Off-Gas Recycling Control in Microorganism Culture Tanks

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional microorganism culture systems face safety risks due to the potential for explosive gas compositions when reusing off-gases containing combustible gases, which can lead to inefficient and unsafe fermentation processes.

Innovation Solution

A culture system and method that adjust the concentration of combustible and combustion-supporting gases in recycled off-gases to stay within a prescribed safe range, using a recycled gas adjusting unit with feedback and feedforward mechanisms to ensure the concentration of combustion-supporting gases remains below the explosion limit, thereby preventing explosions and enhancing safety and efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If off-gas containing combustible gas is recycled to improve productivity, then fermentation efficiency is improved, but the risk of gas explosion increases

Engineering Contradiction:
Improvefermentation efficiencyVSAvoidgas explosion risk
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the concentration parameters of combustion-supporting gas and combustible gas in the recycled off-gas by mixing with fresh gas. This parameter adjustment ensures the gas composition remains outside the explosive range while maintaining fermentation efficiency, directly resolving the contradiction between productivity improvement and explosion risk reduction.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements a feedback control system using gas concentration meters to continuously monitor the concentrations of combustion-supporting gas and combustible gas in the recycled off-gas. The system automatically adjusts the mixing ratio of fresh gas based on measured concentrations, ensuring safe operation while maximizing fermentation productivity.

Inventive Principle:
Principle #23Feedback

2Reliability

If gas composition is controlled outside explosive range to ensure safety, then explosion risk is reduced, but fermentation productivity may be compromised

Engineering Contradiction:
ImprovesafetyVSAvoidfermentation productivity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent employs dynamic control of gas composition by continuously adjusting the mixing ratio of fresh gas to recycled off-gas based on real-time concentration measurements. This dynamic approach allows the system to maintain safety margins while optimizing fermentation conditions for maximum productivity, rather than using fixed conservative settings.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system dynamically changes gas concentration parameters within safe ranges to optimize fermentation productivity. By adjusting the concentrations of combustion-supporting gas and combustible gas through controlled mixing, the system maintains safety while creating optimal conditions for microbial growth and product formation.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If high oxygen concentration is supplied to enhance microbial proliferation, then biosynthetic reactions are increased, but the risk of creating explosive gas composition increases

Engineering Contradiction:
Improvebiosynthetic reaction rateVSAvoidexplosive composition risk
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the oxygen concentration parameter in the gas supply by mixing oxygen-enriched air or pure oxygen with combustible gas and recycled off-gas. This parameter adjustment increases oxygen availability for aerobic microorganisms while controlling the overall gas composition to remain outside the explosive range through balanced mixing ratios.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The feedback control system monitors both oxygen concentration and combustible gas concentration simultaneously. When oxygen concentration is increased to enhance biosynthetic reactions, the system automatically adjusts the mixing ratio to maintain safe overall composition, preventing explosive conditions while supporting high productivity.

Inventive Principle:
Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system provides a safer and more efficient fermentation process by maintaining gas concentrations within non-explosive limits, reducing the risk of explosions and optimizing microbial culture conditions for enhanced productivity.

Implementation Method 1

the recycled gas adjusting unit mixing, in at least a portion of an off-gas discharged from the culture tank, one or a plurality of gas components selected from the group consisting of a combustible gas, a combustion-supporting gas, and an incombustible gas

Methodology Applied
Scientific EffectGas mixing:

Implementation Method 2

Microorganisms can, due to the fermentation effect thereof, convert a gas containing much carbon, such as carbon dioxide, carbon monoxide, and methane, into various chemical products such as a fuel, a protein, an alcohol, and an organic acid

Methodology Applied
Scientific EffectFermentation: Fermentation

Implementation Method 3

the amount of oxygen transferred from a gas phase and dissolved in a liquid phase is increased

Methodology Applied
Scientific EffectGas dissolution: Absorption (physical)

Data Source

PatentEP4682238A1Microorganism culturing system and method for culturing in said system by recycling off-gas
Publication Date: 2026.01.21 JGC HLDG CORP
  • EP4682238A1 patent drawingFigure 1
  • EP4682238A1 patent drawingFigure 2
  • EP4682238A1 patent drawingFigure 3

AI summary

The present invention provides a microorganism culturing system, the culturing system comprising a culturing tank, a recycled gas adjustment unit, a first gas circulation line having one end connected to an upper part of the culturing tank and the other end connected to the recycled gas adjustment unit, and a second gas circulation line having one end connected to the recycled gas adjustment unit and the other end connected so as to supply the recycled gas into the culturing tank, wherein the recycled gas adjustment unit mixes one or more gas components selected from the group consisting of combustible gas, combustion-supporting gas, and incombustible gas with at least a portion of off-gas discharged from the culturing tank so that the concentration of the combustion-supporting gas in the recycled gas falls within a predetermined range. The present invention also provides a method for culturing in a culturing system that uses microorganisms by recycling off-gas.