that follow the Wood-Ljungdahl pathway (WLP) to produce acetyl-CoA as a key intermediate.…”