METHOD FOR PRODUCING BIOMASS USING NATURAL GAS AND TWO-CIRCUIT CIRCULATION Russian patent published in 2023 - IPC C12N1/00 C12N1/20 C12M1/04 C12M1/12 C12M1/36 

FIELD: biotechnology.

SUBSTANCE: invention relates to biotechnology. A method is proposed for obtaining biomass using natural gas by cultivating bacteria under conditions of continuous two-circuit circulation of a liquid medium in closed circuits and regulating the concentration parameters of salts, nutrients and dissolved gases in the reactor. Fermentation is carried out in a reactor with a gas-lift principle of circulation organization, provided by the ascending zone of the reactor and a concentrator with a descending zone of the reactor, and the intensification of the oxygen transfer process in the liquid phase by using an oxygen carrier liquid inert to bacteria. To separate the saturation zones of the culture liquid with oxygen and methane, methane is fed into the reactor in the gaseous state in the ascending zone and in the dissolved state is fed into the concentrator with the descending zone of the reactor, and the filtrate, purified in the unit for the elimination of by-products, is sectionally saturated with oxygen and mineral salts in the reactor profile. Using a centrifuge, the flow of culture liquid in the concentrator is divided into a gas mixture and a liquid phase. A gas mixture consisting of methane, carbon dioxide, oxygen and nitrogen is fed to the gas separation unit, from which nitrogen and carbon dioxide are removed, and methane and oxygen are again fed into the return circulation circuit of the reactor through the methane saturation unit and to the input of the fermentation reactor. From the liquid phase, the culture liquid more saturated with biomass remains circulating in the reactor, and isolated separate flow of culture fluid containing the number of bacteria corresponding to the specific growth rate 0.25-0.29 1/h, and the oxygen carrier liquid is supplied from the concentrator to the inactivation unit, where bacteria are inactivated in the shell-and-tube heat exchanger of the inactivation unit. A flow of culture fluid, oxygen carrier fluid with dissolved carbon dioxide and carbon dioxide in the gas phase is fed from the outlet of the heat exchanger of the inactivation unit to the degasser, in which carbon dioxide is degassed and removed from the installation. From the degasser, the culture liquid is fed into the separation unit, followed by the removal of the finished concentrate and filtrate from it and the release of the oxygen carrier liquid into a separate stream, followed by feeding the oxygen saturation node to the input. The finished concentrate is fed to the drying, granulation and packaging units, and the filtrate is passed through filters in which biomass residues are captured and fed to the by-product elimination unit, and solutes are removed from the filtrate in the by-product elimination unit. The solution of mineral salts is fed through the mineral salt solution injection unit into the filtrate purified in the by-product elimination unit, the composition of which is analyzed online by the analytical unit. The filtrate enriched with mineral salts is pumped to separate oxygen and methane saturation units, after which the filtrate saturated with oxygen and mineral salts and the oxygen carrier liquid are fed to the return the circulation circuit of the reactor and the input devices in the reactor to maintain the oxygen and mineral salts content along the height of the reactor.

EFFECT: invention provides optimal conditions for the growth of biomass throughout the reactor volume and the achievement of the required concentration of nutrients.

1 cl, 1 dwg