Abstract: A process is provided for fermenting CO-containing gaseous substrates in a low phosphate medium. The process includes blending a liquid medium that includes at least one transition metal element with a liquid medium that includes at least at least one other transition metal element and one non-metal element to provide a fermentation medium. The process is effective for preventing precipitation of one or more transition metal elements with one or more non-metal elements. The fermentation medium used in the process is prepared in a way that requires significantly lower amounts of water and reduced levels of phosphate.

Abstract: Process are provided which are effective for controlling medium conductivity during fermentation of a CO-containing gaseous substrate while providing an STY of about 10 g ethanol/(L·day) or more. The process includes balancing medium conductivity, specific carbon uptake or cell density levels.

Abstract: A process and apparatus are provided for reducing content of tar in a tar containing syngas. The process includes contacting the tar containing syngas with a molecular oxygen containing gas in a first reaction zone to produce a gas mixture. The gas mixture is passed through a heat treatment zone maintained at a temperature between about 900° C. to about 2000° C. for a contact time of about 0.5 to about 5 seconds. In this aspect, at least a portion of the tar undergoes at least partial oxidation and/or cracking to produce a hot syngas.

Abstract: A process provides high ethanol productivity levels during fermentation of a CO-containing substrate. The process controls CO-substrate feed rates and cell density to avoid culture upset and CO inhibition. The process includes fermenting a CO-containing gaseous substrate to obtain a target cell density and a target CO feed rate, and then periodically reducing and increasing the CO feed rate.

Abstract: A process is provided for producing syngas that is effective for use in downstream processes. The process for producing syngas includes operating a gasification apparatus in a start-up mode until the gasification apparatus and equipment downstream of the gasification apparatus are adequately warmed up to a first target temperature. Upon reaching a first target temperature, the process is then operated in a production mode to produce a second syngas with a higher CO/CO2 molar ratio. Operation in a start-up mode until reaching a first target temperature, provides a process that is effective for reducing fouling in downstream equipment and for providing a second syngas can be more effectively cooled and cleaned.

Abstract: The present invention relates to a process for the production of ethanol and butanol from biomass, and in particular to a process for the production of ethanol and butanol using two separate fermentation step subjecting the biomass feedstock to anaerobic fermentation at a pH below 6.0 and at a temperature in the range 20 to 700° C. and so as to convert the biomass to a product predominantly comprising acetic acid and butyric acid with at least a 2:1 ratio by weight of acetic acid to butyric acid, c) treating the product of stream of step (b) to separate a solution comprising the acetic acid and butyric acid by: (i) separating a solution comprising the acetic acid and butyric acid from any residual solids and (ii) separating bacteria and/or pasteurizing or sterilizing the solution from the first fermentation step, and d) in a second fermentation step fermenting the solution comprising the acetic acid and butyric acid from the step (c) to form ethanol and butanol.

Abstract: A process for controlling concentration of CO in a bioreactor provides a direct and real time measurement of dissolved CO in a fermentation medium. The process for controlling concentrations of CO in a bioreactor includes contacting an aliquot of fermentation medium with at least one CO binding ligand and at least one microbial inactivator.

Abstract: A process is provided that is effective for reducing CO2 emissions, enhancing STY and/or increasing cell density. The process allows for utilization of syngas from different sources by controlling concentration levels of CO, CO2 and H2 in syngas provided to the fermentation and by controlling relative concentrations of CO, CO2 and H2 in the syngas provided to the fermentation. The process includes providing syngas to a first fermentation zone and fermenting the syngas. If the first fermentation zone off-gas includes about 4 mole % or more CO, then at least a portion of the first fermentor off-gas is provided to one or more subsequent fermentation zones.

Abstract: A process is provided for fermenting CO-containing gaseous substrates. The process is effective for decreasing lag times and maintaining a culture in steady state by controlling CO concentration and minimizing effects of high or low CO concentrations during fermentation. The process includes providing syngas to a first fermentation zone, fermenting the syngas, and determining a CO concentration in a fermentation medium in the first fermentation zone. If the CO concentration in fermentation medium in the first fermentation zone has a calculated value of about 0.12 mM or greater, then at least a portion of the syngas being provided to the first fermentation zone is provided to one or more subsequent fermentation zones in an amount effective for providing a calculated CO concentration in any subsequent fermentation zone of about 0.12 mM or less.

Abstract: A process is provided for fermenting CO-containing gaseous substrates. The process is effective for decreasing lag times and maintaining a culture in steady state by controlling CO concentration and minimizing effects of high or low CO concentrations during fermentation. The process includes providing syngas to a first fermentation zone, fermenting the syngas, and determining a CO concentration in a fermentation medium in the first fermentation zone. If the CO concentration in fermentation medium in the first fermentation zone has a value of about 0.12 ?M or greater, then at least a portion of the syngas being provided to the first fermentation zone is provided to one or more subsequent fermentation zones in an amount effective for providing a CO concentration in any subsequent fermentation zone of about 0.12 ?M or less.

Abstract: A process for fermenting syngas is provided which is effective for decreasing an amount of time needed to inoculate a main reactor. The process includes propagating a culture of acetogenic bacteria to provide an incoulum for a main reactor and fermenting syngas in the main reactor.

Abstract: The present invention relates to a process for the production of ethanol and butanol from biomass, and in particular to a process for the production of ethanol and butanol using two separate fermentation step subjecting the biomass feedstock to anaerobic fermentation at a pH below 6.0 and at a temperature in the range 20 to 700° C. and so as to convert the biomass to a product predominantly comprising acetic acid and butyric acid with at least a 2:1 ratio by weight of acetic acid to butyric acid, c) treating the product of stream of step (b) to separate a solution comprising the acetic acid and butyric acid by: (i) separating a solution comprising the acetic acid and butyric acid from any residual solids and (ii) separating bacteria and/or pasteurizing or sterilizing the solution from the first fermentation step, and d) in a second fermentation step fermenting the solution comprising the acetic acid and butyric acid from the step (c) to form ethanol and butanol.

Abstract: A process for fermenting syngas is provided which is effective for decreasing an amount of time needed to inoculate a main reactor. The process includes propagating a culture of acetogenic bacteria to provide an inoculum for a main reactor and fermenting syngas in the main reactor.

Abstract: The present invention relates to a process for the production of ethanol and butanol from biomass, and in particular to a process for the production of ethanol and butanol using two separate fermentation steps, said process comprising: a) passing a biomass feedstock to a first fermentation step, b) in said first fermentation step subjecting the biomass feedstock to anaerobic fermentation at a pH below 6.0 and at a temperature in the range 20 to 700° C.

Abstract: The present disclosure provides methods of gaseous substrate fermentation comprising: adding gaseous substrate into an aqueous medium in a bioreactor. The methods of the present disclosure comprise: measuring cell density; adjusting input of gaseous substrate to increase cell density; changing hydrogen uptake.

Abstract: A process is provided for management of ethanol concentration during syngas fermentation. A process for fermentation of syngas includes inoculating a medium to provide an inoculated medium. Inoculated medium is contacted with syngas and cells and medium are removed and separated to provide concentrated cells and permeate. Ethanol is separated from the permeate to provide ethanol and a reduced ethanol aqueous stream. The reduced ethanol aqueous stream is returned to the fermentation.