Abstract: Multi-stage, biological processes and systems for converting a C1 carbon source to desired end products are described. The processes comprise dividing a gaseous C1-containing substrate, in parallel, among multiple bioreactor stages. Liquid products are successively fed, in series, from a first bioreactor stage to downstream bioreactor stages. Operation can be simplified by avoiding the requirement for microorganism separation and recycle at each stage. In addition, overall vapor-liquid mass transfer for the combined stages is very favorable, leading to high end product productivity with comparably low byproduct metabolite productivity.

Abstract: A reactor system is provided for improved fermentation of a gaseous substrate through the introduction of a secondary loop to a forced-circulation loop reactor. The reactor comprises a primary loop through which fermentation broth comprising a gaseous substrate is circulated through a riser segment and a downcomer section by a loop pump. Downstream of the loop pump a portion of fermentation broth is withdrawn from the downcomer section and is directed to the top of the reactor via a secondary loop. Further provided is a method for improving the mass transfer of a gaseous substrate to a fermentation broth in a fermentation vessel comprising a secondary loop. Further provided is a method for reducing foam in the headspace of a fermentation vessel comprising a secondary loop.

Abstract: Processes, as well as associated systems, are disclosed for the biological conversion of CO into desired end products such as ethanol. The use of a plurality of perforated plates, for example in the riser section of a bioreactor, which are positioned substantially horizontally and normal to the upward flow of both a CO-containing substrate and liquid culture medium, can significantly improve CO utilization of the bacteria and consequently the overall process economics. The geometry of apertures in the perforated plates is an important determinant of their performance, with fractal patterns and other multi-edged shapes leading to particularly advantageous results.

Abstract: Multi-stage, biological processes and systems for converting a C1 carbon source to desired end products are described. The processes comprise dividing a gaseous C1-containing substrate, in parallel, among multiple bioreactor stages. Liquid products are successively fed, in series, from a first bioreactor stage to downstream bioreactor stages. Operation can be simplified by avoiding the requirement for microorganism separation and recycle at each stage. In addition, overall vapor-liquid mass transfer for the combined stages is very favorable, leading to high end product productivity with comparably low byproduct metabolite productivity.

Abstract: A reactor system is provided for improved fermentation of a gaseous substrate through the introduction of a secondary loop to a forced-circulation loop reactor. The reactor comprises a primary loop through which fermentation broth comprising a gaseous substrate is circulated through a riser segment and a downcomer section by a loop pump. Downstream of the loop pump a portion of fermentation broth is withdrawn from the downcomer section and is directed to the top of the reactor via a secondary loop. Further provided is a method for improving the mass transfer of a gaseous substrate to a fermentation broth in a fermentation vessel comprising a secondary loop. Further provided is a method for reducing foam in the headspace of a fermentation vessel comprising a secondary loop.

Abstract: Processes, as well as associated systems, are disclosed for the biological conversion of CO into desired end products such as ethanol. The use of a plurality of perforated plates, for example in the riser section of a bioreactor, which are positioned substantially horizontally and normal to the upward flow of both a CO-containing substrate and liquid culture medium, can significantly improve CO utilization of the bacteria and consequently the overall process economics. The geometry of apertures in the perforated plates is an important determinant of their performance, with fractal patterns and other multi-edged shapes leading to particularly advantageous results.

Abstract: The invention relates to the microbial fermentation of gaseous substrates, particularly to gas/liquid contact modules and bioreactors configured to improve the efficiency of fermentations, particularly microbial fermentations of substrates comprising CO. In a particular embodiment, a gas/liquid contact module with multiple channels is configured to produce products in a liquid fermentation broth. In a further particular embodiment, there is provided a method of fermentation of a gaseous substrate to produce a product in a liquid fermentation broth.

Abstract: The invention relates to the microbial fermentation of gaseous substrates, particularly to gas/liquid contact modules and bioreactors configured to improve the efficiency of fermentations, particularly microbial fermentations of substrates comprising CO. In a particular embodiment, a gas/liquid contact module with multiple channels is configured to produce products in a liquid fermentation broth. In a further particular embodiment, there is provided a method of fermentation of a gaseous substrate to produce a product in a liquid fermentation broth.