SYSTEM AND METHOD FOR FEEDBACK CONTROL OF GAS SUPPLY FOR ETHANOL PRODUCTION VIA SYNGAS FERMENTATION USING pH AS A KEY CONTROL INDICATOR

摘要

According to an embodiment, there is provided herein a system and method wherein knowledge of the syngas fermentation is combined with standard instrumentation to provide a stable control of gas supply to automatically poise the fermentation to provide both high conversion of CO and H2, and high selectivity for production of ethanol. The control is based on an automatic feedback loop that corrects for operational imbalance and maintains a stable continuous fermentation required for commercial operation. In a further embodiment, feed of syngas to ethanol fermentation can be optimally controlled using the pH of the broth as the input variable for flow control of the gas. This concept will automatically maintain the correct supply of syngas to the fermentation, and provide stable operation at optimal rates.

主权项

1. A method of ethanol production via syngas fermantion, comprising the steps of:
a. selecting an acetogenic microbial culture with solventogenic potential; b. selecting a pH set point; c. selecting a medium supportive of said acetogenic bacterial culture; d. selecting a feed gas; e. providing said medium to a bioreactor; f. providing a flow of said feed gas to said bioreactor at a first rate; g. operating said bioreactor to mix together said feed gas and medium; h. determining a pH of said provided medium and said feed gas within said bioreactor; i. if said determined pH is greater than said pH set point, decreasing said flow of said feed gas to said bioreactor to a rate lower than said first rate; j. if said determined pH is less than said pH set point, increasing said flow of said feed gas to said bioreactor to a rate higher than said first rate; and, k. continuing to perform at least steps (f) through (j) until a quantity of said ethanol is produced.