High hydrogen utilization and gas recycle
AssigneeInvista North America S.A.R.L.
InventorsGary J. Smith, Paul S. Pearlman, Gregory S. Kirby
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Abstract
Provided herein are systems and methods for recycling and supplementing off-gas from a gas fed reaction process. The systems and methods are particularly useful for bioprocesses that convert hydrogen gas into one or more biosynthetic products. By maintaining separate hydrogen and oxygen feed gas streams, and forming a recycle gas that introduces a target component of the supply gas to the bioreactor within a target concentration range, the yields, productivities, and safety profiles of the bioprocess can be enhanced.
Claims20
A method for recycling an off-gas stream in a gas fermentation biosynthetic system, the method comprising:
- providing a culture of a chemoautotrophic organism capable of synthesis of one or more biosynthetic products to a gas fermentation reactor system;
- introducing a supply gas to the culture, wherein the supply gas comprises a recycle gas, wherein the concentration of nitrogen in the supply gas is less than 5% (v/v), wherein the concentrations of one or more target components in the supply gas are each independently within a target concentration range, and wherein the one or more target components are selected from the group consisting of hydrogen, carbon dioxide, and oxygen;
- producing, with the culture, an off-gas;
- forming the recycle gas from at least a portion of the off-gas;
- measuring the concentrations of each of the one or more target components in the recycle gas;
- calculating an amount of each of the one or more target components to be combined with the recycle gas to form the supply gas having concentrations of the one or more target components within the target concentration ranges;
- and
- introducing the recycle gas and the calculated amounts of each of the one or more target components to the culture.
A reactor system for an aerobic gas fermentation process, the system comprising:
- a gas fermentation reactor comprising at least two oxygen addition points;
- a culture of a chemoautotrophic organism capable of synthesis of one or more biosynthetic products;
- a supply gas comprising a recycle gas, wherein the concentration of nitrogen in the supply gas is less than 5% (v/v), wherein the concentrations of one or more target components in the supply gas are each independently within a target concentration range, and wherein the one or more target components are selected from the group consisting of hydrogen, carbon dioxide, and oxygen
- a first control loop configured to measure and control dissolved oxygen content in a fermentation liquid in the gas fermentation reactor;
- a second control loop configured to measure and control gaseous oxygen concentration in a headspace of the gas fermentation reactor;
- a recycle loop configured to recycle at least a portion of an off-gas stream to the culture;
- analytical equipment to measure the concentrations of each of the one or more target components in the recycle gas;
- and
- a third control loop configured to calculate an amount of each of the one or more target components to be combined with the recycle gas to form the supply gas having concentrations of the one or more target components within the target concentration ranges, wherein the third control loop is further configured to introduce the recycle gas and the calculated amounts of each of the one or more target components to the culture.
Dependencies are inferred from the claim text.