Control of bioreactor processes

摘要

Processes, as well as associated systems and computer program (software) products, are disclosed for the biological conversion of CO into desired end products such as ethanol. The control methodologies used for these processes can advantageously result in a reduced time required for a batch operation or other initial operating period, prior to achieving a continuous operation, which may be demarcated either by the addition of fresh culture medium at a defined flow rate or by another process initiation target. The control methodologies may alternatively, or in combination, improve a process performance parameter, such as productivity of the desired end product or bacterial growth rate, during this batch operation or other initial operating period.

主权项

1. A fermentation process comprising:
a) feeding a gaseous substrate stream comprising CO and a basic neutralizing agent to a bioreactor comprising a carboxydotrophic bacterial culture in a liquid nutrient medium; b) fermenting the culture wherein at least a portion of the CO in the gaseous substrate stream is converted to a product comprising ethanol and an acidic metabolite; c) optimizing the production of said product by:
1) measuring an acidic metabolite concentration, a carboxydotrophic bacteria concentration, and a carboxydotrophic bacteria productivity;2) determining an acidic metabolite set point concentration according to either formula (1) or (2):
A1·BIOCONmv+B1  (1)A2·BIOPRODmv+B2  (2)wherein BIOCONmv represents the carboxydotrophic bacteria measured concentration in the culture medium, BIOPRODmv represents the carboxydotrophic bacteria measured productivity and A1, A2, B1 and B2 are constants; 3) increasing a basic neutralizing agent flow rate if the acidic metabolite concentration is less than the acidic metabolite set point concentration; and 4) decreasing the basic neutralizing agent flow rate if the acidic metabolite concentration is greater than the acidic metabolite set point concentration.